8 Common Causes Of Sudden Weight Loss In Cats

Written by: Adri Sandoval
Adri Sandoval is the Special Projects Manager for iHeartDogs and iHeartCats. Her work has deepened her love for animals, fostering a strong passion for rescue and animal advocacy.Read more
| Published on April 21, 2017

Many people want to lose weight and many pets should lose weight. But what can cause your cat to lose weight when you haven’t changed what or how much you feed them? Should you be concerned? Only the vet can determine the reason for your cat’s unexpected weight loss, but here are 8 common causes of weight loss in cats.

#1 – Cancer

This is potentially the scariest thing on the list, so let’s get it out of the way first. Not all cat weight loss is caused by cancer, but it is a fairly common diagnosis. Other symptoms tend to include loss of appetite, lethargy, and hiding.

#2 – Toothache

On the other end of the “scary spectrum,” sore teeth may cause a cat to stop eating, resulting in weight loss. Other signs of tooth problems include drooling and pawing at the mouth. A tooth extraction may be all that’s needed to get your kitty back to their old self.

#3 – Hyperthyroidism

If your cat is eating more than usual but still losing weight, hyperthyroidism is a likely culprit. It’s the result of a benign hormone-producing tumor on the thyroid gland, which elevates levels of the thyroid hormone. Other symptoms include increased drinking and urination, increased activity, vomiting, diarrhea, and muscle wasting.

#4 – Anxiety, stress, or depression

Stress affects everybody differently. In cats, stress can cause them to stop eating. A few things that can upset cats include excessive noise, other animals near their feeding area, dirty food dishes, or having the food dish too close to the litter box. Or, if something tragic has happened – like a death in the household – they may become depressed.

#5 – Diabetes

Weight loss is a common symptom of diabetes, which may be caused by either a failure to produce insulin or a reduced ability to respond to it. Other symptoms include excessive thirst and urination, sluggishness, urinary tract infections, and sweet-smelling breath.

#6 – Intestinal parasites

Otherwise known as worms, intestinal parasites can cause weight loss. Symptoms may not be present, but worms can cause diarrhea, bloating, vomiting, and trouble breathing.

#7 – Organ failure

As cats age, diseases that involve organs, such as diabetes and kidney disease, become more prevalent. These problems are usually detected with blood and urine tests.

#8 – Gastrointestinal issues

Many different problems with the gastrointestinal tract may cause unexpected weight loss, such as inflammatory bowel disease, food allergies, and infections. Other symptoms may include diarrhea, loss of appetite, and vomiting.

As you can see, there are far too many possibilities for you to guess about the problem. Your cat should be taken to a veterinarian for testing to determine the cause of any unplanned weight loss.

(H/T: WebMD)