A HERDSMAN'S HANDBOOK FOR THE MODERN HOMESTEADER

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Flukes—flat leaf-like creatures that range in size from one-half inch up to four inches in length—are by no means as common as roundworms, but in areas where they do exist they're worthy of consideration.

Flukes have a fascinating and very complex life cycle. The adults live in the bile ducts of a ruminant's liver and pass their eggs into the intestines where they're voided in the host animal's droppings. In water, these eggs hatch into a larval stage called miracidia, which will perish unless they find and penetrate into the body of a water snail within a few hours. Inside the snail the miracidia grow and multiply and finally emerge as an intermediate stage called cercariae.

The cercariae form cysts on submerged plants or other objects and enter their new host with contaminated plants or water. Once in the body, the parasites then migrate through the tissues until they finally find their way to the liver to complete the cycle.

The life cycle of the lancet fluke is even more complicated than that of other flatworms. Once its eggs are expelled, the species' larvae must develop in a dry-land snail, then further mature in the body of an ant (Formica fusca) . . . and THEN the ant must be eaten by the final host.

Flukes are often responsible for poor gains in young animals and in older animals that have been undernourished. The greatest economic loss is from the livers that are condemned at slaughter because of enlarged bile ducts and other damage.

» RUMINANT PARASITE DETECTION

Much of the danger and economic loss ruminant parasites cause can be eliminated by the application of a few, often overlooked, management practices . . . the most important of which is the early detection of the culprits.

Symptoms shown by animals that are heavily parasitized can vary a great deal, depending on the number and kinds of worms present. Anemia, a fairly common indication of infestation, is caused by roundworms drawing blood from the lining of the gut and may be coupled with a poor appetite and slow gains or actual weight loss.

A persistent watery diarrhea and a dry hacking cough also may be noticed and an animal afflicted with worms will usually have an unthrifty appearance, dull eyes and a rough, dry haircoat.

In short, the worm-ridden ruminant is in a very run-down condition, and looks it. In this state, the animal is very susceptible to other infections of a bacterial or viral nature. If you notice any of these symptoms in your cattle, sheep, or goats, (this discussion applies to all three) it would be wise to consider a diagnosis of parasitism.

Your next step should be to collect a small sample, one or two ounces, of fresh droppings from each affected animal and take it to your veterinarian for analysis. He will examine the specimen microscopically to determine which—if any—worms are present. If there is an infestation, the vet will be able to estimate its severity by identifying and counting the parasite eggs present in a measured amount of the sample. This service also available from some private laboratories and possibly from your State Agricultural Extension Service.

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