PCR survey of vectorborne pathogens in dogs living in and around Barcelona, an area endemic for leishmaniasis

High serological and molecular prevalence of Ehrlichia canis and other vector-borne pathogens in dogs from Boa Vista Island, Cape Verde

Despite the high global impacts of canine vector-borne diseases (CVBD) due to their wide distribution and zoonotic potential, the current epidemiological situation of CVBD in many tropical and subtropical regions remains unknown. This study examines the seroprevalence and molecular prevalence of Ehrlichia canis and other pathogens causing CVBDs (Leishmania infantum, Dirofilaria immitis, Babesia spp., Anaplasma spp. and Hepatozoon canis) in dogs living on the island of Boa Vista (Cape Verde Republic). Blood samples and infesting ticks were taken from 150 dogs across the island (stray, shelter, and pet dogs). Serum samples were tested using a rapid immunochromatographic test (Uranotest® Quattro) that detects antibodies against E. canis, L. infantum, Anaplasma spp. and D. immitis antigen. Levels of serum antibodies against E. canis were measured using the immunofluorescence antibody test (IFAT). In addition, tick-borne pathogens in blood samples (Anaplasma spp., Babesia spp., Hepatozoon spp., and Ehrlichia canis) were detected by microscopy observation and/or PCR plus sequencing. The seroprevalence of E. canis was extremely high at 82% (123/150), as revealed by both immunochromatography and IFAT. Most dogs returning a seropositive test result (82.92%; 102/123) had antibody titres > 1:1280 but showed no clinical signs or notable laboratory abnormalities. Of the 123 animals testing seropositive for E. canis, 67 (54.47%) also presented antibodies against Anaplasma spp., and 13 (10.56%) showed the presence of Hepatozoon spp. gamonts in the blood smear. Ehrlichia canis infection was detected in 17.1% (25/146) of dogs tested by direct sequencing of polymerase chain reaction (PCR) products. Co-infections were detected in seven of these dogs: four dogs tested PCR-positive for both E. canis and A. platys, two dogs tested positive for E. canis and Hepatozoon spp., and one dog tested positive for E. canis, A. platys and Hepatozoon spp. Rhipicephalus sanguineus sensu lato was the only tick species found infesting the canine study population. The high prevalence of tick-borne pathogens detected in dogs from Boa Vista Island highlights a need for improved control measures designed to prevent the transmission of these pathogens.

First Molecular Evidence of Babesia vogeli, Babesia vulpes, and Theileria ovis in Dogs from Kyrgyzstan

Tick-borne parasitic diseases cause mild to severe infections among vertebrate hosts, including dogs. Species in the genus Babesia are important tick-borne pathogens and have worldwide distributions. Although there are data on the prevalence and distribution of Babesia species among dogs around the world, there is no information available in Kyrgyzstan, according to a literature review. In this study, 337 dogs were screened by nested PCR for the presence of the 18S small subunit ribosomal RNA (18S SSU rRNA) gene of piroplasm species. Overall prevalence was 6.23% (21/337) for Babesia/Theileria spp. DNA sequencing of positively tested samples revealed that eighteen samples were infected with Babesia vogeli (B. vogeli) (5.34%), two samples with B. vulpes (0.59%), and one sample with Theileria ovis (T. ovis) (0.29%). The phylogenetic analyses and nucleotide sequences in contrast with those present in GenBank revealed that two nucleotide substitutions (594th and 627th) were found between B. vogeli isolates, including ours, indicating that the mutation is relatively rare. The sequences of other pathogens obtained in this study confirmed 100% nucleotide identity with B. vulpes and T. ovis sequences in GenBank. To the best of our knowledge, B. vogeli, B. vulpes, and T. ovis were detected for the first time in dogs from Kyrgyzstan, and it is thought that results will contribute to the understanding of the epidemiology of canine tick-borne pathogens in the country.

The estimated distribution of autochthonous leishmaniasis by Leishmania infantum in Europe in 2005-2020

BACKGROUND

This study describes the spatial and temporal distribution between 2005 and 2020 of human and animal leishmaniasis by Leishmania infantum in European countries reporting autochthonous cases, and highlights potential activities to improve disease control.

METHODOLOGY/PRINCIPAL FINDINGS

It was based on a review of the scientific literature and data reported by the World Health Organization (WHO), the World Organization for Animal Health (WOAH) and the Ministries of Health, including hospital discharges in some countries. Autochthonous infections were reported in the scientific literature from 22 countries, including 13 and 21 countries reporting human and animal infections, respectively. In contrast, only 17 countries reported autochthonous human leishmaniasis cases to the WHO and 8 countries animal infections to the WOAH. The number of WOAH reported cases were 4,203, comprising 4,183 canine cases and 20 cases in wildlife. Of 8,367 WHO reported human cases, 69% were visceral leishmaniasis cases-of which 94% were autochthonous-and 31% cutaneous leishmaniasis cases-of which 53% were imported and mostly in France. The resulting cumulative incidence per 100,000 population of visceral leishmaniasis between 2005-2020, was highest in Albania (2.15 cases), followed by Montenegro, Malta, Greece, Spain and North Macedonia (0.53-0.42), Italy (0.16), Portugal (0.09) and lower in other endemic countries (0.07-0.002). However, according to hospital discharges, the estimated human leishmaniasis incidence was 0.70 in Italy and visceral leishmaniasis incidences were 0.67 in Spain and 0.41 in Portugal.

CONCLUSIONS/SIGNIFICANCE

Overall, there was no evidence of widespread increased incidence of autochthonous human leishmaniasis by L. infantum in European countries. Visceral leishmaniasis incidence followed a decreasing trend in Albania, Italy and Portugal, and peaked in Greece in 2013, 2014 and 2017, and in Spain in 2006-2007 and 2011-2013. Animal and human cutaneous leishmaniasis remain highly underreported. In humans, hospital discharge databases provide the most accurate information on visceral leishmaniasis and may be a valuable indirect source of information to identify hotspots of animal leishmaniasis. Integrated leishmaniasis surveillance and reporting following the One Health approach, needs to be enhanced in order to improve disease control.

Investigation of comorbidities in dogs with leishmaniosis due to Leishmania infantum

In endemic areas, dogs with leishmaniosis due to Leishmania infantum frequently have comorbidities, including mostly neoplastic, infectious, and parasitic diseases. The aim of this study was to compare the prevalence of comorbidities among dogs that are not infected by L. infantum, dogs that are infected but do not present leishmaniosis, and dogs with leishmaniosis, and to examine if certain comorbidities are independent risk factors for the infection by L. infantum and/or for the development of canine leishmaniosis (CanL). A total of 111 dogs, older than 1-year and non-vaccinated against CanL, were allocated into three groups: group A (n = 18) included dogs that were not infected by L. infantum, group B (n = 52) included dogs that were infected by L. infantum but did not present CanL, and group C (n = 41) included dogs with CanL. Signalment and historical data were obtained using a structured questionnaire. Laboratory examinations included complete blood count, serum biochemistry, urinalysis, fecal parasitology, modified Knott's test, microscopic examination of capillary blood, buffy coat, lymph node, bone marrow and conjunctival smears, qualitative serology for Dirofilaria immitis, Anaplasma phagocytophilum/A. platys, Borrelia burgdorferi and E. canis, IFAT for L. infantum, ELISA for Babesia spp. and Neospora caninum, and real-time PCR for L. infantum in bone marrow, skin biopsies and conjunctival swabs. A variety of comorbidities were found in all three groups. No independent risk factors for infection by L. infantum were found. On the contrary, among dogs infected by L. infantum, being a mongrel [odds ratio (OR): 11.2], not receiving prevention for dirofilariosis (OR: 26.5) and being seropositive to N. caninum (OR: 17.1) or to Babesia spp. (OR: 37.6), were independent risk factors for presenting CanL. Although no comorbidities influence the probability of canine infection by L. infantum, certain comorbidities may be precipitating factors for the transition from the subclinical infection by L. infantum to the overt CanL.

Clinical, diagnostic and epidemiological implications of Hepatozoon spp., Babesia spp. and Leishmania infantum infection in cats and dogs in a Mediterranean periurban setting

Hepatozoon spp., Babesia spp. and Leishmania infantum are common parasites of dogs in Mediterranean countries and are less frequent in cats, particularly Babesia spp. and L. infantum. Moreover, there is limited information on coinfections between these parasites and on L. infantum's distribution in blood, skin and lymphoid tissue in cats. We used PCR and DNA sequencing to investigate the prevalence of these parasites and the aetiology of Hepatozoon spp. and Babesia spp., in blood, skin, spleen and lymph node samples from up to 212 stray cats and 82 abandoned dogs in southeast Spain. All except 2 dogs were healthy; instead, 112 cats had clinical signs. The estimated PCR prevalences (95% confidence interval) were 25% (19-31%) Hepatozoon felis in cats, 13% (6-21%) Hepatozoon canis in dogs, 1% (0-4%) Babesia vogeli in dogs, 0% Babesia spp. in cats and 21% (15-26%) and 44% (33-55%) L. infantum in cats and dogs, respectively, and infections were not associated with each other. Leishmania infantum prevalence in lymphoid tissue was significantly higher in dogs than in cats (p < 0.001), and dogs had higher parasite loads than cats (p = 0.012). Moreover, L. infantum prevalence was significantly higher in the skin and lymphoid tissue compared to blood in infected, asymptomatic animals but it was similar in cats with clinical signs, which also had higher parasite loads compared to infected, asymptomatic cats (p < 0.05). The study highlights significant differences between sympatric dogs and cats with respect to the parasite infections investigated, as well as the need to examine both lymphoid tissue and skin samples to maximise the sensitivity of L. infantum infection diagnosis.

