Worms and Parasites
A guide to keeping your companion animal healthy
Worms and parasites can be found in both dogs and cats. Some infections can be dangerous to the companion animal's health as well as the guardian's. Dogs and cats should be routinely tested for parasites, both with a stool sample and a blood sample.
A fecal (stool) exam is used to diagnose the presence of most intestinal parasites.* A fresh stool sample from healthy pups or kittens should be tested by the veterinarian when they are 6 - 8 weeks of age. If an animal under 6 weeks old seems to have a health problem, the pet and a fresh stool sample should be taken to a veterinarian right away. If young pups or kittens test positive for parasites, their mother should also be treated at the same time. Adult companion animals should have their stools tested as part of their annual physical examination.
*A blood test is used to search your pet for evidence of heartworm infection. Heartworms cannot be found through a stool test. Click here for more information on heartworm.
TYPES OF INTERNAL PARASITES:
Roundworms (ascarids) are intestinal parasites found in both dogs and cats, but the common ascarid of dogs does not infect cats and vice versa. A pregnant animal can transmit roundworms to her offspring before they are born. Symptoms include vomiting and diarrhea. Heavey infestation can often be fatal to young animals. Roundworms are passed in your animal's stools, look like strands of spaghetti and can be transmitted to humans by direct contact with the infected feces.
Hookworms are the most prevalent gastrointestinal parasites found in dogs and cats of all ages. They do not commonly spread between dogs and cats. Infection is caused by ingestion or direct contact with hookworm larvae, generally shed in an infected animal's stool.
A pregnant animal can trasmit hookworms to her offspring while pregnant or through her milk when nursing. Infestation can souse rapid, severe, enen fatal, anemia and stunted growth in your puppies and kittens. Older animals may show symptoms such as diarrhea, anemia, weight loss or a thinning hair coat.
Direct contact with hookworms can cause infection in humans. To prevent infestation, humans should never lie on bare ground, always wear shoes outside, always lay on a lounge chair or blanket (never on the bare ground) and always wear gloves when working in the yard or garden.
Tapeworms are common intestinal parasites of companion animals. Fleas, rabbits, mice, rats and other animals carry the parasite at an intermediate stage of it's life cycle. Animals become infected with tapeworms by eating these carriers. The most common tapeworm of dogs and cats is carried by fleas. If your companion animal is exposed to fleas, hunts and eats any small animals or has a ravenous appetite yet is losing weight, he may have tapeworms. If you companion animal is infested, you may see rice-like segments in his stool or around his rectum.
Whipworms are microscopic intestinal parasites common in dogs and pups older than 4 months. Infection results from ingestion of mature whipworm eggs, which are shed in the stool of infected dogs. The eggs can live in the soil for several years. Symptoms of whipworm infection include diarrhea containing fresh blood and mucus, vomiting, weight loss and, with heavy infestation, anemia.
Coccidia are microscopic intestinal parasites of dogs and cats, which can cause diarrhea and, in severely affected animals, vomiting, lack of appetite, dehydration and, in some cases, death. Coccidiosis, spread by the feces of infected animals, is very contagious to young companion animals.
Toxoplasma are microscopic intestinal parasites found in any warm-blooded animal, bird or human, although cats are the only primary hosts. The main source of infection for a cat is ingestion of raw or uncooked meats or infected small animals or birds. Ways for humans to avoid toxoplasmosis include cooking meat well and washing fruits and vegetables thoroughly before eating, avoiding unpasteurized milk, wearing gloves when gardening, washing your hands often and keeping your cat indoors. Indoor cats, since they will not be out hunting and eating small prey, are less prone to encounter toxoplasma.
Giardia are microscopic intestinal parasites that live in the intestines of infected humans and animals. While many otherwise healthy people and animals show no symptoms when infected, children, compromised adults and younger animals can experience diarrhea, greasy stools, nausea, dehydration or weight loss. Giardia are passed in the feces and can be found in soil, food, water or on any surface that has been contaminated with infected feces. Giardiasis in humans is most often traced to their drinking contaminated water or swallowing water from infected pools, lakes, rivers, ponds and other recreational sources. Avoiding feces and dirty or contaminated water and surfaces, such as bath-room fixtures, changing tables, etc., will lower the risk of infection to both humans and animals.
Heartworms are parasites that spend their adult lives in the heart and large blood vessels. Mature heartworms look like strands of spaghetti. They are most common in dogs, but the incidence in cats is growing. Heartworm is transmitted to companion animals by mosquitoes and can be detected through a blood test. Symptoms are not usually seen until there is a large number of heartworms present and may include coughing, listlessness and tiring easily.
Heartworm infection is difficult and expensive to treat -- prevention is a far better alternative.
Pups should be started on heartworm preventative at 6 weeks of age and the dosage increased, per your veterinarian, as he grows.
Adult dogs must be blood-tested before they can be started on heartworm preventative.
Heartworm preventative in a chewable or tablet form is given monthly. Dosage is based on the animal’s weight. Give as directed by your companion animal’s veterinarian.
Parasitic infections in animals can be treated medically by a veterinarian. If your pet shows symptoms of such an infection, he should be seen by a veterinarian and have a stool sample tested.
There are some parasites, such as roundworms, hookworms, toxoplasma and giardia, that can be transmitted from pets to people. However, the risk is extremely small if you make sure your companion animals receive proper health care, including regular physical examinations, fecal analyses, vaccinations and appropriate treatment when ill.
Many infections can be prevented by avoiding the feces of other animals. If your companion animal has been infected with an intestinal parasite, picking up his feces right away, and disposing of them properly, can minimize the chances of reinfection. Pet food should never be placed directly on the ground. Food and water bowls cleaned daily will help decrease exposure to parasites.
Taking the steps necessary to keep your pets free from parasites is a vital part of caring for them.
(Taken in part, with permission, from Pet Veterinarian, January-February 1990)