Evolution of clinical, haematological and biochemical findings in young dogs naturally infected by vector-borne pathogens

New paradigms in the prevention of canine vector-borne diseases

The prevention of canine vector-borne diseases (CVBDs) is pivotal for the health and welfare of dogs as well as for reducing their zoonotic risk to humans. Scientific knowledge gained in recent years contributed to the development of new strategies for the control of these diseases in different social and cultural contexts. Here, we discuss recent advances in the prevention of vector-borne pathogens (VBPs) affecting dogs with a focus on those of zoonotic relevance.

Effect of Breed on Hematological and Biochemical Parameters of Apparently Healthy Dogs Infected with Zoonotic Pathogens Endemic to the Mediterranean Basin

Dogs are considered the main reservoir of several zoonoses endemic to the Mediterranean Basin. In this study, a prevalence of infections and coinfections of canine vector-borne diseases was analyzed in apparently healthy dogs of different canine pure breeds in Sicily (Italy), where these diseases are endemic. The seroprevalence of Leishmania infantum, Ricketsia ricketsii, Anaplasma phagocytophilum, and Erlichia canis was assessed, as single and coinfections. Biochemical and hematological parameters were evaluated, and epidemiological factors, including sex, age, and canine breed, were recovered. The most frequent infection was L. infantum (45.61%), following R. ricketsii (36.84%), both as single, double, or triple coinfections. Coinfections change the biochemical and hematological parameters of the host, and canine breeds are related to the infection frequency and the parameters observed during infections. Changes in the complete blood count (CBC) and biochemical values also differ between canine breeds, with the Cirneco dell'Etna dogs infected with L. infantum being the animals presenting the most interesting results in our study. High values of RBC, hemoglobin, hematocrit, mean corpuscular hemoglobin (MCH), the albumin/globulin (A/G) ratio, and albumin and low levels of β-2 globulin and γ-globulin were found only in this canine breed, suggesting some resistance to infection in these dogs. Future studies about the immune response of this canine breed could be interesting to determine their possible resistance to zoonotic pathogens, such as L. infantum.

Nanopore Sequencing Using the Full-Length 16S rRNA Gene for Detection of Blood-Borne Bacteria in Dogs Reveals a Novel Species of Hemotropic Mycoplasma

Dogs across the globe are afflicted by diverse blood- and vector-borne bacteria (VBB), many of which cause severe disease and can be fatal. Diagnosis of VBB infections can be challenging due to the low concentration of bacteria in the blood, the frequent occurrence of coinfections, and the wide range of known, emerging, and potentially novel VBB species encounterable. Therefore, there is a need for diagnostics that address these challenges by being both sensitive and capable of detecting all VBB simultaneously. We detail the first employment of a nanopore-based sequencing methodology conducted on the Oxford Nanopore Technologies (ONT) MinION device to accurately elucidate the "hemobacteriome" from canine blood through sequencing of the full-length 16S rRNA gene. We detected a diverse range of important canine VBB, including Ehrlichia canis, Anaplasma platys, Mycoplasma haemocanis, Bartonella clarridgeiae, "Candidatus Mycoplasma haematoparvum", a novel species of hemotropic mycoplasma, and Wolbachia endosymbionts of filarial worms, indicative of filariasis. Our nanopore-based protocol was equivalent in sensitivity to both quantitative PCR (qPCR) and Illumina sequencing when benchmarked against these methods, achieving high agreement as defined by the kappa statistics (k > 0.81) for three key VBB. Utilizing the ability of the ONT' MinION device to sequence long read lengths provides an excellent alternative diagnostic method by which the hemobacteriome can be accurately characterized to the species level in a way previously unachievable using short reads. We envision our method to be translatable to multiple contexts, such as the detection of VBB in other vertebrate hosts, including humans, while the small size of the MinION device is highly amenable to field use. IMPORTANCE Blood- and vector-borne bacteria (VBB) can cause severe pathology and even be lethal for dogs in many regions across the globe. Accurate characterization of all the bacterial pathogens infecting a canine host is critical, as coinfections are common and emerging and novel pathogens that may go undetected by traditional diagnostics frequently arise. Deep sequencing using devices from Oxford Nanopore Technologies (ONT) provides a solution, as the long read lengths achievable provide species-level taxonomic identification of pathogens that previous short-read technologies could not accomplish. We developed a protocol using ONT' MinION sequencer to accurately detect and classify a wide spectrum of VBB from canine blood at a sensitivity comparable to that of regularly used diagnostics, such as qPCR. This protocol demonstrates great potential for use in biosurveillance and biosecurity operations for the detection of VBB in a range of vertebrate hosts, while the MinION sequencer's portability allows this method to be used easily in the field.

Co-infection patterns of vector-borne zoonotic pathogens in owned free-ranging dogs in central Chile

We investigated the co-occurrence of the nine of the most relevant canine vector-borne pathogens (CVBP) using conventional and real-time PCR and evaluated risk factors and potential non-apparent haematological alterations associated with co-infection in 111 rural, owned, free-ranging dogs in the Metropolitan Region of Chile.

At least one pathogen was detected in 75% of the dogs. DNA of Anaplasma platys (Ap; 36%), Candidatus Mycoplasma haematoparvum (CMhp; 31%), Mycoplasma haemocanis (Mhc; 28%), Trypanosoma cruzi (17%), Leishmania spp. (4.5%), and Acanthocheilonema reconditum (1%) was detected. All dogs were negative for Ehrlichia spp., Rickettsia spp., Bartonella spp., Piroplasmida, and Hepatozoon spp. Thirty-eight dogs (34%) were coinfected. CMhp was involved in 71%, Mhc in 58%, and Ap in 50% of the co-infections. The most common co-infection pattern was CMhp–Mhc (37% of the cases). The prevalence of Ap was higher in juvenile than in adult dogs, whereas the opposite was found for CMhp and Mhc. Adult dogs were four times more likely of being co-infected than juveniles. Co-infected animals showed higher white blood cell count, segmented neutrophil count, and GGT levels than non-co-infected dogs. Clinically healthy but infected dogs may act as reservoirs of CVBP, and their free-ranging behavior would facilitate the spread of these pathogens to other dogs as well as human beings or wild carnivores.

Molecular detection of vector-borne pathogens in semen from dogs in southeastern Brazil

Vector-borne pathogens (VBPs) are primarily transmitted by arthropod vectors, but secondary ways of transmission have been described, including via venereal route. Nonetheless, there is still limited research on possible sexual transmission of VBPs in dogs. We molecularly investigated the presence of vector-borne pathogens in semen from dogs living in an area where these agents are endemic. Upon PCR testing, seven out of 22 (31.8%) semen samples tested positive for at least one VBP, whereas simultaneous positivity to two or more pathogens was detected in three (13.6%) dogs. Among pathogens detected in semen, Trypanosoma cruzi (n = 1) and Leishmania infantum (n = 3) were identified to species level by restriction fragment length polymorphism analysis. Attempts to sequence PCR products from other pathogens were unsuccessful, but coupled epidemiological and molecular data suggest the presence of Anaplasma platys (n = 5), Babesia vogeli (n = 1) and Ehrlichia canis (n = 1) in semen from dogs. Further experimental studies would be needed to confirm the sexual transmission hypothesis for these VBPs and also the possible implications of these findings for canine reproduction.