Ehrlichiosis in Dogs: A Comprehensive Review about the Pathogen and Its Vectors with Emphasis on South and East Asian Countries

Ehrlichiosis in dogs is an emerging vector borne rickettsial zoonotic disease of worldwide distribution. In general, three Ehrlichial species (Ehrlichia canis, E. ewingii, and E. chaffeensis) are involved in infecting dogs. Among them, E. canis is the well-known etiological pathogen affecting platelets, monocytes, and granulocytes. Dogs act as a reservoir, while the main vector responsible for disease transmission is Rhipicephalus sanguineus. However, in east Asian countries, Haemaphysalis longicornis is considered the principal vector for disease transmission. This disease affects multiple organs and systems and has three clinical manifestations, including acute, subclinical, and chronic. Definitive diagnosis involves visualization of morulae on cytology, detection of antibodies through an indirect immunofluorescence test (IFAT), and DNA amplification by polymerase chain reaction (PCR). In canine ehrlichiosis, no predilection of age or sex is observed; however, Siberian Huskies and German Shepherds are more likely to develop severe clinical manifestations. Doxycycline, rifampicin, and minocycline are proven to be effective drugs against canine ehrlichiosis. This review is intended to describe a brief overview of Ehrlichia infection in dogs, its reported prevalence in east and south Asian countries, and the latest knowledge regarding chemotherapy and associated vectors responsible for the disease transmission. This manuscript also identifies the prevailing knowledge gaps which merit further attention by the scientific community.

Vector-borne pathogens in dogs from areas where leishmaniosis is endemic

Many vector-borne pathogens (VBPs), including Ehrlichia canis and Dirofilaria immitis, may infect simultaneously dogs in areas where Leishmania infantum is endemic, especially in the tropics, where highly abundant arthropod vectors thrive. The aim of this study was to compare the frequency of simultaneous VBPs infection in Leishmania-positive and Leishmania-negative dogs. Animals enrolled in this study were divided in two groups (G1 and G2), G1 being comprised of L. infantum-infected dogs (n = 58) and the G2 of L. infantum-negative dogs (n = 58). Blood samples were screened using a qualitative ELISA test (SNAP® 4Dx® Plus, IDEXX Laboratory, Westbrook, Maine, USA) for detection of antibodies against Anaplasma spp., Borrelia burgdorferi sensu lato, Ehrlichia spp. and antigens of Dirofilaria immitis. Overall, 89.7% (52/58) of dogs from G1 were positive for at least one VBP, whereas 50.0% (29/58) of dogs from G2 dogs were positive as well. The highest positivity was to E. canis (67.2%; 78/116), followed by D. immitis (12.9%; 15/116), and A. platys (6.0%; 7/116). None of the animals scored positive for B. burgdorferi s.l.. There was a statistically significant difference for the simultaneous positivity to E. canis plus D. immitis between groups. Furthermore, 43.1% (25/58) of dogs from G1 were infested by ectoparasites (ticks, fleas, or both), compared to 20.6% (12/58) of dogs from G2. In conclusion, Leishmania-infected dogs were more co-infected with other VBPs than Leishmania-negative animals. Therefore, it is pivotal to increase the awareness of veterinarian and dog owners about the importance of testing Leishmania-infected dogs for other VBPs, as this may directly affect treatment decisions and management.

Detection of vector-borne pathogens in owned dogs with cranial cruciate ligament rupture living in the Mediterranean area

Background

Cranial cruciate ligament rupture (CCLR) results from a multifactorial degenerative process that leads to rupture of the ligament. Vector-borne pathogens (VBP) in dogs can induce joint disease but their role in CCLR has not been previously investigated. The aim of the present work is to evaluate the prevalence of VBP in dogs with CCLR.

Methods

This was a prospective study that included 46 dogs presented for CCLR surgical treatment and 16 control dogs euthanized for diseases unrelated to the joints. Specimens collected included blood, synovial fluid, and synovial membrane biopsy. Pathogen testing consisted of serology for Leishmania infantum (quantitative ELISA), Ehrlichia canis/ewingii, Borrelia burgdorferi, Anaplasma phagocytophilum/platys, and Dirofilaria immitis (4DX IDEXX test), and PCR for L. infantum, Ehrlichia/Anaplasma spp., Bartonella spp., piroplasms (Babesia spp. and Theileria spp.), and filariae (D. immitis, Dirofilaria repens, Acanthocheilonema dracunculoides, Acanthocheilonema reconditum, and Cercopithifilaria spp.) on both EDTA-whole blood (EB) and synovial fluid (SF) samples. SF cytology and histopathological evaluation of synovial membrane were also performed.

Results

The prevalence of VBP was 19.6% in the CCLR group and 18.8% in the control group, with no statistical difference among them. The presence of synovitis was not more frequent in CCLR dogs (45.6%) than in control dogs (43.7%). Lymphoplasmacytic infiltration was the most common inflammatory pattern detected in the joints of both groups of dogs.

Conclusions

This study failed to demonstrate a role of canine VBP in CCLR or the presence or different pattern of joint inflammation in pathogen-positive dogs.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05205-x.

The Etiology, Incidence, Pathogenesis, Diagnostics, and Treatment of Canine Babesiosis Caused by Babesia gibsoni Infection

Babesia gibsoni is one of the small Babesia species and the infection this pathogen causes is usually asymptomatic, which complicates the capture of potential parasite carriers. In endemic areas, especially in Asia, B. gibsoni occurs quite often due to direct transmission by way of a tick vector. Due to the absence of vectors, its occurrence is described only sporadically in Europe; but, it is increasingly occurring in predisposed, so-called fighting breeds, especially the American pit bull terrier. This review describes the etiology, incidence, clinical signs, pathogenesis, diagnostics, and treatment of B. gibsoni infection, with an emphasis on the clinical and laboratory peculiarities of the disease. As the treated dogs do not eliminate the parasite from the body-only reducing parasitemia and improving clinical signs-the treatment of B. gibsoni infection is a challenge in many cases, and its study therefore deserves great attention.

A Questionnaire-Based Survey on the Long-Term Management of Canine Leishmaniosis by Veterinary Practitioners

Simple Summary

Canine Leishmaniosis is a chronic and potentially fatal disease, caused by Leishmania infantum, a zoonotic microorganism. In economically disadvantaged regions, costs associated with long-term patient monitoring may determine that some owners decline veterinary follow-up of their dogs, with potentially severe implications for animal welfare and public health. This online, questionnaire-based survey aimed to assess how Portuguese veterinary practitioners perform long-term patient management and recognize relapses. More than half of the respondents stated that most dog owners declare having financial restraints, which condition the use of diagnostic tests during long-term follow-up. Allopurinol ad aeternum or until disease remission and domperidone were the most prescribed treatment, and relapses were detected by the reappearance or worsening of clinical signs by most veterinary practitioners. The rate of relapse detection was higher in the most economically favored regions, probably because of a lesser constraint on the use of the appropriate diagnostic tests. This study confirms that owner financial restraints negatively influence veterinary follow-up and relapse recognition, potentially compromising clinical decision making and favoring the maintenance of Leishmania infantum infection endemic status in Portugal.

Abstract

Canine Leishmaniosis (CanL) is a chronic and potentially fatal disease. In economically disadvantaged regions, costs associated with long-term patient monitoring may determine that some owners decline veterinary follow-up of their dogs. This online, questionnaire-based survey aimed to assess how Portuguese veterinary practitioners perform long-term patient monitoring and recognize relapses. More than 50% of respondents reported that 50–100% of dog owners declared financial restraints. Hence, in these circumstances, most veterinary practitioners only performed clinical examination and serology. However, when owners did not declare financial restriction, other tests were additionally performed, such as renal and hepatic profiles, hemogram, serum protein electrophoresis and urine protein creatinine ratio. The mean number of exams performed when owners presented financial restraints was significantly lower than the number of exams performed without economic limitations. Most veterinary practitioners prescribed allopurinol ad aeternum or until disease remission and domperidone. CanL relapses were recognized by more than half of respondents “Always”, through the reappearance or worsening of clinical signs, whereas about a quarter detected an increase in anti-Leishmania antibody levels and identified abnormalities in the serum protein electrophoresis profile. The relapse rate was higher in the Lisbon Metropolitan Area and north, the most economically favored regions of Portugal. This study confirms that owner financial restraints negatively influence veterinary follow-up and relapse recognition, ultimately compromising clinical decision making and favoring the maintenance of Leishmania infantum infection endemicity.

