Sheep-to-cattle link suspected in digital dermatitis infection

WHERE PRODUCERS suspect cattle or sheep may be infected with digital dermatitis or contagious ovine digital dermatitis (CODD), mixing of sheep and cattle should be avoided to prevent possible spread.

There is no proof of a link between CODD in sheep and digital dermatitis in cattle, but that is not to say there isn’t one, said Moredun’s Willie Donachie.

“The best thing sheep producers can do to prevent CODD entering their flocks is quarantining all stock coming onto the farm and checking their feet regularly, for at least four weeks, to see whether infection develops.

No sheep treatment

At present, there is no treatment licensed to treat CODD in sheep, although treatments currently used to treat digital dermatitis in cattle can help. These include antibiotic footbaths containing lincomycin alone, lincomycin and spectinomycin combinations or erythromycin.

“However, these products are expensive and aren’t licensed for use in sheep, so they should only be used when a vet diagnosis has been obtained,” warned Prof Donachie.

The likelihood of a vaccine being developed for digital dermatitis is some years away, as the infectious agent, the Spirochaete bacteria, is difficult to isolate and work on.

“Additionally, this problem appears to be confined to the UK, with no reports of CODD in Europe or other major sheep keeping countries, such as Australia and New Zealand.”

However, while treating the condition is difficult, Prof Donnachie believes treating quarantined sheep with formalin may be a wise precaution.

“Treatment with formalin may be ineffective, but it may prevent infection occurring.”