Vector-borne pathogens of zoonotic concern in dogs from a Quilombola community in northeastern Brazil

Canine vector-borne pathogens (CVBPs) comprise a group of disease agents mainly transmitted by ticks, fleas, mosquitoes and sand flies. In this study, we assessed the presence of CVBPs in an Afro-descendent community (Quilombola) of northeastern, Brazil. Dog blood samples (n = 201) were collected and analyzed by rapid test for the detection of antibodies against Leishmania spp., Anaplasma spp., Ehrlichia spp. and Borrelia burgdorferi sensu lato (s.l.), and antigens of Dirofilaria immitis. In addition, polymerase chain reactions were performed for Anaplasmataceae, Babesia spp., Hepatozoon spp., Rickettsia spp. and B. burgdorferi s.l. Overall, 66.7% of the dogs scored positive to at least one pathogen at serological and/or molecular methods. Antibodies against Ehrlichia spp. were the most frequently detected (57.2%; n = 115/201), followed by Anaplasma spp. (8.5%; n = 17/201), Leishmania spp. (8.5%; n = 17/201) and B. burgdorferi s.l. (0.5%; n = 1/201). For D. immitis, 11 out of 201 (5.5%) animals scored positive. At the molecular analysis, 10.4% (n = 21/201) of the samples scored positive for Babesia spp./Hepatozoon spp., followed by Anaplasmataceae (5.0%; n = 10/201) and Rickettsia spp. (3.0%; n = 6/201). All samples were negative for B. burgdorferi s.l. Our data demonstrated the presence of CVBPs in the studied population, with a high seropositivity for Ehrlichia spp. In addition, considering the detection of zoonotic pathogens in dogs and their relationship with people from Quilombola communities, effective control strategies are advocated for minimizing the risk of infection in this socially vulnerable human population and their pets.

High-throughput microfluidic real-time PCR for the simultaneous detection of selected vector-borne pathogens in dogs in Bosnia and Herzegovina

A scarcity of information on the occurrence of zoonotic vector-borne pathogens (VBPs), alongside a lack of human and animal health authorities' awareness of pre-existing data, augment the risk of VBP infection for local people and limit our ability to establish control programs. This holds especially true in low-middle income countries such as Bosnia and Herzegovina (BiH). This dearth of information on zoonotic VBPs is bolstered by the inability of previously used diagnostic tests, including conventional molecular diagnostic methods, to detect the full spectrum of relevant pathogens. Considering this, we set out to apply a microfluidic qPCR assay capable of detecting 43 bacterial and protozoan pathogens from blood to accrue critical baseline data for VBPs occurrence in BiH. A total of 408 dogs were tested of which half were infected with at least one VBP of zoonotic or veterinary importance. Leishmania infantum was found in 18% of dogs, reaching a prevalence as high as 38% in urbanized areas of Sarajevo. These data highlight substantially higher levels of L. infantum prevalence when compared to that previously reported using conventional methods using the same samples. Additionally, this high-throughput microfluidic qPCR assay was able to detect pathogens rarely or never reported in canines in BiH, including Anaplasma phagocytophilum (3%), Anaplasma platys (0.2%), haemotropic Mycoplasma (1%) and Hepatozoon canis (26%). Our report of the endemicity of important zoonotic pathogens and those of clinical significance to dogs emphasizes the need for urgent implementation of surveillance and control for VBPs in BiH, targeting both animal and human infections within the country.

Vector-borne disease and its relationship to hematologic abnormalities and microalbuminuria in retired racing and show-bred greyhounds

Background

Reference intervals for platelets and white blood cell (WBCs) counts are lower in greyhounds than other breeds. Proteinuria is common. Vector‐borne diseases (VBD) cause thrombocytopenia, leukopenia, and proteinuria. Racing greyhounds are commonly exposed to vectors that carry multiple organisms capable of chronically infecting clinically healthy dogs.

Hypothesis/Objectives

Vector‐borne disease prevalence is higher in retired racing greyhounds than in show‐bred greyhounds. Occult infection contributes to breed‐related laboratory abnormalities.

Animals

Thirty National Greyhound Association (NGA) retired racing and 28 American Kennel Club (AKC) show‐bred greyhounds.

Methods

Peripheral blood was tested for Anaplasma, Babesia, Bartonella, Ehrlichia, hemotropic Mycoplasma, and Rickettsia species using PCR. Antibodies to Anaplasma, Babesia, Bartonella, Ehrlichia, and Rickettsia species and Borrelia burgdorferi were detected using immunofluorescence and ELISA assays. Complete blood counts, semiquantitative platelet estimates, and microalbuminuria concentration were determined.

Results

Seven of 30 NGA and 1/28 AKC greyhounds tested positive for ≥1 VBD (P = .05). More positive tests were documented in NGA (10/630) than in AKC dogs (1/588; P = .02). Exposure to Bartonella species (3/30), Babesia vogeli (2/30), Ehrlichia canis (1/30), and infection with Mycoplasma hemocanis (3/30) occurred in NGA dogs. Platelet counts or estimates were >170 000/μL. White blood cell counts <4000/μL (4/28 AKC; 5/30 NGA, P > .99; 1/8 VBD positive; 8/51 VBD negative, P = .99) and microalbuminuria (10/21 AKC; 5/26 NGA, P = .06; 1/8 VBD positive; 14/25 VBD negative, P = .41) were not associated with VBD.

Conclusions and Clinical Importance

The prevalence of thrombocytopenia and B. vogeli exposure was lower than previously documented. Larger studies investigating the health impact of multiple VBD organisms are warranted.

Epidemiology, Diagnosis, and Control of Canine Infectious Cyclic Thrombocytopenia and Granulocytic Anaplasmosis: Emerging Diseases of Veterinary and Public Health Significance

This review highlights the diagnostic methods used, the control strategies adopted, and the global epidemiological status of canine cyclic thrombocytopenia and granulocytic anaplasmosis at the animal–human interface. Canine anaplasmosis is an important worldwide disease, mainly caused by Anaplasma platys and A. phagocytophilum with zoonotic implications. A. platys chiefly infects platelets in canids, while A. phagocytophilum is the most common zoonotic pathogen infecting neutrophils of various vertebrate hosts. Diagnosis is based on the identification of clinical signs, the recognition of intracellular inclusions observed by microscopic observation of stained blood smear, and/or methods detecting antibodies or nucleic acids, although DNA sequencing is usually required to confirm the pathogenic strain. Serological cross-reactivity is the main problem in serodiagnosis. Prevalence varies from area to area depending on tick exposure. Tetracyclines are significant drugs for human and animal anaplasmosis. No universal vaccine is yet available that protects against diverse geographic strains. The control of canine anaplasmosis therefore relies on the detection of vectors/reservoirs, control of tick vectors, and prevention of iatrogenic/mechanical transmission. The control strategies for human anaplasmosis include reducing high-risk tick contact activities (such as gardening and hiking), careful blood transfusion, by passing immunosuppression, recognizing, and control of reservoirs/vectors.

First Confirmed Clinical Case of Anaplasma platys in a Dog in Serbia

In September 2018, a four-month-old dog with fever and petechial bleeding came to the internal clinic at the Faculty of Veterinary Medicine University of Belgrade. On hematology analysis, thrombocytopenia and mild anemia were observed. Examination of the blood smear revealed platelet inclusions. The commercial serology test was positive for Anaplasma spp. The dog was treated with doxycycline for 14 days, and after 48 hours from the beginning of the treatment, the symptoms subsided. PCR analysis and sequencing confirmed infection with A. platys.

