Hepatozoonosis in foxes 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.

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 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.

Fox on the run--molecular surveillance of fox blood and tissue for the occurrence of tick-borne pathogens in Austria

BACKGROUND

The red fox (Vulpes vulpes) is a widespread species, harbouring many pathogens relevant for humans and pets. Indeed, Anaplasma spp., Ehrlichia canis and Rickettsia spp. among the bacteria and Hepatozoon canis as well as Babesia sp. among the parasites have been the focus of several studies.

FINDINGS

In a cohort of 36 foxes shot on one day in the north-eastern part of Austria, Babesia microti-like pathogens were found in 50%, while H. canis was detected in 58.3% of the samples. The spleen was more useful for detection of H. canis, whereas B. microti-like parasites were more frequently found in the blood. Bacteria could not be confirmed in any of the cases to demonstrate the occurrence of such tick-borne pathogens using PCR and sequencing on blood and spleen samples.

CONCLUSIONS

The occurrence of B. microti-like and H. canis parasites raised many questions, because these infections have never been found autochthonously in dogs. Furthermore in the case of H. canis the main vector tick, Rhipicephalus sanguineus, is absent in the sampling area, leaving space for further hypotheses for transmission such as vertical transmission, transmission via ingestion of prey animals or other vector ticks. Further studies are needed to evaluate the risks for pets in this area. PCRs delivered differing results with the different tissues, suggesting the use of both spleen and blood to obtain an integral result.

Molecular assessment of Hepatozoon (Apicomplexa: Adeleorina) infections in wild canids and rodents from north Africa, with implications for transmission dynamics across taxonomic groups

Parasites play a major role in ecosystems, and understanding of host-parasite interactions is important for predicting parasite transmission dynamics and epidemiology. However, there is still a lack of knowledge about the distribution, diversity, and impact of parasites in wildlife, especially from remote areas. Hepatozoon is a genus of apicomplexan parasites that is transmitted by ingestion of infected arthropod vectors. However, alternative modes of transmission have been identified such as trophic transmission. Using the 18S rRNA gene as a marker, we provide an assessment of Hepatozoon prevalence in six wild canid and two rodent species collected between 2003 and 2012 from remote areas in North Africa. By combining this with other predator-prey systems in a phylogenetic framework, we investigate Hepatozoon transmission dynamics in distinct host taxa. Prevalence was high overall among host species (African jerboa Jaculus jaculus [17/47, 36%], greater Egyptian jerboa Jaculus orientalis [5/7, 71%], side-striped jackal Canis adustus [1/2, 50%], golden jackal Canis aureus [6/32, 18%], pale fox Vulpes pallida [14/28, 50%], Rüppell's fox Vulpes rueppellii [6/11, 55%], red fox Vulpes vulpes [8/16, 50%], and fennec fox Vulpes zerda [7/11, 42%]). Phylogenetic analysis showed further evidence of occasional transmission of Hepatozoon lineages from prey to canid predators, which seems to occur less frequently than in other predator-prey systems such as between snakes and lizards. Due to the complex nature of the Hepatozoon lifecycle (heteroxenous and vector-borne), future studies on these wild host species need to clarify the dynamics of alternative modes of Hepatozoon transmission and identify reservoir and definitive hosts in natural populations. We also detected putative Babesia spp. (Apicomplexa: Piroplasmida) infections in two canid species from this region, V. pallida (1/28) and V. zerda (1/11).

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.

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

Background

Hepatozoon canis is a protozoan tick-borne pathogen of dogs and wild canids. Hepatozoon spp. have been reported to infect foxes in different continents and recent studies have mostly used the polymerase chain reaction (PCR) for the detection and characterization of the infecting species. Surveying red foxes (Vulpes vulpes) may contribute to better understanding the epidemiology of canine vector-borne diseases, including hepatozoonosis caused by H. canis in domestic dogs. The present study investigated the prevalence of Hepatozoon spp. by means of histopathology and molecular analysis of different tissues in red foxes from different parts of Portugal.

Methods

Blood and tissues including bone marrow, heart, hind leg muscle, jejunum, kidney, liver, lung, popliteal or axillary lymph nodes, spleen and/or tongue were collected from 91 red foxes from eight districts in northern, central and southern Portugal. Tissues were formalin-fixed, paraffin-embedded, cut and stained with hematoxylin and eosin. Polymerase chain reaction (PCR) amplified a ~650 bp fragment of the 18S rRNA gene of Hepatozoon spp. and the DNA products were sequenced.

