Molecular and histopathological detection of Hepatozoon canis in red foxes (Vulpes vulpes) from Portugal

A review of Hepatozoonosis caused by Hepatozoon canis in dogs

Hepatozoon canis is a type of single-celled organism is spread by ticks and commonly affects dogs. It is responsible for causing one of the most significant parasitic diseases in dogs, called Hepatozoonosis. It is considered one of the most common causes of canine vector-borne diseases because it is closely linked to Rhipicephalus sanguineus (the brown dog tick), a species found worldwide. Hepatozoonosis caused by H. canis is prevalent in regions such as South Europe, South America, Asia, and Africa. H. canis often causes emaciation, anemia, and intermittent fever in infected dogs. The drugs used to treat H. canis infection in dogs include the combination of imidocarb dipropionate with doxycycline, toltrazoril, tetracycline hydrochloride, and the combination of trimethoprim-sulfamethoxazole.The primary solution to prevent the spread of infections caused by H. canis is to control the population of R. sanguineus ticks because H. canis is spread through ticks. This review aims to provide a brief overview of various studies conducted on the morphology, life cycle, hosts, epidemiology, clinical symptoms, laboratory diagnosis, autopsy findings, differential diagnosis, treatment, and prevention methods of H. canis.

Molecular Detection and Genetic Variability of Hepatozoon canis in Golden Jackals (Canis aureus L. 1758) in Serbia

Hepatozoon canis is a protozoan tick-borne parasite infecting domestic and wild canids, including foxes, wolves, and jackals. It is mainly found in dogs but has also been detected in several wild carnivores, including foxes, wolves, and jackals. Host transmission primarily occurs through the ingestion of infected ticks, typically Rhipicephalus sanguineus, with documented instances of transplacental transmission from infected females to cubs. In Serbia, the golden jackal is common throughout the country, and its population has increased in recent years. Previous research has documented the presence of several vector-borne pathogens in the jackal population in Serbia, so we conducted this study to determine the presence, prevalence, and genetic variability of H. canis. Over eleven years (2010-2020), 114 animal samples were collected from 23 localities in Serbia. A total of 90/114 (78.95%) jackals were positive for H. canis, and they came from 22 localities. Among 15 juveniles, almost half (6/15 (40%)) tested positive for H. canis. In addition to the high prevalence, high genetic variability of the pathogen was also found. According to the mutated positions, four sequence types (S4-S7) of H. canis were determined. Based on our earlier research on the grey wolf and on this study, it can be observed that various sequence types of H. canis circulate within wild canid populations in Serbia. The prevalence of H. canis infection in wild carnivores raises significant concerns for wildlife conservation and animal health. Infected animals may act as reservoirs for the disease, posing a potential risk to domestic animals by acting as a source of infection.

Hepatozoon (Eucoccidiorida: Hepatozoidae) in wild mammals of the Americas: a systematic review

BACKGROUND

The study of parasites provides insight into intricate ecological relationships in ecosystem dynamics, food web structures, and evolution on multiple scales. Hepatozoon Eucoccidiorida: Hepatozoidae) is a genus of protozoan hemoparasites with heteroxenous life cycles that switch infections between vertebrates and blood-feeding invertebrates. The most comprehensive review of the genus was published 26 years ago, and currently there are no harmonized data on the epizootiology, diagnostics, genotyping methods, evolutionary relationships, and genetic diversity of Hepatozoon in the Americas.

METHODS

Here, we provide a comprehensive review based on the PRISMA method regarding Hepatozoon in wild mammals within the American continent, in order to generate a framework for future research.

RESULTS

11 out of the 35 countries of the Americas (31.4%) had data on Hepatozoon, with Carnivora and Rodentia orders having the most characterizations. Bats, ungulates, and shrews were the least affected groups. While Hepatozoon americanum, H. americanum-like, H. canis, H. didelphydis, H. felis, H. milleri, H. griseisciuri, and H. procyonis correspond to the identified species, a plethora of genospecies is pending for a formal description combining morphology and genetics. Most of the vectors of Hepatozoon in the Americas are unknown, but some flea, mite, and tick species have been confirmed. The detection of Hepatozoon has relied mostly on conventional polymerase chain reaction (PCR), and the implementation of specific real time PCR for the genus needs to be employed to improve its diagnosis in wild animals in the future. From a genetic perspective, the V4 region of the 18S rRNA gene has been widely sequenced for the identification of Hepatozoon in wild animals. However, mitochondrial and apicoplast markers should also be targeted to truly determine different species in the genus. A phylogenetic analysis of herein retrieved 18S ribosomal DNA (rDNA) sequences showed two main clades of Hepatozoon: Clade I associated with small mammals, birds, and herpetozoa, and Clade II associated with Carnivora. The topology of the tree is also reflected in the haplotype network.

CONCLUSIONS

Finally, our review emphasizes Hepatozoon as a potential disease agent in threatened wild mammals and the role of wild canids as spreaders of Hepatozoon infections in the Americas.

