What could be causing my 9 month old kitten to lose weight?

One of the reasons he might be throwing up is because he's eating it too fast. My cat will throw up her food if she consumes it REALLY fast. Try putting down only a little bit three times a day, so that it will equal up to as much as you usually give him.

Another reason might be that the food is too rich for him. Having a rich food can upset an animal's stomach, causing them to throw up or other things. Find a less rich cat food, and SLOWLY switch it over to the new one.

Another reason could be that your cat has a sensitive stomach. Try switching over (again switch over slowly) to a sensitive stomach pet food, or something all natural (good all natural ones are Core, Nature's Logic, Eagle Pack Hollistic and so on).

I hope those will solve it, and help your cat get back to a health weight! Good luck!

Note: also like the person above said, worms will make a cat loose weight. If nothing else works, take him to the vet and have him tested for worms

First off 9 is not old. Cats can live past 20 so don't attribute anything to age here 2ndly, you probably did the worst thing. This isn't worms unless you have seen them. Is there excess drinking? There are many treatable possibilities here like diabetes, hyperthyroid ect. By not going to the vet,fo a much needed blood test, this poor cat is probably being condemned Find a way to go to the vet

Yeah it could be worms.

I would try to scrape up the $ to take him to the vet tho. Just to make sure there isn't anything else going on in his little system.

Good luck.

has your kitten had any shots? you should take a stool sample to your vet so they can rule out any internal parasites. sounds like it could be worms or a feline disease.

worms can make them sick and thin