Summer mastitis is usually seen in dry cows and heifers during the summer months from late June to mid-September.
It is caused by a combination of bacteria that work together to cause the condition – the main bacteria involved are S. dysgalactice, Peptostreptococcus indolicus and Acranobacterium pyogenes.
Prevention
One of the easiest was of keeping summer mastitis at bay is to keep dry cows and replacement heifers away from susceptible fields.
It is advised to avoid fields with a large number of tall weeds or fields that provide a large amount of tree cover.
A common method of prevention on Irish farms is the application of Stockholm tar around the teats.
Once of the major drawbacks of using Stockholm tar is that it must be applied to the udder at least once a week – to deter flies.
But, this also offers you a chance to train heifers into the parlour – as the parlour is the best place to apply Stockholm tar.
Another common prevention method is the use of fly repellents in conjunction with some of the other preventative methods.
These usually contain synthetic pyrethroids and will come in the form of a pour-on or in a tag that is put into the animal’s ear. The frequency with which the pour-on is used will depend on the product used.
Symptoms
The ‘tell tale’ sign of summer mastitis is a swelling of the teat and infected quarter, with frequent kicking, as large numbers of flies gather around the teat tip causing irritation to the animal.
Animals affected by summer mastitis will often lie away from the group and will spend more time lying. Once on their feet they can show stiffness in the back legs and are reluctant to walk.
As the condition progresses you can see noticeable weight loss. If checked they will often have a high temperature and they run the risk of aborting if they are in-calf or are left untreated.
The infected quarter can often eventually burst and the discharge is yellow in colour and foul smelling – in severe cases it can be fatal.
Treatment
Like with many infections, treatment will often depend on how advanced the condition is – mild cases will be treated with antibiotics and possible use of intramammary tubes.
More severe cases will also need a course of anti-inflammatory drugs; some vets will opt to amputate the teat to allow it to drain freely.
In all cases the affected quarter needs to be frequently stripped out to reduce toxin build up and affected animals should be isolated from the group.