Molecular Survey of Hepatozoon canis Infection in Domestic Dogs from Sardinia, Italy

Tick-borne protozoans of the genus Hepatozoon have been associated with infections of domestic and wild animals over the world. The occurrence of these apicomplexan agents in Sardinia has been poorly explored so far. In this study, the occurrence of Hepatozoon spp. has been investigated in domestic dogs from nine cities of Sardinia, Italy. Blood samples from each dog were collected and tested molecularly for the presence of Hepatozoon and Babesia/Theileria DNAs. Out of fifty-one dogs, nine were positive for Hepatozoon species based on the molecular detection of the parasite in blood samples. The phylogenetic relationships of strains detected here were also established. The PCR for amplification of the 18S rRNA fragment gene of Babesia/Theileria spp. did not give amplicons in any of the analyzed samples. Our results report the first molecular confirmation of Hepatozoon canis in Sardinian pet dogs and contribute to better understand the presence of these protozoans on the island. This study highlights the importance of recognizing and predicting the risk levels for the canine population, thus increasing the development of specific control measures. Also, since the distribution of hepatozoonosis is closely related to that of the definitive tick host, Rhipicephalus sanguineus, more accurate studies on Rhipicephalus ticks will be needed due to increasing the epidemiological knowledge of Hepatozoon species on the island.

Molecular Survey and Genetic Characteristics of Vector-Borne Pathogens in Domestic Dogs from Four Regions of China

Canine vector-borne diseases are widely distributed around the world. They are transmitted by arthropods, and many seriously threaten the health of animals and humans. In China, our knowledge of Ehrlichia, Hepatozoon, and Mycoplasma species circulating in dogs is still poorly understood. Therefore, the aim of this study was to understand the prevalence and genetic characteristics of canine Ehrlichia spp., Hepatozoon spp., and Mycoplasma spp. in Chongqing (southwest), Fujian (southeast), Shandong (southeast), and Hubei (central) Provinces of China. Blood samples from healthy pet dogs were processed to detect Ehrlichia, Hepatozoon, and Mycoplasma DNA with PCR. Haplotype and phylogenetic analyses were performed on 18S rRNA sequences. Among 306 dogs, no Ehrlichia spp. or Mycoplasma spp. were detected, whereas one Hepatozoon sp. was detected in 10 (3.27%) of the animals. Only Hepatozoon canis was identified and was endemic to Chongqing (2.46%) and Hubei (8.77%). A haplotype analysis identified eight haplotypes among the H. canis isolates. A phylogenetic analysis showed that the H. canis isolates in this study clustered into four clades, together with isolates from different countries and hosts, forming a large group that was clearly separate from other Hepatozoon species. These findings provided new information on the epidemiological characteristics of canine vector-borne diseases in China and will be helpful in the development of efficient measures to safeguard the health and well-being of companion animals and their owners.

Arthropod-Borne Pathogens in Wild Canids

Wild canids, as well as other wild animal species, are largely exposed to bites by ticks and other hematophagous vectors where the features favoring their presence and spread are found in wooded and semi-wooded areas. Much of the information about arthropod-borne infections concerns domestic and companion animals, whereas data about these infections in wild canids are not exhaustive. The present study is a narrative review of the literature concerning vector-borne infections in wild canids, highlighting their role in the epidemiology of arthropod-borne bacteria and protozoa.

Diversity of Hepatozoon species in wild mammals and ticks in Europe

BACKGROUND

Hepatozoon spp. are tick-borne parasites causing subclinical to clinical disease in wild and domestic animals. Aim of this study was to determine Hepatozoon prevalence and species distribution among wild mammals and ticks in Europe.

METHODS

Samples of wild mammals and ticks, originating from Austria, Bosnia and Herzegovina, Croatia, Belgium and the Netherlands, were tested with PCR to amplify a ~ 670-bp fragment of the small subunit ribosomal RNA gene.

RESULTS

Of the 2801 mammal samples that were used for this study, 370 (13.2%) tested positive. Hepatozoon canis was detected in samples of 178 animals (3 Artiodactyla, 173 Carnivora, 1 Eulipotyphia, 1 Lagomorpha), H. martis in 125 (3 Artiodactyla, 122 Carnivora), H. sciuri in 13 (all Rodentia), Hepatozoon sp. in 47 (among which Hepatozoon sp. Vole isolate, all Rodentia) and H. ayorgbor in 4 (all Rodentia). Regarding origin, 2.9% (6/208) tested positive from Austria, 2.8% (1/36) from Bosnia and Herzegovina, 14.6% (173/1186) from Croatia and 13.9% (190/1371) from Belgium/the Netherlands. Of the 754 ticks collected, 0.0% (0/35) Hyalomma sp., 16.0% (4/25) Dermacentor spp., 0.0% (0/23) Haemaphysalis spp., 5.3% (24/50) Ixodes and 1.4% (3/221) Rhipicephalus spp. tested positive for Hepatozoon (4.2%; 32/754), most often H. canis (n = 22).

CONCLUSIONS

Hepatozoon canis is most present in mammals (especially in Carnivora such as gray wolves and golden jackals) and ticks, followed by H. martis, which was found merely in stone martens and pine martens. None of the rodent-associated Hepatozoon spp. were detected in the ticks, suggesting the possible implication of other arthropod species or non-vectorial routes in the transmission cycle of the hemoprotozoans in rodents. Our findings of H. canis in ticks other than R. sanguineus add to the observation that other ticks are also involved in the life cycle of Hepatozoon. Now that presence of Hepatozoon has been demonstrated in red foxes, gray wolves, mustelids and rodents from the Netherlands and/or Belgium, veterinary clinicians should be aware of the possibility of spill-over to domestic animals, such as dogs.

