Roundworms are common feline parasites that can infect cats of all ages. During their lifetime, practically all cats get infected at one time or another because roundworms can even transmit to kittens through the lactating mother.
There are two species of roundworm that predominantly infect cats:
- Toxocara cati
- Toxascaris leonina
Eggs of Toxocara cati pass through the feces of an infected cat. The embryonic worm in the microscopic egg needs a month in the open environment to reach its infective stage. Having reached the infective stage, Toxocara eggs can weather harsh conditions and survive for years.
This second stage larvae are ingested by a cat or by another animal. They hatch in the intestines. This is the primary host of the roundworm. The young roundworm then migrates and gets encysted in other body tissues of the host.
If the primary host is a cat, larvae get enclosed in the cat’s liver. From here onward, the larvae can take two routes depending upon the condition of the host cat.
- A trigger, like stress, can induce the larvae to move on to the lungs and the air passages. From here, it can be coughed up. This third stage larva is generally swallowed and reaches the intestinal tract.
- If the host cat is a nursing mother, larvae move on to the mammary glands instead of the lungs. From here, it passes on to the young kittens through milk.
If the primary host is another animal like mice and rodents, the larvae remain enclosed in the host until it is ingested by a cat.
Toxascaris leonina are a less migratory type of roundworm. When the second stage larvae reach the intestines, they start maturing. The species can mature in the primary host itself.
Symptoms of worms in cats and dogs are very similar. Severe infestation can cause pneumonia when the second stage larvae reach the lungs. In the intestines, roundworms can multiply faster than any other worms in cats and dogs and can therefore cause a blockage in the passage.
Like dog tapeworm, roundworms too pose a substantial threat to humans. The main source of infection is the soil where cats and dogs have defecated. Rather than barring children from playing in such areas, it is better to get the area cleared of animal feces. Adults who work in contaminated areas should take proper precaution against accidental ingestion.