Results

Hepatozoon canis was detected in 68 out of 90 foxes (75.6%) from all the sampled areas by PCR and sequencing. Histopathology revealed H. canis meronts similar in shape to those found in dogs in the bone marrow of 11 (23.4%) and in the spleen of two (4.3%) out of 47 foxes (p = 0.007). All the 11 foxes found positive by histopathology were also positive by PCR of bone marrow and/or blood. Positivity by PCR (83.0%) was significantly higher (p < 0.001) than by histopathological examination (23.4%) in paired bone marrow samples from the same 47 foxes. Sequences of the 18S rRNA gene of H. canis were 98–99% identical to those in GenBank.

Conclusions

Hepatozoon canis was found to be highly prevalent in red fox populations from northern, central and southern Portugal. Detection of the parasite by histopathology was significantly less sensitive than by PCR. Red foxes are a presumptive reservoir of H. canis infection for domestic dogs.

The first report of Hepatozoon canis identified in Vulpes vulpes and ticks from Italy

This is the first report on the presence of Hepatozoon canis in Vulpes vulpes in Italy. During the years 2005 and 2006, a total of 119 foxes were collected and their spleen tissues were screened by microscopy, polymerase chain reaction, and sequencing. In the same area, 290 ticks were picked off from dogs or collected from the environment. Microscopy detected inclusion bodies regarded as belonging to the genus Hepatozoon in four samples, whereas molecular diagnostics evidenced 16 foxes (13.4%) and 6 ticks (2.1%) positive to H. canis. The H. canis isolates we found in foxes, compared with the strains we previously detected in dogs from the same area and with the strains found in foxes from other European countries, show a certain genetic heterogeneity. In fact, seven isolates cluster with the Italian dog strain and nine isolates cluster with the fox strain found in Spain and Slovakia; moreover, the dog's strain is closely related to one tick's isolate, and the strain found in three Rhipicephalus sanguineus and in one Ixodes ricinus collected from the environment cluster with the aforementioned Spanish and Slovak fox strains. Our findings confirm the importance of R. sanguineus as final host and suggest that I. ricinus might also be implicated in parasite transmission, explaining in that way the occurrence of hepatozoonosis in areas considered R. sanguineus-free. The peridomestic habits of V. vulpes and the increasing global temperature are expected to amplify the impact of this vector-borne disease and to enforce the transmission of Hepatozoon to domestic animals.

Imported and travelling dogs as carriers of canine vector-borne pathogens in Germany

BACKGROUND

With the import of pets and pets taken abroad, arthropod-borne diseases have increased in frequency in German veterinary practices. This is reflected by 4,681 dogs that have been either travelled to or relocated from endemic areas to Germany. The case history of these dogs and the laboratory findings have been compared with samples collected from 331 dogs living in an endemic area in Portugal. The various pathogens and the seroprevalences were examined to determine the occurrence of, and thus infection risk, for vector-borne pathogens in popular travel destinations.

RESULTS

4,681 dogs were examined serological for Leishmania infantum, Babesia canis and Ehrlichia canis. Buffy coats were detected for Hepatozoon canis and blood samples were examined for microfilariae via the Knott's test. The samples were sent in from animal welfare organizations or private persons via veterinary clinics. Upon individual requests, dogs were additionally examined serological for Anaplasma phagocytophilum, Borrelia burgdorferi and Rickettsia conorii. Overall B. canis was the most prevalent pathogen detected by antibody titers (23.4%), followed by L. infantum (12.2%) and E. canis (10.1%). Microfilariae were detected in 7.7% and H. canis in 2.7% of the examined dogs. In 332/1862 dogs A. phagocytophilum, in 64/212 B. burgdorferi and in 20/58 R. conorii was detected. Of the 4,681 dogs, in total 4,226 were imported to Germany from endemic areas. Eighty seven dogs joined their owners for a vacation abroad. In comparison to the laboratory data from Germany, we examined 331 dogs from Portugal. The prevalence of antibodies/pathogens we detected was: 62.8% to R. conorii, 58% to B. canis, 30.5% to A. phagocytophilum, 24.8% to E. canis, 21.1% to H. canis (via PCR), 9.1% to L. infantum and 5.3% to microfilariae.