Wild Mesocarnivores as Reservoirs of Endoparasites Causing Important Zoonoses and Emerging Bridging Infections across Europe

Mesocarnivores are small- or mid-sized carnivore species that display a variety of ecologies and behaviours. In Europe, wild mesocarnivores are represented by the red fox (Vulpes vulpes), the golden jackal (Canis aureus), the European wildcat (Felis silvestris), the Mustelidae of the genera Meles, Martes, Mustela, Lutra, the invasive species of raccoon dog (Nyctereutes procyonoides), raccoons (Procyon lotor), and American mink (Neogale vison). These abundant animals thrive in various habitats and often develop their activity close to human settlements. Thus, they may play an important role in the introduction, maintenance, and transmission of major parasitic zoonoses and promote bridging infections with domestic animals. Against this background, this article reports and discusses some of the most important endoparasites of wild mesocarnivores living in Europe, on the basis of their actual role as reservoirs, spreaders, or sentinels. The data derived from epizootiological studies in different European countries, and the proven or speculated implications of the detected endoparasites in human and domestic animals' health, are discussed. Through older and recent literature review, the state-of-the-art knowledge on the occurrence and prevalence of the parasites under consideration is presented, showing further, warranted investigations and the need for surveillance and vigilance.

Red fox (Vulpes vulpes) play an important role in the propagation of tick-borne pathogens

The red fox (Vulpes vulpes) is the most widespread free-living carnivore in the world. Over the years, foxes have been recognized as hosts for a number of tick-borne pathogens. However, their role as reservoirs for zoonotic tick-borne diseases is poorly understood. The aim of our study was to investigate tick-borne pathogens in the red fox population in the Czech Republic. Out of 117 red foxes, 110 (94.02%) individuals tested positive for the presence of at least one pathogen by the combined PCR and sequencing approach. Hepatozoon canis was the most frequently detected pathogen (n = 95; 81.2%), followed by Babesia vulpes (n = 75; 64.1%). Babesia canis was not detected in our study. Four (3.42%) red foxes were positive for Candidatus Neoehrlichia sp., 3 (2.56%) for Anaplasma phagocytophilum, and one red fox (0.85%) tested positive for the presence of Ehrlichia sp. DNA. Overall, DNA of spirochetes from the Borrelia burgdorferi s.l. complex was detected in 8.6% of the foxes and B. miyamotoi in 5.12% of the samples. As a carnivore found in all ecosystems of Central Europe, foxes obviously contribute to transmission of tick-borne pathogens such as A. phagocytophilum, B. burgdorferi s.l., and B. myiamotoi. In addition, foxes apparently harbour a community of pathogens, associated with this host in local ecological context, dominated by H. canis and B. vulpes (possibly also Candidatus Neoehrlichia sp.). These species have the potential to spread to the domestic dog population and should be included in the differential diagnosis of febrile diseases with hematologic abnormalities in dogs.

High Prevalence and Genetic Variability of Hepatozoon canis in Grey Wolf (Canis lupus L. 1758) Population in Serbia

Wild canids are globally recognised as hosts and reservoirs of a large number of ecto- and endoparasites. Data that reveal the importance of the grey wolf (Canis lupus L.1758) in the spread of hepatozoonosis are very scarce. There are a large number of different potential host species that can be infected by Hepatozoon canis, but the most common are domestic and wild carnivores, such as dogs, jackals, foxes, and wolves. In this study, the epidemiological significance of the grey wolf as a host for the pathogen was analysed for the first time in Serbia, as well as the genetic variability of H. canis. The presence of H. canis in wolf spleens has been demonstrated using molecular methods. A total of 107 wolf spleen samples from 30 localities in Serbia were analysed. The presence of H. canis was confirmed in 62 (57.94%) individuals from 26 out of 30 localities. According to the analysis, the sampled H. canis sequences were found to be characterised by a certain heterogeneity. Based on five mutated nucleotide sites in the sequences, H. canis could be divided into five sequence types, S1 to S5. The five sequence types can potentially circulate in grey wolf populations as well as among other domestic and wild canids. This study is the first confirmation of the presence of H. canis in grey wolf populations in Serbia. Considering that the role of this vector-borne disease is poorly researched in wild carnivores, it is very important to indicate the role of this species in the circulation of this pathogen in natural ecosystems.

A Unique Case of Fatal Coinfection Caused by Leptospira spp. and Hepatozoon canis in a Red Fox Cub (Vulpes vulpes)

Red foxes are the most abundant wild carnivore species in Europe commonly exposed to pathogenic Leptospira and Hepatozoon canis. Despite high seroprevalence, the clinical disease caused by these pathogens in red foxes has never been reported. Herein, we report the first-ever case of a fatal Leptospira spp. and H. canis coinfection in a two-month-old red fox cub with acute haemolytic anaemia, mild bronchopneumonia, intraalveolar haemorrhage, and tubulonephrosis. The presence of pathogenic Leptospira spp. DNA was detected in the kidney and lung tissues of the infected animal. In contrast to our previous knowledge, we believe that such fatal cases due to concomitant infection by Leptospira spp. and H. canis, especially in young animals, may commonly occur in nature. However, further studies are required to identify other factors that possibly contribute to the severity and the pathogenic effect of Leptospira spp. and H. canis infections in red foxes.

