Lungworm is a lung infection most commonly found in stray cats, free-roaming cats, and outdoor cats that hunt.
What Is Lungworm?
Lungworm is a parasite that infects your cat’s lungs. There are several types of parasites that cause infection, but the most common is Aelurostrongylus abstrusus. Others include Eucoleus aerophilus, also called Capillaria aerophila, and Troglostrongylus brevoir.
Different strains tend to commonly infect different areas of the lung. A. abustrus normally infects the branches of the lungs called the bronchioles, the tiny air sacs called alveoli, and the alveolar ducts that connect the bronchioles to the sacs. E. aerophilus grows in the lungs, but also attaches to the windpipe.
As the larvae grow, the immune system sends different types of immune cells to the area. If, in spite of this, they reach maturity, the parasites can begin to cause damage to the lungs and lead to more noticeable symptoms.
How Do Cats Get Lungworm?
Cats get lungworm from the environment. The parasite infects slugs, snails, frogs, lizards, cockroaches, birds, and rodents. Cats get infected when they drink water or eat animals infected with larvae.
From the gut, the young worms migrate through the bloodstream to the lungs and lay eggs. Cats cough up the eggs, swallow them, and pass them into the environment through their stool. Slugs, snails, and other animals eat the stool, become infected, cats eat them, and the cycle continues on.
Outdoor cats, stray cats, or cats that hunt and eat animals are more likely to get lungworm. Cats don’t get lungworm from people and usually don’t get them from another cat. Some studies suggest that an infected mother cat might be able to pass them to her kittens, though.
What Are the Symptoms of Lungworm in Cats?
Most healthy cats can easily handle a mild lungworm infection, and they have no signs or symptoms. In general, though, the more parasites there are, the worse the symptoms, and your cat’s age and general health can also affect the infection. Young, old, and sick cats might have a harder time.
Symptoms of lungworm in cats can include:
How Is Lungworm in Cats Diagnosed?
Your vet will take your cat’s history and symptoms and do a physical examination. If your cat hunts or free-roams outdoors, and you live in an area where lungworm is common, your vet might suspect the parasite. However, lungworm can look like other conditions and can be hard to diagnose, so your vet will need to run some tests.
In some cases, your vet might analyze a stool sample for larvae, but cats don’t always pass eggs through the stool, so while it’s a simple test, it’s not always the most reliable.
Sometimes your vet might do a lung wash sample, where they flush sterile fluid into your cat’s windpipe and then quickly suction the fluid out. They test the sample for parasites and larvae and to rule out bacteria or other problems.
Your vet might also do a chest X-ray, which can show inflammation in the lungs. Parasites don’t typically show up on an X-ray scan, though, so diagnosis usually results from other tests.
What Is the Treatment for Lungworms in Cats?
If your cat has a mild lungworm infection without symptoms, it usually gets better on its own within a few weeks.
If your cat has serious symptoms, you’ll need to take them to the vet. With treatment, cats get better without complications. If an infection goes untreated, though, it can lead to worse lung problems, so you shouldn’t rely on at-home or natural treatment for lungworm in cats.
Your vet will prescribe a deworming medication, which can include:
- Ivermectin
- Moxidectin
- Selamectin
- Emodepside
- Fenbendazole
Sometimes, a parasite infection can also lead to other bacterial infections. If your cat gets pneumonia at the same time, your vet will prescribe antibiotics, too. If the infection is severe, your vet might also give your cat steroid medications, oxygen therapy, and keep them in the hospital for monitoring.
Can You Prevent Lungworm in Cats?
Since cats get lungworm from eating infected animals, the best way to prevent cats is to limit free-roaming and outdoor hunting.
Regular worming medication can also help kill parasites before they become a problem. The worm medications you find in the store might not treat lungworm in cats, though. Your vet can give a regular medication called a spot-on, which is given on the back of the neck. It can help treat other problems like ticks or fleas, too.
Most cats get better with treatment, so talk to your vet if yours show signs of a lung problem.
