Taranaki salmonella spike mystery

A senior vet at Taranaki Vet Services, Craig Hassell told Rural News it's the first time in 22 years he's encountered such a big outbreak around Stratford.

"We've had the odd case and generally it has affected one or two animals at the most and they have tended to get pretty sick and die. What we are now seeing is a high infection rate, with not such a high mortality rate – although some farmers have lost in excess of 10 cows."

Hassell says there's a lot of speculation as to the causes of the salmonella outbreak. A committee of local vets, MAF, dairy companies, the Veterinary Association and Massey University is gathering information. "The Massey University Epicentre has identified a number of risk factors, and is hoping to extend the survey into the Waikato and Bay of Plenty regions."

Unusually, it doesn't appear to be spreading from farm to farm. "There seems to be something triggering the disease on a particular farm. Maybe carrier animals on that farm have had their immune systems compromised or something happening in the gut of these cows and is triggering the disease. It seems to be farm specific."

It's important farmers recognise infected cows as soon as possible, then isolate the infected animals and call their vets. Once a widespread Salmonella problem has been identified, the farmer should also tell their dairy company. "Ideally they should contact their neighbours as well."

Hassell says farmers worried about their cows getting Salmonella can vaccinate them inexpensively. And hygiene must be watched because of the risk of the disease spreading to people or other animals.

"Washing hands and maintaining good hygiene in the shed is extremely important," he says.