Babesia gibsoni Infection in Dogs—A European Perspective

Simple Summary

Canine babesiosis is a tick-borne, protozoal, hemoparasitic disease caused by infection by parasites of the genus Babesia. Numerous species of Babesia exist worldwide. These protozoa are classified as either large forms (e.g., Babesia canis) or small forms (e.g., Babesia gibsoni). Reports of infections with small protozoan species are far less numerous. In most European countries where B. gibsoni has been reported, the percentage of infected dogs is around 1%. The literature review suggests that B. gibsoni should not only be considered a random and imported pathogen, but also a possible emerging parasite in Europe. The disease is much more severe than B. canis infections in most cases. Accurate molecular detection and species identification are important for selecting the correct therapy and predicting the course of the disease in dogs with babesiosis. In the future, it is expected that B. gibsoni infections may appear in other non-endemic regions in Europe, which may pose significant diagnostic and therapeutic challenges for veterinary practitioners.

Abstract

Canine babesiosis is a disease caused by infection with parasites of the genus Babesia. These protozoa are classified as either large (e.g., Babesia canis) or small (e.g., Babesia gibsoni). So far, only three small Babesia species of clinical importance, able to infect dogs, have been described: B. gibsoni, B. conradae, and B. vulpes. This review presents the current epidemiological situation of Babesia gibsoni infections in dogs in Europe. In most European countries where B. gibsoni has been reported, the percentage of infected dogs is around 1%. The higher prevalence of the B. gibsoni infection among American Pit Bull Terriers suggests breed susceptibility. An analysis of the available data makes it possible to conclude that B. gibsoni infections may appear in the future in other non-endemic regions of Europe, which may pose significant diagnostic and therapeutic challenges for veterinary practitioners.

Babesia gibsoni infection in Italy: a cross sectional study of 607 blood samples belonging to dogs that needed a molecular analysis investigation (2016-2019)

Babesia gibsoni (B. gibsoni) infection was sporadically described in Europe. In Italy, in particular, it was detected by PCR analysis only in one dog with unclear source of infection, while it has never been found in molecular studies involving more subjects. The aim of this retrospective, cross-sectional study was to determine the presence and the proportion of B. gibsoni infected dogs in a convenient Italian canine population. Babesia spp PCR analysis reports of canine blood samples collected from January 2016 to December 2019 were selected from the San Marco veterinary laboratory database and evaluated. Piroplasms PCR analysis was performed on 18S rRNA gene and positive samples were sequenced. Available data about signalment, living area and season of diagnosis were evaluated and statistically analyzed. The studied canine population had a median age of 62 months (interquartile range, IQR: 72.5) and was composed of male/female purebred and mixed breed dogs. Through sequencing, B. canis (26/40, 65%), B. vogeli (7/40, 17.5%), B. gibsoni (6/40, 15%) and B. vulpes (1/40, 2.5%) infections were reported. The proportion of B. gibsoni infected dogs in the described population was of 0.99%. The infection resulted more likely in male (6/6, 100%), purebred (5/6, 83.3%) dogs with median age of 40.5 months (IQR:32.3). In one case, the clinical signs and parasitemia appeared after a dogfight with a cohabitant infected dog. No other plausible sources of infection were detected. Likely, this could be considered the first autochthonous B. gibsoni infection case documented in Italy. Our results underline the need of considering B. gibsoni not only an exotic, random and rare cause of disease for dogs in Italy, but a possible emerging pathogen to take into account during diagnostic and epidemiological investigations, in symptomatic as well as in asymptomatic patients.

An epidemiological study in wild carnivores from Spanish Mediterranean ecosystems reveals association between Leishmania infantum, Babesia spp. and Hepatozoon spp. infection and new hosts for Hepatozoon martis, Hepatozoon canis and Sarcocystis spp

The aetiology and epidemiology of vector borne apicomplexan Babesia and Hepatozoon and kinetoplastid Leishmania infantum infections in wildlife have not been explored in wide areas of southern Spain. We investigated these infections in 151 wild carnivores, including foxes, badgers, beech martens, hedgehogs, wild cats, Egyptian mongooses, otters, genets and racoons. Overall, Hepatozoon, Babesia and L. infantum infections were detected in 68%, 48% and 23% of the wild animals surveyed, respectively. L. infantum-infected wildlife were more likely to be also infected with the apicomplexan Hepatozoon and Babesia spp. compared to the non-infected counterparts (p < .05). We report for the first time Hepatozoon martis in badgers and wild cats and H. canis in beech martens, and a Babesia sp. in wild cats from Spain. Our results also indicate the widespread distribution of H. canis in foxes (91%) and beech martens (13%), H. martis in beech martens (81%), wild cats (20%) and badgers (13%), H. felis in wild cats (60%), B. vulpes in foxes (64%), Babesia sp. type A closely related to B. vulpes, in badgers (58%) and Babesia sp. in wild cats (20%). Moreover, L. infantum infection was found in foxes (29%), beech martens (13%), badgers (8%) and 1/3 Egyptian mongooses. We also detected Cytauxzoon sp. in a wild cat and the first Sarcocystis sp. in a genet. This study provided evidence of increased risk of L. infantum infection in wildlife animals co-infected with Babesia spp. or Hepatozoon spp. and indicated that these infections are widespread in wild carnivores from Spanish Mediterranean ecosystems.

Molecular survey of vector-borne diseases in two groups of domestic dogs from Lisbon, Portugal

BACKGROUND

Canine vector-borne diseases (CVBDs) are caused by a wide range of pathogens transmitted by arthropods. They have been an issue of growing importance in recent years; however, there is limited information about the vector-borne pathogens circulating in Portugal. The aim of the present study was to detect canine vector-borne bacteria and protozoa of veterinary and zoonotic importance using molecular methods.

METHODS

One hundred and forty-two dogs from Lisbon, southern Portugal, were tested: 48 dogs from a veterinary hospital clinically suspected of vector-borne diseases and 94 apparently healthy dogs from shelters. Anaplasma spp./Ehrlichia spp., Babesia/Theileria spp., Hepatozoon spp., and Mycoplasma spp. infections were detected by PCR from blood samples and examined under light microscopy. Other information including clinical status and diagnostic test results were collected for each animal.

RESULTS

Infections were detected by PCR in 48 (33.80%) dogs. Single infections were found in 35 dogs (24.64%), and co-infections were found in 13 (9.15%) dogs. Twenty-nine (20.42%) dogs were positive for Hepatozoon spp., 15 (10.56%) for Mycoplasma spp., 11 (7.75%) for Anaplasma spp./Ehrlichia spp., and six (4.21%) for Babesia spp. DNA sequencing was used to identify Babesia vogeli (2.81%), Babesia canis (1.40%), Hepatozoon canis (20.42%), Mycoplasma haematoparvum (2.11%), Mycoplasma haemocanis (8.45%), Anaplasma platys (7.04%), and Ehrlichia canis (0.70%).

CONCLUSIONS

This is the first molecular identification of B. canis and M. haematoparvum in dogs from southern Portugal. This study highlights the importance of molecular methods to identify CVBD pathogens in endemic areas and helps to guide the clinical approach of veterinarians in practice.

Babesia gibsoni emerging with high prevalence and co-infections in “fighting dogs” in Hungary

Babesia gibsoni is considered as an emerging protozoan parasite of dogs in North America and Europe. However, no data have been published on its prevalence, molecular-phylogenetic characteristics and associated co-infections in dogs used for illegal fighting (i.e. predisposed to acquiring this piroplasm via biting) in Europe. In this study, blood samples from 79 American Staffordshire Terrier dogs, confiscated for illegal dog fights, were molecularly analyzed for tick-borne pathogens. Babesiagibsoni was detected in 32 dogs, i.e. with a prevalence of 40.5%. In addition, Babesia vulpes was found in 8 samples (prevalence of 10.1%), for the first time in dogs in Hungary. Canine hemoplasmas were also identified in 49 samples (62%): only Mycoplasma haemocanis in 32 (40.5%) dogs, only “Candidatus Mycoplasma haematoparvum” in 9 (11.4%) dogs, and both hemoplasmas in 8 (10.1%) dogs. Thus, hemoplasma infections also showed a particularly high prevalence in this dog population. Based on a partial fragment of the 18S rRNA gene, B. gibsoni from Hungary exhibited complete sequence identity with conspecific strains reported from Europe and Asia. The cytochrome c oxidase subunit 1 (cox1) gene sequence of this isolate showed the closest identity with B. gibsoni reported from Japan but had a nonsynonymous mutation (M33I). Furthermore, the 11 B. gibsoni-positive samples analyzed for sequence variants of the cytochrome b (cytb) gene showed the presence of a common mutation (P310S). Most importantly, B. gibsoni had two further nonsynonymous mutations, M121I and F258L, in a dog with severe and relapsing anemia following atovaquone treatment. Phylogenetically, both cytb sequence variants clustered together, with a clear geographical pattern showing the closest relationship of both haplotypes identified in Hungary with those from China and Japan. To the best of our knowledge, this is the first cox1 and cytb characterization of B. gibsoni in Europe, as well as the first report on the emergence of this piroplasm and hemoplasmas with high prevalence among “fighting dogs” north of the Mediterranean Basin.

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High prevalence of Babesia gibsoni and canine hemoplasmas in “fighting dogs”.

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Molecular evidence for infection with Babesia vulpes in dogs in Hungary.

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Closest identity with sequences from Asia in two of the three genetic markers tested.

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Two unique nonsynonymous mutations of B. gibsoni in the case of a dog.

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First report of atovaquone resistance for B. gibsoni in Europe.

