9 Health Risks for Overweight Cats (Vet Answer)

Written and fact-checked by Dr. Stacie GrannumVet Approved

Reviewed & Fact-Checked byDr. Stacie GrannumDVM (Veterinarian)Dr. Stacie Grannum was born and raised in Arizona. When she was five, an encounter with a tiny animal changed her life forever. A baby bird fell high from its nest, and Dr. Grannum diligently cared for it. Sadly, despite her attempts to save the little birds life, the little bird did not survive. From this heartbreaking loss came a new ambition, carving the path that Dr. Grannum followed. She knew that she wanted to pursue a career in veterinary medicine. She worked hard toward that goal and dedicated her time to pursuing her dream.View authorThe information is current and up-to-date in accordance with the latest veterinarian research. Read about our vetsUpdated on October 11, 2026

“Chonky” cats, though rather adorable, may be prone to serious health risks due to being overweight. Nearly 60% of cats in North America are overweight, making obesity one of the most common and preventable diseases affecting domestic cats today. A cat is considered overweight when they are more than 10–20% above their ideal body weight and obese when they’re over 20% of their ideal body weight.

Why Is Excess Body Fat Unhealthy in Cats?

Fat secretes inflammatory hormones and produces oxidative stress in tissues and organs. Oxidative stress occurs when there are excessive free radicals in the body and not enough antioxidants to get rid of them. This can damage organs and tissues and may result in various diseases. Currently, obesity is treated as a chronic, low-level inflammatory condition in cats.

Here are the types of felines that are prone to obesity:

Middle-aged cats (8–12 years old)
Spayed or neutered cats
Indoor cats

The 9 Risks Associated With Being Overweight or Obese

1. Diabetes

Obesity can make diabetes more difficult to control. Insufficient insulin production or response to the insulin hormone can lead to diabetes mellitus. Insulin is essential for the regulation of glucose, or blood sugar.

domestic striped kitten with a sad face feels sick — Image Credit: Julia Cherk, Shutterstock

2. Heart Disease and High Blood Pressure

Excessive weight can place extra stress on the heart and circulatory system. Extra weight can also impair lung function.

3. Anesthesia Complications

Extra fat may prevent anesthetic drugs from being metabolized properly, which can lead to an overdose.

4. Kidney and Urinary Disease

Kidney-related issues may develop due to excessive body fat, including enlarged kidneys and scarring of the delicate filtering units in the organs. Obesity can also be a risk factor for feline lower urinary tract disease.

Siamese-elder-cat-sick-with-cancer-has-a-feeding-food-tube-attached-to-its-nose-to-stomach — Image Credit: SUJITRA CHAOWDEE, Shutterstock

5. Liver Disease

Obese cats that suddenly stop eating may develop a serious and life-threatening liver condition known as hepatic lipidosis. Excessive fat accumulation in the liver can lead to liver failure.

6. Arthritis

Excessive weight on joints adds to the wear and tear of the bones and cartilage and can lead to painful chronic conditions, such as osteoarthritis.

male vet examining a cat with stethoscope in clinic — Image Credit: Africa Studio, Shutterstock

7. Immunodeficiency

Chronic inflammation due to excessive fat may cause an immunodeficiency and may make it difficult for your cat to fight off infections. This may also lead to cancer.

8. Grooming Issues

Obese cats may have difficulty reaching and grooming themselves, which can lead to a matted, greasy, soiled, and unkempt hair coat. Improper grooming may also lead to skin infections.

9. Shorter Life Expectancy

Excess body fat can shorten a cat’s lifespan and lead to disease. According to the VCA, “a 2.8-fold increase in mortality has been shown in obese cats (8–12 years old) compared to lean cats.”

We recommend getting advice from a veterinarian if you have any questions or concerns regarding your pet's diet and weight.

Conclusion

Obesity in cats can lead to several health issues. Preventing obesity, however, often incorporates the right amount of exercise and nutrition to keep your cat fit and trim. Discussing your cat’s medical history, lifestyle, and diet with your veterinarian often leads to healthier pets in the long run.