Rickettsiales in Italy

There is no updated information on the spread of Rickettsiales in Italy. The purpose of our study is to take stock of the situation on Rickettsiales in Italy by focusing attention on the species identified by molecular methods in humans, in bloodsucking arthropods that could potentially attack humans, and in animals, possible hosts of these Rickettsiales. A computerized search without language restriction was conducted using PubMed updated as of December 31, 2020. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology was followed. Overall, 36 species of microorganisms belonging to Rickettsiales were found. The only species identified in human tissues were Anaplasma phagocytophilum,Rickettsia conorii, R. conorii subsp. israelensis, R. monacensis, R. massiliae, and R. slovaca. Microorganisms transmissible by bloodsucking arthropods could cause humans pathologies not yet well characterized. It should become routine to study the pathogens present in ticks that have bitten a man and at the same time that molecular studies for the search for Rickettsiales can be performed routinely in people who have suffered bites from bloodsucking arthropods.

Evaluation of hematological alteration of vector-borne pathogens in cats from Bangkok, Thailand

Background

Cats can be carriers of infected arthropods and be infected with several vector-borne pathogens (VBPs) but there is limited knowledge about their pathogenic role in cats. This study aimed to assess the prevalence of some feline vector-borne agents by molecular technique and to characterize the hematological findings associated with these infections in a cat population from Bangkok Thailand.

Results

PCR was positive with at least one pathogen in 237 out of 372 subjects (63.7%), with prevalence of 39.5% (147/372) for Babesia spp., 36.9% (137/372) for hemoplasmas and 3.2% (12/372) for Hepatozoon spp. The cats older than 1 year were at significantly greater risk for VBPs infection (P = 0.001; OR = 1.43; 95% CI: 1.12 – 1.81) and hemoplasmas infection (χ2 = 10.8, df = 1; P < 0.0001; OR = 2.45; 95% CI: 1.49 – 4.01). A significant association between hematological findings and hemoplasma infection were identified in the present study. Besides, VBPs infection revealed more frequent in male cats (χ2= 6.38, df = 1, P = 0.01). Macrocytic hypochromic type of anemia was observed in cats infested with blood-sucking arthropods compared to the non-infested cats presented.

Conclusions

The current study confirmed that Babesia, Hepatozoon and hemoplasmas had infected semi-domesticated cats in Bangkok, Thailand, with Babesia and hemoplasmas being dominant in prevalence. Some hematological findings were significantly associated with cats infected with vector-borne pathogens in this study including leukocyte count and platelets count that may help support veterinary technicians in diagnosis and appropriate treatment. Campaigns of VBPs monitoring in Bangkok emphasizing on the investigation of vectors and possible routes of the infection in animals should be conducted to prevent the transmission of the pathogens.

Clinicopathological and molecular profiles of Babesia vogeli infection and Ehrlichia canis coinfection

BACKGROUND AND AIM

Canine babesiosis, a tick-borne parasitic disease, is caused by the hemoprotozoa, Babesia vogeli, and Babesia gibsoni. Infection with these parasites, which is endemic globally, leads to life-threatening immunosuppression in dogs. The merozoites invade the red blood cells (RBCs) of infected dogs. Ehrlichia canis, an intracellular bacterium that infects monocytes, is transmitted by the same tick species (Rhipicephalus sanguineus) during blood consumption and coinfection with B. vogeli and E. canis has been reported. Although the hematology and biochemistry of canine babesiosis have been studied, more studies are needed to develop a better understanding of the hematobiochemical and molecular profiles associated with cases of single infection and coinfection of canine babesiosis in Thailand. This study aimed to investigate the hematological, biochemical, and molecular profiles of B. vogeli infection and E. canis coinfection.

MATERIALS AND METHODS

The study included 33 B. vogeli-positive blood samples and 11 E. canis-coinfected blood samples. To exclude coinfection with Hepatozoon canis and Anaplasma platys, only dogs with B. vogeli infection and B. vogeli-E. canis coinfection were included in the study. A multiplex polymerase chain reaction (PCR) assay was conducted to detect B. vogeli, E. canis, and H. canis, and a conventional PCR assay was conducted for the detection of A. platys. Besides, the PCR assay and sequencing, comprehensive data analysis was conducted, including a microscopic blood parasite examination and hematological and biochemical data analysis.

RESULTS

The comparison of the hematobiochemical data between the B. vogeli-positive and E. canis coinfection groups identified that there were statistically significant differences in the RBC parameters, including RBC count, hemoglobin concentration, hematocrit, and RBC distribution width (p=0.001). Neither B. vogeli infection nor coinfection with E. canis was associated with the sex, breed, recorded clinical signs, geographic origin of the dog and also B. vogeli 18S rRNA gene sequencing results.

CONCLUSION

Coinfection with E. canis increased the severity of babesiosis. The pathogenic mechanisms underlying this infection, such as destruction of RBCs, require further investigation. This study may enhance diagnosis, treatment, and prevention of canine babesiosis.

Prevalence and incidence of vector-borne pathogens in unprotected dogs in two Brazilian regions

Background

Various vector-borne pathogens (VBPs) affect dogs worldwide, with their diversity and force of infection being usually higher in the tropics. Cross-sectional studies have been conducted to investigate the prevalence of VBPs in dogs, but data from longitudinal studies are scarce. Herein, we assessed the prevalence and the year-crude incidence (YCI) of Leishmania spp. and other VBPs in privately-owned dogs from two geographical regions of Brazil.

Methods

A total of 823 dogs were initially screened for Leishmania spp. by both serology and polymerase chain reaction (PCR). From the negatives, 307 (103 from São Joaquim de Bicas, Minas Gerais, and 204 from Goiana, Pernambuco) were randomly selected for the longitudinal study. These dogs were tested for various VBPs at baseline, after 8 and 12 months.

Results

Out of 823 dogs initially screened, 131 (15.9%) were positive for Leishmania spp. Out of the 307 dogs enrolled in the longitudinal study, 120 (39.1%) were lost for different reasons (e.g. animal death, owner decision, and lost to follow-up). In São Joaquim de Bicas, the baseline prevalence and YCI were as follows: 16.5% and 7.1% for Anaplasma spp.; 81.6% and 100% for Babesia spp.; 0% and 1.3% (only one faint positive) for Dirofilaria immitis; 37.9% and 22.9% for Ehrlichia spp.; 19.5% and 43.8% for Leishmania spp. In Goiana, the baseline prevalence and YCI were as follows: 45.1% and 38.3% for Anaplasma spp.; 79.9% and 96.0% for Babesia spp.; 36.3% and 39.8% for D. immitis; 64.7% and 58.5% for Ehrlichia spp.; 14.7% and 19.6% for Leishmania spp. Anti-Borrelia burgdorferi antibodies were not detected in any of the samples tested herein. The prevalence and YCI of Anaplasma spp., D. immitis and Ehrlichia spp. were significantly higher in Goiana. In contrast, the YCI of Leishmania spp. infection was significantly higher in São Joaquim de Bicas.

Conclusions

We confirmed a high prevalence and YCI of various VBPs among privately-owned dogs in two geographical regions of Brazil. Our data also indicate that the risk of infection varies significantly for individual VBPs and between the regions, which may be related to several factors that are still poorly understood.

