If your cat is having difficulty breathing and experiencing coughing fits, lungworms could potentially be the cause. Although lungworms are relatively uncommon in cats compared to intestinal parasites, if they're contracted, they can negatively impact your cat's health. Therefore, it's important to understand what these microscopic invaders do. Read on to learn more about what lungworms are and what cat lungworm treatment would consist of.
Understanding Lungworms in Cats
According to CriticalCareDVM, lungworms are parasites that live in and negatively impact the respiratory system of cats. Roundworms are the most common type of lungworm seen in cats, the two main species seen being Eucoleus aerophilus and Aelurostrongylus abstrusus.

- Eucoleus aerophilus: This species lives in the windpipe (trachea) and large airways. Cats become infected with Eucoleus aerophilus by accidentally consuming parasitic eggs or larvae.
- Aelurostrongylus abstrusus: This species lives in the lungs, and it can infect cats if they have eaten a bird, rodent, frog or lizard that has recently eaten a snail or slug that contains the worms.
When a cat ingests the larval or egg stage of a worm, the larva develops in the intestine, migrates out of the intestines through the bloodstream and travels to the lungs, where it develops into an adult and lays more eggs. The eggs then hatch into larvae which are coughed up, swallowed and passed out in the feces where they are eaten by snails and slugs, and the cycle starts all over again.
Cats that hunt or scavenge, roam freely or live in multi-animal households are at higher risk for contracting lungworms than other cats.
Identifying the Clinical Signs
Clinical signs of lungworms in cats are usually related to the respiratory tract and associated with bronchitis or pneumonia. Some of these signs may include:
- Coughing (which may look like retching or attempting to vomit)
- Fast or abnormal breathing patterns
- Pale gums
- Wheezing
- Nasal discharge
- Increased sleep
- Decreased energy
- Decreased appetite
You may also find your cat hiding more, grooming less, or not wanting to jump or play like they normally do. In some cases, lungworms in cats may cause no signs at all and may only be diagnosed during a routine annual fecal exam by your veterinarian.
