What could be the medical reason for a cat being fat besides eating too much?

While overfeeding is the most common reason for feline obesity, several medical conditions can also contribute to weight gain in cats. Here are some possibilities:

Hormonal Imbalances:

* Hypothyroidism: This condition occurs when the thyroid gland doesn't produce enough thyroid hormone, slowing down metabolism and leading to weight gain.

* Cushing's Disease (Hyperadrenocorticism): Excess production of cortisol can cause increased appetite, weight gain, and a redistribution of fat.

Other Medical Conditions:

* Diabetes Mellitus: This disease prevents the body from properly utilizing glucose, leading to increased hunger and weight gain despite potentially eating less.

* Polycystic Kidney Disease (PKD): This genetic condition can cause kidney dysfunction, leading to fluid retention and weight gain.

* Feline Leukemia Virus (FeLV): This virus can suppress the immune system and contribute to weight loss or gain, depending on the stage of the disease.

* Feline Immunodeficiency Virus (FIV): This virus can weaken the immune system and lead to various health problems, including weight gain.

* Certain Medications: Some medications can cause weight gain as a side effect.

Other Factors:

* Age: As cats age, their metabolism slows down, making them more susceptible to weight gain.

* Spaying or Neutering: These procedures can lead to changes in metabolism and increased appetite.

* Lack of Exercise: Cats that are inactive are more likely to gain weight.

* Breed Predisposition: Certain breeds are more prone to obesity, such as Persians and Maine Coons.

Important Note: If your cat is gaining weight despite eating a normal diet and being active, it's crucial to consult a veterinarian. They can conduct a physical examination, run blood tests, and perform other diagnostic tests to determine the underlying cause of weight gain and recommend appropriate treatment.