Hepatozoon canis and Babesia vogeli infections of dogs in Tunisia

A paucity of studies is available on haemoparasites in dogs in Tunisia. In this study, we used molecular techniques (PCR/sequencing) to detect and characterize haemoprotozoa in sick dogs from Tunisia. A total of 99 dogs displaying such clinical symptoms as fever, anorexia, and depression were presented for treatment to the hospital of the Veterinary School of Sidi Thabet (Tunisia). Among dogs screened by PCR, five (5%) proved to be infected with a hemoprotozoa species. An analysis of all the sequences that were obtained enabled us to identify two species of Protozoa: Babesia vogeli (in three dogs) and Hepatozoon canis (in two other dogs). This is the first time that an infection of dogs by Hepatozoon canis in Tunisia has been reported. Veterinary practitioners should be aware that these two haemoparasites can infect dogs and should include them in any differential diagnosis of clinical illnesses with manifestations compatible with tick-borne diseases.

Prognostic Factors and Life Expectancy in Canine Leishmaniosis

Canine leishmaniosis (CanL) is a chronic and potentially fatal disease. The prognosis of CanL depends on the severity of the clinical signs and clinicopathological abnormalities presented by the dog at the time of diagnosis. This study aims to estimate the survival time of dogs with CanL, determining the prognostic value of different clinical and clinicopathological parameters. Medical records of 99 dogs diagnosed with CanL in five veterinary centers of the Alentejo region (Portugal) were examined retrospectively. The majority of dogs presented hyperproteinemia, moderate normocytic normochromic anemia, normal blood urea and creatinine levels and were classified as stage 1 according to the International Interest Society (IRIS) guidelines at the time of diagnosis. The severity of anemia, presence of concomitant infectious diseases at the time of diagnosis and the anti-Leishmania therapy were correlated with the survival time. The influence of renal dysfunction was evaluated by Receiver Operating Characteristic (ROC) curve and survival analysis. Survival analysis demonstrated that patients classified as IRIS 1 at the time of diagnosis survived more than four years, in contrast with dogs classified as IRIS 2 that survived around two and half years and dogs classified as IRIS 3-4 that survived around one month. IRIS stage deteriorated during the course of CanL in one third of the dogs and was the principal cause of death or euthanasia in a high proportion of animals. In some cases, dogs did not receive anti-Leishmania treatment or abandoned the veterinary follow-ups, which may have considerable repercussions for animal wellbeing and public health. This study reinforces the value of blood urea and creatinine levels as prognostic factors in CanL.

The role of healthy dog carriers of Babesia microti-like piroplasms

BACKGROUND

While in Europe Babesia canis has been traditionally held responsible for canine piroplasmosis, Babesia microti-like piroplasm (Bml) infection is being ever more observed in dogs, with the first clinical cases reported in northwestern Spain. This study examines the epidemiological role of healthy dogs living in endemic areas of Bml infection in Spain. The data obtained were used to describe the clinical status and map the geographical distribution of Bml infection in healthy dogs in northwestern Spain.

RESULTS

Blood samples and ticks were taken from 756 healthy dogs representatively across the whole Galicia region (northwestern Spain): stray (n = 211), hunting dogs (n = 333) and pets (n = 212). Blood samples were tested by microscopy parasite observation, nested PCR-RFLP and sequencing. Piroplasm infection prevalences in healthy dogs from northwestern Spain were 17.1% (129/756) by PCR and 3.4% (26/756) by microscopy observation. The species found by PCR were: 2.2% (17/756) for B. canis and 15.1% (114/756) for Bml. Co-infection with B. canis and Bml was noted in 2 dogs. The higher prevalences detected were Bml in hunting dogs (25.5%; 85/333) and B. canis in stray dogs (6.6%; 14/211). In fox-hunting dogs from any area and dogs from the A Coruña Province, significantly higher prevalences of Bml infection were detected (P < 0.001). Upon physical examination, tick infestation was observed: 130 ticks in 18 hunting and three pet dogs. These were subsequently identified as Rhipicephalus sanguineus (s.l.) (49.2%), Ixodes hexagonus (38.5%), Ixodes ricinus (6.9%) and Dermacentor reticulatus (5.4%). Among the more prevalent ticks infesting healthy carrier dogs were I. hexagonus, followed by D. reticulatus and I. ricinus.

CONCLUSIONS

Babesia canis and Bml were the only piroplasm species found infecting healthy dogs in Galicia, the prevalence of Bml being higher than of B. canis. Factors correlated with a higher Bml infection risk were being a hunting dog and living in the A Coruña Province. Healthy dogs travelling to other countries could act as carriers and probably contribute to the spread of Bml infection in dogs and wild carnivores throughout Europe.

Bartonella infections in cats and dogs including zoonotic aspects

Bartonellosis is a vector-borne zoonotic disease with worldwide distribution that can infect humans and a large number of mammals including small companion animals (cats and dogs). In recent years, an increasing number of studies from around the world have reported Bartonella infections, although publications have predominantly focused on the North American perspective. Currently, clinico-pathological data from Europe are more limited, suggesting that bartonellosis may be an infrequent or underdiagnosed infectious disease in cats and dogs. Research is needed to confirm or exclude Bartonella infection as a cause of a spectrum of feline and canine diseases. Bartonella spp. can cause acute or chronic infections in cats, dogs and humans. On a comparative medical basis, different clinical manifestations, such as periods of intermittent fever, granulomatous inflammation involving the heart, liver, lymph nodes and other tissues, endocarditis, bacillary angiomatosis, peliosis hepatis, uveitis and vasoproliferative tumors have been reported in cats, dogs and humans. The purpose of this review is to provide an update and European perspective on Bartonella infections in cats and dogs, including clinical, diagnostic, epidemiological, pathological, treatment and zoonotic aspects.

Hepatozoon canis in three imported dogs: a new tickborne disease reaching the United Kingdom

An increasing number of non-endemic vectorborne pathogens have been described in dogs imported to the UK in the past two decades. Recently, an outbreak of canine babesiosis in south-east England has raised veterinary awareness with regard to the impact of such diseases on the UK canine population. Canine hepatozoonosis, caused by Hepatozoon canis and transmitted by the ingestion of Rhipicephalus sanguineus ticks, is widespread in the Mediterranean basin. Herein we describe the first three molecularly confirmed clinical cases of canine hepatozoonosis in dogs imported into the UK. Veterinarians in the UK should be aware of H canis as a potential infection in imported dogs, especially in the face of the expanding distribution of R sanguineus ticks in Europe.

A comprehensive review on past, present and future aspects of canine theileriosis

Canine theileriosis is a notorious tick borne piroplasmid infection of wild and domestic canines. The causative agent has not yet been accurately classified. PCR studies revealed that causative agent resembles to Theileria genus and thus provisionally named as Theileria annae. The other Theileria species reported in canines is Theileria annulata, Theileria equi and unnamed Theileria specie. This emergent canine infection is considered to be endemic in most of the European countries. However in Asia this disease has not been reported till date. The vectors responsible for transmission of this disease have not been determined. It has been suggested that DNA of Theileria annae has been detected in hard tick Ixodes hexagonus in Northwestern Spain and several other tick species. Clinically canine theileriosis is characterized by severe weakness, fever, hemoglobinuria and anemia. Recently atovaquone or buparvaquone plus azithromycin therapy showed better clinical efficacy. This comprehensive review is intended to summarize the current knowledge on prevalence and epidemiology of canine theileriosis in different countries of the world and associated tick vectors.

Dermacentor reticulatus in Berlin/Brandenburg (Germany): Activity patterns and associated pathogens

Dermacentor reticulatus is one of the most important European tick species. However, its spatial distribution, seasonality and regional vector role are not well known. This study aimed to gather information about abundance patterns of questing ticks and associated pathogens in unfed female adult D. reticulatus in the Berlin/Brandenburg area. Using the flagging method, questing ticks were collected at four sites in 2010-2012 and 2000 D. reticulatus were analysed regarding infection with Rickettsia, Babesia, Borrelia and Anaplasmataceae by conventional or real-time PCR. Dermacentor reticulatus showed a bimodal activity pattern: highest numbers of adult ticks were recorded between March and end of May (mean 50 ticks/h) and from mid-August until end of November (mean 102 ticks/h). During summer, almost complete inactivity was observed (mean 0.4 ticks/h). Sporadic samplings from December to February revealed tick activity also during winter (mean 47 ticks/h), which was characterised by large fluctuations. Using negative binomial regression analysis, significant influences of the variables sampling site, season and temperature on the abundance of questing D. reticulatus were determined. The parameters relative humidity and year were not of significant importance. PCR analyses showed an average prevalence of 64% for Rickettsia sp. Large differences in pathogen frequencies were observed between sampling sites (31.4-78.3%). Regression analysis demonstrated a significant influence of the sampling site but not of season and year. Examinations regarding other pathogen groups indicated prevalences of 0.25% (Borrelia sp.) and 0.05% (Anaplasmataceae) but absence of Babesia sp. Sequencing of positive samples revealed infections with Rickettsia raoultii, Borrelia miyamotoi, Borrelia afzelii and Anaplasma phagocytophilum. The study shows stable populations of D. reticulatus in Berlin/Brandenburg. People should be aware of ticks throughout the year since Ixodes ricinus is co-endemic and active in spring, summer and autumn while adult D. reticulatus are active throughout the year and even in winter during periods of frost as long as it is warming up during the day. Prevalence of R. raoultii in the present study is among the highest described for D. reticulatus. Borrelia miyamotoi was detected for the first time in D. reticulatus, illustrating the importance of screening studies to evaluate the pathogen structure in D. reticulatus populations.

