Experimental cryptosporidiosis in calves: clinical manifestations and pathological findings

Abstract

Twenty-two calves between one and 20 days old were infected orally or by contact with cryptosporidia. Calves were maintained as either specific pathogen free, colostrum fed or sucking and were inoculated with either a bacteria free or a contaminated cryptosporidium preparation. Enteritis was characterised by depression, anorexia and diarrhoea and cryptosporidium oocysts were excreted during the clinical course of the illness. In the initial stages of the disease, cryptosporidium infestation was found throughout the small intestine; in the later stage the large intestine was also affected. Villous atrophy and fusion was present at small intestinal sites infected with cryptosporidia and lactase levels were depressed. No lesions were seen in infected large intestinal mucosa. Although the incubation period was longest (five to seven days) in calves infected by contact, there were few differences in the clinical course of disease or the pathological findings between any of the infected calves.

Prevalence of Cryptosporidium Infection Among Domestic Cats in the Tokyo Metropolitan District, Japan

“…Furthermore, Iseki (10) Cryptosporidium may be a common cause of diarrhea among infants and children, particularly in developing countries (11)(12)(13)(14). Experimental studies have shown that young animals are more susceptible than older ones to Cryptosporidium infection (15,16). Our study also showed that the infection was more common among younger cats, although it was detected also in older ones.…”

A newborn mouse Cryptosporidium parvum infection model: its application to the study of therapeutic and prophylactic measures for controlling cryptosporidiosis in ruminants

“…In another study, 100% of mice were infected with the same infective dose (10 5 oocysts per mouse), remaining infected during the first 15 days pi (Novak and Sterling 1991). In view of the foregoing, it was decided to use a very high infective dose of 5×10 5 oocysts per mouse, so as to enable the study of the infection during the 6th to the 16th days pi, a period similar to that for which cryptosporidiosis is present in ruminants Tzipori et al 1983;Snodgrass et al 1984;OrtegaMora and Wright 1994;Fayer et al 1998). In this respect, most of the studies so far carried out using a neonatal mice model have checked the efficacy of therapeutic or prophylactic measures (drugs or antibodies) in controlling cryptosporidiosis on only 1 day, frequently the 7th day pi Blagburn et al 1998).…”

Cryptosporidiosis in Animals and Man: 1. Taxonomic Classification, Life Cycle, Epidemiology and Zoonotic Importance

“…as primary entero-pathogens was uncertain until 1980, when Tzipori et al (1980) attributed an outbreak of neonatal diarrhea to cryptosporidial infection alone. In the following years methods to free the infective oocysts from other contaminating pathogens become available, which permitted the experimental demonstration that Cryptosporidium was capable of causing clinical diarrhoea in calves (Tzipori et al, 1983;Heine et al, 1984). In cattle, two species of the genus Cryptosporidium were distinguished, C. parvum is infecting the distal small intestine and C. muris infecting the abomasum.…”