Testing suggests M. bovis is more widespread than thought

Results from veterinary practices across the UK suggest Mycoplasma bovis is more widespread than previously thought.

A new surveillance programme indicates M. bovis affects beef and dairy cattle across the country – although it can be easily detected through bulk milk serology testing, which the results suggest are more sensitive than other forms of detection. 

“For a few years, I have suspected that M. bovis is more prevalent than expected,” says Graeme Fowlie, of Meadows Vets. “From working with vets across the country taking part in the surveillance programme, it’s become clear that that is the case.”

The results, from vet practices across England, Scotland, Wales and Northern Ireland, show that M. bovis is present in every region, in both beef and dairy herds.

“It is probably present in your area, so you should be aware of it.”

The disease causes pneumonia, mastitis, swelling, sore joints and otitis., It is also likely responsible for a range of chronic underlying health issues, which have a significant impact on welfare and productivity. 

As part of the surveillance programme, vets were offered free M. bovis tests, regardless of whether herds were showing signs of disease or not. Of 41 farms taking part, 18 tested positive, six were inconclusive or void, and 17 were negative.

But the results also revealed some types of analysis were more sensitive than others. 

 The five bulk milk serology tests all came back positive. The 11 PCR tests – mainly of bulk milk samples – failed to show a single positive result.

Mr Fowlie said: “We have used blood tests on calves over five months old to screen herds. Dairies could also be screened via bulk milk serology. Sick animals can be identified with PCR testing of either nasal swabs, post mortem material, joint fluid or milk samples.” 

Since he started using these tests two years ago, Mr Fowlie has returned more positive samples than in the previous 20 years. Some of these
would have been false negatives when using traditional bacterial culture testing, which is less sensitive, he believes.

Hard to treat

“One of the biggest problems with M. bovis is that it’s very hard to treat – it doesn’t respond to many common antibiotics, so prevention is much better than cure,” says Mr Fowlie.

“That means screening herds via blood/bulk milk serology testing and PCR testing of sick animals/post-mortem samples to confirm the presence of the disease initially and have confidence in those results. 

Farmers should adopt stringent biosecurity measures with careful herd management changes and vaccination where appropriate, says Mr Fowlie. Vets can now prescribe a multi-strain vaccine in the UK under the Cascade system.

When combined with appropriate testing, vaccines will enable farmers to take a proactive and informed approach to disease management.

The surveillance programme will continue this winter, with further free testing available to vets.