Canine Babesiosis: Where Do We Stand?

Canine babesiosis is a tick-borne disease caused by protozoal haemoparasites of different Babesia species. Babesiosis is one of the most important globally extended and quickly spreading tick-borne infections of dogs. This comprehensive review gives an in-depth overview of Babesia species currently identified in dogs together with relevant vector tick species and their geographical distribution, life cycle and transmission of parasite. The main mechanisms in the pathogenesis of babesiosis are described and elucidated by recent literature overview. As Babesia infection causes a disease with very variable clinical manifestations, special attention is given to clinical signs, laboratory features and clinicopathological findings. The diagnosis of canine babesiosis by microscopy, serological and molecular methods is reviewed, together with recent advances in mass spectrometry based assays. Accurate detection and species recognition are important for the selection of the appropriate therapy, monitoring and prediction of the outcome of the disease. Finally, guidelines for the treatment and prevention of canine babesiosis are given.

Association between canine leishmaniosis and Ehrlichia canis co-infection: a prospective case-control study

Background

In the Mediterranean basin, Leishmania infantum is a major cause of disease in dogs, which are frequently co-infected with other vector-borne pathogens (VBP). However, the associations between dogs with clinical leishmaniosis (ClinL) and VBP co-infections have not been studied. We assessed the risk of VBP infections in dogs with ClinL and healthy controls.

Methods

We conducted a prospective case-control study of dogs with ClinL (positive qPCR and ELISA antibody for L. infantum on peripheral blood) and clinically healthy, ideally breed-, sex- and age-matched, control dogs (negative qPCR and ELISA antibody for L. infantum on peripheral blood) from Paphos, Cyprus. We obtained demographic data and all dogs underwent PCR on EDTA-blood extracted DNA for haemoplasma species, Ehrlichia/Anaplasma spp., Babesia spp., and Hepatozoon spp., with DNA sequencing to identify infecting species. We used logistic regression analysis and structural equation modelling (SEM) to evaluate the risk of VBP infections between ClinL cases and controls.

Results

From the 50 enrolled dogs with ClinL, DNA was detected in 24 (48%) for Hepatozoon spp., 14 (28%) for Mycoplasma haemocanis, 6 (12%) for Ehrlichia canis and 2 (4%) for Anaplasma platys. In the 92 enrolled control dogs, DNA was detected in 41 (45%) for Hepatozoon spp., 18 (20%) for M. haemocanis, 1 (1%) for E. canis and 3 (3%) for A. platys. No Babesia spp. or “Candidatus Mycoplasma haematoparvum” DNA was detected in any dog. No statistical differences were found between the ClinL and controls regarding age, sex, breed, lifestyle and use of ectoparasitic prevention. A significant association between ClinL and E. canis infection (OR = 12.4, 95% CI: 1.5–106.0, P = 0.022) was found compared to controls by multivariate logistic regression. This association was confirmed using SEM, which further identified that younger dogs were more likely to be infected with each of Hepatozoon spp. and M. haemocanis, and dogs with Hepatozoon spp. were more likely to be co-infected with M. haemocanis.

Conclusions

Dogs with ClinL are at a higher risk of co-infection with E. canis than clinically healthy dogs. We recommend that dogs diagnosed with ClinL should be tested for E. canis co-infection using PCR.

Does co-infection with vector-borne pathogens play a role in clinical canine leishmaniosis?

BACKGROUND

The severity of canine leishmaniosis (CanL) due to Leishmania infantum might be affected by other vector-borne organisms that mimic its clinical signs and clinicopathological abnormalities. The aim of this study was to determine co-infections with other vector-borne pathogens based on serological and molecular techniques in dogs with clinical leishmaniosis living in Spain and to associate them with clinical signs and clinicopathological abnormalities as well as disease severity.

METHODS

Sixty-one dogs with clinical leishmaniosis and 16 apparently healthy dogs were tested for Rickettsia conorii, Ehrlichia canis, Anaplasma phagocytophilum and Bartonella henselae antigens by the immunofluorescence antibody test (IFAT) and for E. canis, Anaplasma spp., Hepatozoon spp., Babesia spp. and filarioid DNA by polymerase chain reaction (PCR).

RESULTS

Among the dogs examined by IFAT, the seroprevalences were: 69% for R. conorii, 57% for E. canis, 44% for A. phagocytophilum and 37% for B. henselae; while the prevalences found by PCR were: 8% for Ehrlichia/Anaplasma, 3% for Anaplasma platys and 1% for H. canis. No other pathogen DNA was detected. Statistical association was found between dogs with clinical leishmaniosis and seroreactivity to R. conorii antigen (Fisher's exact test: P = 0.025, OR = 4.1, 95% CI = 1-17) and A. phagocytophilum antigen (Fisher's exact test: P = 0.002, OR = 14.3, 95% CI = 2-626) and being positive to more than one serological or molecular tests (co-infections) (Mann-Whitney test: U = 243, Z = -2.6, n ₁  = 14, n ₂  = 61, P = 0.01) when compared with healthy dogs. Interestingly, a statistical association was found between the presence of R. conorii, E. canis, A. phagocytophilum and B. henselae antibodies in sick dogs and some clinicopathological abnormalities such as albumin and albumin/globulin ratio decrease and increase in serum globulins. Furthermore, seroreactivity with A. phagocytophilum antigens was statistically associated with CanL clinical stages III and IV.

CONCLUSIONS

This study demonstrates that dogs with clinical leishmaniosis from Catalonia (Spain) have a higher rate of co-infections with other vector-borne pathogens when compared with healthy controls. Furthermore, positivity to some vector-borne pathogens was associated with more marked clinicopathological abnormalities as well as disease severity with CanL.

Babesia microti-like piroplasm (syn. Babesia vulpes) infection in red foxes (Vulpes vulpes) in NW Spain (Galicia) and its relationship with Ixodes hexagonus

Piroplasmosis is caused by several species of protozoa such as the Babesia microti-like piroplasm (Bml), an emerging blood protozoan also known as Theileria annae or Babesia vulpes. Infection by Bml was first reported in dogs in Spain where it is endemic today. Recently, a high prevalence of Bml has been increasingly detected in red foxes (Vulpes vulpes) in European countries. The objective of this study was to determine infection levels of this parasite in foxes from Galicia, NW Spain, and ticks species infestation in these carnivores, where they are so far unknown. Samples of blood, spleen and ticks (if present) were taken from 237 hunted red foxes in the Galicia region. Blood smears were prepared for direct parasite observation, and spleen and tick samples were examined by nested PCR. Prevalences of Bml infection in Galician red foxes were estimated at 72% (171/237) by PCR and 38.23% (26/68) by direct observation. Among 837 ticks collected, the main tick identified was Ixodes hexagonus (present in 82.4% of the foxes) followed by Ixodes ricinus (12.3%), Dermacentor reticulatus (12.3%) and Rhipicephalus sanguineus sensu lato (3.5%). From 34 foxes testing positive for Bml, 616 ticks were collected: positive Bml PCR results were obtained in 55.6% (227/408) of ticks collected from 9 foxes, while the 208 ticks from the remaining 25 infected foxes returned negative PCR results. Given that canine piroplasmosis is endemic in this area, our observations point to the red fox as the main reservoir for Bml infection and the high proportion of I. hexagonus among ticks collected from red foxes suggests its likely role as vectors of B. microti-like piroplasm in this region. Further studies are needed for a better understanding of the link between the wild and domestic life cycles of this piroplasm.

First description of Bartonella koehlerae infection in a Spanish dog with infective endocarditis

BACKGROUND

Bartonella koehlerae has been recently described as a new cat- and cat fleas-associated agent of culture-negative human endocarditis. It has been also encountered in one dog from Israel and six dogs from the USA, but other clinically relevant reports involving this bacterium are lacking.

RESULTS

A 7-year-old intact male mixed dog presented with clinico-pathological signs consistent with mitral endocarditis and cutaneous hemangiosarcoma. Molecular studies revealed the presence of Bartonella koehlerae DNA in samples from blood and mitral valve tissue.

CONCLUSIONS

This is the first description of B. koehlerae in Spain, corroborating that it can also be detected in dogs. Bartonella koehlerae infection should also be considered in Spain in humans and dogs presenting with clinical disease suggestive of it, such as culture-negative endocarditis.

Molecular detection of vector-borne pathogens in blood and splenic samples from dogs with splenic disease

Background

The spleen is a highly perfused organ involved in the immunological control and elimination of vector-borne pathogens (VBP), which could have a fundamental role in the pathogenesis of splenic disease. This study aimed to evaluate certain VBP in samples from dogs with splenic lesions.

Methods

Seventy-seven EDTA-blood and 64 splenic tissue samples were collected from 78 dogs with splenic disease in a Mediterranean area. Babesia spp., Bartonella spp., Ehrlichia/Anaplasma spp., Hepatozoon canis, Leishmania infantum, hemotropic Mycoplasma spp. and Rickettsia spp. were targeted using PCR assays. Sixty EDTA-blood samples from dogs without evidence of splenic lesions were included as a control group.

