Autochthonous canine babesiosis in The Netherlands

Outbreaks of autochthonous babesiosis, caused by Babesia canis, occurred in The Netherlands in the spring and autumn of 2004 affecting 23 dogs. Nineteen animals recovered after treatment, whereas four dogs died. Adult Dermacentor reticulatus ticks collected from these dogs indicate that canine babesiosis could become endemic in The Netherlands.     

The prevalence of Babesia canis canis in marsh ticks (Dermacentor reticulatus) in the Saarland

An accumulation of autochthonous cases of canine babesiosis caused by Babesia canis has been registered in a small animal clinic in the Saarland since the beginning of 2006, some cases with fatal outcome. This study aims to contribute to the explanation of strong focal occurrence of infections with B. canis in this region.Therefore, patient owners who had presented their dogs in the years 2006 and 2007 because of babesiosis and who had claimed not having left the Saarland with their dogs at least six months before the outbreak of Babesiosis, were asked for their dog walking habits. Accordingly, a selection often tick collection sites of various landscape structures was made.Tick sampling by flagging the vegetation took place every month from March to December 2008. The collected ticks were identified morphologically. In eight of ten collecting sites a total of 397 adult Dermacentor reticulatus ticks were collected from March to December with the highest frequencies during the months of May, October and November. All collected specimens were examined by genus-specific conventional PCR for the presence of Babesia-DNA. In positive samples, the PCR-products were differentiated by sequencing. ten D. reticulatus (2.5%) ticks examined were found positive for DNA of B. canis canis originating from three out of eight collection sites. Consequently, an endemic distribution of D. reticulatus was confirmed and a natural     

Autochthonous cases of canine babesiosis in the canton Solothurn

Starting in November 2003 a series of five clinical cases of canine babesiosis was registered in the region of Oberg?sgen (canton Solothurn). All presented dogs showed increased body temperature, thrombocytopenia and hemoglobinuria, and none of the dogs had been abroad or visited endemic regions in the southern or western part of Switzerland so far. Babesia canis was detected in the blood smears of all five patients, but only three had detectable specific antibodies against this parasite. However, seroconversion was found in a second sample collected from the negative dogs at a later timepoint, confirming the diagnosis of canine babesiosis. The blood samples of two parasitized dogs were used for DNA-isolation and were tested with a Babesia-specific PCR, detecting the 18S rRNA-gene. Sequencing of the amplified products revealed a 100% identity with the sub-species B. canis canis. The ticks Rhipicephalus sanguineus and Dermacentor marginatus are potential vectors for B. canis. In the area where the infection with B. canis was suspected a total of 152 ticks was collected and characterized; one was a female R. sanguineus.Although babesia could not be detected in the latter tick and the final prooffor the complete life cycle is still lacking, it is very probable that B. canis has become autochthonous in the canton Solothurn.     

The prevention of transmission of Babesia canis canis by Dermacentor reticulatus ticks to dogs using a novel combination of fipronil, amitraz and (S)-methoprene

Four groups of seven dogs were treated topically with a novel combination of fipronil, amitraz and (S)-methoprene in a spot-on formulation (CERTIFECT?, Merial Limited, GA, USA) on 28, 21, 14 and 7 days prior to tick infestation, respectively and acaricidal efficacy and transmission blocking compared with an untreated control group (seven dogs). All dogs were infested with adult Dermacentor reticulatus ticks harbouring Babesia canis canis. Babesia canis canis was transmitted by D. reticulatus to all seven untreated control dogs, confirmed following demonstration of clinical signs, by the detection of B. canis parasites in thin blood smears and B. canis canis PCR-RLB DNA assay on blood and the development of B. canis canis antibody titres by 14-21 days after tick infestation. The majority of treated dogs remained sero-negative for 42 days after infestation. Therefore, the treatment of dogs with CERTIFECT applied up to 28 days prior to infestation with D. reticulatus harbouring B. canis canis, successfully prevented the development of clinical signs of canine babesiosis.     

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 ní?ina 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.     