CONCLUSIONS

The examination of 4,681 dogs living in Germany showed pathogens like L. infantum that are non-endemic in Germany. Furthermore, the German data are similar in terms of multiple pathogen infection to the data recorded for dogs from Portugal. Based on these findings the importation of dogs from endemic predominantly Mediterranean regions to Germany as well as travelling with dogs to these regions carries a significant risk of acquiring an infection. Thus we would conclude that pet owners seek advice of the veterinarians prior to importing a dog from an endemic area or travel to such areas. In general, it might be advisable to have a European recording system for translocation of dogs.

Apicomplexan parasites of red foxes (Vulpes vulpes) in northeastern Poland

Molecular detection of apicomplexan parasites in splenic samples of red foxes collected from northeastern Poland was conducted by PCR amplification of a fragment of the 18S rRNA spanning the V4 gene region of Apicomplexa. Positive PCR products were further analysed by restriction fragment length polymorphism (RFLP) and sequencing to identify species. One hundred and eleven red foxes (Vulpes vulpes) were acquired from 15 localities in the Mazovian Province and 27 foxes were acquired from the Mazurian Lakeland. Apicomplexan 18S rDNA was detected in 15.9% of 138 fox spleens examined. Three apicomplexan species were identified: Hepatozoon canis was detected in 11.6% of the spleen samples, Toxoplasma gondii was detected in 3.6% of the spleen samples and a Babesia sp. was sequenced from 1 sample (0.7%). This data represent the first record of H. canis, T. gondii and a B. sp. from naturally infected red foxes in Poland. Infected foxes may act as sylvatic reservoirs of these apicomplexan parasites as well as serving as a source of infection for arthropod definitive hosts and vectors.

Molecular epizootiology of canine hepatozoonosis in Croatia

An epizootiological survey was conducted to investigate the prevalence of hepatozoonosis in a population of 924 apparently asymptomatic dogs from different regions of Croatia. DNA was isolated from canine blood and screening PCR on the 666 bp fragment of 18S rRNA revealed that 108 (11.8%) of dogs were infected. Positive samples were confirmed by partial sequencing of the 18S rRNA gene. The consensus sequences, derived from various sequence data sets, were compared with sequences of 18S ssrRNA of Hepatozoon spp. available in GenBank. The alignments revealed 106 Hepatozoon canis and two Hepatozoon sp. sequences. Among H. canis isolates, we found a certain amount of heterogeneity, while both Hepatozoon sp. isolates were identical to the Spanish isolate (Accession No. AY600625) from Clethrionomys glareolus. On the basis of eight commonly mutated nucleotide positions in the partial 18S rRNA gene sequence, we divided the H. canis isolates into five groups. The results obtained indicate a higher prevalence and significance of hepatozoonosis in Croatia than previously believed and demonstrate that the organisms belonging to H. canis that infect European dogs are genetically very heterogeneous.

Entomopathogenic fungi against South American tick species

Ticks are parasites of serious concern for humans, domesticated animals and wild animals. Despite scientific advances, in South America the principal control method for ticks is the use of chemical acaricides. Indiscriminate use of these products causes environmental pollution, food contamination and development of tick resistance to acaricides. In vitro studies and field trials have demonstrated that pathogenic fungal isolates not only cause mortality of many tick species, but also reduce subsequent generations due to effects on their reproductive efficacy. Accordingly, this review presents results of several studies which were conducted in South America. Furthermore, it outlines current information on fungal pathogens of ticks and discusses the need to develop and implement effective strategies for use of entomopathogenic fungi to control ticks in the near future.

The first report of Hepatozoon sp. (Apicomplexa: Hepatozoidae) in neotropical felids from Brazil

In order to investigate the occurrence of Hepatozoon infection in Neotropical felids from Brazil, blood from the jugular or cephalic vein was taken from 29 non-domestic felids including ocelot (Leopardus pardalis), little spotted cat (Leopardus tigrinus), margay (Leopardus wiedii), and jaguarondi (Puma yagouaroundi) from the Northeast region of Brazil. Hepatozoon infection was confirmed by light microscopy and molecular techniques. The results showed five naturally infected felids. Partial sequences of the 18S rRNA gene of the Hepatozoon sp. from these felids were further analyzed. Sequences revealed that the isolates found are closely related to Hepatozoon sp. from domestic cats in Spain. Hepatozoon species from Neotropical felids were identified molecularly and characterized for the first time. This is also the first report of Hepatozoon infection in a little spotted cat.