Results

More than half (51.56%) of the biopsies (33/64) were consistent with benign lesions and 48.43% (31/64) with malignancy, mostly hemangiosarcoma (25/31). PCR yielded positive results in 13 dogs with spleen alterations (16.67%), for Babesia canis (n = 3), Babesia gibsoni (n = 2), hemotropic Mycoplasma spp. (n = 2), Rickettsia massiliae (n = 1) and “Babesia vulpes” (n = 1), in blood; and for B. canis, B. gibsoni, Ehrlichia canis and L. infantum (n = 1 each), in spleen. Two control dogs (3.3%) were positive for B. gibsoni and H. canis (n = 1 each). Benign lesions were detected in the 61.54% of infected dogs (8/13); the remaining 38.46% were diagnosed with malignancies (5/13). Infection was significantly associated to the presence of splenic disease (P = 0.013). There was no difference in the prevalence of infection between dogs with benign and malignant splenic lesions (P = 0.69); however B. canis was more prevalent in dogs with hemangiosarcoma (P = 0.006).

Conclusions

VBP infection could be involved in the pathogenesis of splenic disease. The immunological role of the spleen could predispose to alterations of this organ in infected dogs. Interestingly, all dogs with B. canis infection were diagnosed with hemangiosarcoma in the present survey. As previously reported, results support that VBP diagnosis could be improved by analysis of samples from different tissues. The sample size included here warrants further investigation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-017-2074-z) contains supplementary material, which is available to authorized users.

A review of canine babesiosis: the European perspective

Canine babesiosis is a significant tick-borne disease caused by various species of the protozoan genus Babesia. Although it occurs worldwide, data relating to European infections have now been collected for many years. These data have boosted the publication record and increased our working knowledge of these protozoan parasites. Both the large and small forms of Babesia species (B. canis, B. vogeli, B. gibsoni, and B. microti-like isolates also referred to as "B. vulpes" and "Theileria annae") infect dogs in Europe, and their geographical distribution, transmission, clinical signs, treatment, and prognosis vary widely for each species. The goal of this review is to provide veterinary practitioners with practical guidelines for the diagnosis, treatment and prevention of babesiosis in European dogs. Our hope is that these guidelines will answer the most frequently asked questions posed by veterinary practitioners.

Molecular detection of vector-borne pathogens in wild and domestic carnivores and their ticks at the human-wildlife interface

Urbanization of natural areas is considered one of the causes of the current apparent emergence of infectious diseases. Carnivores are among the species that adapt well to urban and periurban environments, facilitating cross-species disease transmission with domestic dogs and cats, and potentially with their owners. The prevalence of vector-borne pathogens (VBP) of zoonotic and veterinary interest was studied in sympatric wild and domestic carnivores into Barcelona Metropolitan Area (NE Spain). Blood or spleen samples from 130 animals, including 34 common genets (Genetta genetta), 12 red foxes (Vulpes vulpes), 10 stone martens (Martes foina), three Eurasian badgers (Meles meles), 34 free-roaming domestic cats and 37 dogs with outdoor access, were collected either in protected or adjacent residential areas. A total of 309 ticks (chiefly Rhipicephalus turanicus) were collected on these animals. The samples were analyzed with a battery of PCR assays targeting the DNA of Rickettsia spp., Anaplasmataceae, Coxiella burnetii, Bartonella spp., and Piroplasmida, and the amplicons were sequenced. The fox showed the highest prevalence (58%) and diversity of VBP (four pathogens), whereas none of the dogs were infected. Bartonella spp. (including B. clarridgeiae, B. henselae, and B. rochalimae) was the most prevalent pathogen. Infection of wild carnivores with Ehrlichia canis, C. burnetii, Theileria annae and Babesia vogeli was also confirmed, with some cases of coinfection observed. The presence of DNA of T. annae and B. vogeli was also confirmed in tick pools from four species of wild carnivores, supporting their role in piroplasmid life-cycle. By the sequencing of several target genes, DNA of Rickettsia massiliae was confirmed in 17 pools of Rh. turanicus, Rh. sanguineous, and Rh. pusillus from five different species, and Rickettsia conorii in one pool of Rh. sanguineous from a dog. None of the hosts from which these ticks were collected was infected by Rickettsia. Although carnivores may not be reservoir hosts for zoonotic Rickettsia, they can have an important role as mechanical dispersers of infected ticks.

Theileria annae (syn. Babesia microti-like) infection in dogs in NW Spain detected using direct and indirect diagnostic techniques: clinical report of 75 cases

Background

In north-western Spain, piroplamosis caused by Theileria annae is now recognized as a serious problem because veterinarians, despite being aware of the clinical signs of piroplasmosis, lack the necessary information on its epidemiology or specific diagnostic tools for its management. This, along with the fact that T. annae infection is also refractory to current piroplamosis treatments, prompted this study designed to assess the clinical presentation and diagnosis of this largely unknown parasitic disease in dogs.

Methods

One hundred and twenty dogs in NW Spain suspected clinically of having piroplasmosis were examined and piroplasm species detected by light microscopy (LM) observation of Giemsa-stained blood smears, immunofluorescent antibody test (IFAT), and PCR plus sequencing.

Results

Seventy five of the sick dogs were confirmed to be infected with T. annae by PCR (designated “true infection cases”). Intraerythrocytic ring-shaped bodies morphologically compatible with small piroplasms were observed by LM in 59 (57 true infections) of the 120 blood samples. Anti-Babesia antibodies were detected by IFAT in 59 of the 120 sera (55 of which were “true infections”). Using PCR as the reference method, moderate agreement was observed between positive LM vs PCR and IFAT vs PCR results (kappa values: 0.6680 and 0.6017, respectively). Microscopy examination and IFAT were moderately sensitive in detecting the pathogen (76% and 73.3%, respectively). In the 75 cases of “true infection”, the most common clinical signs observed were pale mucous membranes, anorexia and apathy. Blood cell counts consistently revealed severe regenerative anaemia and thrombocytopenia in dogs with piroplasmosis due to T. annae. Young dogs (≤3 year) (p = 0.0001) were more susceptible to the disease.

Conclusion

Microscopy showed moderate diagnostic sensitivity for acute T. annae infection while IFAT-determined antibody titres were low (1/64 to 1/128). The infecting species should be therefore confirmed by molecular tests. Our results suggest that the disease affects dogs in regions of Spain bordering the endemic Galicia area where this piroplasm has not been previously reported (Asturias, northern Spain). Further epidemiological surveys based on serological and molecular methods are required to establish the current geographical range of T. annae infection.

Reclassification of Theileria annae as Babesia vulpes sp. nov

Background

Theileria annae is a tick-transmitted small piroplasmid that infects dogs and foxes in North America and Europe. Due to disagreement on its placement in the Theileria or Babesia genera, several synonyms have been used for this parasite, including Babesia Spanish dog isolate, Babesia microti-like, Babesia (Theileria) annae, and Babesia cf. microti. Infections by this parasite cause anemia, thrombocytopenia, and azotemia in dogs but are mostly subclinical in red foxes (Vulpes vulpes). Furthermore, high infection rates have been detected among red fox populations in distant regions strongly suggesting that these canines act as the parasite’s natural host. This study aims to reassess and harmonize the phylogenetic placement and binomen of T. annae within the order Piroplasmida.

Methods

Four molecular phylogenetic trees were constructed using a maximum likelihood algorithm based on DNA alignments of: (i) near-complete 18S rRNA gene sequences (n = 76 and n = 93), (ii) near-complete and incomplete 18S rRNA gene sequences (n = 92), and (iii) tubulin-beta gene sequences (n = 32) from B. microti and B. microti-related parasites including those detected in dogs and foxes.

Results

All phylogenetic trees demonstrate that T. annae and its synonyms are not Theileria parasites but are most closely related with B. microti. The phylogenetic tree based on the 18S rRNA gene forms two separate branches with high bootstrap value, of which one branch corresponds to Babesia species infecting rodents, humans, and macaques, while the other corresponds to species exclusively infecting carnivores. Within the carnivore group, T. annae and its synonyms from distant regions segregate into a single clade with a highly significant bootstrap value corroborating their separate species identity.

Conclusion

Phylogenetic analysis clearly shows that T. annae and its synonyms do not pertain to Theileria and can be clearly defined as a separate species. Based on the facts that T. annae and its synonyms have not been shown to have a leukocyte stage, as expected in Theileria, do not infect humans and rodents as B. microti, and cluster phylogenetically as a separate species, this study proposes to name this parasite Babesia vulpes sp. nov., after its natural host, the red fox V. vulpes.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-015-0830-5) contains supplementary material, which is available to authorized users.

Bacterial and protozoal agents of canine vector-borne diseases in the blood of domestic and stray dogs from southern Portugal

Background

The so-called canine vector-borne diseases (CVBD) are caused by a wide range of pathogens transmitted by arthropods. In addition to their veterinary importance, many of these canine vector-borne pathogens can also affect the human population due to their zoonotic potential, a situation that requires a One Health approach. As the prevalence of vector-borne pathogens in cats from southern Portugal has been recently evaluated, the aim of the present study was to assess if the same agents were present in dogs living in the same area, and to assess positivity-associated risk factors.

