Animals – Update on Bovis

While the outbreak and control measures to contain Mycoplasma Bovis have caused disruption to many farm businesses and considerable mental anguish, this has been mainly in the South Island. As of June 2018, only four or five properties have been found infected in the North Island. At this point, all spread of the disease can be attributed to animal or milk movement between properties, but there is a risk that the disease could be spread by cattle contact over fences or by vehicles, equipment or people.

Even if the battle for eradication is lost, I envisage that over the coming months and years some people will have a lot to lose but most won’t. If M. Bovis does become endemic, then as the years go by, the loss will be spread more evenly. It will become an everyday concern for animal welfare and cattle farming profitability, just as a number of other endemic diseases already are.

M. Bovis can cause serious disease in cattle. It does not respond to treatment and often sits dormant in carrier bovines where it frequently evades detection by available tests. It is seen around the world, but was not diagnosed in New Zealand until it was found on a south Canterbury farm in July 2017. Epidemiologists are confident the infection arrived in New Zealand at a Southland farm about January 2016.

Ministry of Primary Industries (MPI) officials and cabinet felt the disease had been discovered early enough to attempt eradication. Since July 2017, MPI has been stopping, then rigidly controlling the movement of cattle off and on to properties where M. Bovis has been found, and also properties that have received cattle or milk from infected properties. Cattle on properties where the infection has been found are slaughtered, usually at a freezing works. Extensive testing is initiated on properties that received cattle or milk from infected properties.

What can you do? The Privacy Act prevents us from looking up on a website to find out which properties are infected and which others are under movement control, but there is no law against asking probing questions of individuals about their MPI status. Meanwhile, everybody in charge of cattle must always comply with the National Animal Identification Tagging (NAIT) regulations. You must be registered with NAIT. With a few exceptions, all cattle must have a radio frequency identification ear tag before they leave the property they were born on.

Sending cattle away from one property and its arrival at another property has  to be recorded with NAIT. You can use a NAIT accredited information provider if you don’t want to do it yourself.  It is recommended that if you buy raw milk to rear calves, only buy it from farms where you buy calves from.

Pasteurisation kills M. Bovis, so milk powder is safe. If you are buying four-day-old calves on a farm, turn up with clean boots and gear and be ready to comply with the farmer’s disinfection demands. If you see arthritis, pneumonia or balance loss in calves, or if you see arthritis, mastitis or premature births in older cattle then  beware. There is a possibility it could be M. Bovis at work.

David Haugh, Wellsford Vet Clinic
www.vetsonline.co.nz/wellsfordvet