Roundworms are parasites that live freely in the intestine, feeding off of partially digested intestinal contents. Toxocara canis and Toxascaris leonina are two important species of roundworms in dogs. Infected dogs shed the microscopic roundworm eggs in their feces. Other dogs may become infected by sniffing or licking infected feces. There are many safe and effective preparations available to kill adult roundworms in the intestine.
Sarcoptic mange is caused by a parasitic mite that burrows just beneath the surface of the skin. The Sarcoptes mites can bury into the skin of healthy adult dogs and puppies and feeds on material in and on the skin. The presence of the sarcoptic mite causes intense itching. There are several medications that are effective against Sarcoptes.
Tapeworms are flat, segmented intestinal parasites of the cat and dog. They use their hook-like mouthparts to attach to the wall of the small intestine. As the adult matures, individual segments, called proglottids, are passed in the feces of an infected dog. Clinical diagnosis is usually made by observing the white mobile tapeworm segments in the feces or crawling around the anus.
Ticks are parasites that feed on the blood of their host and can in turn transmit diseases to your pets or even you. They are prolific breeders and their life cycles can extend through multiple seasons. Prompt removal or use of preventatives limit or prevent the spread of disease, or kill the ticks.
Whipworms are intestinal parasites that are about 1/4 inch (6 mm) long. They live in the intestinal tract of dogs where they cause severe irritation. Whipworm infection results in watery, bloody diarrhea, weight loss, and general debilitation. Any dog with chronic large bowel diarrhea should be suspected to have whipworms, even if the stool sample was negative. Whipworms are far less common today than in previous years, because of widespread use of modern heartworm prevention products.