Methods

One thousand and ten dogs (521 domestic and 489 stray) from veterinary medical centres and animal shelters in southern Portugal were enrolled. Anaplasma spp./Ehrlichia spp., Bartonella spp., Borrelia burgdorferi sensu lato, Babesia spp., Hepatozoon spp. and Leishmania infantum infections were evaluated by polymerase chain reaction (PCR) assays in blood samples.

Results

Sixty-eight (6.7%) dogs were PCR-positive to at least one of the tested CVBD agent species, genera or complex, including one dog found positive to two different genera. Nineteen (1.9%) dogs were positive to Anaplasma spp./Ehrlichia spp., eight (0.8%) to B. burgdorferi s.l., 31 (3.1%) to Hepatozoon spp. and 11 (1.1%) to L. infantum. Anaplasma platys, Ehrlichia canis, B. burgdorferis.l. and Hepatozoon canis were identified by DNA sequencing, including one animal confirmed with both A. platys and H. canis. Furthermore, Wolbachia spp. was amplified in blood from four dogs. None of the tested dogs was positive by PCR for Bartonella spp. or Babesia spp.

Conclusions

The molecular identification of CVBD agents in southern Portugal, some of them with zoonotic concern, reinforces the importance to alert the veterinary community, owners and public health authorities to prevent the risk of transmission of vector-borne pathogens among dogs and to other vertebrate hosts including humans. The prevalence of the selected pathogens was lower than that previously found in cats from the same region, probably because veterinarians and owners are more aware of them in the canine population and control measures are used more often.

Guideline for veterinary practitioners on canine ehrlichiosis and anaplasmosis in Europe

Canine ehrlichiosis and anaplasmosis are important tick-borne diseases with a worldwide distribution. Information has been continuously collected on these infections in Europe, and publications have increased in recent years. Prevalence rates are high for Ehrlichia and Anaplasma spp. infections in dogs from different European countries. The goal of this article was to provide a practical guideline for veterinary practitioners on the diagnosis, treatment, and prevention of ehrlichiosis and anaplasmosis in dogs from Europe. This guideline is intended to answer the most common questions on these diseases from a practical point of view.

Questionnaire-based survey on the distribution and incidence of canine babesiosis in countries of Western Europe

The incidence of canine babesiosis may vary considerably from one country to another depending on the distribution of the causative parasite species and their specific vectors. The aim of the present study was to evaluate the clinical occurrence of canine babesiosis diagnosed in European veterinary clinics and propose an updated map of the disease distribution in Western Europe. Questionnaires were sent to companion animal veterinary clinics in Spain, France, Benelux, Germany and Austria. The annual number of babesiosis cases in 2010, the number of practitioners in the clinic and the location of the clinic were recorded. The total numbers of dogs and practitioners in each country were used for definition of the reference populations and the annual incidence of canine babesiosis was calculated by dividing the total number of reported babesiosis cases by the total number of dogs in the veterinary practices involved in the study. Data were georeferenced for distribution map construction. The overall annual incidence of clinical babesiosis amongst the investigated dog population was 0.7%, with significant variations amongst countries and regions. Three epidemiological situations were described: (i) Spain, with co-existence of several species of piroplasms and patchy distribution of babesiosis, (ii) France, with overall presence of babesiosis due to Babesia canis and local variations and (iii) Benelux, Germany and Austria, with overall low prevalence of the disease associated with localised description related either to imported cases or to small autochthonous foci of B. canis infection.

Pathologic mechanisms underlying the clinical findings in canine leishmaniasis due to Leishmania infantum/chagasi

In dogs with symptomatic or asymptomatic leishmaniasis, Leishmania infantum appears to induce a mixed Th1/Th2 immune response that in the sick dog may eventually result in tissue damage via different pathomechanisms, notably granulomatous inflammation (eg, nodular dermatitis, osteomyelitis), immune complex deposition (eg, glomerulonephritis), and/or autoantibody production (eg, polymyositis). This is a compensatory but detrimental mechanism generated mainly because of the insufficient killing capacity of macrophages against the parasite in the susceptible dog. Clinical disease is typically exemplified as exfoliative and/or ulcerative dermatitis, with or without nasodigital hyperkeratosis and onychogryphosis, glomerulonephritis, atrophic myositis of masticatory muscles, anterior uveitis, keratoconjunctivitis sicca, epistaxis, and/or polyarthritis, appearing alone or in various combinations. The pathogenesis of these clinical conditions has recently been highlighted, to a greater or lesser extent. The usually subclinical conditions expressed as chronic colitis, chronic hepatitis, vasculitis, myocarditis, osteomyelitis, orchiepididymitis, and meningoencephalomyelitis, though uncommon, are of pathologic importance from a differential point of view. The leading cause of death among canine leishmaniasis patients is chronic proteinuric nephritis that may progress to end-stage kidney disease, nephrotic syndrome, and/or systemic hypertension. However, even the asymptomatic proteinuria, when profuse, may be a serious problem because it predisposes to arterial thromboembolism and eventually contributes to the deterioration of the body condition.

Seropositivity rates for agents of canine vector-borne diseases in Spain: a multicentre study

Background

Controlling canine vector-borne diseases (CVBD) is a major concern, since some of these diseases are serious zoonoses. This study was designed to determine seropositivity rates in Spain for agents causing the following five CVBD: leishmaniosis (Leishmania infantum: Li), heartworm (Dirofilaria immitis: Di), ehrlichiosis (Ehrlichia canis: Ec), anaplasmosis (Anaplasma phagocytophilum/Anaplasma platys: An) and Lyme disease (Borrelia burgdorferi: Bb).

Methods

Anti-An, -Bb, and -Ec antibodies and the Di antigen were determined using the 4DX SNAP® Test (IDEXX Laboratories) and anti-L. infantum (Li) antibodies using the Leishmania SNAP® Test (IDEXX Laboratories) in blood and/or serum samples.

Results

Among 1100 dogs examined, overall seropositivity rates were: Li (15.7%), Ec (5%), An (3.1%), Di (1.25%) and Bb (0.4%). While seropositivity towards Bb and Di was similar in all geographic regions, rates were significantly higher in the east of Spain (8.3%) for An, significantly higher in the north (20%) for Ec, and significantly higher in the Southeast (46.6%) and South (27.4%), and significantly lower in the north (0%) for Li.

No statistical associations were observed between sex and the CVBD analyzed (p ≥ 0.05) while the following associations with other variables were detected: a higher seropositivity to Ec (40%) and Bb (6.7%) in dogs under one year of age compared with adults (p < 0.05); and a higher seropositivity to An and Li in dogs that lived outdoors versus indoors (p = 0.01; p < 0.001, respectively). Seropositivity rates of 2.1%, 0%, 1.7%, 0.5% and 4.2% were recorded respectively for An, Bb, Ec, Di and Li in dogs with no clinical signs (n = 556) versus 3.8%, 0.6%, 7.5%, 1.8% and 25.9% for those with signs (n = 507) suggestive of a CVBD.

Conclusion

The data obtained indicate a risk for dogs in Spain of acquiring any of the five CVBD examined. Veterinarians in the different regions should include these diseases in their differential diagnoses and recommend the use of repellents and other prophylactic measures to prevent disease transmission by arthropod vectors. Public health authorities also need to become more involved in the problem, since some of the CVBD examined here also affect humans.

Serological and molecular survey of Leishmania parasites in apparently healthy dogs in the West Bank, Palestine

BACKGROUND

Canine visceral leishmaniasis (CVL) is caused by Leishmania infantum in all Mediterranean countries. The Leishmania parasite is transmitted by the bite of a corresponding sand fly vector and primarily maintained in nature by wild and domestic reservoirs, including dogs, foxes and jackals. Infected dogs are the primary reservoir host in endemic regions and are the most significant risk disposing humans to infection. The present study aimed at assessing the prevalence of infection with Leishmania and identification of Leishmania infantum in domestic dogs in the West Bank, Palestine.

METHODS

The infection rate among domestic dogs collected from seven districts in the Palestinian West Bank was investigated by examination of parasites in culture from the buffy coat using serological and molecular methods; based on ELISA, internal transcribed spacer 1 (ITS1) and cysteine protease (CPB) PCR.

RESULTS

Out of 215 dogs examined for Leishmania, 36 (16.7%) were positive in at least one method. Twenty three animals (11.5%) were positive for Leishmania DNA, whereas, ELISA and culture revealed 16 (7.5%), and 4 (1.5%) respectively. CPB-PCR on one of three culture-positive isolates revealed Leishmania infantum as the causative agent for Leishmania infection in dogs.

CONCLUSIONS

Our study showed that canine leishmania infection is prevalent with varying degrees in all the seven studied districts in Palestine despite the absence of human VL cases in 4 of these districts. The causative agent was confirmed to be Leishmania infantum.

Gammopathy in a Spanish dog infected with Bartonella henselae

Generalised pyogranulomatous disease and hyperviscosity syndrome associated with a presumed monoclonal gammopathy was diagnosed in a three-year-old intact female Pomeranian. The Bartonella henselae antibody titer was 1:64 and Bartonella species DNA was amplified from the splenic tissue. Monoclonal gammopathies in dogs are typically associated with plasma cell and lymphoid dyscrasias and other inflammatory or infectious diseases such as ehrlichiosis and leishmaniosis. Based on this case report, infection with Bartonella species should also be added to the differential diagnoses for gammopathy in dogs. To the authors' knowledge, this is the first report of molecular evidence of Bartonella species infection in a sick dog in Spain.