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

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

Detection and molecular characterization of Babesia canis vogeli from naturally infected dogs and Rhipicephalus sanguineus ticks in Tunisia

Canine babesiosis, caused by intra-erythrocytic Babesia, is a tick-borne disease of worldwide importance. No information on canine babesiosis has been documented in Tunisia. Detection and analysis of Babesia species from naturally infected dogs and ticks recovered from dogs were attempted by reverse line blot hybridization and nucleotide sequence analysis based on 18S rRNA gene. Out of 180 blood samples collected from domestic dogs in 4 villages situated in different bioclimatic zones, 12 were positive for Babesia canis vogeli. In addition, a total of 160 Rhipicephalus sanguineus were analysed; only one male was infected by B. canis vogeli. This is the first report on the detection of DNA belonging to B. canis vogeli in domestic dogs and in R. sanguineus in Tunisia.     

Prevalence of Babesia canis, Borrelia afzelii, and Anaplasma phagocytophilum infection in hard ticks removed from dogs in Warsaw (central Poland)

The purposes of this study were to specify the occurrence and prevalence of Babesia canis, Borrelia burgdorferi sensu lato, and Anaplasma phagocytophilum in ticks removed from dogs in Warsaw, and to determine the Borrelia species occurring in Ixodes ricinus ticks. Among 590 collected ticks, 209 were identified as I. ricinus, and 381 as Dermacentor reticulatus. DNA of B. canis was detected in 11% of D. reticulatus ticks. We found that 6.2% of I. ricinus ticks harbored B. burgdorferi s.l. specific DNA and 2.9% harbored A. phagocytophilum DNA. In these samples sequencing of the detected Borrelia amplicon confirmed infection with Borrelia afzelii genospecies. New sequences were submitted to the GenBank database (accession no. EU152128, EU152127, EU152126). This work is the first detection of B. afzelii and A. phagocytophilum in ticks from Warsaw, and the first survey for the prevalence of B. canis, B. afzelii, and A. phagocytophilum in ticks in central Poland.     

Babesia canis canis in dogs from Hungary: detection by PCR and sequencing

Canine babesiosis in Hungary has always been a severe and frequent disease, attributed to infection with Babesia canis transmitted by Dermacentor reticulatus. Identification of the disease agent has been based merely on size and morphology of the intraerythrocytic parasites and no evidence has been found concerning the subspecies (genotype) of B. canis. Therefore, a molecular survey on natural Babesia infection of dogs in Hungary using PCR and sequence analysis was attempted to clarify the subspecies (genotype) and to obtain information on the occurrence of B. canis. A total of 44 blood samples from dogs showing clinical signs of babesiosis were collected. A piroplasm-specific PCR amplifying the partial 18S rRNA gene yielded an approximately 450 bp PCR product in 39 (88.6%) samples. Thirteen positive samples originated from Budapest and 26 from 21 other locations. Five PCR products were chosen randomly for sequencing. The partial 18S rDNA sequences were submitted to GenBank (accession numbers AY611729; AY611730; AY611731; AY611732 and AY611733). The sequences showed 100% homology to one another or differed by one nucleotide. BLAST search against GenBank revealed the highest similarity (99.8 or 100%) with Babesia canis canis. The implication of these data, for the further study and diagnosis of canine babesiosis is discussed.     

Imidocarb: A chemoprophylactic experiment with Babesia canis

Summary

Eight dogs, given imidocarb dipropionate subcutaneously at a dose of 6 mg/kg, were challenged with a sporozoite stabilate of a French strain of Babesia canis, prepared from infected Dermacentor reticulatus ticks, 2, 3, 4 or 5 weeks after treatment. Three control dogs were similarly infected but not preventively treated. One of the controls and one of the dogs treated 5 weeks prior to challenge died of babesiosis. Prepatent and incubation periods were similar in treated and control dogs, and all dogs showed important reductions in the packed cell volume. Relaps'es were commonly seen after recovery from the initial reaction. Although further work is needed before a final conclusion can be drawn to whether imidocarb is suitable as a chemoprophylactic against B. canis infection, it can be used as a curative drug.     

