Rapid Weight Gain in Cats

A cat suddenly may experience rapid weight gain for several reasons. Keep in mind, however, that it is best to take your cat to the vet if you suspect underlying health problems.

  1. Pregnancy

    • Just as in humans, female cats experience significant weight gain during pregnancy, as much as 20 to 30 percent of total body weight, according to the VetInfo website. This weight gain occurs during the middle stages of pregnancy, and a trip to your veterinarian will determine if your cat is pregnant.

    Overconsumption and Inactivity

    • Some cats are susceptible to overeating and laziness, reports the Pet Place website. Prevent unhealthy weight gain by giving your kitty a set feeding schedule and don't allow friends or family members to feed your cat table scraps. Buy interactive toys to engage your cat in physical activity.

    Neutering or Spaying

    • Your cat may experience weight gain after being spayed or neutered. This is because it is less likely to roam and may become more docile. Weight gain after spaying or neutering is prevented through dietary management.

    Hypothyroidism

    • While rare, hypothyroidism is another cause for rapid weight gain in cats. Hypothyroidism causes the metabolism to slow and is often an unintentional result of treating hyperthyroidism. Hyperthyroidism causes the metabolism to increase significantly, bringing weight loss rather than weight gain, among other issues.