Hepatozoon canisInfection in Slovakia: Imported or Autochthonous?

Tissue samples from nine red foxes (four samples of striated muscle tissue and five samples of heart tissue) that originated from the Michalovce district (Slovakia), an area with endemic occurrence of canine babesiosis were examined by PCR method using primers amplifying a fragment of the 18S rRNA spanning the V4 region of Babesia and Theileria. An unexpected determination of 450 bp DNA fragment of Hepatozoon canis was found in four samples. Partial sequences of the 18S rRNA gene from the H. canis showed 100% similarity with the sequence from Brasil isolate of H. canis from a pampas fox (Pseudalopex gymnocercus) (AY471615) as well as from a fox in Spain (AY150067) and from a dog in Brazil (AY864677). In the present study, we report the first PCR detection of Hepatozoon canis in a naturally infected red fox from Slovakia, a Rhipicephalus sanguineus-free region. We assume that the infection was spread by infected R. sanguineus that might have been brought to Slovakia by travelers, by golden jackals, or by foxes migrating because of expansion of golden jackals and environmental and climate changes.

Myocarditis and myositis due to infection with Hepatozoon species in pine martens (Martes martes) in Scotland

Postmortem examinations of four pine martens which had died as a result of road accidents in Scotland revealed focal, granulomatous lesions in the heart and skeletal muscles of three of them. An immunoperoxidase staining technique showed that the lesions were due to infection with Hepatozoon species. A PCR-based assay was used to confirm the presence of Hepatozoon DNA in the infected tissues. The nucleotide base sequence of the PCR products suggested that the infecting organism was probably a new species of Hepatozoon, most closely related to, but distinct from, Hepatozoon canis. The pine martens were in good physical condition and there was no indication that the infection was causing ill health.

The first report of Hepatozoon spp. (Apicomplexa, Hepatozoidae) in domestic cats from São Paulo state, Brazil

Hepatozoon sp. was diagnosed in three naturally infected cats from São Paulo state, Brazil. The first animal was admitted to the veterinary clinic with renal failure. During the hematological examination, gamonts of Hepatozoon sp. were observed within polymorphonuclear cells. Another two cats, which lived in the same house as the first cat, were also positive for this hemoparasite. This is the first report of a Hepatozoon sp. infection in domestic cats from Brazil.

A serosurvey of Hepatozoon canis and Ehrlichia canis antibodies in wild red foxes (Vulpes vulpes) from Israel

A seroepidemiological survey was conducted to investigate the prevalence of antibodies reactive with Ehrlichia canis and Hepatozoon canis antigens in free-ranging red foxes (Vulpes vulpes) in Israel. Of 84 fox sera assayed, 36% were seropositive for E. canis by the indirect fluorescent antibody (IFA) test and 24% were positive for H. canis using an enzyme-linked immunosrbent assay (ELISA). Canine ehrlichiosis and hepatozoonosis appear to be endemic in the wild red fox populations in Israel, and foxes may serve as a reservoir for infection of domestic dogs and other wild canine species.

Molecular studies on Babesia, Theileria and Hepatozoon in southern Europe. Part II. Phylogenetic analysis and evolutionary history

Following a study on molecular epizootiology of Hepatozoon canis and piroplasmids (Babesia spp. and Theileria spp.) in southern Europe, newly obtained sequences of 18s rRNA gene were used for phylogenetic analysis. Partial sequences were analysed in isolates showing high degree of homology (>99%) with previous GenBank entries: H. canis, B. canis vogeli, B. equi (two isolates, Spain1 and Spain2), T. annulata and Theileria sp. The complete gene sequences were used for B. ovis and B. bovis, that showed lower homology (<95%) with rapport to previously reported species or isolates. A first set of phylogenetic trees constructed with partial 18s rRNA sequences showed that most European isolates clustered unambiguously with previously described species, so that minor sequence dissimilarities found are due probably to strain variations. The second set of phylogenetic trees was made using the complete 18s rRNA sequences of 44 species from GenBank and the newly sequenced B. ovis and B. bovis. The analysis revealed for the first time a division of piroplasmids in five clades: (1) B. microti group, with B. rodhaini, B. felis, B. leo, B. microti and T. annae (proposed name for the group, without taxonomic value: Archaeopiroplasmids), (2) Western USA Theilerid-like group (proposed name: Prototheilerids), (3) Theileria group, containing all Theileria species from Bovinae (proposed name: Theilerids), (4) A first group of Babesia species including B. canis and B. gibsoni from canids together with B. divergens and B. odocoilei (proposed name: Babesids), (5) A second group composed mainly by Babesia species from ungulates: B. caballi, B. bigemina, B. ovis, B. bovis and Babesia sp. from cow (proposed name: Ungulibabesids). The bootstrap support obtained with several analytical procedures for this new dicotomy of Babesiidae was always very high. Taking into account the present phylogenetic analysis and additional paleogeographic, parasitological and zoological evidences, two hypothesis on the origin and evolution of piroplasmids groups are presented.

