At 11-13 weeks, your kitten will need a second round of deworming. Flea, tick and heartworm prevention can begin at this age as well. Remember, prevention is the best defense against these nasty parasites. We recommend Revolution monthly topical to prevent heartworms, fleas and ticks in cats, but never use parasite preventative not approved specifically for kittens.
Cats can get heartworm after being bitten by a single infected mosquito, and as little as 2-3 heartworms can kill cats. For more information, visit the American Heartworm Society, which has guidelines and information for detection, treatment and prevention of heartworms.