By Jennifer Copley (Last Updated 21 November 2011)
An insatiable appetite is usually a symptom of a larger problem. Excessive eating (polyphagia) may be accompanied by some of the following behaviours:
- Accepting less desirable food that would have been ignored in the past
- Jumping on kitchen counters to steal food
- Eating an entire meal in one session
- Eating rapidly enough to induce vomiting
- Pestering owners for extra feedings and snacks
- Begging or stealing food from neighbours
Additional symptoms indicating a health problem include:
- Drinking more than usual
- Increased vocalization (howling)
- Persistent vomiting
- Urinating more frequently
- Urinating or defecating outside the litter box
- Weight loss
Medical Conditions That Increase Appetite in Cats
Medical conditions that can trigger intense hunger include the following.
Brain Injury or Disease
A trauma, tumour, or infection affecting the brain’s satiety center can make it impossible for a cat to know when he’s full and should stop eating. Treatment varies depending on the illness or injury.
Cancerous or Benign Tumours
Tumours that produce insulin, interfere with nutrient absorption, or cause the secretion of growth hormone may trigger an insatiable appetite. Treatments include surgery, radiation, or chemotherapy.
Long-term use of corticosteroid medications and tumours of the adrenal and pituitary glands can cause the body to release excess cortisol, leading to hyperadrenocorticism (Cushing’s Syndrome). The symptoms of this relatively uncommon disease include polyphagia, increased thirst and urination, and the development of a pot belly. Approximately 50% of adrenal tumours and the majority of pituitary tumours are benign. Treatment may involve weaning the cat off corticosteroids, surgically removing the afflicted gland, radiation, or medication.
The prevalence of diabetes among cats has skyrocketed due to cheap, high-carbohydrate cat foods. In addition to polyphagia, symptoms of diabetes include increased thirst, increased urination, and weight loss (or in some cases, weight gain). Diabetes can be controlled with proper diet and insulin injections.
Hyperthyroidism speeds the body’s metabolism, leading to hyperactivity, weight loss, intense hunger, and possibly diarrhea and vomiting. Treatment may involve medication, surgery, or radioactive iodine therapy.
Although microbial infections are more likely to cause loss of appetite, in some cases, particularly when the infection interferes with nutrient absorption, the cat may feel ravenous.
Inflammatory Bowel Disease (IBD)/Irritable Bowel Syndrome (IBS)
IBD/IBS interferes with the absorption of nutrients, causing diarrhea, vomiting, weight loss (even if the cat eats large amounts of food), and in some cases, defecating outside the litter box. Treatments include medication and dietary changes.
Parasitic infestations that can trigger increased appetite include tapeworms, roundworms, hookworms, and heartworms. Flea infestation and feeding raw meat increase the risk of parasite infestation. Prevention includes eradicating fleas, keeping cats indoors, and routine deworming, particularly for outdoor cats.
This disease of the liver can cause weight loss despite a big appetite. Lymphocytic Cholangitis is treated with medication.
Benzodiazepines, antihistamines, and many other medications can stimulate appetite in cats.
Disorders of the pancreas can cause vomiting and diarrhea or the passing of bulky, foul-smelling stools because nutrients are not digested properly. Treatment may involve medication, dietary changes, and withholding oral food and fluids while rehydrating with intravenous fluids.
Additional Causes of Insatiable Appetite in Cats
A big appetite doesn’t always indicate a medical problem. Non-medical causes of polyphagia include the following.
Metabolism may be increased via heat generation. Cold temperatures can cause animals to burn more calories producing heat and thus feel hungrier.
Competition at the Food Bowl
Worry that his food will be stolen by other pets may cause a cat to gorge out of panic. This problem can be solved by feeding pets in separate rooms with closed doors.
If an owner plays with his cat more often, purchases an exciting new toy or cat tree, or takes the cat out walking on a leash, the cat will burn more calories than usual. The arrival of a new pet that the cat plays with or fights with can also increase calorie burning, as can moving to a new home with stairs.
Poor Quality Cat Food
Cheap high-carbohydrate cat foods don’t meet a cat’s nutritional requirements, so he may eat large amounts yet feel starved all the time, even if he’s becoming obese. This problem can be fixed by switching to a premium high-protein cat food.
Pregnant and nursing cats and kittens experiencing growth spurts have very high calorie requirements. See How Much Food Does a Cat Need? for feeding recommendations at various life stages.
Many cats engage in comfort eating when under stress. The loss of a beloved human or animal, moving house, the arrival of a new pet or baby, or any other major change may trigger overeating. Polyphagia that results from psychological distress can be treated by:
- Providing extra attention
- Engaging in play therapy
- Substituting catnip for high-calorie treats
- Feeding reasonable portions
- Refusing to give in to demands for extra food
To be on the safe side, consult a veterinarian regarding any unexplained change in eating habits to rule out medical issues before assuming that the problem is psychological.
This article is not intended as a substitute for veterinary care and consultation. Medical concerns should be referred to a qualified veterinarian.
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