In summer, it is typical to see increased prevalence of Salmonella sp. in horses, says Brandy Burgess, DVM, MSc, PhD, DACVIM (LAIM), DACVPM. Scientists think it is related to a sort of stress, such as heat stress. It is found everywhere. Different strains wax and wane in different areas at different times of the year.
A large proportion of horses shed the bug asymptomatically. They’re not sick with it, but they seem to carry it, and so then they can shed it intermittently. Salmonella is zoonotic so therein lies the challenge with this disease, says Burgess.
While Salmonella is recognized as something that causes illness, it can also be shed subclinically. This poses a problem for other animals, so other horses on the farm, dogs, cats and people.” – Brandy Burgess, DVM, MSc, PhD, DACVIM (LAIM), DACVPM
Source: Morris Animal Foundation, March 9, 2021. Link. Discussing current Foundation-funded research to determine the duration of salmonella shedding among test-positive horses, Burgess says part of our takeaway is that we know horses can intermittently shed. Estimates from study data suggest 42 days for a median duration of shedding.