with a smooth colonial morphology characteristic of pathogenic, capsule-producing
strains, and/or Salmonella spp.
b) Viral
Rota- and Coronaviruses
Rota- and coronavirus particles are frequently detected in foal stool samples
submitted to the WDL. Interestingly, although the majority of diarrhoea outbreak
samples tested are positive for rotavirus particles, most of these stool samples also
test positive either for a pathogenic E. coli strain or a pathogenic E. coli strain as well
as a prominent Clostridium sp. These results indicate that foal diarrhoea cases are
often the result of multiple pathogenic agents and that a single agent may seldom be
responsible for mortality due to gastrointestinal illness.
c) Other gastrointestinal pathogens
No Cryptosporidium spp. oocysts have ever been detected by the WDL in stool
samples tested.
Foal joint sepsis
A summary of bacterial culture results obtained from the septic joints (septic arthritis)
of 40 foals (<6 months) in a review written by Schneider (1998) demonstrated that
members of the family Enterobacteriaceae (especially E. coli) dominated the
pathogenic isolates (Table 6). The second largest group (32.5%) consisted of
idiopathic cases in which no bacterial growth was obtained.
Similarly, the WDL synovial fluid cultures of foals in the last 3 years (Table 6)
indicated that E. coli was the predominant isolate; however, the majority (50%) of the
synovial fluid cultures were negative for bacterial growth.
Table 6
Synovial fluid culture results of foals published by Schneider
(1998) compared to the WDL results from 2013-2015.
Bacterial species
E. coli
Klebsiella
Enter