First case of babesiosis caused by Babesia canis canis in a dog from Norway

ACVIM consensus statement on the diagnosis of immune thrombocytopenia in dogs and cats

Immune thrombocytopenia (ITP) is the most common acquired primary hemostatic disorder in dogs. Immune thrombocytopenia less commonly affects cats but is an important cause of mortality and treatment-associated morbidity in both species. Immune thrombocytopenia remains a diagnosis of exclusion for which diagnostic guidelines are lacking. Primary, or non-associative, ITP refers to autoimmune platelet destruction. Secondary, or associative, ITP arises in response to an underlying disease trigger. However, evidence for which comorbidities serve as ITP triggers has not been systematically evaluated. To identify key diagnostic steps for ITP and important comorbidities associated with secondary ITP, we developed 12 Population Evaluation/Exposure Comparison Outcome (PECO) format questions. These questions were addressed by evidence evaluators utilizing a literature pool of 287 articles identified by the panelists using a structured search strategy. Evidence evaluators, using panel-designed templates and data extraction tools, summarized evidence and created guideline recommendations that then were integrated by diagnosis and comorbidity domain chairs. The revised PECO responses underwent a Delphi survey process to reach consensus on final guidelines. A combination of panel expertise and PECO responses were employed to develop algorithms for diagnosis of ITP in dogs and cats, which also underwent 4 iterations of Delphi review. Comorbidity evidence evaluators employed an integrated measure of evidence (IME) tool to determine evidence quality for each comorbidity; IME values combined with evidence summaries for each comorbidity were integrated to develop ITP screening recommendations, which also were subjected to Delphi review. Commentary was solicited from multiple relevant professional organizations before finalizing the consensus. The final consensus statement provides clinical guidelines for the diagnosis of, and underlying disease screening for, ITP in dogs and cats. The systematic consensus process identified numerous knowledge gaps that should guide future studies. This statement is a companion manuscript to the ACVIM Consensus Statement on the Treatment of Immune Thrombocytopenia.

A global systematic review and meta-analysis on the babesiosis in dogs with special reference to Babesia canis

BACKGROUND

Canine babesiosis is a clinically significant tick-transmitted disease caused by several species of the intraerythrocytic protozoan parasite Babesia, which result in a wide range of clinical manifestations, from mild, transient infection to serious disease and even death.

OBJECTIVES

The current study aimed to estimate the global prevalence and associated risk factors of Babesia in dogs.

METHODS

Multiple databases (PubMed, Scopus, ProQuest, Web of Science and Google Scholar) were searched for relevant literature published from January 2000 up to December 2022. The statistical analyses were performed based on the R software (version 3.6) meta-package.

RESULTS

Out of 23,864 publications, 229 studies met the inclusion criteria. The pooled prevalence of canine babesiosis was 0.120 (95% CI; 0.097-0.146). The highest pooled prevalence was found in Europe (0.207, 95% CI; 0.097-0.344). Among several species, Babesia canis was the most prevalent parasite (0.216, 95% CI; 0.056-0.441). The highest pooled prevalence of Babesia in dogs was observed in the summer season (0.097, 95% CI; 0.040-0.174).

CONCLUSIONS

Regular screening and appropriate control strategies are recommended for the prevention of transmission of tick-borne disease transmission among dogs.

Detection and Molecular Characterization of Canine Babesiosis Causative Agent Babesia canis in Naturally Infected Dogs in the Dobrogea Area (Southeastern Romania)

Canine babesiosis is an emerging tick-borne disease of major veterinary concern in Europe. Its prevalence has increased in the last two decades and is spreading rapidly toward the north. The aim of this study was to investigate the genetic diversity of Babesia spp. strains isolated from naturally infected dogs in a tick-endemic area (Dobrogea) in southeastern Romania. For this purpose, a total of twenty-three samples from dogs diagnosed with various clinical forms of babesiosis, evaluated by means of clinical history, physical examination, and hematological tests, were subjected to a molecular investigation using PCR, sequencing analysis, and genetic characterization. A microscopic examination of thin Diff-quick-stained blood smears revealed large intra-erythrocytic Babesia piroplasms in all dogs. The PCR and sequencing analysis results indicated the presence of Babesia canis in 22 dogs (95.7%) and Babesia vogeli in 1 dog (4.3%). Among the B. canis isolates, two genotypes were distinguished based on two nucleotide substitutions (GA→AG) observed in the 18S rRNA gene sequences (at positions 609 and 610), with the AG genotype predominating (54.5% of samples), while the GA variant was identified in 9.1% of samples. In the remaining isolates (36.4%), both variants were identified. The B. vogeli-positive dog also tested positive for antibodies against Ehrlichia canis and displayed severe disease. This study reports, for the first time, the presence of genetically heterogenic B. canis strains in dogs with clinical babesiosis in Romania. These findings provide a basis for future studies on the relationship between the genetic structure of the causative agents of canine babesiosis in Romania and the course of the disease.

Molecular Prevalence of Selected Tick-Borne Pathogens in Dermacentor reticulatus Collected in a Natural Park in Italy

Dermacentor reticulatus is one of the most important vectors of tick-borne pathogens (TBPs) in Europe causing diseases in animals and humans. A longitudinal study was planned, aimed to detect the molecular prevalence of tick-borne pathogens, i.e., Babesia spp. and the spotted fever group Rickettsiae, and its seasonal variation in D. reticulatus questing ticks to define the temporal infection risk. Ticks were collected monthly over a period of 15 months in a peri-urban park in Lombardy, Italy. DNA extraction and molecular analyses were performed. Statistical analysis was carried out. Out of 488, 53 (P = 10.9%) adult questing ticks were positive for Babesia DNA. A higher prevalence was revealed in male (32/241, P = 13.3%) than in female (21/247, P = 8.5%) ticks. Positive ticks were mostly collected in winter months (P = 13.3%) compared to early (P = 7.9) and late (P = 12.8) spring months. A similar percentage of positive ticks was evidenced in transects 1 and 3 (5.8% and 6.5%, respectively); instead, a significant higher prevalence was recorded in transect 2 (P = 16.0%). Obtained sequences confirmed a homology of 100% with B. canis sequences deposited in GenBank. No ticks tested positive for Rickettsia spp. DNA (0/488, P = 0%). The conspicuous circulation of B. canis infection in D. reticulatus adult questing ticks confirms their role in the epidemiology of canine babesiosis and requires preventive measures for dogs in this recreational area. Even if no tick was positive for the spotted fever group Rickettsia, its capacity as a vector of zoonotic pathogens should not be neglected.

