Adult lungworms live in the lungs, primarily in bronchioles and alveoli (basically deep in the lung). The female lungworm lays its eggs about twenty five days following ingestion. The eggs then hatch and afterwards become larvae. These larvae then migrate to the bronchi and trachea where they are coughed up, swallowed again, travel through the intestinal tract and end up in the infected cat's feces.
It is here that the infected feces is often picked up by snails and slugs and starts the whole infection cycle again.
Indoor, non-feral cats are much less likely to contract lungworm since they are not often exposed to slugs / snails or infected birds, rodents. I'm a big fan of keeping cats indoors for this and many other reasons.
If your cat is infected you should isolate your cat from any other cats or dogs lest you risk additional infections.
Lung worms are detected through blood tests, tracheal wash and / or fecal analysis.
Many cats with lungworm show no symptoms. However, others show clinical signs of lung disease. Some common clinical signs include coughing, possible harsh lung sounds and sometimes even fluid in the chest. Your cat may appear to have trouble breathing and might also appear depressed or tired. Some cats lose weight and experience rapid heart rates and respiration.
Several drugs have been used to treat lungworm in cats. Depending on the type of lungworm your vet may use fenbendazole, albendazole or other drugs. Depending on the severity of the infection your vet may even recommend no treatment since many times cats naturally eliminate the lungworms in three to four months. They do this with an intense immune response that causes an intense interstitial pneumonia that helps eliminate the lungworms.
The prognosis is generally good for most cats unless they develop severe secondary pneumonia or other infections.
I have not heard of cat lungworm being transmitted to humans (unlike Roundworms & ringworm et al). However, common sense hygiene especially around the litter box is well advised. Keep me posted. Simba