Molecular detection, characterization of Anaplasma spp. in domestic cats from Rio de Janeiro state

Species of the genus Anaplasma, in the family Anaplasmatacae, are responsible to vector-borne diseases that affecting animals and humans. Feline anaplasmosis is poorly reported in Brazil. This study aimed at investigating the occurrence of Anaplasma spp. in domestic cats from Greater Rio de Janeiro, and evaluating hematological changes associated with this rickettsial infection. Were sampled 216 cats, we performed nested PCR (nPCR) and real-time PCR (qPCR) assays targeting A. platys-16S-rDNA, A. platys-gltA and A. phagocytophilum-msp2 sequences. As evaluated with gltA-qPCR the frequency of cats positive for A. platys was 3.7% (n = 8/216) and by 16S-rDNA nested-PCR it was 0.9% (n = 2/216). No cats were positive to msp2-qPCR to A. phagocytophilum. The sequences of A. platys presented 100% similarity with previously described isolates around the world and Brazil. Two cats that were positive in the gltA-qPCR reactions have platelet inclusions in the microscopic examination. However, no significant (p > 0.05) hematological changes were observed, probably due to low parasite load. This study showed that A. platys occur in domestic cats from Greater Rio de Janeiro. Further studies are needed to more precisely characterize these organisms.

Anaplasma spp. in North Africa: A review on molecular epidemiology, associated risk factors and genetic characteristics

The genus Anaplasma belonging to the Anaplasmataceae family (order Rickettsiales) comprises obligate intracellular Gram-negative bacteria of veterinary and public health importance. Six species and five types of strains genetically related are currently assigned to the genus Anaplasma including Anaplasma marginale, A. centrale, A. bovis, A. phagocytophilum, A. ovis and A. platys as classified species, and "A. capra", A. odocolei sp. nov., A. phagocytophilum-like 1 (Anaplasma sp.-Japan), A. phagocytophilum-like 2 (Anaplasma sp.-China) and A. platys-like (also named Candidatus Anaplasma camelii) as unclassified strains. Most of these Anaplasma species and strains have been molecularly identified in several animal and/or tick species in the north of Africa. The aim of this review is to summarize the current knowledge about molecular epidemiology, associated risk factors and genetic diversity of Anaplasma species and related strains infecting animals and/or their incriminated tick vectors in North Africa. All these data should be considered when establishing of common management and control programs for anaplasmosis infecting humans and different animal species in North African countries.

Detection of Ehrlichia, Anaplasma, and Babesia spp. in dogs of Cebu, Philippines

Background

Ehrlichia, Anaplasma, and Babesia spp. are canine pathogens transmitted by the Rhipicephalus sanguineus tick which can cause varied clinical signs. These pathogens have been investigated in the Philippines, but coinfection has not been reported yet.

Aim

The aim of this study was to evaluate the presence of Ehrlichia/Anaplasma and Babesia spp. in Philippine dogs.

Materials and Methods

A total of 100 dogs from seven different veterinary establishments in Cebu, Philippines, were examined for Ehrlichia/Anaplasma and Babesia spp. infection using peripheral blood smear examination and polymerase chain reaction (PCR). Inclusion criteria included a history or presence of tick infestation, anemia, and/or thrombocytopenia. Clinical signs were recorded. Statistical analyses were performed between PCR positivity and clinical signs and hematological results.

Results

A total of 10 and 18 dogs were found to be positive for Ehrlichia/Anaplasma and Babesia spp., respectively. One animal was PCR positive for both pathogens, which is the first report of coinfection in the country. The most common clinical signs observed include inappetence (89%), lethargy (80%), thrombocytopenia (85%), and anemia (74%). Analyses revealed that inappetence (p=0.044) and weight loss (p=0.028) were found statistically significant with Ehrlichia/Anaplasma infection. Basophil (p=0.001) and eosinophil counts (p=0.000) were also found significantly different between Ehrlichia/Anaplasma spp.-positive and -negative dogs. On the other hand, differential monocyte count (p=0.009) was found significantly different between Babesia spp.-positive and -negative dogs.

Conclusion

The present study showed low infection rates of canine ehrlichiosis/anaplasmosis and babesiosis and provided additional evidence for the presence of the pathogens in the area.

Detection and identification of blood-borne infections in dogs in Nigeria using light microscopy and the polymerase chain reaction

Many sick dogs brought to the University of Ibadan Veterinary Teaching Hospital (UIVTH) are infested with ticks and are anemic. Up until recently, light microscopy (LM) has been the only available means used for detection of blood-borne infections. In other parts of the world, PCR-based assays been used as a gold standard for accurate diagnosis of blood-borne infections. In this study, we used LM and broad-spectrum rRNA gene PCR-based assays on 116 blood samples from dogs brought to the UIVTH for detection of the 18S rRNA gene of Babesia and the 16S rRNA genes of Ehrlichia and hemotropic mycoplasmas. The relationship between clinicopathological findings and PCR results was evaluated. Age, sex, presence of ticks, anemia, co-infection status, and fever were also assessed in relation to PCR positivity to determine the risk factors using stepwise logistic regression analyses. Light microscopic examination revealed an overall prevalence of infection of 14.7% (17/116). Organisms detected were Babesia canis (3.5%), Ehrlichia canis (10.3%) and Trypanosoma congolense (0.9%) and a single co-infection with Babesia canis and Ehrlichia canis (0.9%). PCR analysis revealed 89/116 (76.7%) positive samples. Infections with 1, 2 and 3 infectious agents occurred in 49 (55.1%), 36 (40.4%) and 4 (4.5%) samples, respectively. Specifically, among the 89 PCR positive samples, Babesia spp. (85.4%) was the most abundant infection followed by Ehrlichia spp. (46.1%) and hemoplasmas (13.5%). Sequencing of PCR products identified two samples (1.7%) that contained Hepatozoon canis DNA. Sequencing of hemoplasma positive samples identified 'Candidatus Mycoplasma haemobos' in 0.8% of dogs. Using PCR, a 5-fold higher prevalence of blood-borne infections was found in the dogs (76.7%, 89/116) than with LM (14.7%, 17/116) alone" Dogs between 1 and 12months were the most frequently infected with multiple agents (47.2% double and 50.0% triple infections). Male dogs had the highest prevalence of infection (80.4%) and more triple infections (75.0%). A total of 57.3% of infected dogs were anemic. Anemic dogs were 2.77 times more likely to test positive for Ehrlichia spp. (OR: 2.77 95% CI: 1.25-6.16) and dogs with ticks were 3.6 times more likely to test positive for hemoplasmas (OR=3.60 95% CI: 1.05-12.38). This study underscores the abundance of blood-borne infections in dogs in Ibadan, Nigeria, which is underestimated using light microscopy. This is also the first evidence of existence of 'Candidatus Mycoplasma haemobos' in a dog in Nigeria and in Africa. Consequently there is a need for molecular diagnostic facilities for routine screening of sick animals, as multiple infections were not found by light microscopy.

Molecular epidemiology of Anaplasma platys, Ehrlichia canis and Babesia vogeli in stray dogs in Paraná, Brazil

ABSTRACT: Hemoparasitic infections are tick-borne diseases, which affect animals and humans. Considering the importance of canine hemoparasitic infections in veterinary clinics, this study aimed to determine the occurrence of Anaplasma platys, Ehrlichia canis and Babesia vogeli in blood samples from 182 dogs not domiciled in the city of Pato Branco, southwestern region of Paraná State, Brazil, using polymerase chain reaction (PCR). The prevalence of A. platys and B. vogeli was 32.9% and 10.9% respectively, and A. platys infection prevailed (p<0.001). The number of dogs positive for A. platys was larger in Winter (p<0.05). All blood samples were negative for E. canis. In the dogs, infestation by Amblyomma cajennense predominated over that by Rhipicephalus sanguineus (p<0.001); but there was no significant association between PCR and the variables presence of ticks, sex and age. Dogs infected by A. platys and B. vogeli showed thrombocytopenia, lymphopenia and leukocytosis; but there was no correlation between such hematological changes and infection by hemoparasites. This appears to be the first molecular study that demonstrates the existence of A. platys and B. vogeli in dogs from the southwestern region of Paraná.

