First evidence of Besnoitia bennetti infection (Protozoa: Apicomplexa) in donkeys (Equus asinus) in Belgium

Abstract

BackgroundBesnoitiosis is caused by different species of intracellular protozoan parasites belonging to the family Sarcocystidae and affecting multiple host species worldwide. Including B. besnoiti, ten species are described infecting animals. Among ungulates, Besnoitia bennetti infects horses, donkeys and zebras and was described in Africa and in the USA where donkey besnoitiosis is considered as an emerging disease.Case presentationA two-year-old male donkey was purchased in May 2016 in poor body condition (cachexia, alopetic areas and pruritus mainly on neck and head) by the present owner in Le Roeulx (Belgium) from a milk producing donkey farm in Frasnes-lez-Buissenal (Belgium). Shortly after its purchase and shearing, the donkey presented with crusts, hyperkeratosis (both flanks and neck) anorexia and cachexia. A treatment with phoxim was given with no improvement. A cutaneous biopsy of hyperkeratotic skin was performed in July. It showed a perivascular eosinophilic infiltrate with a large thick walled cyst located in the dermis containing numerous bradyzoites. This was highly suggestive of besnoitiosis. Several skin biopsy samples were obtained for qPCR analysis and confirmed the presence of Besnoitia spp. DNA. Further laboratory diagnosis tests were performed (western blot and rDNA sequencing) confirming Besnoitia bennetti aetiology for the male. For the female, the punch-biopsy, haematology and qPCR were negatives but the western blot showed the presence of antibodies directed to Besnoitia spp. Further clinical examination performed in August highlighted scleral pinhead sized cysts (pearl) in the right eye and between nares. Another ten-year-old female donkey purchased in France and sharing the same accommodation showed a good clinical condition, but a thorough clinical examination showed the presence of numerous cysts on the inner face of upper labial mucosa. A daily treatment based on sulfamethaxzole and trimethoprim (Emdotrim 60% Mix®, 30 mg/kg) was given orally and some improvement was noticed.ConclusionThis is the first evidence of Besnoitia bennetti infection (Protozoa: Apicomplexa) in donkeys (Equus asinus) in Belgium.Electronic supplementary materialThe online version of this article (10.1186/s13071-018-2993-3) contains supplementary material, which is available to authorized users.

First record of besnoitiosis caused by Besnoitia bennetti in donkeys from the UK

“…in donkeys, mules and horses [16]. Two cases of besnoitiosis in donkeys were reported in Belgium where B. bennetti infection was suspected based on clinical, histological, serological and molecular tools [5]. Recently, serological evidence for Besnoitia sp.…”

“…These limitations have driven the development of more efficient alternative methods to histopathology in order to provide accurate information about the etiological agent. These methods were designed to detect specific Besnoitia ribosomal DNA in tissue biopsies using PCR followed by DNA sequencing of the amplicon to identify the species [2,4,5] or measure the level of anti-Besnoitia spp. specific antibodies in the serum using serological assays such as ELISA, immunofluorescent and immunoblotting analysis [4][5][6][7][8][9].…”

“…These methods were designed to detect specific Besnoitia ribosomal DNA in tissue biopsies using PCR followed by DNA sequencing of the amplicon to identify the species [2,4,5] or measure the level of anti-Besnoitia spp. specific antibodies in the serum using serological assays such as ELISA, immunofluorescent and immunoblotting analysis [4][5][6][7][8][9]. Recently, a more specific genotyping method based on microsatellite markers has been developed to distinguish B. bennetti from the closely related B. besnoiti and B. tarandi, which cause besnoitiosis in cattle and reindeer, respectively [10].…”

“…Besnoitiosis in donkeys went from a rarely detected parasite to being reported in donkeys in many countries, including the USA [2,4,7], Spain, [8], Belgium [5], Italy [9] and Portugal [11]. This increase in the number of reports of B. bennetti infection in donkeys and other equids is probably attributed to the increasing awareness of the disease [12].…”

Skin disease in donkeys (Equus asinus): a retrospective study from four veterinary schools

“…It also is interesting to note that besnoitiosis, a disease caused by the protozoal organism Besnoitia bennetti , was diagnosed in only one case in our series (which was included in a prior report). This disease is presumably common in donkeys based upon the large number of cases reported in the literature, and both the disease and antibodies directed against the organism are more prevalent in donkeys than in horses …”