Three groups of Babesia canis distinguished and a proposal for nomenclature

Summary

Two stocks of large Babesiae from dogs originating in France, transmitted by Dermacentor reticulatus, two from North Africa, having Rhipicephalus sanguineus as vector, and one from South Africa, transmitted by Haemaphysalis leachi, were compared in cross‐immunity tests in dogs and in the indirect fluorescent antibody test (IFAT).

The French and North African stocks did not immunise against the South African one, while the North African stocks did not protect against a French one. The South African stock partially protected against a French one.

The three groups could be clearly distinguished in the IFAT These differences have practical implications for existing and future vaccines against canine babesiosis and for the serological diagnosis of atypical and chronic cases.

It is proposed to use a trinomial system of nomenclature for these groups: Babesia canis canis (Piana and Galli‐Valerio, 1895), Babesia canis vogeli Reichenow, 1937, and Babesia canis rossi (Nuttall, 1910), having Dermacentor, Rhipicephalus and Haemaphysalis ticks as their vectors respectively.     

Molecular and serological detection of Ehrlichia canis and Babesia vogeli in dogs in Colombia

Ehrlichiosis and babesiosis are tick-borne diseases, caused mainly by Ehrlichia canis and Babesia canis, respectively, with a worldwide occurrence in dogs, whose main vector is the brown-dog tick, Rhipicephalus sanguineus. The present work aimed to detect the presence of E. canis and Babesia sp. in 91 dog blood samples in Colombia, by molecular and serological techniques. We also performed sequence alignment to indicate the identity of the parasite species infecting these animals. The present work shows the first molecular detection of E. canis and B. vogeli in dogs from Colombia. Immunoglobulin-G (IgG) antibodies to E. canis and Babesia vogeli were found in 75 (82.4%) and 47 (51.6%) sampled dogs, respectively. Thirty-seven (40.6%) and 5 (5.5%) dogs were positive in PCR for E. canis and Babesia sp., respectively. After sequencing, amplicons showed 99% of identity with isolates of E. canis and B. vogeli. The phylogenetic trees based on 16S rRNA-Anaplasmataceae sequences and 18S rRNA-piroplasmid sequences supported the identity of the found E. canis and B. vogeli DNAs, respectively. The present work shows the first molecular detection of E. canis and B. vogeli in dogs in Colombia.     

Ixodes hexagonus is the main candidate as vector of Theileria annae in northwest Spain

Babesia canis and Babesia gibsoni have, until recently, been considered the only piroplasms that parasitise dogs. However, recent reports indicate that "small" Babesia infections in Spanish dogs are surprisingly frequent and molecular phylogenetic analysis indicates that the infecting agent is closely related to Babesia microti. Because the 18SrDNA sequence was not completely identical to that of B. microti, the new name "Theileria annae" was assigned to the canine agent. No information is available regarding the possible vector of the new piroplasm, T. annae. As part of an effort to identify the tick that may transmit T. annae in northwest Spain we asked veterinary surgeons practising in the region to collect and send to our laboratory ticks from dogs visiting their clinics. Seven hundred and twenty ticks collected from dogs of unknown clinical status during 1998 and 636 ticks collected between November 2001 and March 2002 from 38 dogs infected with T. annae and 131 uninfected dogs were identified. Results from the first study indicated that among the Ixodidae, Ixodes hexagonus clearly predominates over Ixodes ricinus (26.11% versus 6.67%). This observation was consistent with results of the second study, in which I. hexagonus was detected in all infected dogs and 71.8% of non-infected dogs and I. ricinus was not detected in either the infected or non-infected dogs. Results from the 2001-2002 study also indicate that the presence of Dermacentor reticulatus adult females is significantly less frequent among infected than non-infected dogs (OR=0.44; 95% CI: 0.21-0.92). On the other hand, I. hexagonus adult females and males are 6.75 and 4.24 times more likely to be detected among infected than non-infected dogs, respectively, with the association being, in both cases, statistically significant (95% CI: 1.97-23.12 and 1.92-9.36, respectively). I. hexagonus emerges as the main candidate as vector of T. annae because it feeds on dogs more frequently than other ticks and because B. microti is transmitted by Ixodes ticks, both in North America and Europe. In the absence of definitive confirmation of this hypothesis, our observations suggest that I. hexagonus might serve the same role as does Ixodes scapularis (=Ixodes dammini), the vector of B. microti in eastern North America.     