Detection of Mycoplasma haemocanis, Mycoplasma haematoparvum, Mycoplasma suis and other vector-borne pathogens in dogs from Córdoba and Santa Fé, Argentina

Background

In Argentina, only very few reports are available for canine tick-borne diseases where most are related to parasitic diseases. The objective of this survey was to investigate the prevalence of tick-borne pathogens in 70 dogs from Santa Fé and Córdoba, Argentina.

Methods

Microscopic blood smear examination as well as polymerase chain reaction (PCR) amplification using species-specific markers of Anaplasma, Babesia, Bartonella, Borrelia, Ehrlichia, Francisella, Mycoplasma (hemotropic group) and Rickettsia, followed by DNA sequencing were used to establish the prevalence of each infecting pathogen.

Results

Blood smear analysis showed 81% (57/70) prevalence of structures morphologically compatible with hemotropic mycoplasmas. No structures resembling either piroplasms or Anaplasma/Ehrlichia were detected. Hemotropic mycoplasma species (Mycoplasma haematoparvum, Mycoplasma haemocanis and Mycoplasma suis) were the most prevalent pathogens detected with an overall prevalence of 77.1%. Anaplasma platys was detected and identified in 11 of the 70 dogs (15.7%), meanwhile two Bartonella spp. (B. clarridgeiae and an uncharacterized Bartonella sp.) and Babesia vogeli were detected at 3 and 7% prevalence, respectively.

Conclusions

The work presented here describes a high molecular prevalence for hemotropic mycoplasma species in each of the five locations selected. Three Mycoplasma spp., including Mycoplasma suis, reported for the first time in dogs have been identified by DNA amplification and sequencing. This study highlights the risk that these bacterial pathogens represent for companion animals and, due to their potential zoonotic nature, also for people.

Exposure to vector-borne pathogens in candidate blood donor and free-roaming dogs of northeast Italy

Background

Many vector-borne pathogens including viruses, bacteria, protozoa and nematodes occur in northeast Italy, representing a potential threat to animal and human populations. Little information is available on the circulation of the above vector-borne pathogens in dogs. This work aims to (i) assess exposure to and circulation of pathogens transmitted to dogs in northeast Italy by ticks, sandflies, and mosquitoes, and (ii) drive blood donor screening at the newly established canine blood bank of the Istituto Zooprofilattico Sperimentale delle Venezie.

Methods

Blood samples from 150 privately-owned canine candidate blood donors and 338 free-roaming dogs were screened by serology (IFA for Leishmania infantum, Ehrlichia canis, Anaplasma phagocythophilum, Babesia canis, Rickettsia conorii, R. rickettsii), microscopic blood smear examination, and blood filtration for Dirofilaria spp. All candidate donors and seropositive free-roaming dogs were tested by PCR for L. infantum, E. canis, A. phagocythophilum, Babesia/Theileria and Rickettsia spp. The dogs had no clinical signs at the time of sampling.

Results

Overall, 40 candidate donors (26.7 %) and 108 free-roaming dogs (32 %) were seroreactive to at least one vector-borne pathogen. Seroprevalence in candidate donors vs free-roaming dogs was: Leishmania infantum 6.7 vs 7.1 %; Anaplasma phagocytophilum 4.7 vs 3.3 %; Babesia canis 1.3 vs 2.7 %; Ehrlichia canis none vs 0.9 %; Rickettsia conorii 16 vs 21.3 % and R. rickettsii 11 vs 14.3 %. Seroreactivity to R. rickettsii, which is not reported in Italy, is likely a cross-reaction with other rickettsiae. Filariae, as Dirofilaria immitis (n = 19) and D. repens (n = 2), were identified in free-roaming dogs only. No significant differences were observed between candidate donors and free-roaming dogs either in the overall seroprevalence of vector-borne pathogens or for each individual pathogen. All PCRs and smears performed on blood were negative.

Conclusions

This study demonstrated that dogs are considerably exposed to vector-borne pathogens in northeast Italy. Although the dog owners reported regularly using ectoparasiticides against fleas and ticks, their dogs had similar exposure to vector-borne pathogens as free-roaming dogs. This prompts the need to improve owner education on the use of insecticidal and repellent compounds in order to reduce the risk of arthropod bites and exposure to vector-borne pathogens. Based on the absence of pathogens circulating in the blood of healthy dogs, the risk of transmission of these pathogens by blood transfusion seems to be low, depending also on the sensitivity of the tests used for screening.

Alpha proteobacteria of genusAnaplasma(Rickettsiales: Anaplasmataceae): Epidemiology and characteristics ofAnaplasmaspecies related to veterinary and public health importance

TheAnaplasmaspecies are important globally distributed tick-transmitted bacteria of veterinary and public health importance. These pathogens, cause anaplasmosis in domestic and wild animal species including humans.Rhipicephalus, Ixodes, DermacentorandAmblyommagenera of ticks are the important vectors ofAnaplasma.Acute anaplasmosis is usually diagnosed upon blood smear examination followed by antibodies and nucleic acid detection. All age groups are susceptible but prevalence increases with age. Serological cross-reactivity is one of the important issues amongAnaplasmaspecies. They co-exist and concurrent infections occur in animals and ticks in same geographic area. These are closely related bacteria and share various common attributes which should be considered while developing vaccines and diagnostic assays. Movement of susceptible animals from non-endemic to endemic regions is the major risk factor of bovine/ovine anaplasmosis and tick-borne fever. Tetracyclines are currently available drugs for clearance of infection and treatment in humans and animals. Worldwide vaccine is not yet available. Identification, elimination of reservoirs, vector control (chemical and biological), endemic stability, habitat modification, rearing of tick resistant breeds, chemotherapy and tick vaccination are major control measures of animal anaplasmosis. Identification of reservoirs and minimizing the high-risk tick exposure activities are important control strategies for human granulocytic anaplasmosis.

Retrospective analyses of dogs found serologically positive for Ehrlichia canis in Cebu, Philippines from 2003 to 2014

AIM

The study aimed to document the clinical and hematological observations of dogs found serologically positive for Ehrlichia canis and to identify parameters or factors that are associated with the disease with focus on the anemic and thrombocytopenic state of the infected dogs.

MATERIALS AND METHODS

From 7 participating veterinary establishments, a total of 913 cases from 2003 to 2014 were initially assessed using inclusion criteria, including E. canis diagnosis by the attending veterinarian and the presence of ticks or history of infestation, thrombocytopenia, and/or anemia. From these, 438 cases that were found serologically positive for E. canis using commercial test kits were selected. Profile, clinical observations and hematological test results were obtained from the selected cases. Computations for statistical associations between the anemic and thrombocytopenic state of the infected dogs and their profile, observed clinical signs and other hematological values were performed.

