Animal Health Notes 2009

Control parasites – worms, fluke and external parasites can do damage even after the animals are removed from grass. These can include the Ostertagia larvae, which is ingested in the autumn. They lie in an inhibited stage in the stomach wall waiting to hatch out and cause disease in late winter and early spring. It is very important to remove any lungworm so that they will not put the calves at greater risk of severe pneumonia.  

It has been another wet season and liver fluke levels will again be high. The early immature fluke live in the soft tissue of the liver causing extensive damage before moving into the bile ducts as immature fluke where they mature into adult fluke and begin to lay eggs. The number of fluke is vitally important as this determines the nature of the disease, from potential sudden death of acute fluke to failure to thrive of chronic fluke. How do you know how bad the fluke problem is on your farm? Is the farm very wet, have you any post mortem reports from your meat plant or APHIS online?  You may take faecal samples for egg counts or blood samples.

There are therefore choices to make now. There are many worm and fluke treatments available. It is essential to choose a product that kills the inhibited stage larvae of Ostertagia, and lung worm. Some fluke medicines kill all three stages of liver fluke, some kill immatures and adults and some only kill adults.

There are drenches, injections and pour-ons, and drugs that continue to work for some weeks after treatment. There are combination drugs that kill both worms and fluke and external parasites. Any external parasites can also be controlled at housing.

Discuss your best option with your technical advisor, veterinary surgeon or agricultural merchant.

Improve you animal’s immunity – complete your first course or booster vaccinations.
Vaccines introduce a harmless form of the disease to a healthy animal. But you must allow time for the animal to prime its white blood cells and prepare antibodies against the natural disease before it is exposed to the disease. Pneumonia is a complex disease with a variety of bacteria and virus pathogens involved. Every farm is different with different challenges. What is the history of pneumonia and other diseases on your farm? As the levels of fluke are likely to be very high it might be useful to consider Clostridial vaccination. Discuss your best option for pneumonia vaccination with you veterinary surgeon.

Prepare your housing for the new arrivals  - This is the environment that the animals will remain in for several months. Think of the welfare of your animals or how your animals will perform in their new home. The house should be cleansed and disinfected and should be comfortable and provide adequate feeding and watering facilities. Welfare laws demand a well drained place to lie down and precise space measurements. A 150KG animal needs a minimum of two square metres of floor space. But it is also recommended that a 150 KG calf needs 12 cubic metres of overall air space.

Do you know the measurements of your buildings? Is there enough space? Is ventilation and air exchange adequate? Do you keep young animals in a different air space from older animals to avoid spread of infection? Are all draughts excluded? Do you wait until you get a good day for housing?

Reduce stress - Stress is a major player in all diseases. Reducing stress is easier said than done. There is so much to do. Good management of weaning and all routine husbandry is essential. Dosing, vaccinating, batching, change of diet and housing, can all cause considerable stress leaving the animals weak and vulnerable to disease.

These are only some of the main health issues to consider before housing cattle. It is much better to make a plan and draw up a timetable of actions.  Discuss your health plan with your advisor or veterinary surgeon.