An Hepatozoon americanum-like protozoan in crab-eating (Cerdocyon thous) and grey pampean (Lycalopex gymnocercus) foxes from Uruguay

In South America, apicomplexan parasites of the genus Hepatozoon have been sporadically detected in mammals. Previous studies in wild canids from Brazil and Argentina demonstrated infections by species genetically related to Hepatozoon americanum. The aim of the present work was to detect the presence of Hepatozoon in road-killed foxes encountered in Uruguayan highways. Blood samples from 45 crab-eating (Cerdocyon thous) and 32 grey pampean (Lycalopex gymnocercus) foxes were analyzed by PCR for Hepatozoon 18S rRNA gene. Eight foxes (10.4%) were found to be infected with an H. americanum-like protozoan, an Hepatozoon closely related to H. americanum. Bayesian and maximum-likelihood phylogenetic analyses revealed that the sequences obtained in this study cluster with H. americanum from the United States, and with an H. americanum-like species from dog and foxes from Brazil and Argentina. In the Unites States, H. americanum causes severe disease in dogs. In addition to this, an increasing habitat overlap between dogs and foxes makes the presence of H. americanum-like protozoan in foxes acquires veterinary relevance. This work represents the first report of L. gymnocercus infected with an H. americanum-like protozoan, and of wild canids infected with Hepatozoon in Uruguay.

Molecular investigation of bacterial and protozoal pathogens in ticks collected from different hosts in Turkey

Background

The emergence of tick-borne disease is increasing because of the effects of the temperature rise driven by global warming. In Turkey, 19 pathogens transmitted by ticks to humans and animals have been reported. Based on this, this study aimed to investigate tick-borne pathogens including Hepatozoon spp., Theileria spp., Babesia spp., Anaplasma spp., Borrelia spp., and Bartonella spp. in tick samples (n = 110) collected from different hosts (dogs, cats, cattle, goats, sheep, and turtles) by molecular methods.

Methods

To meet this objective, ticks were identified morphologically at the genus level by microscopy; after DNA isolation, each tick sample was identified at the species level using the molecular method. Involved pathogens were then investigated by PCR method.

Results

Seven different tick species were identified including Rhipicephalus sanguineus, R. turanicus, R. bursa, Hyalomma marginatum, H. anatolicum, H. aegyptium, and Haemaphysalis erinacei. Among the analyzed ticks, Hepatozoon spp., Theileria spp., Babesia spp., and Anaplasma spp. were detected at rates of 6.36%, 16.3%, 1.81%, and 6.36%, respectively while Borrelia spp. and Bartonella spp. were not detected. Hepatozoon spp. was detected in R. sanguineus ticks while Theileria spp., Babesia spp., and Anaplasma spp. were detected in R. turanicus and H. marginatum. According to the results of sequence analyses applied for pathogen positive samples, Hepatozoon canis, Theileria ovis, Babesia caballi, and Anaplasma ovis were identified.

Conclusion

Theileria ovis and Anaplasma ovis were detected for the first time to our knowledge in H. marginatum and R. turanicus collected from Turkey, respectively. Also, B. caballi was detected for the first time to our knowledge in ticks in Turkey.

MOLECULAR INVESTIGATION OF VECTOR-BORNE PATHOGENS IN RED FOXES (VULPES VULPES) FROM SOUTHERN FRANCE

Because of their free-ranging nature, the probability of wild animals being exposed to vector-borne pathogens is likely higher than that of humans and pets. Recently, the red fox (Vulpes vulpes) has been suspected as being a reservoir or host of several pathogens of veterinary and public health importance. We conducted a molecular survey on 93 red foxes hunted in 2008-18, in the departments of Bouches-du-Rhône and Var, in southeastern France, for pathogens including Leishmania infantum, Piroplasmida, Hepatozoon spp., nematodes, Coxiella burnetii, Borrelia spp., Rickettsia spp., and Anaplasmataceae. Spleen samples were screened for the presence of vector-borne pathogens by PCR followed by sequencing. Pathogens were detected in 94% (87/93) of red foxes, and coinfections were identified in 24% (22/93) of foxes. We identified DNA from Hepatozoon canis, L. infantum, and Babesia vogeli in 92% (86/93), 15% (14/93), and 3% (3/93) of red foxes, respectively. We also found DNA of nematodes in 3% (3/93) of foxes; Spirocerca vulpis was identified in one fox and Dirofilaria immitis in the two others. Interestingly, C. burnetii genotype 3, previously described in humans from the same region, was identified in 3% (3/93) of foxes and Anaplasma platys in 2% (2/93) of foxes. We did not detect DNA of Borrelia spp., Bartonella spp., or Rickettsia spp. In our study, the prevalence of pathogens did not vary by fox origin, sex, or tick carriage. Molecular evidence of B. vogeli, H. canis, S. vulpis, D. immitis, C. burnetii, and A. platys in red foxes has not previously, to our knowledge, been reported from southern France. We propose that red foxes are potential reservoirs for several pathogens, including major zoonotic agents such as L. infantum. They could be incidental hosts for pathogens, such C. burnetii. The high prevalence for H. canis suggests an important role of foxes in domestic dog (Canis lupus familiaris) infection. These animals may pose a threat to human and animal health.

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.