Molecular studies on Babesia, Theileria and Hepatozoon in southern Europe. Part I. Epizootiological aspects

Molecular epizootiology of piroplasmids (Babesia spp., Theileria spp.) and Hepatozoon canis was studied in mammals from southern Europe (mainly from Spain, but also from Portugal and France). Partial amplification and sequencing of the 18s rRNA gene was used for molecular diagnosis. In some particular cases (B. ovis and B. bovis) the complete 18s rRNA gene was sequenced. Blood samples were taken from domestic animals showing clinical symptoms: 10 dogs, 10 horses, 10 cows, 9 sheep and 1 goat. In addition, DNA samples were isolated from blood of 12 healthy dogs and from spleen of 10 wild red foxes (Vulpes vulpes). The results of the survey were the following: Piroplasmid infections: Approximately from 50 to 70% of wild or domestic mammals (symptomatic) were infected. Piroplasmids detected in ruminants were:COW: B. bovis, T. annulata and Theileria sp. (type C). Sheep and goat: B. ovis. Piroplasmids present in canids were: Babesia canis vogeli, Babesia canis canis, Theileria annae and B. equi. The only piroplasmid found in asymptomatic dogs was B. equi. Piroplasmids found in horse were: B. equi and B. canis canis.H. canis infections in canids: H. canis was absent of domestic dog samples, whereas all foxes studied were infected by this protozoa. Genetic analysis showed that most of piroplasmid and Hepatozoon isolates from southern Europe matched unambigously with previously described species, as demonstrated by the high level sequence identity between them, usually between 99 and 100%. Minor differences, usually detected in hypervariable regions of 18s rRNA gene are probably due to strain variations or rare genetic polymorphisms. A possible exception was B. bovis, which shows a relatively lower degree of homology (94%) with regard to other B. bovis isolates from several countries. The same is true for B. ovis, that showed a 94% identity with regard to Babesia sp. from South African cow and a 92% with rapport to B. bovis from Portugal.

Antibodies to selected canine pathogens and infestation with intestinal helminths in golden jackals (Canis aureus) in Israel

Blood and fecal samples, collected from 46 healthy adult free-ranging golden jackals captured in two different locations in Israel, were examined. A serological Study was conducted to investigate the prevalence of circulating antibodies reacting with four common canine pathogens: canine distemper virus (CDV), canine parvovirus (CPV), Ehrlichia canis and Leishmania infantum. Faecal flotation and haematological tests were also performed. The seroprevalence of CPV, E. canis, CDV, and L. infantum were 72.3% (34/47), 54.3% (25/46), 52.2% (24/46), and 6.5% (3/46) respectively. Faecal flotation tests revealed a high prevalence of Ancylostoma caninum (13/17, 76%) and a low prevalence of Dipilidium caninum infestation. Examination of blood smears revealed Hepatazoon canis gamonts in one jackal. Golden jackals are among the most common free-ranging carnivores in Israel and neighboring countries. Their habitats are in proximity to densely populated areas and they bear close phylogenic relation to the domestic dog. These facts, combined with the high prevalence of the jackals' exposure to the major canine pathogens demonstrated in this study, suggest that they may serve as a reservoir for the transmission of certain diseases to domestic dogs.