RESULTS

Most of the dogs were purebred (60.0%) and female (51.1%) and were within the age range of 1-5 years (38.4%). The mean packed cell volume (PCV), red blood cell (RBC) count, and platelet count were lower than the normal values while the absolute count of basophils were higher than normal values. Creatinine and blood urea nitrogen (BUN) appear to be elevated. The most common clinical signs observed were inappetence (41.3%), lethargy/depression (35.6%), vomiting (32.4%), fever (18.5%), paleness (8.2%), and epistaxis (6.6%). Analyses showed that there were no significant differences on the hematological values and clinical signs between thrombocytopenic and non-thrombocytopenic seropositive dogs. Moreover, very weak correlations between platelet count and RBC count, absolute lymphocyte count, and neutrophil count were found. On the other hand, only paleness (p=0.008) and epistaxis (p=0.004) were found to be significantly different between anemic and non-anemic patients. This coincided with the linear regression results where PCV (p=0.000, R=0.787, R(2)=0.619) was moderately correlated with the RBC count. In addition, eosinophil count was found weakly correlated.

CONCLUSION

E. canis infection in dogs may produce varied clinical signs that may be influenced by the thrombocytopenic and anemic states of affected animals. Complete blood counts remain important in the diagnosis of the disease, especially the platelet and RBC counts. Creatinine, BUN and alanine aminotransferase can be of value in the diagnosis of the infection. Several cases were lost to follow-up and appeared to be a challenge for handling veterinarians to monitor compliance of owners and progress of infected patients.

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.

Diagnosis and incidence risk of clinical canine monocytic ehrlichiosis under field conditions in Southern Europe

Background

Canine Monocytic Ehrlichiosis (CME), due to the bacterium Ehrlichia canis and transmitted by the brown dog tick Rhipicephalus sanguineus, is a major tick-borne disease in southern Europe. In this area, infections with other vector-borne pathogens (VBP) are also described and result in similar clinical expression. The aim of the present study was to evaluate the incidence risk of clinical CME in those endemic areas and to assess the potential involvement of other VBP in the occurrence of clinical and/or biological signs evocative of the disease.

Methods

The study was conducted from April to November 2011 in veterinary clinics across Italy, Spain and Portugal. Sick animals were included when fitting at least three clinical and/or biological criteria compatible with ehrlichiosis. Serological tests (SNAP®4Dx, SNAP®Leish tests, Idexx, USA) and diagnostic PCR for E. canis, Anaplasma platys, Anaplasma phagocytophilum, Babesia spp, Hepatozoon canis and Leishmania infantum detection were performed to identify the etiological agents. Ehrlichiosis was considered when three clinical and/or biological suggestive signs were associated with at least one positive paraclinical test (serology or PCR). The annual incidence risk was calculated and data were geo-referenced for map construction. The probabilities of CME and other vector-borne diseases when facing clinical and/or biological signs suggestive of CME were then evaluated.

Results

A total of 366 dogs from 78 veterinary clinics were enrolled in the survey. Among them, 99 (27%) were confirmed CME cases, which allowed an estimation of the average annual incidence risk of CME amongst the investigated dog population to be 0.08%. Maps showed an increasing gradient of CME incidence risk from northern towards southern areas, in particular in Italy. It also suggested the existence of hot-spots of infections by VBP in Portugal. In addition, the detection of other VBP in the samples was common and the study demonstrated that a dog with clinical signs evocative of CME is as likely to be positive to Ehrlichia canis as to another VBP.

Conclusions

The study confirms the endemicity of CME in southern Europe and highlights the difficulties encountered by veterinarians to differentiate CME from other vector-borne diseases under field conditions.

Evaluation of blood and bone marrow in selected canine vector-borne diseases

BACKGROUND

Bone marrow (BM) is a major hematopoietic organ that can harbour a variety of vector-borne pathogens; however, knowledge of BM pathological changes in dogs infected with vector-borne pathogens is limited. Thus, the aim of the present study was to assess the pathological changes in canine BM associated with natural infections by four vector-borne pathogens, as well as to determine the relationships between such changes and abnormalities of the peripheral blood.

METHODS

Cytological disorders and pathological changes of the BM of 83 dogs naturally-infected with one or more of four vector-borne pathogens (i.e., Anaplasma platys, Leishmania infantum, Babesia vogeli and Hepatozoon canis) were evaluated and compared with the corresponding hematological findings.

RESULTS

Dysgranulopoiesis and dysmegakaryocytopoiesis were the most frequently observed BM abnormalities in infected dogs. Erythroid suppression, and lymphocytic, monocytic and macrophage hyperplasia were also observed. Interestingly, associations between suppression and hyperplasia of specific cell lines in the marrow and corresponding changes in numbers of circulating peripheral blood cells were not observed.

CONCLUSIONS

Infections with one or more of the vector-borne pathogens examined in this study should be considered as differential diagnoses for secondary dysmyelopoiesis.

Case report: Molecular evidence of Anaplasma platys infection in two women from Venezuela

This article presents two case reports of Anaplasma platys detection in two women from Venezuela. Both patients were exposed to Rhipicephalus sanguineus, the presumed tick vector, and experienced chronic, nonspecific clinical signs including headaches and muscle pains. Intra-platelet inclusion bodies resembling A. platys were observed in buffy coat smears and A. platys DNA was amplified and sequenced from whole blood; however, treatment with doxycycline did not alleviate their symptoms. These cases provide further support for A. platys as a zoonotic tick-borne pathogen, most likely of low pathogenicity; nonetheless, the cause of illness in humans by A. platys is yet to be confirmed.

Intravascular persistence of Anaplasma platys, Ehrlichia chaffeensis, and Ehrlichia ewingii DNA in the blood of a dog and two family members

Background

Anaplasmosis, caused by Anaplasma phagocytophilum and Anaplasma platys, and ehrlichiosis, caused by Ehrlichia chaffeensis, Ehrlichia ewingii, the "Panola Mountain Ehrlichia" and Ehrlichia muris-like pathogens have been identified as emerging tick borne infectious diseases in dogs and human patients. Persistent intravascular infection with these bacteria is well documented in dogs, but is less well documented in human beings.

Methods

Serology and PCR targeting multiple microbial genes, followed by DNA sequencing, was used to test sequential blood samples. Tissue culture isolation was attempted in two laboratories.

Results

A. platys, E. chaffeensis, and E. ewingii DNA was amplified from two Anaplasma and Ehrlichia seronegative family members and their dog, all lacking typical symptoms of anaplasmosis or ehrlichiosis. Following treatment with doxycycline, the dog and mother were Anaplasma and Ehrlichia spp. PCR negative.

Conclusions

Sequential PCR testing provided molecular evidence supporting intravascular persistence of A. platys and Ehrlichia spp. in two humans and their dog. Diagnosticians and clinicians should consider the potential for co-infections due to these tick borne organisms.

The enigma of the dog mummy from ancient Egypt and the origin of 'Rhipicephalus sanguineus'

BACKGROUND

Ticks belonging to the Rhipicephalus sanguineus group are amongst the most important vectors of pathogenic microorganisms to dogs and humans. However, the taxonomy of this species group is still the subject of debate, especially because there is no type specimen or reliable morphological description for Rhipicephalus sanguineus sensu stricto. Recently, a comprehensive morphological and genetic study on representative tick specimens from Europe, Africa, Americas, and Oceania, revealed the existence of at least four morphologically and genetically distinct species under the name 'R. sanguineus' infesting dogs from different countries.

METHODS

Herein, we examined morphologically tick specimens retrieved on a dog mummy from Ancient Egypt (ca. 1st century - 4th century A.D.). The dog mummy and associated ticks were found during an archaeological expedition conducted in El Deir.

