Babesia gibsoni is increasingly recognized globally as a cause of canine tick-borne anemic disease; however, only a few clinical reports of naturally acquired infection are available. In this systematic study of dogs presenting with B. gibsoni infection, clinical and laboratory data were collected for dogs with PCR-confirmed B. gibsoni infection admitted to the National Taiwan University Veterinary Teaching Hospital (NTUVH) from January 2014 through December 2015. Of the 60 dogs recruited, 20 (33.3%) had concurrent disease and 40 (66.7%) had only B. gibsoni infection. The severity of anemia in B. gibsoni infected dogs with concurrent or without concurrent infection was not significantly different. The most commonly observed hematological abnormalities were anemia (49/60, 81.7%) and thrombocytopenia (37/60, 61.7%). Of 49 dogs, 24 (49%) had severe to very severe anemia (PCV < 20%). The main biochemical abnormalities included hyperglobulinemia (28/53, 52.8%), hyperbilirubinemia (10/28, 35.7%) and elevated hepatic enzyme activity (7/48, 14.6%). In addition, 2 of the 60 the client-owned dogs and 5 of the 33 B. gibsoni-positive stray dogs were detected as having a naturally atovaquone-resistant strain, using the SimpleProbe® assay. The study results provide a useful clinical presentation of B. gibsoni infection and raise the issue of the naturally atovaquone-resistant strain currently existing in Taiwan.

Babesia gibsoni (B. gibsoni) infection was sporadically described in Europe. In Italy, in particular, it was detected by PCR analysis only in one dog with unclear source of infection, while it has never been found in molecular studies involving more subjects. The aim of this retrospective, cross-sectional study was to determine the presence and the proportion of B. gibsoni infected dogs in a convenient Italian canine population. Babesia spp PCR analysis reports of canine blood samples collected from January 2016 to December 2019 were selected from the San Marco veterinary laboratory database and evaluated. Piroplasms PCR analysis was performed on 18S rRNA gene and positive samples were sequenced. Available data about signalment, living area and season of diagnosis were evaluated and statistically analyzed. The studied canine population had a median age of 62 months (interquartile range, IQR: 72.5) and was composed of male/female purebred and mixed breed dogs. Through sequencing, B. canis (26/40, 65%), B. vogeli (7/40, 17.5%), B. gibsoni (6/40, 15%) and B. vulpes (1/40, 2.5%) infections were reported. The proportion of B. gibsoni infected dogs in the described population was of 0.99%. The infection resulted more likely in male (6/6, 100%), purebred (5/6, 83.3%) dogs with median age of 40.5 months (IQR:32.3). In one case, the clinical signs and parasitemia appeared after a dogfight with a cohabitant infected dog. No other plausible sources of infection were detected. Likely, this could be considered the first autochthonous B. gibsoni infection case documented in Italy. Our results underline the need of considering B. gibsoni not only an exotic, random and rare cause of disease for dogs in Italy, but a possible emerging pathogen to take into account during diagnostic and epidemiological investigations, in symptomatic as well as in asymptomatic patients.

Babesia rossi infection has been reported to be associated with the high prevalence of pancreatitis in dogs. In this study, we retrospectively investigated whether pancreatitis occurs in B. gibsoni-infected dogs. The clinical manifestations, and hematological and serum biochemical examination results, including canine pancreatic-specific lipase (cPL), in 20 B. gibsoni-infected dogs were analyzed. The cPL concentration exceeded 400 µg/l in only 2 dogs, and they were suspected of having pancreatitis. Although the cPL concentration did not correlate with the degree of anemia or the level of parasitemia, it correlated with the band neutrophil count, platelet count, and blood urea nitrogen (BUN) level. Our study suggested that the prevalence of pancreatitis is lower among B. gibsoni-infected dogs than B. rossi-infected dogs.

Canine babesiosis is a serious disease among tick-borne haemoprotozoan diseases, globally. The present study was envisaged for carrying out thorough investigation of the disease among working dogs of organised kennels situated in different agro-climatic zones of India as comprehensive understanding of the disease from this country was pertinently lacking. During the study period of three years (2012-2014), 330 dogs suspected for babesiosis were examined for clinicopathology by their physical examination, haematological and biochemical parameters estimation, while the detection of apicomplexan parasites was confirmed by using various diagnostic techniques i.e. by conventional microscopy, by two different Babesia specific 18S rRNA based PCR protocols (conventional/simple PCR and nested PCR assays) followed by sequencing of obtained PCR amplicons for Babsesia spp. identification. Out of 330 clinical cases screened 5.15% (17/330), 9.09% (30/330) and 15.45% (51/330) were found to be positive in microscopic examination, simple- and nested- PCR assay, respectively. Comparative statistical analyses of these diagnostic assay results revealed that significant difference exists among the three diagnostic methodologies and thus it is recommended that the nested PCR technique be relied upon as a screening molecular assay and also for epidemiological studies of the disease in this country. Phylogenetic analysis based on 18S rRNA depicted the monophyletic nature and clonal expansion among all the B. gibsoni, under study. Sequencing results of PCR amplicons revealed that B. gibsoni has predominantly established itself over B. vogeli as former was incriminated in 47 cases while latter was confirmed in only four animals. Based on the clinical severity, these 51 affected animals were classified into three main groups\' of 17 animals each viz., apparently healthy-, simple or uncomplicated babesiosis- and atypical or complicated babesiosis- group. Haematological and biochemical profiling of these dogs confirmed the characteristics findings of infection by both the Babesia spp. It was observed that the infection by small form of Babesia (B. gibsoni) is posing a significant therapeutic challenge and chemosterilization by commonly prescribed anti-protozoal drugs was not achieved as clinical relapses were often observed. The clinical signs, sequence based confirmation and severity of the infection suggested that there is a positive selection of B. gibsoni (smaller form) over B. vogeli (larger form) in this country and raises serious concerns as prognosis in former is considered to be poor compared to latter. Thus, these findings have opened new paradigms for planning of pragmatic control strategies against this emerging canine health problem.