Petco Text Logo
Petco Pet Logo

Why is my cat suddenly gaining weight and aggressive to other cats?

Updated On September 23rd, 2025

Pet's info: Cat | American Shorthair | Female | spayed | 2 years and 5 months old

Why has my skinny 3 year old cat gained so much weight so fast and very miserable towards the other cats all of a sudden hisses and spits at our other 2 cats and never did before?

1 Answer

Most Helpful Answer

Image profile

Answered By Andrea M. Brodie, DVM

Veterinarian

Published on November 4th, 2016

Gaining so much weight all of a sudden could be a sign of metabolic disease or an endocrine disease such as diabetes. She may feel ill and vulnerable and therefore tries to keep the other kitties away from her. Please take her to your vet ASAP for an exam and blood tests.

Vote icon

1Pet Parents found this answer helpful

image
Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Sponsored