Ixodid tick species attaching to dogs in Hungary

A survey was carried out to investigate the occurrence of hard tick species (Acari: Ixodidae) infesting domestic dogs in Hungary. Forty veterinary clinics from a wide geographical area were asked to collect hard ticks from dogs and to complete a questionnaire. In total, 25 veterinary clinics submitted 900 ticks from 310 dogs. Intensity of infestation ranged from one to 78 per dog. The most preferred sites of tick attachment in decreasing order were head, neck and legs. The majority of ticks (91.7%) were adults, which were identified to species level, the others were nymphs. Six species were found: Dermacentor reticulatus (48.9%), Ixodes ricinus (43.2%), Ixodes canisuga (5.6%), Haemaphysalis concinna (2%) and there was one specimen of both Dermacentor marginatus and Ixodes hexagonus. Single species infestation with I. ricinus or D. reticulatus was found on 145 (46.8%) and 120 animals (38.7%), respectively. Mixed infestation caused by these two species was detected on 24 dogs (7.7%). I. canisuga and H. concinna were found on seven and five dogs, respectively. D. reticulatus and I. ricinus were collected almost throughout the year, except for a single month. The activity peaks were in spring and in autumn for both species. Based on clinical signs, canine babesiosis was diagnosed by the veterinarians in 66 (21.3%) tick infested dogs. These dogs were more frequently infested with D. reticulatus than the others. Our data contribute to the understanding of geographical and seasonal distribution of ixodid tick species infesting dogs in Hungary. The implication of these data, for the risk of canine tick borne diseases is discussed.     

Ectoparasites of dogs belonging to people in resource-poor communities in North West Province, South Africa

A total of 344 dogs belonging to people in resource-poor communities in North West Province, South Africa, was examined for ectoparasites, and all visible arthropods were collected from the left side of each dog. By doubling these numbers it was estimated that the dogs harboured 14,724 ixodid ticks, belonging to 6 species, 1,028 fleas, belonging to 2 species, and 26 lice. Haemaphysalis leachi accounted for 420 and Rhipicephalus sanguineus for 14,226 of the ticks. Pure infestations of H. leachi were present on 14 dogs and of R. sanguineus on 172 dogs. Small numbers of Amblyomma hebraeum, R. appendiciulatus, R. evertsi evertsi and R. simus were also collected. The predominance of R. sanguitneus accounts for the high prevalence of canine ehrlichiosis (Ehrlichia canis) within the survey region, compared to canine babesiosis (Babesia canis), which is transmitted by H. leachi, and is a much rarer disease.     

Spatial distribution of Dermacentor reticulatus and Ixodes ricinus in Hungary: evidence for change?

A survey was conducted to investigate the spatial distribution of Ixodes ricinus and Dermacentor reticulatus in Hungary and to compare these data with the results of a previous large-scale survey. In the survey conducted in the 1950s, D. reticulatus adults were detected in two isolated areas of two counties, and the presence of these ticks in the collection was explained by accidental introduction. In the present survey, D. reticulatus became the second most common species occurring in all 16 counties involved in the monitoring and showed high prevalence. The change in the spatial distribution of this tick species, the increase of incidence of Babesia canis infection in Hungary, and the increasing number of canine babesiosis case reports from other Central and Central Eastern European countries since the 1970s suggest an expansion of the geographic range of D. reticulatus and intensification of the transmission rate of B. canis and probably other D. reticulatus-borne diseases (e.g. tularemia and tick-borne lymphadenopathy) in the region. The spatial distribution of I. ricinus was roughly in line with the results of the earlier survey. I. ricinus was the most common tick species being present in all 16 counties with the highest prevalence. Nevertheless, the comparison of the data of the previous and current survey cannot be used for fine-scale analysis; thus, it cannot be dismissed that the spatial distribution of I. ricinus also changed during the past decades. The spatial distribution patterns of tick-borne encephalitis in Hungary and other Central Eastern European countries may indicate such a change.     

