Each summer we investigate several cases of calves souring post weaning. While there are many causes of diarrhoea in weaned calves i.e. parasitic enteritis, Salmonella, and BVD, we regularly diagnose Yersinia, which is a bacteria that causes diarrhoea. We often see Yersinia 'roll' through a mob of calves - with a small number of calves being affected at any one time. Treatment is aimed at correcting dehydration and administration of antibiotics. Prognosis is usually good except in advanced cases.
There is circumstantial evidence that Yersinia is often associated with concurrent disease i.e. BVD, parasite burden, low trace element status - especially selenium and copper. Remember - that Yersinia (both Y. pseudotuberculosis and Y. enterocolitica) are zoonotic - and hence are a common cause of food poisoning in people. Keep the hygiene standards high if you are dealing with scouring animals! Please contact the clinic if you are concerned about ill thrift or scouring in your weaned calves.