Babesiosis in Southeastern, Central and Northeastern Europe: An Emerging and Re-Emerging Tick-Borne Disease of Humans and Animals

There is now considerable evidence that in Europe, babesiosis is an emerging infectious disease, with some of the causative species spreading as a consequence of the increasing range of their tick vector hosts. In this review, we summarize both the historic records and recent findings on the occurrence and incidence of babesiosis in 20 European countries located in southeastern Europe (Bosnia and Herzegovina, Croatia, and Serbia), central Europe (Austria, the Czech Republic, Germany, Hungary, Luxembourg, Poland, Slovakia, Slovenia, and Switzerland), and northern and northeastern Europe (Lithuania, Latvia, Estonia, Iceland, Denmark, Finland, Sweden, and Norway), identified in humans and selected species of domesticated animals (cats, dogs, horses, and cattle). Recorded cases of human babesiosis are still rare, but their number is expected to rise in the coming years. This is because of the widespread and longer seasonal activity of Ixodes ricinus as a result of climate change and because of the more extensive use of better molecular diagnostic methods. Bovine babesiosis has a re-emerging potential because of the likely loss of herd immunity, while canine babesiosis is rapidly expanding in central and northeastern Europe, its occurrence correlating with the rapid, successful expansion of the ornate dog tick (Dermacentor reticulatus) populations in Europe. Taken together, our analysis of the available reports shows clear evidence of an increasing annual incidence of babesiosis across Europe in both humans and animals that is changing in line with similar increases in the incidence of other tick-borne diseases. This situation is of major concern, and we recommend more extensive and frequent, standardized monitoring using a "One Health" approach.

The raccoon dog (Nyctereutes procyonoides) as a reservoir of zoonotic diseases in Denmark

Raccoon dogs have successfully invaded Europe, including Denmark. Raccoon dogs are potential vectors and reservoir hosts of several zoonotic pathogens and thus have the potential for posing a threat to both human and animal health. This study includes analysis of four zoonotic parasites, 16 tick-borne pathogens and two pathogen groups from 292 raccoon dogs collected from January 2018 to December 2018. The raccoon dogs were received as a part of the Danish national wildlife surveillance program and were hunted, found dead or road killed. The raccoon dogs were screened for Alaria alata and Echinococcus multilocularis eggs in faeces by microscopy and PCR, respectively, Trichinella spp. larvae in muscles by digestion, antibodies against Toxoplasma gondii by ELISA and screening of ticks for pathogens by fluidigm real-time PCR. All raccoon dogs tested negative for E. multilocularis and Trichinella spp., while 32.9% excreted A. alata eggs and 42.7% were T. gondii sero-positive. Five tick-borne pathogens were identified in ticks collected from 15 raccoon dogs, namely Anaplasma phagocytophilum (20.0%), Babesia venatorum (6.7%), Borrelia miyamotoi (6.7%), Neoehrlichia mikurensis (6.7%) and Rickettsia helvetica (60.0%). We identified raccoon dogs from Denmark as an important reservoir of T. gondii and A. alata infection to other hosts, including humans, while raccoon dogs appear as a negligible reservoir of E. multilocularis and Trichinella spp. infections. Our results suggest that raccoon dogs may be a reservoir of A. phagocytophilum.

Epidemiological Study of Canine Babesiosis and Hepatozoonosis in the South of Romania

PURPOSE

The aim of this study was to evaluate the prevalence and distribution of canine babesiosis and hepatozoonosis in the south of Romania as well as to assess if there are differences in the prevalence between regions in that area.

METHODS

Blood samples from 300 dogs from the south of Romania were screened for the presence of piroplasmids by PCR. Positive samples were further tested for the presence of Babesia spp. and Hepatozoon canis. Pearson's chi-square with Yates correction was used to determine if there is statistical difference between infected populations.

RESULTS

Fifty-four percent (163/300) of the dogs were positive for Hepatozoon spp. or piroplasmids. Forty-eight percent (143/300) were infected with H. canis and 9.6% (29/300) were positive to B. canis. Three percent (9/300) of the dogs were co-infected with Babesia spp. and H. canis. The prevalence of H. canis in the south-west of Romania was significantly higher (p < 0.05) than that of three other regions while the prevalence of Babesia spp. infection in the south-east of the country was significantly higher (p < 0.05) compared to its south-west.

CONCLUSIONS

A high rate of H. canis infection was found in the stray dog population surveyed with the highest infection rate detected in south-western Romania. Babesia canis was found to pose the highest threat in south-eastern Romania, whereas B. vogeli infection was focused in the same region of high H. canis infection in south-western Romania. These infections should be of important concern to veterinarians and dog owners in Romania.

Parasites in the changing world - Ten timely examples from the Nordic-Baltic region

The world is changing, and parasites adapt. The Nordic-Baltic region in northern Europe - including the Nordic countries Denmark, Finland, Iceland, Norway and Sweden, and the Baltic States Estonia, Latvia and Lithuania - is facing new parasitological challenges due to changes in populations of parasites and their hosts and the spread of new parasites to the region due to climate change. Some changes can also be ascribed to increased awareness and detection. In this paper, we review and discuss a convenience selection of ten timely examples of recent observations that exemplify trends and challenges from different fields of parasitology, with particular focus on climate change and potential changes in epidemiology of pathogens in northern Europe. The examples illustrate how addressing parasitological challenges often requires both intersectoral and international collaboration, and how using both historical baseline data and modern methodologies are needed.

Evidence of acute phase reaction in asymptomatic dogs naturally infected with Babesia canis

Asymptomatic outdoor dogs can be carriers of Babesia canis, but data describing the development of an acute phase response (APR) are not available. We hypothesised that these dogs have a moderate APR that could be detected by hematological and biochemical changes. Two groups of Babesia-exposed dogs were represented by nine B. canis PCR-positive and twenty B. canis PCR-negative, seroreactive dogs. The control group consisted of ten Babesia-naïve dogs. Serum amyloid A (SAA), paraoxonase-1 (PON-1), complete blood count, and biochemistry parameters were analysed by standard methodologies. Protein and lipoprotein fractions were separated using agarose gel electrophoresis (GE), and the dominant diameters of lipoproteins were assessed on gradient GE. Results were evaluated using non-parametric tests and the Receiver Operating Characteristic curve. SAA (median 39.0 μg/mL, range 2.2-48.8 μg/mL), total protein (median 74.7 g/L, range 57.1-98.3 g/L) and the dominant diameter of α-lipoproteins (median 13.31 nm, range 12.09-14.17 nm) in B. canis PCR-positive dogs were higher relative to dogs in the control group or dogs that were PCR-negative but seroreactive (p < 0.001 for both groups). Mild to moderate anemia (4/29), thrombocytopenia (7/29), and leukocyte counts that were close to the upper limit of the reference range were encountered in both Babesia-exposed groups. When compared to controls, Babesia-exposed dogs displayed decreased a PON-1 activity and protein GE pattern consistent with low-grade chronic inflammation (p < 0.001 for both groups). Dogs with detectable amounts of B. canis DNA in blood contain increased levels of SAA and total protein along with α-lipoproteins that display an increased diameter relative to those dogs with positive Babesia serology but undetectable levels of B. canis DNA in blood.

