In the last week I’ve seen my first case of summer mastitis that needed treatment. It is caused by the fly carrying bacteria which subsequently affects one to four quarter s of the animal. Summer mastitis is usually a disease of non-lactating cows and heifers during the summer months.

However we have seen cases affecting bulls and steers also. There is a higher incidence of disease in areas where there is increased fly activity, generally in dry shaded fields with heavy tree cover.

The clinical signs can vary depending on how early the animal is noticed as sick.

Usually it will start with animals isolated from the herd and appear lame or very stiff when walking. The first signs can be enlargement of the teat with animal frequently kicking at themselves. On closer inspection you will often see a lesion or sore on teat which the flies have been attracted to. The disease can progress into swelling of the udder and the animal becoming quiet sick and dehydrated. At the end stage, cattle can lose a lot of condition and frequently will be reluctant to move and be very dull and depressed. These animals need urgent veterinary attention.

Treatment

The aim of treatment is often to save the animal prevent abortions, as opposed to saving the damaged quarters. Unless the disease is spotted very early then the quarter cannot often be saved. Treatments generally consist of injectable antibiotics and anti-inflamatorries for 4-5 days (steroids should never be given to pregnant animals). The teat or quarters must also be vigorously stripped out this may difficult to achieve.

However often the best treatment is to amputate or lance the teat which allows the infection to drain naturally. This usually will allow quick relieve for the animal however all affected pregnant animals should be scanned to ensure no abortions have taken place.

Controlling this disease can be difficult as in some areas where there are heavy fly populations. Often with dairy cows the use of teat seals and/or long acting dry cow preparations can be very effective. The use of dry cow tubes can be as effective in beef cattle however it may be more difficult to carry out. The frequent use of long acting fly spot on preparations can be very effective if used frequently in combination with the use of udder treatments such as Stockholm tar or diluted jeyes fluid. There are also ear tags available with synthetic pyrethroids.

The best course of action if encountering an increased frequency of summer mastitis in your herd is to develop a control plan with your vet. Summer mastitis can cause serious economic losses due to abortions, reduced long term milking capacity, treatment costs and reduced carcass weights.