Vets report rise in cases of summer mastitis

Vets are reporting a rise in the number of cases of summer mastitis as high temperatures combine with drying-off periods to create the ideal environment for the disease.

The bacteria that causes summer mastitis is ever-present on farms, but it will only thrive when the conditions are right. The recent prolonged, warm spell has provided that environment by encouraging the hatching and activity of flies that spread the highly contagious bacteria between cows.

Maarten Boers, of The Livestock Partnership in West Sussex, says beef cattle and dairy heifers seem to be hardest hit.

“I have seen it in some autumn-calving beef herds after calves have been weaned off their mothers,” he says.

“Dairy farmers seem to have got wise to it and have the right preventions in place, but there are still issues with heifers reared on off-lying land, because these aren’t observed as frequently as a cow going through a parlour.”

“This means that a mild case may go unnoticed, but the mammary gland will be damaged. It only comes to light when a heifer calves and has one or more blind quarters. If this is the case, two years of rearing costs have been wasted.”

Chris Hudson of Nottingham University also highlights the importance of early detection. He explains that if mastitis goes unnoticed until the cow’s second milking, it reduces their chances of being cured by 50%. Unless the disease is spotted early, often the affected quarter cannot be saved.

Symptoms of mastitis

Clinical signs vary depending on the stage of the disease, although the first sign can be enlargement of the teat with a secretion similar in consistency to clotted cream. The disease can progress into a swelling of the udder and the affected animal can become stiff.

If the disease progresses further, cattle lose condition and will often be reluctant to move. Animals may abort or even die if they are not treated.

Treatment is a course of antibiotics combined with pain relieving anti-inflammatories.

Grazing environment

Mr Boers says that with many beef herds having just been weaned, cows are highly susceptible to summer mastitis. The grazing environment is a major contributory factor, too.

“Often these herds will be grazing conservation grass or meadows and these will have a high abundance of flies and, therefore, the risk is higher.

“Also, there are often thistles on this sort of land and if these cut the udder, the wound will attract flies.”

Mr Boers recommends isolating affected animals from other dry cows.

Disease prevention should be a priority, with prevention and control centred on fly control.

Vet Sally Munday, also of The Livestock Partnership, says applying fly repellent directly to the udder can help.

Pour-on fly dressing is effective. Depending on the product, it should be reapplied every four to eight weeks. Another option is ear tags containing synthetic pyrethroids.