ADLib Glossary (C)

More Information:

Cattle Health Problems

Cystic Ovaries

This is one of the major causes of poor fertility in individual cows. The cyst is often large - greater than 2cm - persistent and filled with fluid. Cows with cystic ovaries usually have abnormal oestrous cycles - shortened or lengthed or, most commonly, a failure to cycle at all. Veterinary diagnosis using ultrasound examination is required.

Early, prompt treatment is important as most cysts will not heal on their own. A wide range of products are available for treatment.

Liver Fluke Infection

Wet weather can increase the risk of liver fluke especially where the parasite is known to occur. The parasite has a flat leaf-like appearance. It produces eggs which pass out of the cow with waste on to pasture. Eggs hatch and infect a certain snail species where they develope further, leave the snail and settle again on pasture ready to be eaten by the cow and re-infect the liver. The flukes cause various degrees of damage to the liver depending upon the degree of infestation. Symptoms include progressive weight loss, a reduced milk yield, bottle-jaw and abdominal swelling. Liver flukes can also infect sheep and goats. Veterinary diagnosis can be done via a blood test or by faecal egg count.

There are a number of antihelminthics available for treating fluke in cattle. Prevention is best, usually by elimination of the snail host. Drainage of wet areas tends to remove the snails habitat. Chemical control of the snails is not available.

Silage Eye

Silage eye is an eye infection cause by the bacterium Listeria monocytogenes. This bacterium is often associated with the brain disease listeriosis. The infection is associated with the feeding of silage to cattle especially big bale silage. The clinical signs are a profuse eye discharge which begins clear but gradually becomes sticky and purulent. The surface of the eye can become bluish and opaque eventually turning yellow with the discharge. The iris may bulge. The condition is very painful. Diagnosis is usually by identifying the above symptoms.

The problem occurs due to silage becoming contaminated with the bacterium usually from the soil and the fermentation process failing to kill it. Animals then become infected during the competion for food. Prevention can therefore be achieved by either feeding clamp silage rather than big bale and by minimising contamination of the silage with soil at harvest. Ensuring that animals have plenty of feeding space will go a long way to minimisng the problem.

Treatment is via a systemic antibiotic applied directly to the eye.

ADLib logo Content provided by the Agricultural Document Library
© University of Hertfordshire, 2011