RESULTS

Scanning electron micrographs allowed us to assess their identity as belonging to the R. sanguineus group. In addition on the basis of the scutal punctation pattern, spiracular plates, width of dorsal tail of spiracular plates relative to the adjacent festoon, female genital aperture, male adanal plates and accessory shields, these ticks were tentatively identified as Rhipicephalus sp. II (=temperate species).

CONCLUSIONS

It can be concluded that R. sanguineus group ticks have infested dogs living in the Mediterranean region since ancient times. This finding represents the oldest record of ticks on any animal species and adds a new piece in the complex puzzle regarding tick parasitism on dogs and humans and their role as vectors of pathogens.

Babesia canis vogeli, Ehrlichia canis, and Anaplasma platys infection in a dog

A 12-month-old male neutered mixed breed dog was presented with a history of diarrhea, lethargy, emaciation, polydypsia, and sniffling. Physical examination findings included pale mucous membranes, increased heart and respiratory rates, and normal rectal temperature (38°C). Hematologic abnormalities included anemia and thrombocytopenia. Biochemical abnormalities included hypoalbuminemia, hyperbilirubinemia, and elevated ALP and ALT activities. A SNAP 4Dx test result was positive for Ehrlichia canis. Babesia canis vogeli organisms were found in the peripheral blood films, while morulae of E canis were not seen. Real-time polymerase chain reaction testing confirmed the presence of both B c vogeli and E canis organisms, and also was positive for Anaplasma platys infection. The dog recovered following treatment with doxycycline and imidocarb dipropionate, with normal hematology and biochemical profiles.

Efficacy of an imidacloprid/flumethrin collar against fleas, ticks and tick-borne pathogens in dogs

BACKGROUND

Tick-borne diseases comprise a group of maladies that are of substantial medical and veterinary significance. A range of tick-borne pathogens, including diverse species of bacteria and protozoa, can infect both dogs and humans. Hence, the control of tick infestations is pivotal to decrease or prevent tick-borne pathogen transmission. Therefore, different commercial products with insecticidal, repellent or both properties have been developed for use on dogs. Recently, a collar containing a combination of imidacloprid 10% and flumethrin 4.5% has proven effective to prevent tick and flea infestations in dogs under field conditions and the infection by some vector-borne pathogens they transmit under laboratory-controlled conditions.

METHODS

From March 2011 to April 2012, a field study was conducted in a private shelter in southern Italy to assess the efficacy of the imidacloprid/flumethrin collar against tick and flea infestations and to determine if this strategy would decrease tick-borne pathogen transmission in young dogs. A total of 122 animals were enrolled in the study and randomly assigned to group A (n = 64; collared) or group B (n = 58; untreated controls). Dogs were examined monthly for ticks and fleas and systematically tested for selected tick-borne pathogens.

RESULTS

Compared to controls, the collar provided overall efficacies of 99.7% and 100% against tick and flea infestation, respectively. The overall efficacy for the prevention of tick-borne pathogens (i.e., Anaplasma platys and Babesia vogeli) was 91.6%.

CONCLUSIONS

This study demonstrates that the imidacloprid/flumethrin collar is efficacious against flea and tick infestation as well as tick-borne pathogen transmission to dogs under field conditions.

Complex formation with nucleic acids and aptamers alters the antigenic properties of platelet factor 4

The tight electrostatic binding of the chemokine platelet factor 4 (PF4) to polyanions induces heparin-induced thrombocytopenia, a prothrombotic adverse drug reaction caused by immunoglobulin G directed against PF4/polyanion complexes. This study demonstrates that nucleic acids, including aptamers, also bind to PF4 and enhance PF4 binding to platelets. Systematic assessment of RNA and DNA constructs, as well as 4 aptamers of different lengths and secondary structures, revealed that increasing length and double-stranded segments of nucleic acids augment complex formation with PF4, while single nucleotides or single-stranded polyA or polyC constructs do not. Aptamers were shown by circular dichroism spectroscopy to induce structural changes in PF4 that resemble those induced by heparin. Moreover, heparin-induced anti-human-PF4/heparin antibodies cross-reacted with human PF4/nucleic acid and PF4/aptamer complexes, as shown by an enzyme immunoassay and a functional platelet activation assay. Finally, administration of PF4/44mer-DNA protein C aptamer complexes in mice induced anti-PF4/aptamer antibodies, which cross-reacted with murine PF4/heparin complexes. These data indicate that the formation of anti-PF4/heparin antibodies in postoperative patients may be augmented by PF4/nucleic acid complexes. Moreover, administration of therapeutic aptamers has the potential to induce anti-PF4/polyanion antibodies and a prothrombotic diathesis.

Co-infection with Anaplasma platys, Bartonella henselae and Candidatus Mycoplasma haematoparvum in a veterinarian

BACKGROUND

During a two year period, a 27-year-old female veterinarian experienced migraine headaches, seizures, including status epilepticus, and other neurological and neurocognitive abnormalities. Prior to and during her illness, she had been actively involved in hospital-based work treating domestic animals, primarily cats and dogs, in Grenada and Ireland and anatomical research requiring the dissection of wild animals (including lions, giraffe, rabbits, mongoose, and other animals), mostly in South Africa. The woman reported contact with fleas, ticks, lice, biting flies, mosquitoes, spiders and mites and had also been scratched or bitten by dogs, cats, birds, horses, reptiles, rabbits and rodents. Prior diagnostic testing resulted in findings that were inconclusive or within normal reference ranges and no etiological diagnosis had been obtained to explain the patient's symptoms.

METHODS

PCR assays targeting Anaplasma sp. Bartonella sp. and hemotopic Mycoplasma sp. were used to test patient blood samples. PCR positive amplicons were sequenced directly and compared to Gen Bank sequences. In addition, Bartonella alpha Proteobacteria growth medium (BAPGM) enrichment blood culture was used to facilitate bacterial growth and Bartonella spp. serology was performed by indirect fluorescent antibody testing.

RESULTS

Anaplasma platys, Bartonella henselae and Candidatus Mycoplasma haematoparvum DNA was amplified and sequenced from the woman's blood, serum or blood culture samples. Her serum was variably seroreactive to several Bartonella sp. antigens. Despite symptomatic improvement, six months of doxycycline most likely failed to eliminate the B. henselae infection, whereas A. platys and Candidatus M. haematoparvum DNA was no longer amplified from post-treatment samples.

CONCLUSIONS

As is typical of many veterinary professionals, this individual had frequent exposure to arthropod vectors and near daily contact with persistently bacteremic reservoir hosts, including cats, the primary reservoir host for B. henselae, and dogs, the presumed primary reservoir host for A. platys and Candidatus Mycoplasma haematoparvum. Physicians caring for veterinarians should be aware of the occupational zoonotic risks associated with the daily activities of these animal health professionals.

Are vector-borne pathogen co-infections complicating the clinical presentation in dogs?

Background

Infection by two or more canine vector-borne disease (CVBD)-causing pathogens is common in subtropical and tropical regions where vectors are plentiful. Co-infections may potentiate disease pathogenesis, thereby altering clinical manifestations typically associated with singular infections. These factors complicate diagnosis, treatment and can adversely influence prognosis if the practitioner fails to suspect, document, and treat each concurrent infection. The spectrum of pathogens co-infecting dogs may change over time in a given practice location due to the rapid expansion of arthropods and their associated vectored agents, and international transit among pets and wild animals. This applies, for example, to Dirofilaria immitis and Leishmania infantum, the distributions of which have expanded from northern to southern Italy, and vice versa, respectively. Indeed, mixed infections by D. immitis and L. infantum have only been reported once in Italy, probably due to the fact that competent vectors for these infections do not usually occur in the same geographical areas. Thus, information that would help practitioners to identify clinical presentations in dogs co-infected by D. immitis and L. infantum and other CVBD-causing pathogens is scant.