Molecular survey on tick-borne pathogens and Leishmania infantum in red foxes (Vulpes vulpes) from southern Italy

Red foxes (Vulpes vulpes) have been recognised to harbour and transmit a wide range of tick-borne pathogens (TBPs) including those of zoonotic concern. To investigate the prevalence and the distribution of TBPs and of Leishmania infantum in foxes (n = 244), spleen samples were collected within the frame of a multi-regional wildlife health surveillance program in Italy. A combined PCR/sequencing approach was performed for the detection of Anaplasma spp., Babesia spp., Borrelia spp., Ehrlichia spp., Hepatozoon spp. and L. infantum DNA. Overall, 146 foxes (59.8 %, 95 % CI: 53.6-65.8) tested positive for at least one pathogen with Hepatozoon canis being the most prevalent (i.e., n = 124; 50.8 %, 95 % CI: 44.6-57.0), followed by Babesia vulpes (n = 20; 8.2 %, 95 % CI: 5.4-12.3), different spirochete species from Borrelia burgdorferi sensu lato complex (n = 9; 3.7 %, 95 % CI: 1.9-6.9), Ehrlichia canis and L. infantum (n = 7; 2.9 % each, 95 % CI: 1.4-5.8), Anaplasma platys (n = 4; 1.6 %, 95 % CI: 0.6-4.1), Anaplasma phagocytophilum ecotype I and Candidatus Neoehrlichia sp. (n = 3; 1.2 % each, 95 % CI: 0.4-3.5). All samples scored negative for Babesia canis and Borrelia miyamotoi. This study revealed the presence of spirochetes from B. burgdorferi s.l. complex, Ca. Neoehrlichia sp., A. platys and A. phagocytophilum ecotype I in red fox population from Italy, underling the necessity to monitoring these carnivores, mainly because they live in contact with dogs and humans. Data on the tick fauna circulating on wildlife species will complement information herein obtained, instrumentally to establish preventive strategies for minimizing the risk of infection for animals and humans.

The red fox (Vulpes vulpes), a possible reservoir of Babesia vulpes, B. canis and Hepatozoon canis and its association with the tick Dermacentor reticulatus occurrence

The red fox (Vulpes vulpes) is known to be a reservoir host of various vector-borne protozoan parasites. Yet, the impact of these parasitic infections on the health status of the red fox is unknown. In this study, we compared the prevalence of haemoprotozoa in juvenile and adult foxes from four regions in Poland. The abundance of questing adult Dermacentor reticulatus ticks was shown to differ between regions and include a tick-endemic and non-endemic region, as well as two zones in which D. reticulatus recently expanded: an eastern and a western zone. Spleen and kidney enlargement indices were compared between infected, co-infected and non-infected foxes to evaluate pathogenic output of parasitic infections. Blood samples were collected from 383 necropsied red foxes and 25 live-trapped red fox cubs. The weights of spleens, kidneys and bodies were recorded for each necropsied individual. Blood and spleen DNA samples were screened by PCR to detect 18S rRNA and cox1 gene fragments of Babesia spp., and 18S rRNA of Hepatozoon spp. Prevalence of infection and mean organ weight indices were compared in relation to fox age and sex, origin (zone) and infection status. Hepatozoon canis (174/381; 45.7%) and Babesia vulpes (117/381; 30.7%) were the dominant pathogens infecting adult foxes. Babesia canis DNA was detected in 9 (2.4%) individuals. Two fox cubs from Western Poland were infected with B. vulpes (2/14; 14%), while H. canis infection (16/25; 59%) was detected in cubs from all three regions where trapping was carried out. Infection with B. vulpes was associated with significantly higher weights of spleens and kidneys. Spleen weight/ body weight and mean kidney weight/ body weight indices were shown as relevant in evaluating changes occurring during infection with B. vulpes. Babesia and Hepatozoon spp. infections differed in red foxes from D. reticulatus-endemic, non-endemic and newly inhabited areas. The prevalence of B. canis in foxes from four regions of Poland reflects the prevalence recorded in questing adult D. reticulatus collected in these areas. This finding suggests a contribution of red foxes to the establishment of new foci of B. canis-infected D. reticulatus ticks in areas recently invaded by this tick species. Spleen and kidney enlargement was identified in foxes infected with B. vulpes, particularly in individuals co-infected with B. vulpes and H. canis.

Molecular survey of tick-borne pathogens reveals a high prevalence and low genetic variability of Hepatozoon canis in free-ranging grey wolves (Canis lupus) in Germany

Wild carnivores are important hosts for ixodid ticks and presumed reservoirs for several tick-borne pathogens (TBPs) of medical and veterinary importance. However, little is known about the role that the European grey wolf (Canis lupus) plays in the enzootic cycle of TBPs. The recent recolonization of Central European lowland, including some regions in Germany, by the grey wolf, opened up an excellent opportunity for studying the impact of the wolf population on pathogen diversity and transmission dynamics. Therefore, in the present study, we investigated spleen samples collected from 276 grey wolves in 11 federal states in Germany for common TBPs by molecular methods. In total, 127 grey wolves (46.0 %) were found to be positive for Hepatozoon canis. Only two genetic variants of this protozoan parasite (herein designated as G1 and G2) were found to circulate among the grey wolves, which can be potentially shared between populations of domestic and other wild carnivores in the country. Two grey wolves were positive for Anaplasma phagocytophilum (0.7 %), and both were co-infected with H. canis G1 genotype. The presence of other pathogens could not be confirmed by PCR and sequencing. This study represents the first one reporting H. canis in a grey wolf population worldwide, and it provides highly relevant information, which may contribute to a better understanding of the epidemiology of TBPs and the pathogen transmission dynamics among the reintroduced population of grey wolves and other carnivores.