Babesiosis in Latvian domestic dogs, 2016-2019

Canine babesiosis is tick-borne infection that represents a major veterinary issue in Central and Eastern Europe with a tendency to expand northwards. The first published report in Latvia about autochthonous cases of babesiosis in domestic dogs with no travel history was in 2013, and to the best of our knowledge, no other studies on this issue have been published to date. The aim of this study was to analyze the occurrence and clinical manifestations of babesiosis in Latvian domestic dogs with a history of tick exposure to determine the extent to which Babesia sp. causes the disease and to map outbreaks in Latvia. From 2016 to 2019, blood samples from dogs were collected, and molecular testing was performed by nested PCR using Babesia sp.-specific primers. In total, 43 of 262 samples were Babesia canis-positive. A seasonal pattern was observed for the outbreaks, as the majority of B. canis-positive samples (98%) were submitted between April and June, and there was a single canine babesiosis case recorded in October. Nearly half of the cases (46.5%) were recorded in the capital, Riga, and other cases were recorded in southern and western parts of Latvia. Clinical signs were consistent with typical manifestations of acute canine babesiosis; most common hematological changes were thrombocytopenia (89%) and normocytic normochromic anemia (69%). Blood smear microscopy was positive for 79% of cases. Two B. canis genotypes were distinguished on the basis of two nucleotide (GA → AG) substitutions in the 18S rRNA gene at positions 610/611; however, no relationship between the genotypes and the severity of the disease was found. In conclusion, canine babesiosis has become an endemic disease in the southern and western regions of Latvia and is caused solely by the large babesia species B. canis. Awareness among veterinarians and pet owners regarding the disease should be increased.

A short-term and long-term relationship between occurrence of acute canine babesiosis and meteorological parameters in Belgrade, Serbia

Belgrade, the capital of the Republic of Serbia, is an endemic location for canine babesiosis caused by Babesia canis. This tick-borne disease occurs seasonally in regions with moderate continental climate. However, recent clinical data show that: 1) some cases of canine babesiosis have been recorded during the winter, and 2) canine babesiosis is spreading to the northern parts of Europe with a colder climate, which is a region previously free of this disease. Our study investigates the occurrence of canine babesiosis in different seasons over 2013-2016, and explores a short-term link between meteorological parameters and number of diagnosed cases of canine babesiosis in Belgrade. It also looks into possible long-term correlations that span one year before the onset of the disease. Based on 872 recorded cases over four years, our results show a bimodal seasonal distribution of canine babesiosis, with a pronounced peak in the spring, and a less conspicuous one in the autumn. Throughout the year, even over the coldest and warmest periods, there is a broad range of temperatures and relative humidities when the disease is recorded. Over one year prior to the spring and autumn onset of the disease, we found a noticeable impact of temperature and relative humidity, and to a lesser extent, of atmospheric pressure and cloud cover, on the number of diagnosed cases. These findings imply short-term and long-term relationships between occurrence of acute canine babesiosis and certain meteorological parameters, and they open further questions that need to be investigated in order to understand the epidemiology of this disease.

A large-scale screening for the taiga tick, Ixodes persulcatus, and the meadow tick, Dermacentor reticulatus, in southern Scandinavia, 2016

The taiga tick, Ixodes persulcatus, has previously been limited to eastern Europe and northern Asia, but recently its range has expanded to Finland and northern Sweden. The species is of medical importance, as it, along with a string of other pathogens, may carry the Siberian and Far Eastern subtypes of tick-borne encephalitis virus. These subtypes appear to cause more severe disease, with higher fatality rates than the central European subtype. Until recently, the meadow tick, Dermacentor reticulatus, has been absent from Scandinavia, but has now been detected in Denmark, Norway and Sweden. Dermacentor reticulatus carries, along with other pathogens, Babesia canis and Rickettsia raoultii. Babesia canis causes severe and often fatal canine babesiosis, and R. raoultii may cause disease in humans. We collected 600 tick nymphs from each of 50 randomly selected sites in Denmark, southern Norway and south-eastern Sweden in August–September 2016. We tested pools of 10 nymphs in a Fluidigm real time PCR chip to screen for I. persulcatus and D. reticulatus, as well as tick-borne pathogens. Of all the 30,000 nymphs tested, none were I. persulcatus or D. reticulatus. Our results suggest that I. persulcatus is still limited to the northern parts of Sweden, and have not expanded into southern parts of Scandinavia. According to literature reports and supported by our screening results, D. reticulatus may yet only be an occasional guest in Scandinavia without established populations.

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

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

Canine Babesiosis: Where Do We Stand?

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

Variability of species of Babesia Starcovici, 1893 in three sympatric ticks (Ixodes ricinus, Dermacentor reticulatus and Haemaphysalis concinna) at the edge of Pannonia in the Czech Republic and Slovakia

The distribution, variability and host specificity of species of Babesia Starcovici, 1893 were studied in questing ticks collected on the northwestern edge of the Pannonian Basin in the south-easternmost part of the Czech Republic and in western Slovakia. The area is characterised by relatively natural floodplain habitats and the sympatric occurrence of three tick species possessing wide host spectra, namely Ixodes ricinus (Linnaeus), Dermacentor reticulatus (Fabricius) and Haemaphysalis concinna Koch. Analysis was carried out on 1,408 I. ricinus, 2,999 D. reticulatus and 150 H. concinna altogether, collected from 59 localities. We documented the presence of Babesia spp. not only in I. ricinus but also in H. concinna in the Czech Republic. Two isolates from I. ricinus were classified as B. venatorum Herwaldt, Cacciò, Gherlinzoni, Aspöck, Slemenda, Piccaluga, Martinelli, Edelhofer, Hollenstein, Poletti, Pampiglione, Löschenberger, Tura et Pieniazek, 2003 (formerly determined as Babesia sp. EU1), which is a zoonotic parasite and can cause human babesiosis. The rest of our amplicons were very similar to B. canis (Piana et Galli-Valerio, 1895), which is usually transmitted by D. reticulatus. Despite the huge amount of examined samples, all D. reticulatus ticks were Babesia-free. Due to this finding, we did not consider our obtained isolates to be B. canis, but other closely related species possessing a similar sequence of the studied portion of 18S rDNA. Although this genetic marker is most frequently used in PCR-based diagnostic methods of babesias, its low variability compromises its reliability in studies based only on this marker.

