Cat roundworm infestation is usually less severe than other worms in cats. It is, however, a common occurence, and if your cat has it he or she needs to be treated.

Your vet should be testing your kitten at the initial check ups, and will typically treat kittens even when they test negative. After that, testing will be done once per year at your cat's annual check up.

Here are 7 things to know about cat roundworm.

• How Cats Get It :
  Roundworm eggs begin infiltrating your cat's body by getting into the intestinal tract orally. This can be from eating infected prey, or by coming in contact with eggs in the soil.
  
  This makes outdoor cats more susceptible, especially those that hunt. Kittens may contract the worm from their infected mothers. Dormant worms reactivate during pregnancy and sometimes make their way into the mammary glands.
  
  

• Roundworm Gets Around:
  Almost all kittens have roundworm, and even if they test negative, are usually treated for it. Although most cases are not severe, roundworm is dangerous in kittens if left untreated and can cause death.
  
  

• What Roundworm Is:
  Cat roundworm (Toxascaris leonina and Toxocara cati) according to Cornell University's Feline Health Center, are the most common of the feline intestinal parasites.
  
  T. leonina may also infect dogs, so your cat's housemate or neighbor may have it too. Infection rates are an estimated 25 to 75% (higher in kittens).
  
  

• When You See Them:
  Adult roundworms described as having thin, tubelike bodies that resemble strands of spaghetti. I know that's not very appealing, but you usually won't see them unless your cat vomits them up, which is also not very appealing. They are white-ish or cream in color.
  
  

• Where They Go Once Inside:
  Unlike hookworms and some others, roundworms are not tissue feeders. They do not attach themselves to the inside intestinal wall, but freely swim in the gut of the cat.
  
  The lifecycle is different for Toxascaris and Toxocara. T. leonina go straight to the intestines and take two to three months to mature. T. cati, on the other hand, migrate through tissue wall making their way to the throat via the lungs and back into the intestines.