First autochthonous case of clinical Hepatozoon felis infection in a domestic cat in Central Europe

Three different Hepatozoon (Apicomplexa, Hepatozoidae) species have been described infecting domestic cats in Europe (i.e. H. felis, H. canis and H. silvestris), however, reports on clinical hepatozoonosis are uncommon and treatment protocols are not clearly defined.

A six-year-old male European short-hair cat from Austria presented poor general condition, lethargy, anorexia, icterus, a painful abdomen, fever, ruffled hair and a tick infestation, and it had never left Austria. Laboratory tests revealed leukopenia, thrombocytopenia and increased serum levels of symmetric dimethylarginine (SDMA) and bilirubin. In May Grünwald-Giemsa-stained blood smears, structures resembling Hepatozoon gamonts were observed inside neutrophil granulocytes. A PCR targeting a fragment of the 18S rRNA gene of Hepatozoon spp. and DNA sequencing allowed the diagnosis of H. felis-DNA in blood samples. The cat was treated with imidocarb dipropionate (6 mg/kg body weight, repeated after 14 days) and doxycycline monohydrate (5 mg/kg body weight twice a day, p.o., for four weeks) and recovered completely. A broad haematological and biochemical laboratory control after six months showed all evaluated parameters under normal ranges. Coinfection with other feline pathogens (i.e. feline leukaemia virus, feline immunodeficiency virus, feline Coronavirus, Leishmania and Dirofilaria immitis) could not be detected.

This study reveals the presence of H. felis in Austria and provides more evidence on the geographical distribution and pathogenicity of this parasite for domestic cats. To the authors' knowledge, this is the first autochthonous case of feline hepatozoonosis in Central Europe.

•

Clinical Hepatozoon felis infection in a domestic cat was diagnosed in Austria.

•

The diagnosis was achieved by microscopy of blood smears, PCR and DNA-sequencing.

•

Possible coinfections with other feline pathogens were ruled-out.

•

The cat recovered completely after treatment with imidocarb and doxycycline.

•

This represents the first autochthonous case of feline hepatozoonosis in Central Europe.

First evidence of tick-borne protozoan pathogens, Babesia sp. and Hepatozoon canis, in red foxes (vulpes vulpes) in Serbia

Tick-borne haematozoans cause severe diseases in domestic animals, and some of them have zoonotic potential. The results of previous studies in Europe point to the important role of foxes in natural endemic cycles of several tick-borne pathogens, including protozoa. The aim of the present research was to acquire information on the prevalence and distribution of tick-borne protozoan parasites among foxes in Serbia. Legally hunted foxes from 14 localities throughout Serbia were analysed. Spleen samples were collected from 129 animals and tested for the presence of Babesia spp. and Hepatozoon spp. by PCR. In total, 79/129 (61.2%) of the tested foxes were positive for H. canis, while the presence of two Babesia species was confirmed: B. vulpes (37/129, 28.7%) and B. canis (1/129, 0.8%). Coinfection with B. vulpes and H. canis was present in 26/129 (20.2%) foxes and one animal (1/129, 0.8%) was co-infected by B. canis and H. canis. The results of this study indicate the important role of foxes in the epizootiology of B. vulpes and H. canis in the Republic of Serbia and stress the need for further research to clarify all elements of the enzootic cycle of the detected pathogens, including other reservoirs, vectors, and transmission routes.

An Australian dog diagnosed with an exotic tick-borne infection: should Australia still be considered free from Hepatozoon canis?

Recent molecular and sero-surveillance studies of the tick-borne pathogen Hepatozoon canis have identified new hosts, potential vector species, and have revealed that H. canis is more widespread than previously thought. We report the first diagnosed case of canine hepatozoonosis in Australia from a Maremma Sheepdog in Sarina, Queensland. Hepatozoon canis was detected with blood smear examination and 18S rRNA sequencing. It is unknown when or how the organism was introduced into Australia, which raises questions about border biosecurity policies and the H. canis infection status of its potential vectors and hosts in Australia. Surveillance for this pathogen is required to determine whether H. canis has established in Australia.

Occurrence and diversity of arthropod-transmitted pathogens in red foxes (Vulpes vulpes) in western Austria, and possible vertical (transplacental) transmission of Hepatozoon canis

Red fox (Vulpes vulpes) is the most abundant wild canid species in Austria, and it is a well-known carrier of many pathogens of medical and veterinary concern. The main aim of the present study was to investigate the occurrence and diversity of protozoan, bacterial and filarial parasites transmitted by blood-feeding arthropods in a red fox population in western Austria. Blood (n = 351) and spleen (n = 506) samples from foxes were examined by PCR and sequencing and the following pathogens were identified: Babesia canis, Babesia cf. microti (syn. Theileria annae), Hepatozoon canis, Anaplasma phagocytophilum, Candidatus Neoehrlichia sp. and Bartonella rochalimae. Blood was shown to be more suitable for detection of Babesia cf. microti, whilst the spleen tissue was better for detection of H. canis than blood. Moreover, extremely low genetic variability of H. canis and its relatively low prevalence rate observed in this study may suggest that the parasite has only recently been introduced in the sampled area. Furthermore, the data presented here demonstrates, for the first time, the possible vertical transmission of H. canis from an infected vixen to the offspring, and this could explain the very high prevalence in areas considered free of its main tick vector(s).

