At last, we have all been able to enjoy some late-spring sunshine, and let’s hope it continues into the summer. TB testing has almost finished for the summer—we are waiting for culture results from one cow that was found with suspicious lesions at slaughter, but with the rest of the herd testing clear we hope that nothing will come of it.
On the practice front, we are all pleased to welcome back Andrew Doull who has spent the last 16 months travelling. He has gained some valuable experience on his travels, spending 2 months working in different veterinary practices in Australia. Although the majority of cattle work was similar there were a few notable differences, mainly due to the weather, that may have some relevance as summer continues.
Photosensitisation or “fire fever” occurs more commonly and presents as inflammation of the un-pigmented areas of the skin exposed to sunlight. Primary photosensitisation occurs as a result of eating plants containing photosensitising compounds and secondary results from liver damage. The clinical signs are irritation, seeking shade and swelling of affected areas and treatment involves removing the cause if known, keeping the animal indoors and supportive care including anti-inflammatories.
Another condition occurring more regularly are eye tumours, again because of increased exposure to UV rays. There are a range of surgical options if the growth is caught early enough before it spreads to the other eye or the lymph nodes of the head.
Heat stress also occurs more regularly for obvious reasons and most often presents as a sub-clinical drop in performance or milk yield although can progress to anorexia, lethargy and even respiratory distress. Prevention and management involves providing shade, ventilation and active cooling including sprinkler systems.
KETOSIS OR SLOW FEVER.
Energy deficit in early lactation high yielding dairy cows is a common but very under-diagnosed problem. Cows producing a lot of milk can’t eat enough energy to do so and breakdown body tissue to make up the deficit. This leads to weight loss, ketosis and reduced fertility. A handy way to check how your cows are performing is to test for ketones in the milk using a simple dipstick. KEXXTONE bolus is a product specifically designed to prevent ketosis in high yielding cows. Select high-risk cows—older, fatter, thinner, very high yielders and those carrying twins for treatment. The bolus is administered 3-4 weeks before calving. Cost is £33 per cow which is easily recouped as extra milk and reduction in calving to conception time, not to mention prevention of clinical ketosis or displaced abomasum.
We have been doing more post mortems in lambs this spring, whether this is due to there being more losses or a reflection of the market value of the finished product is hard to establish. Causes of death found at post mortem have been varied ( coccidiosis, pneumonia, clostridial disease and navel ill) and in some cases, we have sent either samples or a full carcase to the lab for further testing
- Coccidiosis was rather surprisingly found given the warm dry weather, but the batch of lambs had access to a pond in the field which we think was the source of infection. Appropriate treatment and moving to a different pasture has so far prevented any further losses.
- Losses from both clostridial disease and pneumonia can be reduced by vaccinating the ewes before lambing, with antibodies transferring to the lamb in the colostrum protecting against pneumonia for 4 weeks and clostridial diseases for 8-10 weeks. The lambs will need vaccinating after this to make their own antibodies and so be protected. Just remember two doses of vaccine need to be given 4 –6 weeks apart to ensure adequate protection.
- Navel ill infections are picked up at birth from a wet dirty environment and tend to cause problems immediately, either as a swollen painful navel or as joint ill. In some cases, there may be no obvious signs but the infection remains in the body causing inflammation and damage, resulting in death several weeks later. At post mortem, the signs may be abscesses around the liver, diaphragm, lungs or heart. No treatment at this stage will have any effect.
Sheep abortion vaccines to protect against toxoplasma and enzootic abortion are available—need to be given 1 month before tupping. Please ring the office and we will order them for you.