By Jennifer Copley (Last Updated 6 December 2011)
Unlike intestinal parasites such as tapeworms and roundworms, lungworms attack the respiratory tract. Although far more common in dogs, they do afflict cats as well, particularly outdoor cats. Lungworms can be fatal if left untreated.
Cats and dogs may be infected with lungworms when they eat hosts such as slugs, snails, and crayfish, or the birds, rodents, and raccoons that eat these infected hosts. Puppies may also be infected when they eat the feces of infected dogs or via an infected dog’s saliva (often from being licked by their mothers).
Lungworms are relatively rare in urban environments. Animals that go outside and hunt freely, particularly those that live in rural areas, are at greater risk of infection than indoor pets.
Symptoms of Lungworm in Dogs and Cats
Although some pets show no signs of infection, particularly if the infestation is relatively mild, cats and dogs infected with lungworms may have some or all of the following symptoms:
- Weight loss
Coughing is the most typical symptom of lungworm infection, though there are many other possible causes of coughing in cats and dogs, ranging from serious conditions such as heart disease to relatively minor problems such as hairballs.
If lungworms are suspected, it’s very important to treat as soon as possible. Pets usually make a full recovery unless the infection has been left for too long. If the infection is not treated, scar tissue can form in the lungs, causing the pet to suffer a residual cough. If left for long enough, the infection can even be fatal.
Diagnosis and Treatment of Lungworms in Cats and Dogs
Diagnostic tests may include chest X-rays, bronchioscopy, examination of respiratory secretions, blood tests, cardiac ultrasound, and fecal examination. Many of these tests are done to rule out other diseases that can cause coughing. The veterinarian is also likely to perform a heartworm test, as heartworms are another parasite that can trigger coughing fits.
If a cat or dog is diagnosed with lungworms, the veterinarian will prescribe a deworming medication. If the parasite has triggered a severe reaction, the pet may also require 3-10 days on corticosteroids. Follow-up X-rays and another fecal exam should be performed 2-4 weeks later to ensure that the cat or dog is parasite-free.
How to Prevent Lungworm Infection in Cats and Dogs
To reduce the risk of pets being infected with lungworms:
- Don’t allow pets to hunt.
- Keep cats indoors or leash-train them for supervised outdoor time.
- Don’t allow dogs to snack on snails, slugs, or rodent and bird carcasses when out on walks.
- Clean up dog waste immediately.
Can People Catch Lungworms from Dogs and Cats?
Lungworms can’t be transmitted from pets to humans, but other parasitic worms can. See Roundworms, Tapeworms, Hookworms, and Whipworms in Cats and Dogs for information on how to prevent people and pets from becoming infected.
This article is provided for informational purposes only and is not intended as a substitute for veterinary consultation and care.
- Bayer HealthCare. (2009). “Frequently Asked Questions.” Lungworm.co.uk.
- Hines, R., DVM. (2011). “Why is My Dog or Cat Coughing?” 2ndChance.Inf.
- PetPlace Veterinarians. (2010). “Lungworms in Cats” and “Lungworms in Dogs.” PetPlace.com.
- Runnymede Hill Veterinary Hospital. (23 September 2008). “Lungworm in Dogs – Owners Guide.”
- The Merck Veterinary Manual. (2011). “Lungworm Infection: Introduction.” Whitehouse Station, NJ: Merck & Co., Inc.