Molecular detection of tick-borne pathogens in wild red foxes (Vulpes vulpes) from Central Italy

Spleen samples from 153 red foxes, shot during regular hunting season in the province of Pisa (Central Italy), were examined to detect DNA of Anaplasma phagocytophilum, Ehrlichia canis, Coxiella burnetii, Francisella tularensis, Hepatozoon canis and Babesia sp./Theileria sp. DNA of vector-borne pathogens was detected in 120 (78.43%; 95% CI: 71.06-84.66%) foxes. Specifically, 75 (49%; 95% CI: 40.86-57.22%) animals scored PCR-positive per H. canis, 68 (44.44%; 95% CI: 36.42-52.69%) for E. canis, 35 (22.88%; 95% CI: 16.48-30.35%) for piroplasms (Theileria annae), 3 (1.96%; 95% CI: 0.41-5.62%) for C. burnetii and 1 (0.65%; 95% CI: 0.02-3.59%) for A. phagocytophilum. No positive reaction was observed for F. tularensis. Fifty-six animals (36.6%; 95% CI: 28.97-44.76%) were positive for two or three pathogens. Red foxes result to be involved in the cycle of vector-borne pathogens that are associated to disease in dogs and humans.

The Eurasian otter (Lutra lutra) as a potential host for rickettsial pathogens in southern Italy

Canine monocytic ehrlichiosis and rickettsiosis are zoonotic tick-borne diseases of canids caused by the intracellular obligate bacteria Ehrlichia canis and Rickettsia species respectively. In this study, we investigated using standard and real-time PCR and sequencing, the occurrence and molecular characterization of E. canis and Rickettsia species in the Eurasian otter (Lutra lutra) from the southern Italian population. Samples were screened by using molecular assays also for Neospora caninum, Toxoplasma gondii, Clamydophyla spp., Coxiella burnetii, Leishmania spp., Cryptosporidium spp., and Giardia spp. detection, and helminths were studied by traditional methods. Out of six carcasses tested, three were positive for E. canis and co-infection with Rickettsia sp. occurred in one of those. Sequences of the 16S rRNA E. canis gene were identical to each other but differed from most of those previously found in red foxes (Vulpes vulpes) and wolves (Canis lupus) from southern Italy. Helminths included just cystacanths of Sphaerirostris spp. from the intestine of two Eurasian otters and the nematode Angiostrongylus vasorum from the lungs of a single Eurasian otter. None of the samples was positive for the other investigated selected pathogens. This study is the first report on the evidence of infection by rickettsial pathogens in the Eurasian otter. The present result prompts some inquiries into the pathogenic role of those bacteria for the isolated sub-populations of the endangered Eurasian otter in southern Italy.

Detection of Babesia canis vogeli and Hepatozoon canis in canine blood by a single-tube real-time fluorescence resonance energy transfer polymerase chain reaction assay and melting curve analysis

A real-time fluorescence resonance energy transfer polymerase chain reaction (qFRET PCR) coupled with melting curve analysis was developed for detection of Babesia canis vogeli and Hepatozoon canis infections in canine blood samples in a single tube assay. The target of the assay was a region within the 18S ribosomal RNA gene amplified in either species by a single pair of primers. Following amplification from the DNA of infected dog blood, a fluorescence melting curve analysis was done. The 2 species, B. canis vogeli and H. canis, could be detected and differentiated in infected dog blood samples (n = 37) with high sensitivity (100%). The detection limit for B. canis vogeli was 15 copies of a positive control plasmid, and for H. canis, it was 150 copies of a positive control plasmid. The assay could simultaneously distinguish the DNA of both parasites from the DNA of controls. Blood samples from 5 noninfected dogs were negative, indicating high specificity. Several samples can be run at the same time. The assay can reduce misdiagnosis and the time associated with microscopic examination, and is not prone to the carryover contamination associated with the agarose gel electrophoresis step of conventional PCR. In addition, this qFRET PCR method would be useful to accurately determine the range of endemic areas or to discover those areas where the 2 parasites co-circulate.

The role of wild canids and felids in spreading parasites to dogs and cats in Europe. Part I: Protozoa and tick-borne agents

Over the last few decades, the world has witnessed radical changes in climate, landscape, and ecosystems. These events, together with other factors such as increasing illegal wildlife trade and changing human behaviour towards wildlife, are resulting into thinning boundaries between wild canids and felids and their domestic counterparts. As a consequence, the epidemiology of diseases caused by a number of infectious agents is undergoing profound readjustements, as pathogens adapt to new hosts and environments. Therefore, there is a risk for diseases of wildlife to spread to domestic carnivores and vice versa, and for zoonotic agents to emerge or re-emerge in human populations. Hence, the identification of the hazards arising from the co-habitation of these species is critical in order to plan and develop adequate control strategies against these pathogens. In the first of this two-part article, we review the role that wild canids and felids may play in the transmission of protozoa and arthropod-borne agents to dogs and cats in Europe, and provide an account of how current and future progress in our understanding of the ecology and epidemiology of parasites, as well as of host-parasite interactions, can assist efforts aimed at controlling parasite transmission.

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.

First report of Anaplasma platys infection in red foxes (Vulpes vulpes) and molecular detection of Ehrlichia canis and Leishmania infantum in foxes from Portugal

Background

The bacteria Anaplasma platys and Ehrlichia canis and the protozoan Leishmania infantum are vector-borne agents that cause canine vector-borne diseases, some of which are zoonotic. The present survey investigated the prevalence of Anaplasma, Ehrlichia and Leishmania in red foxes (Vulpes vulpes) from Portugal by molecular analysis, in order to evaluate the epidemiological role of these canids as reservoirs of infection.