Vector-borne parasitic infections in dogs in the Baltic and Nordic countries: A questionnaire study to veterinarians on canine babesiosis and infections with Dirofilaria immitis and Dirofilaria repens

Canine vector-borne diseases have been spreading northwards in Europe, and canine babesiosis and infections with Dirofilaria immitis (heartworm) and Dirofilaria repens have been diagnosed also in the Baltic and the Nordic countries. We used an online questionnaire to survey how large a proportion of veterinarians in the Baltic (Estonia, Latvia, and Lithuania) and the Nordic countries (Denmark, Finland, Iceland, Norway, and Sweden) saw canine babesiosis cases and dogs infected with D. immitis and D. repens in 2016. In addition, questions regarding transmission, zoonotic potential, clinical signs, and treatment of the infections were asked. The questionnaire was completed by 122 veterinarians. In 2016, 23% of them had seen at least one case of canine babesiosis, 15% at least one dog with D. immitis infection, and 9% at least one dog with D. repens infection. A veterinarian working in the Baltic countries had 12.2 times higher odds to have seen a canine babesiosis case and 9.3 times higher odds to have seen a dog with D. repens infection than a veterinarian working in the Nordic countries did. While 48% of the veterinarians knew that canine babesiosis is not considered a zoonosis, 26% knew that D. immitis is zoonotic and 34% knew that D. repens is zoonotic. The results suggested that autochthonous cases of the three vector-borne parasitic infections were seen by veterinarians in the Baltic countries, whereas most cases seen by veterinarians in the Nordic countries appeared to be imported. A substantial proportion of the veterinarians did not know whether the parasites are zoonotic.

An ELISA for the early diagnosis of acute canine babesiosis detecting circulating antigen of large Babesia spp

Babesia canis is the predominant Babesia species in dogs in Europe and is responsible for a severe and fatal disease. An increase in global pet tourism and a widening of the geographic distribution of the tick vector has led to the emergence of infections in areas where previously only imported cases have been reported. Due to the potential for rapid and serious disease progression, direct parasite detection by stained blood smears and light microscopy or DNA-based methods have traditionally been used for the diagnosis of acute infections. This study describes the production of a murine monoclonal antibody ('mAb BcFIII 7/1/2') that reacts to a 65kDa corpuscular epitope present in B. canis-infected erythrocytes and can be used in an ELISA to detect circulating Babesia antigen during acute infections. The sensitivity of the ELISA was 100% (95%CI: 84.5-100) as determined using blood lysate samples from 27 dogs with acute B. canis infections. Sensitivity was reduced to 53.8% in 13 patent Babesia vogeli infections (95%CI: 26.1-79.6) based on the current test design using convalescent serum from a B. canis-infected dog. The specificity was determined to be 86.4% (95%CI: 64-96.4) using 22 samples from healthy canine blood donors. In the course of acute B. canis infections, the ELISA showed a positive result at the same time as a positive PCR result was recorded. This was 24-48h before parasites could be detected by light microscopy. Convalescent samples collected from 6 B. canis-infected dogs at least 14days post treatment resulted in negative ELISA reactions. The hyper-acute to acute phase of a B. canis infection represents an emergency situation with high mortality. To increase the chances of survival, a fast and accurate diagnosis and immediate treatment is required. The current study demonstrates the opportunity of an early and specific detection of acute infections by an AgELISA that is potentially translatable to a rapid diagnostic test design.

Molecular detection of vector-borne pathogens in dogs and cats from Qatar

Background

Vector-borne diseases (VBDs) have been increasingly reported in dogs and cats worldwide. However, no data are currently available regarding canine and feline VBDs in Qatar and limited information is available from other Persian Gulf countries.

Methods

Blood samples from 98 client-owned animals (i.e. 64 dogs and 34 cats) living in Doha (Qatar) were collected and the presence of genomic DNA of Anaplasma spp., Babesia spp., Dirofilaria spp., Ehrlichia spp., Hepatozoon spp., Mycoplasma spp. and Rickettsia spp. was assessed by polymerase chain reaction (PCR), real time-PCR (rt-PCR) and sequence analysis.

Results

Of the 64 dogs, 12 (18.8%) were infected with at least one pathogen (i.e. 7.8% with Mycoplasma spp., 4.7% with Babesia vogeli, 3.1% with Ehrlichia canis, and 1.6% with Anaplasma platys, Babesia gibsoni and Hepatozoon canis, each). One of the 12 dogs was co-infected with B. vogeli and E. canis. Of the 34 cats, seven (20.6%) animals were infected with at least one pathogen (i.e. 5.9% were positive for Mycoplasma spp., and 2.9% for Babesia felis, B. vogeli, E. canis, “Candidatus Mycoplasma haemominutum” and Mycoplasma haemofelis, each). No dogs or cats were positive for Dirofilaria spp. or Rickettsia spp.

Conclusions

Although the sample sizes of dogs and cats herein analysed was moderately small, data from this study report the occurrence of A. platys, B. vogeli, B. gibsoni, E. canis, H. canis and Mycoplasma spp. in domestic dogs and of B. felis, B. vogeli, “Candidatus M. haemominutum”, E. canis and M. haemofelis in domestic cats from Qatar. Further investigations along with prophylactic measures are strongly recommended in order to reduce the risk of dogs and cats acquiring VBDs in Qatar.

Emergence of Babesia canis in southern England

Background

The United Kingdom is considered free of autochthonous transmission of canine babesiosis although cases are reported in dogs associated with recent travel abroad. During the winter months of 2015/16, a cluster of cases of disease in dogs with signs suggestive of canine babesiosis were reported in Harlow, Essex.

