Instructions
Switch your kitten's food to a variety with high protein and fat content. Make sure to keep the food in the same form it is used to, whether dry or canned.
Increase the amount of food you normally feed your kitten by 50 percent. The Hillside Animal Hospital in St. Louis says kittens normally need about one ounce of canned food or 1/3 ounce of dry food daily. Therefore, feed your kitten 1.5 ounces of canned food or 1/2 ounce of dry food each day.
Place all the food for the day in one container and leave it out, allowing the kitten to decide when to eat. This is called free-choice feeding and is recommended for underweight kittens by the Virginia-Maryland Regional College of Veterinary Medicine.
Schedule an appointment with your veterinarian and take the kitten for a checkup if it refuses to eat or its condition doesn't improve within a few days.
How to Feed an Underweight Kitten
Kitten owners need to pay close attention to their pet's physical condition. A kitten may lose weight due to medical reasons or because it has been abused by a previous owner. Whatever the case, make sure to feed the kitten appropriate foods in appropriate amounts and, if the cat's condition does not improve, take it to a veterinarian for diagnosis and treatment.