There are a number of 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 include:
- Has my 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?
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. But to simplify the answer, an adult cat should consume approximately 30 calories per pound, or 60 calories per kilo. So your average 10 pound (4.5 kg) cat should consume approximately 300 calories per day.
Is he getting enough food?
Following the above calorie intake, your cat’s weight should remain consistent. To determine if your cat is overweight or underweight run your hands gently over his ribs. You should be able to feel the ribs but with a slight layer of fat over them. If the cat is obese, you may not be able to feel the ribs at all, if he is underweight the ribs will be prominent.
Another way I like to determine if a cat is getting enough food is by how quickly it is consumed, if it’s all gone within the space of 5-10 minutes and is then back hassling for more, that would indicate to me that he’s not getting enough.
Not consuming enough
There are a number of possible reasons. Multiple cats, where one is dominating the food bowl while another is missing out or an inadequate amount of food, unsuitable food bowl location.
Some cats can become food obsessed. This is especially true of cats who have encountered starvation or food shortages in the past such as former strays or feral cats.
Usually caused by a benign (non-cancerous) tumour on the thyroid gland which leads to an increase in thyroid hormone which speeds up the cat’s metabolism and energy expenditure.
Caused by a tumour of the pituitary gland which stimulates growth hormones. Increased growth burns extra calories.
An endocrine disorder which results in excess production of cortisol. Cortisol stimulates 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.
Insulin-producing tumours of the pancreas. Excess insulin produced by the tumour causes blood sugar levels to drop, 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 a high-quality kitten food and be allowed to eat as much as she wants during this time in her life.
Exocrine pancreatic insufficiency
This condition leads to food not being absorbed as it should.
Which compete with your cat for food.
Such as steroids can stimulate your cat’s appetite.
Your 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 are more commonly seen 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.
If a medical cause is suspected, your veterinarian will need to perform some tests including:
Complete blood count, biochemical profile and urinalysis
These baseline 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
To check for hyperthyroidism.
ACTH stimulation test
To evaluate for Cushing’s syndrome. This measures the ability of the adrenal glands to respond to theadrenocorticotrophic hormone. This 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
To to measure the concentrations of trypsin-like proteins in the serum. A low level indicates exocrine pancreatic insufficiency.
To evaluate the pancreas for insulin-producing tumours.
To check for parasitic worm eggs.
Biopsy of the GI tract via endoscopy
To check for inflammatory bowel disease.
Treatment depends on the underlying cause. If it is behavioural, finding the cause and addressing will be necessary. For multiple cat households, feeding cats separately, even in different rooms if one is snaffling all the food. Feeding smaller quantities of food more often. Trying to slow down consumption of food by making your cat work for it, such as feeding raw/meaty bones or hiding food in kong like toys.
Dietary modifications at first and if this isn’t enough to manage the condition, your cat may have to have daily insulin injections.
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 which is obtained from cow or pig pancreases which help your cat to digest food. Switch to a low-fat, high fibre diet.
This disease has several possible causes and therefore treatments. Gradually withdraw steroids if they are responsible. 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.
Surgery to remove insulin-producing tumours along part of the pancreas if necessary.