Methods

Babesia species were detected in dog blood samples by Giemsa staining of blood smears and by pan-piroplasm PCRs. Babesia species were also detected in extracts of tick DNA using pan-piroplasm PCRs. DNA sequencing and phylogenetic analysis was used to confirm the species of Babesia present in dog blood and tick samples. Tick species were identified by PCR-sequencing based on amplification of the cytochrome c oxidase subunit one (cox1) gene. Dermacentor reticulatus ticks were sampled from field sites in England and Wales.

Results

Blood smear analysis on samples taken from some of the affected dogs confirmed the presence of a large Babesia species within erythrocytes. A tick recovered from one of these cases was identified as Dermacentor reticulatus, a species with a limited distribution in England and Wales, but a known vector of canine babesiosis in continental Europe. Babesia canis was subsequently identified in blood samples obtained from three clinical cases (all dogs) within the area and from ticks associated with these dogs. A field survey detected 17 adult D. reticulatus ticks from one area visited by the affected dogs. Fourteen of these ticks were shown to be positive for the B. canis parasite, implicating them as a potential source for babesiosis in Harlow. In order to assess whether the parasite is present in more than one tick population, D. reticulatus ticks from across England and Wales were screened for the presence of Babesia species. In addition to the Harlow site, a further five locations where D. reticulatus is present were screened for Babesia species. Babesia was not detected from most sites tested but one tick from a single location in Wales was positive for B. canis.

Conclusions

Infection with B. canis was confirmed in a number of dogs in Harlow, Essex, with no history of travel outside of the country. The same pathogen was identified in field-caught D. reticulatus ticks in the same area and is considered the likely source of infection. This highlights the need for vigilance by veterinary surgeons for future outbreaks of tick-borne disease in dogs.

Dermacentor reticulatus: a vector on the rise

Dermacentor reticulatus is a hard tick species with extraordinary biological features. It has a high reproduction rate, a rapid developmental cycle, and is also able to overcome years of unfavourable conditions. Dermacentor reticulatus can survive under water for several months and is cold-hardy even compared to other tick species. It has a wide host range: over 60 different wild and domesticated hosts are known for the three active developmental stages. Its high adaptiveness gives an edge to this tick species as shown by new data on the emergence and establishment of D. reticulatus populations throughout Europe. The tick has been the research focus of a growing number of scientists, physicians and veterinarians. Within the Web of Science database, more than a fifth of the over 700 items published on this species between 1897 and 2015 appeared in the last three years (2013–2015). Here we attempt to synthesize current knowledge on the systematics, ecology, geographical distribution and recent spread of the species and to highlight the great spectrum of possible veterinary and public health threats it poses. Canine babesiosis caused by Babesia canis is a severe leading canine vector-borne disease in many endemic areas. Although less frequently than Ixodes ricinus, D. reticulatus adults bite humans and transmit several Rickettsia spp., Omsk haemorrhagic fever virus or Tick-borne encephalitis virus. We have not solely collected and reviewed the latest and fundamental scientific papers available in primary databases but also widened our scope to books, theses, conference papers and specialists colleagues’ experience where needed. Besides the dominant literature available in English, we also tried to access scientific literature in German, Russian and eastern European languages as well. We hope to inspire future research projects that are necessary to understand the basic life-cycle and ecology of this vector in order to understand and prevent disease threats. We conclude that although great strides have been made in our knowledge of the eco-epidemiology of this species, several gaps still need to be filled with basic research, targeting possible reservoir and vector roles and the key factors resulting in the observed geographical spread of D. reticulatus.

Fatal Babesia canis canis infection in a splenectomized Estonian dog

A previously splenectomized dog from Estonia was presented with a sudden lack of appetite and discoloration of the urine. Despite supportive therapy, its condition deteriorated dramatically during 1 day. Severe thrombocytopenia and high numbers of protozoan hemoparasites were evident in blood smears, and the hematocrit dropped from 46 to 33 %. The dog was euthanized before specific antibabesial treatment was initiated. Blood samples from the dog and from two other dogs in the same household tested positive for Babesia using molecular methods, and the sequences of partial 18S rRNA gene confirmed the causative species as Babesia canis canis. The risk of severe, rapidly progressing babesiosis in splenectomized dogs merits awareness.

Novel foci of Dermacentor reticulatus ticks infected with Babesia canis and Babesia caballi in the Netherlands and in Belgium

Background

Autochthonous populations of Dermacentor reticulatus ticks in the Netherlands were discovered after fatal cases of babesiosis occurred in resident dogs in 2004. The presence of D. reticulatus in the Netherlands has also linked with the emergence of piroplasmosis in the resident horse population. The aim of this study was to put together results of continued surveillance of field sites and hosts for this tick in the Netherlands and also in Belgium and determine their infection status for Babesia and Theileria species.

Methods

Ticks were collected from the vegetation at 11 locations between 2011 and 2013. D. reticulatus ticks were also collected from different hosts between 2007 and 2013. Ticks were screened by PCR and reverse line blot (RLB).

Results

A total of 1368 D. reticulatus ticks were collected from 4 previously known field locations and from 5 new locations in the Netherlands and from 2 sites in Belgium (one old and one new location). A total of 855 ticks collected from 8 locations in the Netherlands and 2 locations in Belgium were tested. Fourteen ticks (1,64%) collected at 4 field locations (Dintelse Gorzen, Rozenburg, Slikken van de Heen and St. Philipsland) were positive for Babesia canis, whereas two ticks were positive for Babesia caballi, one tick in the Dintelse Gorzen in the Netherlands and one tick was found positive in De Panne in Belgium.

A further 1092 D. reticulatus ticks were collected between 2007 and 2013 from 40 dogs (132 ticks), two ticks from two humans, 51 ticks from 15 horses, two ticks from two cats, one tick from a roe deer, whereas most ticks (904) were collected from cattle (n = 25). Ticks were found throughout the year on dogs in nearly all provinces of the Netherlands. None of the ticks collected from these hosts were infected.

Conclusions

D. reticulatus is continuing its spread into novel areas. The finding that some autochthonous ticks are infected with B. canis and B. caballi poses a threat to the resident dog and horse population and justifies year-round tick control measures.

