There are several possible causes of constant hunger in cats, some more serious than others. Cats don’t tend to be as food-obsessed as dogs and most (but not all) will self-regulate their food intake. However, a common question asked by cat owners is ‘why is my cat hungry all the time’?
Questions to ask
- Has the cat always been like this or has he suddenly become hungrier?
- Is he losing or gaining weight?
- The age of the cat?
- How many cats do you have?
- Is the cat getting enough to eat?
- Is the cat displaying any symptoms of illness?
- Weight loss or weight gain can occur along with an increase in appetite.
- Common causes include pregnancy and lactation, hyperthyroidism, inflammatory bowel disease, diabetes, intestinal parasites, Cushing’s disease, exocrine pancreatic insufficiency, acromegaly and certain medications.
- Any appetite changes warrant a visit to the veterinarian.
- The medical term for an increased appetite is polyphagia.
How many calories should a cat consume in a day?
The answer varies depending on the age of your cat, also a pregnant or nursing female will have higher needs, as cats age they tend to slow down, and their calorie requirements may drop a fraction.
To simplify the answer, an adult cat should consume approximately 30 calories per pound, which translates to 60 calories per kilo. This means the average 10 lb (4.5 kg) cat should consume approximately 300 calories per day. More detailed information on energy requirements can be found here.
Is the cat getting enough food?
Following the above calorie intake, a cat’s weight should remain consistent. To determine if a cat is overweight or underweight run your hands gently over the ribs. You should be able to feel the ribs but with a slight layer of fat over them. If the cat is obese, you will not be able to feel the ribs at all, if he is underweight the ribs will be prominent.
Another to determine if a cat is getting enough food is by how quickly it is consumed, if it’s all gone within 5-10 minutes and the cat is asking for more, that indicates there may be a problem.
Causes of constant hunger in cats
Not getting enough food
There are several possible reasons, which include multi-cat homes where one is dominating the food bowl, inadequate amount of food, unsuitable food bowl location.
Some cats can become food-obsessed, which is especially true with cats who have encountered starvation or food shortages in the past such as former strays or feral cats.
Overproduction of thyroid hormones responsible for metabolism due to a benign (non-cancerous) hormone-secreting tumour on the thyroid gland. Elevated levels of thyroid hormone speed up the cat’s metabolism and energy expenditure.
A disease caused by the overproduction of the growth hormone due to a slow-growing, functional growth hormone-secreting tumour (adenoma) of the pituitary gland which is located at the base of the brain.
An endocrine disorder that results in excess production of cortisol which stimulates the metabolism of fat and carbohydrates to increase sugar glucose levels. When blood sugar levels increase, so do insulin levels, which in turn stimulates the appetite.
Diabetes. See hypoglycemia.
Inflammatory bowel disease
Can lead to poor absorption of food, which results in increased hunger.
An abnormally low blood sugar level, there are several causes including diabetes and insulin overdose. This results in the cells being starved of glucose which is necessary for energy. The brain sends out hunger signals to obtain more food to feed the starving cells.
As the female cat’s pregnancy progresses and her unborn kittens become larger, her food intake should be increased to support the growing demands of the unborn kittens.
A huge amount of calories are required to produce milk to feed a litter of kittens. A lactating queen should be given access to high-quality kitten food and be allowed to eat as much as she wants during this time in her life.
Exocrine pancreatic insufficiency
Also known as maldigestion disorder, exocrine pancreatic insufficiency (EPI) is a disease caused by a failure of the pancreas to secrete adequate levels of pancreatic enzymes which results in an inability to properly digest food.
Roundworm and tapeworm are common intestinal parasitic infections that compete with the cat for food.
The veterinarian will perform a complete physical examination of your cat and obtain a medical history from you including the type of diet your cat is eating, how much, have you noticed any other symptoms, are there any other cats (or dogs) in the house and how are the dynamics between pets, has he always been this way or has the increased hunger happened suddenly, if the cat is a female, has she been spayed or is she nursing kittens, is the cat on any medications? Accompanying symptoms may give your veterinarian a clue as to the possible cause.
The most common medical causes of increased appetite in cats are hyperthyroidism and diabetes, which occur most often in middle-aged to older cats. Diabetes often presents with increased thirst and urination and hyperthyroidism with increased activity, I once read the term ‘cats on coffee‘ when describing cats with hyperthyroidism. Vomiting is common in cats with hyperthyroidism or diabetes.
If possible, bring along a stool sample for your veterinarian to evaluate.
Baseline tests: These tests evaluate organ function, as well as blood cell count, infection and hydration status. Hyperglycemia may be present in cats with diabetes. Hypoglycemia may be present in cats with insulin-producing tumours. Increased liver enzymes may indicate hyperthyroidism, diabetes or Cushing’s syndrome. Increased glucose or protein in the urine can also point to diabetes.
Thyroid function tests: The most common test measures T4 concentrations in the blood. Medical conditions (especially chronic kidney disease), nutrition and medications can all affect T4 levels. 90% of symptomatic cats will have an elevation in T4 hormones which is sufficient to diagnose hyperthyroidism.
ACTH stimulation test: To evaluate for Cushing’s syndrome, this test measures the ability of the adrenal glands to respond to the adrenocorticotrophic hormone which is made by the pituitary gland and travels through the bloodstream to the adrenal glands where it stimulates the secretion of other hormones such as hydrocortisone from the adrenal cortex. The ACTH stimulation test measures the levels of cortisol in the blood before and after an injection of synthetic ACTH.
(fTLI ) feline Trypsin-Like Immunoreactivity: This test measures the concentrations of trypsin-like proteins in the serum. A low level indicates exocrine pancreatic insufficiency.
Diagnostic imaging: X-rays, ultrasound, MRI or CT scan to evaluate for tumours.
Fecal flotation: A test to look for worm eggs, proglottids (tapeworm segments) or protozoan (single-celled organisms) cysts in the feces. These parasites live in the intestines and stomach of the cat and reproduce by releasing eggs or cysts which pass out of the cat via the feces.
Biopsy of the GI tract via endoscopy: To check for inflammatory bowel disease.
Multi-cat households: Feed cats separately, even in different rooms if one is dominating other cats, or feed smaller quantities of food more often. Try to slow down the consumption of food by making the cat work for it, such as feeding raw/meaty bones or hiding food in kong like toys.
Feline diabetes: Dietary modifications at first and if this isn’t enough to manage the condition, your cat may have to have daily insulin injections.
Hyperthyroidism: Surgical removal of the affected thyroid gland(s) or radioactive iodine treatment which destroys the tumour while leaving the thyroid gland intact.
Exocrine pancreatic insufficiency: Pancreatic enzyme extract will help the cat to digest food and switch to a low-fat, high fibre diet.
Cushing’s syndrome: This disease has several possible causes and therefore treatments. Gradually withdraw steroids if they are responsible or surgery to remove the affected adrenal gland if a tumour is present.
Inflammatory bowel disease: Dietary changes such as a highly digestible, low-fat diet, as well as corticosteroids and antibiotics where necessary.
Pregnancy or lactation: High-calorie diet and free access to food. Once she has delivered and weaned her kittens, her appetite should subside.