age) and immunocompromised hosts show increased
susceptibility.
Transmission occurs most commonly through feco-oral
infection by sporulated oocysts via fecal contaminated
water or feed, direct contact between infected and
uninfected individuals, indirect transmission by
fomites or mechanical human transfer. In addition, C.
parvum is not host specific and infection from other
species (rodents, feral cats) via contamination of feed
is possible. Oocysts are resistant to most disinfectants
and can survive for several months in cool and moist
conditions.
Pathology
The various stages of cryptosporidium are attached
to the brush border microvilli of epithelial cells lining
the intestine. This attachment to the intestinal villi
induces villous atrophy and the extent of the villous
atrophy is directly related to the severity of clinical
disease. Animals presented for post mortem are
usually dehydrated and emaciated (figure 1 and figure
2). Gross pathology is generally restricted to the
gastrointestinal tract and affected parts of the intestine
usually contain watery yellow ingesta (figure 3). The
distal jejunum and ileum usually demonstrate the
most severe lesions with cecum and colon less severely
affected (figure 4).
Diagnostics
Figure 1. Roan antelope calf- cryptosporidiosis with severe emaciation
and dehydration
Figure 2. Roan antelope calf- cryptosporidiosis with severe dehydration
with sinking of eyes
Figure 3. Roan antelope calf- abdomen opened to reveal gas-filled
abomasum and catarrhal enteritis with yellow discoloration of the small
intestinal content. Cecum and large intestine fluid filled
Figure 4. Roan antelope calf- distended fluid-filled cecum
2018
AUGUST
5