The symptoms of parasites in dogs are largely dependent upon what type of parasite the dog has. Skin parasites in dogs include fleas, ticks, and mites, with symptoms such as scratching, biting at the skin, and hair loss. Intestinal parasites, such as hookworms, tapeworms, and whipworms, may be accompanied by gastrointestinal symptoms, blood in the feces, and abdominal distension. Heartworms may create no symptoms until the parasite load is heavy enough to start damaging the heart. At this point, the symptoms will likely be coughing and coughing up blood.
Parasites in dogs' skin, or topical parasites, are those that dog owners are most likely to see. Many dog owners will not have to wait for symptoms in the case of fleas or ticks, but will see the parasites in their pet’s fur. Mites will not be visible to the naked eye.
With a flea infestation, a primary symptom is the presence of flea dirt. Flea dirt is the parasite’s excrement of undigested blood. If a dog has a substantial flea infestation, flea dirt can be seen anywhere the pet sits or sleeps for any length of time. It will also be visible on the floor or table beneath the dog any time the dog is combed or brushed. Flea dirt looks like black powder.
Other symptoms of skin parasites in dogs are the dog continually licking at its coat, the development of skin lesions, and crusty sores on the dog’s skin. If mites get into the dog’s ears, symptoms may include discharge from the ears as well as the dog frequently scratching the ears and shaking its head. In the case of tick bite, symptoms may include a rash and swelling at the site of the bite. In some instances, if a topical parasite infection is severe, a pet can develop anemia and more serious symptoms.
There are a couple of intestinal parasites that dog owners may actually see. Tapeworms and roundworms are visible in the stool or vomit, while other types of intestinal parasites will need to be diagnosed by a fecal examination from a veterinarian. Additional symptoms of intestinal parasites in dogs include diarrhea, nausea, and vomiting. If a dog has a heavy load of intestinal parasites or if the dog is a young puppy or elderly dog, symptoms may become more serious and include weakness, loss of appetite, and severe weight loss. Puppies often have a bloated abdomen if they have a heavy load of intestinal parasites.