Detection and molecular characterization of canine babesiosis causative agent Babesia canis in the naturally infected dog in Lithuania

Canine babesiosis caused by Babesia canis is an emerging infectious disease in Europe. Although previously uncommon, canine babesiosis has become quite frequent in Lithuania during the past decade. In the last few years an increasing number of cases with a wide variety of clinical signs have been recorded throughout the country. In Lithuania the identification of the disease agent in veterinarian clinics is based on a microscopic analysis of size and morphology. To date, no data on the genetic characterization of Babesia species in dogs have been documented for Lithuania. A total of 123 blood samples from dogs showing clinical signs of babesiosis on the basis of veterinary examination were tested for the presence of babesial parasites. Babesia isolated from dogs were detected and characterized by nested-PCR and sequence analysis of a fragment of the 18S rRNA gene. Babesia parasites were detected in blood smears of 94 dogs (76.4%). The molecular analysis revealed the presence of B. canis in 108 dogs (87.8%). Two genotypes of B. canis were distinguished on the basis on two nucleotide (GA → AG) substitutions observed in 18S rRNA gene sequences. The results of the present study provide knowledge of the distribution of B. canis genotypes in dogs in Lithuania, and show the necessity to use a molecular analysis for an accurate diagnosis of canine babesiosis.

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

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

It shouldn't happen to a dog … or a veterinarian: clinical paradigms for canine vector-borne diseases

Canine vector-borne diseases (CVBDs) comprise a diverse group of viral, bacterial, protozoal, and helminth pathogens, transmitted predominantly by ticks and fleas, and cause significant health problems for dogs worldwide. Growing numbers of reports indicate that CVBDs are emerging in regions where they previously did not exist and this, combined with pathogens that are inherently difficult to detect, is providing companion animal veterinarians with some significant diagnostic challenges. This review discusses six paradigms concerning the diagnosis, treatment, prevention, and zoonotic implications of CVBDs from a veterinary clinical perspective.

Transport of ixodid ticks and tick-borne pathogens by migratory birds

Birds, particularly passerines, can be parasitized by Ixodid ticks, which may be infected with tick-borne pathogens, like Borrelia spp., Babesia spp., Anaplasma, Rickettsia/Coxiella, and tick-borne encephalitis virus. The prevalence of ticks on birds varies over years, season, locality and different bird species. The prevalence of ticks on different species depends mainly on the degree of feeding on the ground. In Europe, the Turdus spp., especially the blackbird, Turdus merula, appears to be most important for harboring ticks. Birds can easily cross barriers, like fences, mountains, glaciers, desserts and oceans, which would stop mammals, and they can move much faster than the wingless hosts. Birds can potentially transport tick-borne pathogens by transporting infected ticks, by being infected with tick-borne pathogens and transmit the pathogens to the ticks, and possibly act as hosts for transfer of pathogens between ticks through co-feeding. Knowledge of the bird migration routes and of the spatial distribution of tick species and tick-borne pathogens is crucial for understanding the possible impact of birds as spreaders of ticks and tick-borne pathogens. Successful colonization of new tick species or introduction of new tick-borne pathogens will depend on suitable climate, vegetation and hosts. Although it has never been demonstrated that a new tick species, or a new tick pathogen, actually has been established in a new locality after being seeded there by birds, evidence strongly suggests that this could occur.

Prevalence of Babesia and Anaplasma in ticks infesting dogs in Great Britain

Ticks are important vectors of disease in companion animals and transmit an extensive range of viral, bacterial and protozoan pathogens to dogs and cats. They may also be vectors of zoonotic pathogens which affect the health of in-contact owners. In recent years, babesiosis, and anaplasmosis have all shown signs of increased prevalence and distribution in various parts of Europe. Here, the prevalence of Anaplasma spp. and Babesia spp. pathogens in Ixodes ticks, collected from dogs in the UK in 2009, were evaluated using PCR and sequence analysis of the 16S rDNA or 18S rDNA regions respectively. Species identification was performed by alignment with existing sequences in GenBank. After sequencing, 5 out of 677 tick samples (0.74%) contained rDNA which shared 97-100%% sequence homology with Anaplasma phagocytophilum. Of these, three samples came from Ixodes ricinus and two from Ixodes hexagonus. Sixteen out of 742 ticks (2.4%) were positive for Babesia and of these 11 showed 97-100% homology with B. gibsoni. All of these 11 samples were derived from I. ricinus. One sample, again from I. ricinus, showed 99% homology for B. divergens. Four of the Babesia spp sequences were of the "venatorum" or EU1 type, three of which came from I. ricinus and one from an Ixodes canisuga. This strain has been associated with severe human cases of babeisiosis. A further 246 positive results, which appeared to show the presence of Anaplasma following PCR, were shown by sequence analysis to be derived from the bacterium Candidatus "Midichloria mitochondrii", which to date has been assumed to be non-pathogenic. The results are of interest because the presence of B. gibsoni in the UK further confirms the worldwide distribution of this piroplasm and supports the inference that I. ricinus may act as a vector for Babesia of the gibsoni-complex.

Tick-borne infections in dogs-an emerging infectious threat

Many viral, bacterial and parasitic pathogens have been associated with tick transmission, including several recently identified pathogens in both humans and domestic animals, especially dogs. The emergence in dogs of these tick-borne infections has a multi factorial origin. Better animal care, better diagnostic tools, and a broader distribution of the vectors in favorable habitats through population migrations including travel with owned pets, translocation or commercial trade of pet dogs, are some of the factors contributing to the emergence and recognition of these new pathogens. The present review focuses on the recent epidemiological studies which support the emergence or re-emergence of tick-borne pathogens in dogs around the world, as well as give some insight on newly recognized potentially tick-borne pathogens, such as Bartonella infections.

Questing Dermacentor reticulatus harbouring Babesia canis DNA associated with outbreaks of canine babesiosis in the Swiss Midlands

In 2011 and 2012, outbreaks of clinical canine babesiosis were observed in 2 areas of the Swiss Midlands that had no history of this disease so far. In one area, cases of canine babesiosis occurred over 2 consecutive tick seasons. The outbreaks involved 29 dogs, 4 of which died. All dogs were infected with large Babesia sp. as diagnosed in Giemsa-stained blood smears and/or PCR. These were identified as B. canis (formerly known as B. canis canis) by subsequent partial sequencing of the 18S rRNA gene of Babesia sp. Interestingly, the sequence indicated either a genotype with heterogeneity in the ssrRNA gene copies or double infection with different B. canis isolates. None of the dogs had a recent travel history, but one had frequently travelled to Hungary and had suffered twice from clinical babesiosis 18 and 24 months prior to the outbreak in autumn 2011. Retrospective sequencing of a stored blood DNA sample of this dog revealed B. canis, with an identical sequence to the Babesia involved in the outbreaks. For the first time in Switzerland, the partial 18S rRNA gene of B. canis could be amplified from DNA isolated from 19 out of 23 adult Dermacentor reticulatus ticks flagged in the same area. The sequence was identical to that found in the dogs. Furthermore, one affected dog carried a female D. reticulatus tick harbouring B. canis DNA. Our findings illustrate that, under favourable biogeographic and climatic conditions, the life-cycle of B. canis can relatively rapidly establish itself in previously non-endemic areas. Canine babesiosis should therefore always be a differential diagnosis when dogs with typical clinical signs are presented, regardless of known endemic areas.

