Mycoplasma and Biosecurity

What is Mycoplasma?

Mycoplasma bovis is a bacterial disease that typically affects both adult dairy cattle and calves. It does not infect humans and poses no risk to food safety. Mycoplasma was first detected in a small number of New Zealand herds on the South Island in July 2017. Currently 39 farms are known to be infected including a number in the North Island. All farms identified to date are linked by animal movements.

What symptoms are typically seen with infected animals?

In adult cows symptoms include:
  • Mastitis that is often poorly responsive to treatment and in multiple quarters
  • Diffuse swelling of the joints/legs with associated lameness
  • Pneumonia
  • Abortion
In calves symptoms include:
  • Acute and severe pneumonia
  • Diffuse swelling of the joints/legs with associated lameness
  • Head tilt caused by an inner ear infection
  • Conjunctivitis
Clinical disease may be seen in an individual animal or in a large percentage of a group of animals. It is not uncommon to see symptoms in cows (like mastitis as described) in conjunction with affected calves.
However not all animals or herds with mycoplasma may show clinical signs of disease. A silent ‘carrier’ state may exist, with clinical disease occurring weeks or months after introduction to a herd.

How is Mycoplasma diagnosed?

Mycoplasma is difficult to grow hence specific microbiological techniques are required.
An alternative testing system, known as PCR, which relies on the detection of the bacterial DNA has been widely used by MPI in the current outbreak. However animals that are truly infected may test negative, and bulk milk may test negative even though a herd is infected, particularly where the infected animals are showing clinical signs and have been removed form supply.

Your Vet is your first point of contact, should you suspect Mycoplasma is present in your herd. They can guide a herd through the required steps to rule out, or confirm, this type of diagnosis. Currently if the disease is confirmed government veterinary involvement will occur.

What are the best, immediate steps for prevention?

Cattle movement onto farm is the greatest risk for introduction of mycoplasma. Currently all known farms in New Zealand with mycoplasma are under movement control (that is they can’t sell cattle), so the risk should be small. Any activity which co-mingles your livestock with cattle from other farms increases the risk of exposure.
Other, best practice, control points involve standard biosecurity measures such as thorough washing of boots, protective clothing and gear after contact with cattle when shifting activities between cattle age groups on a single farm or shifting activities between farms.

If you have any questions or concerns about your stock, please contact your lead Anexa Vet, we're here to help.

 

Dairy NZ Downloadable Files

Not sure what to be looking for in your cows and calves? Wondering how you can effectively clean your gear or are you wanting a checklist of what you can do to protect your farm - Check out these downloadable pdfs from DairyNZ