Why is my kitten suddenly losing weight and sleeping all the time?

The deworming pill and the symptoms you described have nothing to do with each other, if he is losing his fur and losing weight he is suffering from something serious. Sudden weight loss is always a very big warning light that should not be taken lightly, it's usually a sign of an internal disease that needs to be investigated, i strongly recommend taking him to the vet in order to get it checked, he will need to have a blood test done and possibly an xray as well in order to attempt to diagnose the reason for these symptoms.

Sudden weight loss is always a very big warning light that should not be taken lightly, it's usually a sign of an internal disease that needs to be investigated, i strongly recommend taking him to the vet in order to get it checked, he will need to have a blood test done and possibly an xray as well in order to attempt to diagnose the reason for these symptoms.

These are certainly concerning behaviors for your young kitten. I would be suspicious of intestinal parasites causing the problem, especially if he/she has not yet been wormed. I would recommend taking your cat in to the vet to be checked out and make sure nothing too serious is going on. Hopefully it is something simple like parasites that can be treated easily. Best of luck!

Many things can cause lost weight in kittens, for example- intestinal worms, gastrointestinal disease, IBD, infections, liver disease and pancreatic disease. You need to take her to the vet in order to get it checked ASAP.

Poor Rusty! Cats can have worms even if you don't see them in the feces. Oftentimes, there are eggs in the feces, but those can only be seen with a microscope. Sudden weight loss in cats can also be caused by diabetes, kidney disease, systemic illness, infection, or injury among other causes. I would have Rusty seen by a vet asap, and bring along a sample of his feces for the vet to examine. In addition to looking at his feces, the vet can do a physical exam, blood tests, and a urinalysis to diagnose what is causing his weight loss. Once the cause of the weight loss is diagnosed, the vet can discuss treatment options with you.

Significant weight loss is always a concern, especially if his appetite is good. Hormonal conditions such as diabetes and thyroid disease or poor absorption and digestion of his food is possible and I would recommend a full physical and blood panel as soon as possible in order to stabilise his condition before he becomes too frail

Thanks for using Petco Pet Education Center, formerly Petcoach! Without seeing the cats, it is hard to say. I recommend taking them to the vet with a fresh stool sample to rule out other parasites. Not all deworming medications treat all intestinal parasites. If negative, I would have both cats tested for feline leukemia and FIV. These are infectious diseases that could cause poor growth. Good luck and kisses to the kittens!