That Itchy Scratchy Feeling! Cattle and Lice

While it is not quite the same as having your child come home telling you they have head lice, having your cattle rubbing and scratching instead of eating and lying quietly, can be annoying. And our cool winter temperatures from November to March, which ensure thick hair coats on the cattle, create an ideal environment for lice populations to thrive.

There is a fairly simple procedure to check if your cattle have lice. Take a good light and a comb and part the animal's hair, looking for lice on the skin. The brisket, around the eyes, the muzzle and along the back are prime locations to observe. To quantify your problem, examine 5 areas, each about four inches long. If there were fewer than ten lice in total this would be considered a minimal infestation. 10 for 50 lice in total would be a moderate infestation. Over 50 is considered a heavy infestation.

What is the number that makes treating economical? While that question still remains, millions are spent every year on chemicals to control the pest. There are two types of lice: chewing and sucking. Sucking lice feed on the blood of infested cattle. Chewing lice eat debris from the skin surface. Choose a product that has strong persistence when treating lice. The product application will kill all the adults. However, the eggs on the hair survive and hatch seven to fourteen days later, reinfesting the animal. If the product has persistence or lasts that long, the new lice will also be killed off. Otherwise you will have to retreat.

Some other factors to consider in fighting the war against lice are nutrition and environment. Cattle in excellent body condition will have a strong immune system response. Animals that are clean, well bedded and dry are in an environment that minimizes damage or helps prevent lice infestations completely.

There are certain animals that appear to be genetically susceptible to lice infestations. They become chronic for lice and should be culled. Others will seem to develop immunity and never get infested.

Researchers are working on developing a cattle pest index, based on the same techniques used by plant breeders who have developed a crop pest index. This would provide an economic level at which treating would be necessary.

Based on information from the Lethbridge Research Centre.