Evidence for an increased distribution range of Dermacentor reticulatus in south-west Poland

The expansion of Dermacentor reticulatus to new geographical areas has been observed in several countries in Europe, including Poland and it's neighbors. In 2011 and 2012, a total of 148 host-seeking D. reticulatus ticks were collected after flagging the vegetation in Lower Silesia, south-western Poland. Tick monitoring was conducted in mixed and deciduous forest, on meadows, in river valleys and ecotones between forested and grassy areas. The ornate dog ticks were found in 10 out of 33 sites located in five districts: Legnica, Wroclaw, Środa Śląska, Lubin and Boleslawiec County. All sites where D. reticulatus ticks were found are located to the south-west of the Odra River. The greatest distance between these disconnected localities was approximately 90 km. It seems that at present the southern boundary of the range is Wroclaw district. This study indicates that D. reticulatus can be ranked as a typical element of the fauna in Lower Silesia in southwestern Poland.

Autochthonous canine babesiosis caused by Babesia canis canis in Latvia

This is the first report of confirmed canine babesiosis in Latvia supporting the observed geographical expansion of this disease. Between 2009 and 2011 three dogs which have not traveled outside of Latvia were diagnosed with babesiosis. Hematological analysis and serological tests for granulocytic anaplasmosis, ehrlichiosis and borreliosis were negative (Idexx SNAP 4Dx test). Peripheral blood erythrocytes of the three dogs contained large Babesia that were identified as Babesia canis canis by PCR. Sequences of partial 18S rRNA gene were 98-100% similar to the sequences of B. canis canis isolated from dogs in other European countries. We conclude that these are the first autochthonous canine babesiosis cases reported from Latvia.

Prevention of transmission of Babesia canis by Dermacentor reticulatus ticks to dogs treated with an imidacloprid/flumethrin collar

A group of 8 dogs was treated with an imidacloprid/flumethrin collar (Seresto(®)) 28 days prior to infestation with adult Dermacentor reticulatus ticks, infected with Babesia canis. The ability of the collar to prevent transmission of B. canis in the treated group was compared to an untreated control group. All 8 dogs in the untreated control group became infected with B. canis parasites, which were detected in blood smears as early as day 6 post tick-application. All control dogs developed clinical signs of babesiosis and were rescue-treated with imidocarb dipropionate. These dogs also developed specific B. canis antibodies as identified by serology (IFA test) and were confirmed PCR/RLB positive. None of the 8 dogs treated with the imidacloprid/flumethrin collar became infected with B. canis, which was confirmed by the absence of specific B. canis antibodies and babesial DNA as confirmed by PCR/RLB. The collar caused 96.02% of the ticks to die within 48h post challenge and this increased to 100% within 4 days. Although a high percentage of 44% of the Dermacentor ticks were infected with B. canis, they were unable to transmit the infection to the treated group. Hence, the imidacloprid/flumethrin collar effectively prevented transmission of B. canis 1 month after application onto the dogs.

Prevalence and diversity of Babesia spp. in questing Ixodes ricinus ticks from Norway

BACKGROUND

Ixodes ricinus ticks transmit Babesia species to vertebrate hosts. Using molecular tools we were able to detect the presence of this piroplasmid in its vector. The aims of this study were to investigate the prevalence and identity of Babesia species in questing ticks collected in various areas of Norway.

METHODS

DNA from questing l. ricinus ticks were examined with a realtime PCR for the presence of Babesia. Positive samples of tick DNA were identified to species using PCR, and sequence analysis.

RESULTS

From a total of 1908 questing l. ricinus ticks, 17 (0.9%) indicated the presence of Babesia spp. after realtime-PCR screening. Ixodes ricinus harbouring Babesia spp. was detected in 9 out of 22 localities. Further molecular analyses of DNA from these positive ticks indicate the presence of Babesia venatorum, B. divergens, B. capreoli and a currently undescribed Babesia in Norwegian ticks. The most prevalent was B. venatorum found in 71% of the positive ticks.

CONCLUSIONS

A total of 17 out of 1908 (0.9%) ticks were positive for Babesia. Our data confirm that there are several Babesia species in ticks in Norway. Babesia venatorum was the most prevalent. This species has a zoonotic potential and may cause human babesiosis following a tick bite.

Polymerase chain reaction confirmation of Babesia canis canis and Anaplasma phagocytophilum in dogs suspected of babesiosis in Slovakia

Canine babesiosis was considered an imported tick transmitted disease until the first case of autochthonous canine babesiosis in Slovakia was described in 2002. Since then, the number of cases kept increasing every year. The causative agent of babesiosis in dogs is not yet characterized; therefore, the aim of our study was to determine the agent and the rate of infection in the vector tick D. reticulatus in Slovakia. Babesia canis canis was detected in 80 out of 87 blood samples from dogs with clinical manifestations of babesiosis. Six dogs suspected of babesiosis tested positive for presence of Anaplasma phagocytophilum, and one mixed infection of B. c. canis and A. phagocytophilum was detected. B. c. canis was detected in 35.6% questing adults of D. reticulatus. The obtained sequences from blood samples showed 99.7% and from D. reticulatus, 99.4% similarity with the B. c. canis (AY072926) from dogs infected in Croatia. In our study, we characterized the agent of canine babesiosis from blood samples of naturally infected dogs and D. reticulatus, the vector tick. Further, the presence of A. phagocytophilum, bacterium responsible for the canine granulocytic anaplasmosis, was recorded in dogs for the first time in Slovakia.

Transport of Babesia venatorum-infected Ixodes ricinus to Norway by northward migrating passerine birds

Background

Bovine babesiosis is regarded as a limited health problem for Norwegian cows, and the incidence has decreased markedly since the 1930s. Rare cases of babesiosis in splenectomised humans from infection with Babesia divergens and B.venatorum have been described. The objective of this study was to determine whether birds can introduce Babesia-infected ticks. There are between 30 and 85 million passerine birds that migrate to Norway every spring.

