Observational Study on Cryptosporidiosis in an Equine Perinatology Unit

The present study aimed to describe clinical signs of cryptosporidiosis in neonatal foals hospitalized in an Equine Perinatology Unit and to compare the clinical signs between Cryptosporidium parvum and Cryptosporidium horse genotype infection. The study was divided into two parts. In the retrospective study, nine foals infected by C. parvum were considered. In the prospective study, 70 foals, less than 15 days old, were prospectively included. Historical and clinical data were recorded, and in the prospective study, multiple fecal samples were collected. C. parvum (n = 13) and Cryptosporidium horse genotype (n = 7) were isolated. In four foals, there was a mixed infection with both the Cryptosporidium. Diarrhea, when present, showed similar duration and characteristics. Sixteen foals showed decreased abdominal sounds and colic pain before evidence of diarrhea. Nineteen foals had hyperthermia at least once. Although survival rates were similar between C. parvum (77%), C. horse genotype (100%), and cryptosporidial mixed infection (100%), foals affected by C. parvum presented anorexia (P <.0031) and received specific therapy (P <.014) more frequently than the others. Recorded data strengthen the thought that C. parvum infection is more severe in foals, suggesting that they would have developed host adaptations in response to the C. horse genotype or that C. parvum is a more pathogenic strain. Because healthy and asymptomatic foals can shed oocysts of Cryptosporidium spp., students and staff should always wear the personal protective equipment to avoid zoonotic infection.