Kittens can generally be taken from their mother and littermates once they are weaned, beginning at 6 to 7 weeks of age. Kittens, like babies, require a lot of attention, including veterinary care, feeding, and socialization.
Like puppies and human babies, kittens receive a certain degree of immunity (known as maternal immunity) that is passed from their mothers at birth and also shortly thereafter through the milk. Vaccinations cannot effectively stimulate the kitten’s immune system until this maternal immunity wears off. Because maternal immunity declines slowly over time, kittens should be vaccinated according to a regular schedule, beginning at 2 to 3 months of age. This ensures that the kitten receives an effective dose of vaccine soon after maternal protection is gone. Restricting access to unvaccinated cats until the full series of vaccinations has been given is important to avoid disease.
Intestinal parasites are most common in kittens. Larvae may be passed through the placenta or mother’s milk. Worms are so common that kittens are often treated with a broad-spectrum wormer as a routine preventive measure. Fecal examinations, with additional treatments as necessary, are usually repeated after worming until 2 successive fecal examinations are negative. External parasites (including fleas) should also be treated but only with products approved for use on kittens. Cats that are allowed outdoors or that live in mixed-pet households should be treated with appropriate antiparasitic products to prevent infestation of all pets and the house.
Proper nutrition is important throughout a cat’s life and is especially critical during kittenhood. Growing kittens need more calories, fat, protein, vitamins, and minerals to meet their needs for rapid growth and development. Kittens need multiple daily feedings of a specially formulated kitten food. The number of daily feedings can be gradually decreased as the kitten ages, but feeding with a name-brand kitten diet should continue until adulthood (about 9 to 12 months of age).
Cats learn how to socialize with other cats from their mother and littermates. Human contact before kittens reach 10 to 12 weeks of age is usually required for cats to become good pets. Cats that have not had this initial socialization will likely always fear and avoid human contact. This makes it difficult to turn older feral (wild) cats into household pets. Playing with your cat and providing interactive toys can help develop a close bond, as well as decrease destructive behaviors.
Introducing cats to other pets, including—and sometimes especially—other cats, can take additional socialization regardless of age. Some cats can be territorial and view a new cat as an intruder. This can lead to undesirable behaviors such as urine marking, soiling outside the litter box, or fighting with the newcomer. Cats should be introduced to any new animal gradually. For example, the cat and the new animal should be allowed to first smell each other through a gate separating rooms, then each animal should be held while allowed to investigate each other more thoroughly. After a day or two, if both animals appear calm in each other’s presence, they can be allowed together while supervised for short periods, gradually leading to longer times. Patience is often necessary while animals are adjusting to one another in multi-pet households. It can take 6 months or more to completely integrate a new cat into a household with other cats.