The occurrence of Dirofilaria immitis, Borrelia burgdorferi, Ehrlichia canis and Anaplasma phagocytophium in dogs in China

A survey of the occurrence of Dirofilaria immitis, Borrelia burgdorferi, Ehrlichia canis and Anaplasma phagocytophium in dogs was undertaken in the People's Republic of China between October 2008 and October 2009. A total of 600 blood samples were taken from dogs in four cities in China: 300 in Beijing, 150 in Shenzhen, 30 in Shanghai and 120 in Zhengzhou. All samples were tested for the heartworm antigen and antibodies of canine B. burgdorferi, E. canis and A. phagocytophium by using the canine SNAP® 4Dx® test kit. The occurrence of D. immitis, B. burgdorferi, E. canis and A. phagocytophium was 1.17% (7/600), 0.17% (1/600), 2.17% (13/600) and 0.5% (3/600), respectively. In Shenzhen city 2% (3/150), 8.67% (13/150) and 2% (3/150) of samples were positive for D. immitis, E. canis and A. phagocytophium, respectively. The occurrence of heartworm antigen was 0.33% (1/300) in Beijing, 2.00% (3/150) in Shenzhen, 3.33% (1/30) in Shanghai and 1.67% (2/120) in Zhengzhou. We found E. canis and A. phagocytophium only at one site, Shenzhen, while the only occurrence of B. burgdorferi was at Beijing. In conclusion, the dog population in China is at potential risk for D. immitis, B. burgdorferi, E. canis and A. phagocytophium infection, the risk being especially high in southern China.

Perspectives on canine and feline hepatozoonosis

Two species of Hepatozoon are currently known to infect dogs and cause distinct diseases. Hepatozoon canis prevalent in Africa, Asia, southern Europe, South America and recently shown to be present also in the USA causes infection mainly of hemolymphoid organs, whereas Hepatozoon americanum prevalent in the southeastern USA causes myositis and severe lameness. H. americanum is transmitted by ingestion of the Gulf Coast tick Amblyomma maculatum and also by predation on infected prey. H. canis is transmitted by Rhipicephalus sanguineus, in South America also by Amblyomma ovale, and has also been shown to be transmitted transplacentally. Hepatozoonosis of domestic cats has been described mostly from the same areas where canine infection is present and the exact identity of the species which infect cats, their pathogenicity and vectors have not been elucidated. The diagnosis of hepatozoonosis is made by observation of gamonts in blood smears, histopathology, PCR or serology. The main treatment for H. canis is with imidocarb dipropionate whereas H. americanum infection is treated with an initial combination of trimethoprim-sulfadiazine, pyrimethamine and clindamycin followed by maintenance with decoquinate. Treatment for both diseases has not been reported to facilitate complete parasite elimination and new effective drugs are needed for the management of these infections. Prevention of hepatozoonosis should be based on avoidance of oral ingestion of infected tick vectors and infected prey.

Canine leishmaniasis: the key points for qPCR result interpretation

Background

Diagnosis and follow up of CanL is difficult since the range of clinical signs is varied and seroprevalence is high in endemic areas. The aims of this study were: i) demonstrate the advantages of Leishmania qPCR to diagnose and control CanL and highlight its prognostic value and ii) propose guidelines for tissue selection and infection monitoring.

Findings

This study included 710 dogs living in an endemic area of leishmaniasis. Forty percent (285/710) exhibited clinical signs consistent with CanL. Infection was detected in 36.3% (258/710) of the dogs of which 4.5% (32/710) were detected by qPCR, 16.2% (115/710) detected by ELISA and 15.6% (111/710) tested positive for both tests. Only 17.9% (127/710) of the dogs were classified sick (affected) with CanL.

All symptomatic dogs with medium or high ELISA titers were qPCR-positive in blood samples. All dogs with inconclusive or low ELISA results with high or medium qPCR parasitemia values developed the disease. Seventy one percent of asymptomatic ELISA-positive dogs confirmed by qPCR (medium to high parasitemia) developed the disease.

Bone marrow or lymph node aspirate should be selected to ensure the absence of the parasite in asymptomatic dogs: 100-1,000 parasites/ml in bone marrow are detectable in blood, whereas lower parasite loads are usually negative. Almost 10% of negative samples in blood were positive in conjunctival swabs.

Conclusions

Because qPCR allows parasite quantification, it is an effective tool to confirm a diagnosis of CanL in (i) cases of inconclusive ELISA results, (ii) when the dog has not yet seroconverted, or (iii) for treatment monitoring.

Babesiosis due to the canine Babesia microti-like small piroplasm in dogs-first report from Portugal and possible vertical transmission

Background

Canine babesiosis (or piroplasmosis) is endemic in northern Portugal, but molecularly confirmed cases of infection with small piroplasms have not been reported in the country. Three German shepherd dogs - a bitch and its 2-month old pup and an unrelated male - clinically suspected of piroplasmosis were assessed for babesial infection.

Results

Parasitemia with small piroplasms was detected by microscopy in two dogs. All three dogs were positive by PCR and the Babesia microti-like small piroplasm (syn. Theileria annae) was identified by DNA sequencing. These are the first confirmed cases of babesiosis caused by the B. microti-like piroplasm both in dogs from Portugal and in dogs suspected of clinical piroplasmosis outside of Spain.

Conclusions

Although the bitch and the male had visited neighboring Galicia (northwestern Spain), where the disease is endemic, incursion of this piroplasm into northern Portugal is evident and infection of the non-traveled pup was due to either vertical transmission or autochthonous tick infection.

Prevalence of hemotropic mycoplasmas in healthy and unhealthy cats and dogs in Spain

The aims of the present study were to determine the prevalence of hemoplasmas in cats and dogs from the Barcelona area of Spain with the use of species-specific quantitative polymerase chain reaction (qPCR) assays and to evaluate any associations between hemoplasma infection, clinical presentation, and vector-borne infections. Blood samples from cats (191) and dogs (182) were included and were classified as healthy (149) or unhealthy (224). Ethylenediamine tetra-acetic acid blood samples underwent DNA extraction and qPCR analysis. Mycoplasma haemofelis, 'Candidatus Mycoplasma haemominutum', and 'Candidatus Mycoplasma turicensis' were detected in cats, whereas Mycoplasma haemocanis and 'Candidatus Mycoplasma haematoparvum' were detected in dogs, with prevalences of 3.7%, 9.9%, 0.5%, 14.3%, and 0.6%, respectively. In cats, no association between hemoplasma infection and health status, age, breed, presence of anemia, Feline leukemia virus status, and other vector-borne infections was found, but outdoor access (P = 0.009), male sex (P = 0.01), and Feline immunodeficiency virus status (P < 0.001) were significantly associated with hemoplasma infection. In dogs, sex, age, health status, presence of anemia, and breed were not significantly associated with hemoplasma infection, but a significant association was found between hemoplasma infection and vector-borne infections (P < 0.001). The present report documents the occurrence of feline 'Candidatus M. turicensis' and canine 'Candidatus M. haematoparvum' infections in Spain.

Canine babesiosis in northern Portugal and molecular characterization of vector-borne co-infections

Background

Protozoa and bacteria transmitted by arthropods, including ticks and phlebotomine sand flies, may cause a wide range of canine vector-borne diseases. Dogs can be simultaneously or sequentially infected with multiple pathogens. Canine babesiosis caused by Babesia canis canis and Babesia canis vogeli is known to occur in Portugal. This study assessed, by means of blood smear examination, PCR and DNA nucleotide sequencing, the presence of Babesia spp. and co-infecting agents Leishmania, Anaplasma/Ehrlichia and Hepatozoon in 45 dogs from northern Portugal clinically suspected of babesiosis.

Results

Forty-four dogs (98%) had infection with B. canis canis and one with B. canis vogeli. Co-infections were detected in nine animals (20%). Eight dogs were found infected with two vector-borne agents: six with B. canis canis and Leishmania infantum; one with B. canis canis and Ehrlichia canis; and one with B. canis canis and Hepatozoon canis. Another dog was infected with three vector-borne pathogens: B. canis vogeli, E. canis and L. infantum. Overall, L. infantum was found in seven (16%), E. canis in two (4%), and H. canis in one (2%) out of the 45 dogs with babesiosis. Almost 90% of the 45 cases of canine babesiosis were diagnosed in the colder months of October (18%), November (27%), December (20%), February (13%) and March (9%). Co-infections were detected in February, March, April, May, October and November. Twenty-two (50%) out of 44 dogs infected with B. canis were found infested by ticks including Dermacentor spp., Ixodes spp. and Rhipicephalus sanguineus. Mortality (9%) included two co-infected dogs that died spontaneously and two with single infections that were euthanized.

Conclusions

Babesia canis canis is the main etiological agent of canine babesiosis in northern Portugal. A higher sensitivity of Babesia spp. detection was obtained with PCR assays, compared to the observation of blood smears. Twenty percent of the dogs were co-infected with L. infantum, E. canis or H. canis. Furthermore, this is the first molecular identification of H. canis in dogs from northern Portugal.