Methods

Blood and/or bone marrow samples were collected from 78 red foxes obtained in eight districts of northern, central and southern Portugal. Real-time polymerase chain reactions (PCR) amplified a 123 bp fragment of the 16S rRNA gene of Anaplasma spp. and Ehrlichia spp. and a 265 bp fragment of the L. infantum internal transcribed spacer one (ITS1) region of the rRNA operon evaluated by PCR-high resolution melt analysis (PCR-HRM), with sequencing of the DNA products. A phylogenetic analysis was carried out to compare these to other sequences from Anaplasma spp. and Ehrlichia spp. deposited in GenBank®.

Results

A. platys was detected in 10 (14.5%) and E. canis in two (2.9%) out of 69 foxes; and L. infantum was detected in one (1.3%) of the 78 foxes. The prevalence of A. platys was significantly different from the prevalence of E. canis (p=0.016) and from that of L. infantum (p=0.002). No co-infections were found in any one of the 78 foxes. No statistically significant differences were found between the type of sample (blood and bone marrow), geographic regions (north/centre and south), age (<2 years and ≥2 years) and gender for any one of the agents.

Conclusions

This is the first known report of A. platys in red foxes worldwide, as well as the first molecular evidence of E. canis in foxes from Portugal. The moderate prevalence of A. platys suggests that red foxes may play a role in the epidemiology of infection with this bacterium and serve as a reservoir for domestic dogs.

A molecular survey of vector-borne pathogens in red foxes (Vulpes vulpes) from Bosnia and Herzegovina

BACKGROUND

Red foxes (Vulpes vulpes) have recently been recognized as potential reservoirs of several vector-borne pathogens and a source of infection for domestic dogs and humans, mostly due to their close vicinity to urban areas and frequent exposure to different arthropod vectors. The aim of this study was to investigate the presence and distribution of Babesia spp., Hepatozoon canis, Anaplasma spp., Bartonella spp., 'Candidatus Neoehrlichia mikurensis', Ehrlichia canis, Rickettsia spp. and blood filaroid nematodes in free-ranging red foxes from Bosnia and Herzegovina.

METHODS

Spleen samples from a total of 119 red foxes, shot during the hunting season between October 2013 and April 2014 throughout Bosnia and Herzegovina, were examined for the presence of blood vector-borne pathogens by conventional PCRs and sequencing.

RESULTS

In the present study, three species of apicomplexan parasites were molecularly identified in 73 red foxes from the entire sample area, with an overall prevalence of 60.8%. The DNA of B. canis, B. cf. microti and H. canis was found in 1 (0.8%), 38 (31.9%) and 46 (38.6%) spleen samples, respectively. In 11 samples (9.2%) co-infections with B. cf. microti and H. canis were detected and one fox harboured all three parasites (0.8%). There were no statistically significant differences between geographical region, sex or age of the host in the infection prevalence of B. cf. microti, although females (52.9%; 18/34) were significantly more infected with H. canis than males (32.9%; 28/85). The presence of vector-borne bacteria and filaroid nematodes was not detected in our study.

CONCLUSION

This is the first report of B. canis, B. cf. microti and H. canis parasites in foxes from Bosnia and Herzegovina and the data presented here provide a first insight into the distribution of these pathogens among the red fox population. Moreover, the relatively high prevalence of B. cf. microti and H. canis reinforces the assumption that this wild canid species might be a possible reservoir and source of infection for domestic dogs.

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.

First molecular evidence of Hepatozoon canis infection in red foxes and golden jackals from Hungary

Background

Recently, Hepatozoon canis infection has been detected among shepherd, hunting and stray dogs in the southern part of Hungary, which is considered to be free of Rhipicephalus sanguineus sensu lato and close to the border with Croatia. The aim of this study was to acquire information on the possibility that red foxes and/or golden jackals could play a role in the appearance and spread of H. canis in Hungary.

Methods

A conventional PCR was used to amplify a 666 bp long fragment of the Hepatozoon 18S rRNA gene from blood samples collected from 334 foxes shot in 231 locations in 16 counties and 15 golden jackals shot in 9 locations in two southwestern counties close to Croatia. A second PCR assay was performed in some of the samples positive by the first PCR to amplify a larger segment (approximately 1500 bp) of the 18S rRNA gene of Hepatozoon spp. for further phylogenetic analysis.

Results

Hepatozoon infection was detected in canids shot in 30 locations and 9 counties. Altogether 26 foxes (8.0%, 95% CI: 5-11%) and 9 jackals (60%, 95% CI: 33-81%) were PCR positive. Hepatozoon canis sequences were obtained from 12 foxes and 7 jackals. DNA sequences from 16 animals were 99-100% similar to H. canis from Croatian foxes or dogs while two of the sequences were 99% similar to an Italian fox. Half (13/26) of the infected red foxes and all golden jackals were shot in the two southwestern counties.

Conclusions

This is the first report on molecular evidence of H. canis in red foxes (Vulpes vulpes) and golden jackals (Canis aureus) from Hungary, which is considered free from the tick vector of H. canis, R. sanguineus. Although no R. sanguineus sensu lato had been found on infected or non-infected wild canids, the detection of authochnous canine hepatozoonosis in Hungary might imply that the range of R. sanguineus sensu lato has reached this country.