Findings

This manuscript describes the clinical history and physical examination of findings for 7 CVBD co-infected dogs that were examined because of a spectrum of clinical signs. Five dogs were co-infected with L. infantum and Ehrlichia canis, one dog with L. infantum, E. canis and D. immitis and the remaining dog with L. infantum and D. immitis.

Conclusions

The clinical signs and haematological abnormalities associated with the diagnostic evaluation and treatment of these dogs is discussed. Also, the usefulness of bone marrow specimens for the molecular diagnosis of CVBDs and for the enhanced monitoring of treatment response is emphasized.

Fleas infesting pets in the era of emerging extra-intestinal nematodes

Modifications in climatic conditions, movements of hosts and goods, changes in animal phenology and human behaviour and increase of wildlife, are presently concurring in the geographic spread of vectors and cardio-respiratory nematodes, e.g. Dirofilaria immitis, Angiostrongylus vasorum, Aelurostrongylus abstrusus and Capillaria aerophila. All these factors may also influence dispersion and clinical significance of fleas, thus posing relevant challenges in those regions where other parasites are emerging at the same time. Ctenocephalides felis, Ctenocephalides canis and Pulex irritans cause discomfort, nuisance, allergic reactions, anaemia, and may transmit several pathogens, some of them are of importance for public health. The present article reviews the importance of fleas in small animal practice and their sanitary relevance for dogs, cats and humans, and discusses current control methods in the present era of emerging extra-intestinal nematodes, towards a possible changing perspective for controlling key parasites affecting companion animals.

First description of natural Ehrlichia canis and Anaplasma platys infections in dogs from Argentina

Bacteria belonging to the Anaplasmataceae family are vector transmitted agents that affect a variety of vertebrate hosts including the tick-borne pathogens Ehrlichia canis and Anaplasma platys, which cause canine monocytic ehrlichiosis and cyclic thrombocytopenia, respectively. These two infections, typically reported from tropical and sub-tropical regions, have not been previously reported in dogs from Argentina. A total of 86 blood samples from dogs with suspected rickettsial disease and 28 non-suspected dogs were studied. Analysis included evaluation of hematological findings, PCR for Ehrlichia and Anaplasma species and sequencing of the positive PCR products. E. canis was detected in the blood of six dogs and A. platys in eighteen. All the dogs categorized as non-suspected were negative by PCR. Co-infection with Hepatozoon canis and Babesia vogeli was documented. This first report of E. canis and A. platys infections in dogs from Argentina indicates that these tick-borne infections have a considerably broader range than previously recognized in South America.

Comparison of pharmacokinetic variables for creatinine and iohexol in dogs with various degrees of renal function

OBJECTIVE

To compare pharmacokinetics and clearances of creatinine and iohexol as estimates of glomerular filtration rate (GFR) in dogs with various degrees of renal function.

ANIMALS

50 Great Anglo-Francais Tricolor Hounds with various degrees of renal function.

PROCEDURES

Boluses of iohexol (40 mg/kg) and creatinine (647 mg/kg) were injected IV. Blood samples were collected before administration and 5 and 10 minutes and 1, 2, 4, 6, and 8 hours after administration. Plasma creatinine and iohexol concentrations were assayed via an enzymatic method and high-performance liquid chromatography, respectively. A noncompartmental approach was used for pharmacokinetic analysis. Pharmacokinetic variables were compared via a Bland-Altman plot and an ANOVA.

RESULTS

Compared with results for creatinine, iohexol had a significantly higher mean ± SD plasma clearance (3.4 ± 0.8 mL/min/kg vs 3.0 ± 0.7 mL/min/kg) and a significantly lower mean volume of distribution at steady state (250 ± 37 mL/kg vs 539 ± 73 mL/kg), mean residence time (80 ± 31 minutes vs 195 ± 73 minutes), and mean elimination half-life (74 ± 20 minutes vs 173 ± 53 minutes). Despite discrepancies between clearances, especially for high values, the difference was < 0.6 mL/min/kg for 34 (68%) dogs. Three dogs with a low GFR (< 2 mL/min/kg) were classified similarly by both methods.

CONCLUSIONS AND CLINICAL RELEVANCE

Plasma iohexol and creatinine clearances can be used interchangeably for screening patients suspected of having chronic kidney disease (ie, low GFR), but large differences may exist for dogs with a GFR within or above the reference range.

First case of Anaplasma platys infection in a dog from Croatia

Background

It is known that Anaplasma (A.) platys, the causative agent of infectious canine cyclic thrombocytopenia, is endemic in countries of the Mediterranean basin. However, few reports are available from the Balkans. This case report describes a dog, which was imported from Croatia to Germany in May 2010. One month later the dog was presented to a local veterinarian in Germany due to intermittent/recurrent diarrhoea. Diagnostic tests were performed to identify infections caused by Anaplasma spp., Ehrlichia spp., Hepatozoon canis, Babesia spp., Leishmania spp., Borrelia burgdorferi and/or Dirofilaria immitis.

Findings

Haematological examination of a blood smear revealed basophilic inclusions in thrombocytes, which were confirmed as A. platys with a species-specific real-time PCR. Additionally, an infection with Babesia (B.) vogeli was also detected (PCR and serology). No specific antibodies against Anaplasma antigen were detectable. Although the dog showed no specific clinical signs, thrombocytopenia, anaemia and elevated C-reactive protein (CRP) were observed. Sequencing of a 1,348-bp partial ribosomal RNA gene revealed highest homology to A. platys sequences from Thailand, Japan and France.

Conclusions

A. platys was detected for first time in a dog imported from Croatia. As the dog was also co-infected by B. vogeli, unique serological and haematological findings were recorded. Thrombocytopenia, anaemia and elevated values of C-reactive protein were the laboratory test abnormalities observed in this case. A. platys infections should be considered in dogs coming from Croatia and adjacent regions.

First evidence and molecular characterization of Babesia vogeli in naturally infected dogs and Rhipicephalus sanguineus ticks in southern France

Babesiosis is an emerging tick-borne disease of animals and humans caused by intraerythrocytic protozoa of the genera Babesia and Theileria. In France canine babesiosis has a high prevalence with Babesia canis thought to be the main aetiological agent of the disease. Babesia vogeli has already been reported to occur in Europe and in other countries around the Mediterranean Sea. The tick Rhipicephalus sanguineus, the main known vector of B. vogeli, occurs in southern France. However, only one case of a B. vogeli infected dog has been reported to date in France. To gain further insight into the prevalence of Babesia and Theileria infections in dogs and ticks of the R. sanguineus complex, a study was conducted in a veterinary practice in the south of France from January to September 2010. Twelve bloods from dogs and 36 R. sanguineus ticks were analyzed using PCR and sequencing. For the analysis of ticks, a new primer was designed to specifically amplify the B. vogeli 18S rRNA gene. Four dogs (33.3%) and 8 ticks (22.2%) were found to be infected with B. vogeli. This approach has thus revealed for the first time a cluster of cases of canine babesiosis caused by B. vogeli in France and highlights the need to systematically screen for pathogens potentially responsible for canine babesiosis at the species level using suitable molecular tools.