Signs and Symptoms of Internal Parasites in Sheep

As with just about any animal, barnyard or household, sheep are susceptible to infection from internal parasites. These parasites come in a number of varieties, from a wide range of stomach worms to intestinal parasites and even liver flukes. These parasites, left untreated, can cause any number of significant health problems and may even lead to death. While some of the signs may point to other diseases, they are also primary symptoms of parasitic infection.

  1. Weakness

    • Weakness is a common symptom of stomach worm infection. These worms attack the stomach and cause considerable blood and protein loss in sheep. The animal may become weak, making it difficult to eat, stand or ambulate.

    Anemia

    • Another sign of a stomach worm is anemia. This symptom is easily visible in the tissue of the gums and eyelid lining, which become pale when the animal is anemic.

    Wool and Weight Changes

    • Another sign of parasitic infection is the hair, or wool, taking on an unusually rough, coarse quality. The animal's appearance will further deteriorate due to weight loss.

    Diarrhea

    • While not a symptom characteristic of all stomach parasites, diarrhea can occur due to infection. Also called scours, or scouring, this condition, combined with weakness and lack of appetite, is a major sign of worm infection. To be certain the diarrhea isn't the result of another condition, however, testing for worms is imperative. Testing usually entails analysis of the animal's feces to determine the number of eggs per gram of feces. Larval cultures are required for specific identification of parasites.

    Tapeworm Segments

    • Tapeworm infections can generally be identified by one factor: feces. Sheep that are infected with tapeworms typically pass segments of the worm in their feces.

    Bottle Jaw and Brisket Edema

    • Bottle jaw is a symptom of low protein levels caused by parasitic infection. Fluid builds up under the skin of the lower jaw, causing substantial swelling. Brisket edema is another symptom, characterized by swelling between the front legs and the belly.

    Other Symptoms

    • Other symptoms of parasitic infection include loss of appetite, lethargy and difficulty keeping up with the herd. Additionally, infected ewes may not produce enough milk for their lambs or kids.

    Death

    • Unfortunately, there are times when the only visible symptom of parasitic infection is the death of the animal. This primarily occurs as a result of excessive blood loss due to a rapid build up of parasites. Some animals die while exhibiting no symptoms.