Efficacy of a single application of a 12.5% pyriprole topical solution against laboratory infestations with ticks (Ixodes ricinus, Dermacentor reticulatus, and Rhipicephalus sanguineus) on dogs

In three separate studies, the efficacy of a single treatment with a 12.5% pyriprole spot-on solution was investigated against induced infestation with Ixodes ricinus, Dermacentor reticulatus and Rhipicephalus sanguineus on dogs (both sexes; Beagles in Studies 1 and 2, mixed-breed in Study 3). For each tick species, one group of 8 dogs left untreated (Studies 1 and 2) or treated with a placebo solution (Study 3) was compared with another group treated once with the spot-on solution at a dose rate of at least 12.5mg/kg. The dogs were infested with 50 unfed adult ticks of the respective species at various time-points before and after treatment and the surviving attached and unattached ticks were recorded 48 h after re-infestation. For each tick species, efficacy was assessed for each time-point and cumulatively for the whole evaluation period. The dogs were submitted to general health observations and clinical assessments during the study. Efficacy against I. ricinus and R. sanguineus was 100% during the whole evaluation period of 30 days. For D. reticulatus cumulative efficacy for the 30 days after treatment was 98.9%. The product was well tolerated by all the animals.     

Dermacentor reticulatus (Fabricius, 1794)--distribution, biology and vector for Babesia canis in Germany

This work deals with occurrence, distribution as well as biology and vectorial capacity of the ornate dog tick (Dermacentor (D.) reticulatus). Until 30 years ago this tick has only been described in a few natural foci in southern Germany. Its distribution has however expanded in the course of the last years. With the exception of northern Germany it is now covering large areas of Germany. This is particularly the case in the Upper Rhine Valley, Saarland and the Mark Brandenburg. However, it is endemic in many other areas of Germany as well. The transformation of agricultural land into fallow land, an increase in host reservoirs and climatic changes are discussed as main contributors to this change. Little is known about the role of this species as a vector for virus, rickettsia, bacteria and protozoa as well as its medical and veterinary importance. D. reticulatus is a vector for Babesia canis canis. It is reported here about a case of autochthonous babesiosis in a dog from Berlin/Brandenburg.     

Efficacy of a novel combination of fipronil, amitraz and (S)-methoprene for treatment and control of tick species infesting dogs in Europe

Four studies were conducted to show the effectiveness of a novel combination of fipronil, amitraz and (S)-methoprene in a spot-on formulation (CERTIFECT?, Merial Limited, GA, USA) for the therapeutic and preventive control of Ixodid tick species affecting dogs in Europe: Ixodes ricinus, Dermacentor reticulatus and Rhipicephalus sanguineus. In each, untreated control dogs were compared to others treated with the novel combination. All dogs were infested with 50 adult, unfed ticks prior to treatment and at 7-day intervals after treatment. Ticks on all dogs were counted at 18, 24 and 48 h after treatment (therapeutic efficacy) or infestation (preventive efficacy). Therapeutic efficacy of fipronil, amitraz and (S)-methoprene was excellent as shown by significant (p<0.05) and greater than 97% and up to 100% reductions in the 48 h tick counts and significant (p<0.05) detachment/death of ticks evident at 18-24h after treatment for all three tick species. Preventive efficacy was demonstrated by significant (p<0.05) and greater than 93% and up to 100% reductions in tick counts at 48 h after repeat infestations out to 35 days after treatment for I. ricinus and out to 42 days after treatment for D. reticulatus and R. sanguineus. The time to substantial disruption of establishment of new tick infestations after treatment was less than 18-24h and was maintained for up to 28 days after treatment of I. ricinus and D. reticulatus infestations, and 4h to at most 18 h and maintained up to 35 days after treatment of R. sanguineus. Similar preventive efficacy profiles for each of the Ixodid species tested suggest that CERTIFECT kills all Ixodid species starting 4h after contact as demonstrated for R. sanguineus.