Methods

Passerine birds were examined for ticks at four bird observatories along the southern Norwegian coast during the spring migrations of 2003, 2004 and 2005. The presence of Babesia was detected in the nymphs of Ixodes ricinus by real-time PCR. Positive samples were confirmed using PCR, cloning and phylogenetic analyses.

Results

Of 512 ticks examined, real-time PCR revealed five to be positive (1.0%). Of these, four generated products that indicated the presence of Babesia spp.; each of these were confirmed to be from Babesia venatorum (EU1). Two of the four B. venatorum-positive ticks were caught from birds having an eastern migratory route (P< 0.001).

Conclusions

Birds transport millions of ticks across the North Sea, the Skagerrak and the Kattegat every year. Thus, even with the low prevalence of Babesia-infected ticks, a substantial number of infected ticks will be transported into Norway each year. Therefore, there is a continuous risk for introduction of new Babesia spp. into areas where I. ricinus can survive.

Canine vector-borne disease in travelled dogs in Germany--a retrospective evaluation of laboratory data from the years 2004-2008

When importing dogs from various Mediterranean countries into Western Europe canine vector-borne infections are often considered as a major issue. Several diseases including babesiosis, leishmaniosis, hepatozoonosis, canine heartworm disease or ehrlichiosis can potentially be endemic in this region and pose a potential health risk for travelling dogs. Information on such infections in travelled dogs is scarce and therefore this study has been undertaken to examine the frequency of vector-borne infections in travelled dogs from the years 2004-2008. A total of 997 samples were screened by direct and/or indirect methods. Total seroprevalence was 7.5% with individual seroprevalence for the 3 species Leishmania spp., Ehrlichia canis and Babesia canis spp. ranging from 3.1 to 4.9%. Total detection rate for pathogens by direct methods was 3.5%. Nineteen Giemsa-stained blood smears were positive for large Babesia. None of the samples screened for microfilariae by Knott's test or for Dirofilaria immitis antigen by DiroChek(®) were positive. Using PCR methods Leishmania-DNA was detected in 1/42 samples but none of 59 animals screened for E. canis-DNA was positive. The prevalence values as established by indirect and direct pathogen detection are considered as rather low.

Babesiosis in dogs and cats--expanding parasitological and clinical spectra

Canine babesiosis caused by different Babesia species is a protozoal tick-borne disease with worldwide distribution and global significance. Historically, Babesia infection in dogs was identified based on the morphologic appearance of the parasite in the erythrocyte. All large forms of Babesia were designated Babesia canis, whereas all small forms of Babesia were considered to be Babesia gibsoni. However, the development of molecular methods has demonstrated that other Babesia species such as Babesia conradae, Babesia microti like piroplasm, Theileria spp. and a yet unnamed large form Babesia spp. infect dogs and cause distinct diseases. Babesia rossi, B. canis and Babesia vogeli previously considered as subspecies are identical morphologically but differ in the severity of clinical manifestations which they induce, their tick vectors, genetic characteristics, and geographic distributions, and are therefore currently considered separate species. The geographic distribution of the causative agent and thus the occurrence of babesiosis are largely dependent on the habitat of relevant tick vector species, with the exception of B. gibsoni where evidence for dog to dog transmission indicates that infection can be transmitted among fighting dog breeds independently of the limitations of vector tick infestation. Knowledge of the prevalence and clinicopathological aspects of Babesia species infecting dogs around the world is of epidemiologic and medical interest. Babesiosis in domestic cats is less common and has mostly been reported from South Africa where infection is mainly due to Babesia felis, a small Babesia that causes anemia and icterus. In addition, Babesia cati was reported from India and sporadic cases of B. canis infection in domestic cats have been reported in Europe, B. canis presentii in Israel and B. vogeli in Thailand. Babesiosis caused by large Babesia spp. is commonly treated with imidocarb dipropionate with good clinical response while small Babesia spp. are more resistant to anti-babesial therapy. Clinical and parasitological cure are often not achieved in the treatment of small Babesia species infections and clinical relapses are frequent. The spectrum of Babesia pathogens that infect dogs and cats is gradually being elucidated with the aid of molecular techniques and meticulous clinical investigation. Accurate detection and species recognition are important for the selection of the correct therapy and prediction of the course of disease.

Why is Southern African canine babesiosis so virulent? An evolutionary perspective

Canine babesiosis is a common, highly virulent disease in Southern Africa with even pups and juveniles being severely affected. This contrasts with bovine babesiosis, for example, where host, parasite and vector co-evolved and young animals develop immunity after infection without showing clinical signs. Babesia rossi, the main causative organism of canine babesiosis in sub-Saharan Africa, was first described from a side-striped jackal (Canis adustus) in Kenya. Although data are meagre, there is evidence that indigenous African canids, such as jackals and wild dogs (Lycaon pictus), can harbour the parasite without showing untoward effects. Dogs are not indigenous to Africa. The vast majority of dogs presented at veterinary facilities in South Africa represent recently introduced European, Asian or American breeds. The contention is that B. rossi is a new challenge to which these dogs have not adapted. With intensive treatment of clinical cases, natural selection is effectively negated and the status quo will probably be maintained indefinitely. It is postulated that Babesia vogeli, which frequently results in unapparent infections or mild manifestations in dogs, represents or is closely related to the ancestral form of the canine parasite, possibly originating from wolves (Canis lupus).

West-to-east differences of Babesia canis canis prevalence in Dermacentor reticulatus ticks in Slovakia

Babesia canis canis is the most frequent causative agent of canine babesiosis in Central Europe, frequently causing severe disease. Recently, many new endemic foci of this disease have been reported from European countries. Growing incidence of canine babesiosis was recorded also in Slovakia during the last decade, from first cases in eastern Slovakia ten years ago to recent cases all over the south of the country. We have used nested PCR-RFLP method to study prevalence of B. c. canis in its natural tick vector Dermacentor reticulatus, collected at three geographically isolated lowland areas of southern Slovakia situated in the southeast, southwest, and west of Slovakia, respectively. The highest prevalence of B. c. canis was observed in D. reticulatus from eastern Slovakia (14.7%; n=327), whereas the prevalence in southwest was significantly lower (2.3%; n=1205). Notably, all 874 D. reticulatus ticks collected at Záhorská nížina lowland (W Slovakia) were B. c. canis-negative. Recorded differences in Babesia prevalence concurs well with the shift in incidence of clinical cases of canine babesiosis as observed by vet practitioners. Presented results revealed that eastern Slovakia represents an area of high risk of B. c. canis infection, whereas western areas of the country still remain Babesia canis-free.