Hepatozoon species infection in domestic cats: a retrospective study

Hepatozoon sp. is a protozoan parasite of peripheral blood neutrophils in cats. Feline hepatozoonosis has been reported infrequently and little is known about the pathogenesis of this infection. In order to further clarify clinicopathological characteristics of hepatozoonosis in domestic cats, a retrospecitve study of hepatozoonosis in cats admitted during 1989-1995 to the Hebrew University School of Veterinary Medicine was conducted. The study population comprised all the cats whose medical records included a complete blood count with a microscopical examination of a blood smear during this 7-year period (n=1229). Hepatozoon gametocytes were identified in seven cats (0.57%) ranging from 1 to 6 years of age. Infected cats were mostly males (6/7) of mixed breed (5/7) with a variety of complaints and clinical signs. The clinicopathological findings included increased activities of serum lactate dehydrogenase (LDH) (5/6) and creatine kinase (CK) (5/6). The elevated enzymes detected in cats with hepatozoonosis are suggestive of muscular damage. Sixty-seven percent (4/6) of the cats with hepatozoonosis which were tested for a retroviral disease were found infected either in FIV or FELV. In addition, 2/7 cats were co-infected with Hemobartonella felis. In conclusion, parasitemia with Hepatozoon sp. is a rare finding in cats from Israel. The over-representation of cats with a retroviral disease among the cats with hepatozoonosis indicates a possible association between immunosupression and the development of Hepatozoon infection.

Reliability of serological methods for detection of leishmaniasis in Portuguese domestic and wild reservoirs

A direct agglutination test (DAT) and an immunofluorescence technique (IFAT) were compared for detection of Leishmania infantum infection in 43 dogs and five foxes from Alto-Douro and Arrábida, two known endemic areas in Portugal. In four dogs with proved canine leishmaniasis, both DAT and IFAT showed positive readings (titres > or = 1:320 and > or = 1:128). Of 34 samples collected from apparently healthy dogs, ten were positive by both serological tests and eight were serologically positive by one test or the other. Three foxes out of five captured in this area, scored titres indicative of leishmaniasis in both DAT and IFAT. The concordance between DAT and IFAT in all collected samples (48) was 81.25%. Considering these and previous studies in the adjacent Mediterranean areas, the seroprevalence of L. infantum infection in the canine and vulpine populations appear to be of high magnitude.

Life cycle of Hepatozoon mehlhorni sp. nov. in the viper Echis carinatus and the mosquito Culex pipiens

Hepatozoon mehlhori sp. nov. and its developmental stages from the tissues of the Egyptian viper Echis carinatus and the mosquito Culex pipiens are described. The erythrocytic parasites were differentiated into the small form (trophozoite) measuring 14.5 +/- 0.6 x 4 +/- 0.12 micron and the mature form (gametocyte) measuring 17.2 +/- 1.6 x 5.4 +/- 0.5 micron. Merogony took place in the pulmonary endothelial cells and in the parenchyma cells of the liver and spleen of the infected vipers. Two types of meront were found. The large meronts (macromeronts) were 30.2 +/- 1.73 x 22.6 +/- 1.2 microns in size and yielded 16-40 (average, 28) micromerozoites measuring 17.2 +/- 0.7 x 5 +/- 0.15 microns. The small meronts (micromeronts) measured 18.2 +/- 0.6 x 13.5 +/- 0.5 microns and yielded 2-14 (average, 8) macromerozoites that were 15.1 +/- 0.12 x 6.2 +/- 0.8 microns in size. After syzygy in the haemocoel of the mosquito, the microgamont produced four uniflagellate microgametes (6.4 +/- 0.3 x 4.5 +/- 0.5 microns in size, with a short flagellum measuring 3.2 +/- 0.1 microns); on the 3rd day post-infection (p.i.)., one of these fertilized the macrogamete, giving rise to the zygote. The oocyst developed from the zygote on the 5th day p.i. and measured 135 +/- 2.6 x 120 +/- 1.8 microns. About 11-60 (average, 35) sporoblasts were formed by centripetal invaginations from each oocyst on the 8th day p.i. and developed into sporocysts on the 14th day p.i. Inside each sporocyst, 5-12 (average, 8) sporozoites, each measuring 12.6 +/- 1.2 x 4.1 +/- 0.3 microns, developed on the 16th day p.i. According to the above-mentioned characteristics the parasite was recorded as being a new species and was named Hepatozoon mehlhorni. Experimental transmission was accomplished by i.p. inoculation of the infectious stages (sporozoites) into uninfected vipers and led to the appearance of blood stages at 4-6 weeks p.i.