Last Updated on March 10, 2021 by Julia Wilson
At a glance
About: Anorexia is the medical term for loss of appetite; it is a symptom rather than a disease and a sign that something is not right with your cat.
Causes: There are many causes which include systemic disease, cancer, pain, nausea, infection, parasites and dental problems.
Diagnosis: Your veterinarian will perform baseline tests, plus some additional tests depending on his index of suspicion.
Treatment: Depends on the underlying cause but will include supportive care such as appetite stimulants, anti-nausea medications, and nutritional support, if necessary.
Anorexia is the medical term for loss of appetite. It is not a disease; rather, it is a symptom of a disease or underlying problem. It can begin as a decrease in appetite at first, and progress to a complete refusal to eat.
Loss of appetite is very common in cats who are not feeling well. Reasons can be divided into fussiness, stress or sickness.
Dozens of medical causes can lead to a loss of appetite. Pain and/or nausea can both cause a cat to stop eating.
- Gastrointestinal ulcers: Gastric ulcers (peptic ulcers) are open sores that develop in the deep layers of the stomach lining or duodenum (the first part of the small intestine leading out of the stomach) due to exposure to the stomach acid (hydrochloric acid) and digestive enzymes which are required for the digestion of food
- Bacterial infections: Salmonella, E-coli, leptospirosis.
- Coccidiosis: Protozoal infection, most commonly occurs in kittens under six months of age.
- Haemobartonellosis: Infection caused by one of two mycoplasma (a type of bacteria) which attach themselves to the walls of red blood cells causing destruction.
- Histoplasmosis: Fungal infection primarily affecting the lungs and gastrointestinal system.
- Heartworm: Parasitic worm infection of the heart.
- Viral infection: Feline herpesvirus, feline panleukopenia virus, calicivirus, feline leukemia virus.
- Pyometra: Bacterial infection of the uterus in intact females.
- Addison’s disease: Insufficient secretion of adrenal hormones.
- Anemia: Reduced number of red blood cells due to several factors such as disease or blood loss.
- Feline diabetes: A condition in which the pancreas doesn’t make enough insulin or because cells fail to respond to insulin.
- Glomerulonephritis: Inflammation of the glomeruli, which are tiny filtering units in the kidneys.
- Hypercalcemia: High levels of calcium in the blood.
- Kidney failure: Either acute (sudden onset) or chronic (slow and progressive), kidney failure is a medical condition in which kidney function begins to fail, leading to a build-up of toxins in the body which can make the cat feel nauseous.
- Portosystemic shunt: Abnormality of the liver caused by the abnormal development of blood vessels draining into the intestinal tract. As the liver is unable to function efficiently, toxins build up in the bloodstream causing nausea and neurological disturbances.
- Abscess: A walled-off collection of blood and other debris within the tissue.
- Certain medications can affect appetite.
- Injury or trauma.
- Intestinal obstruction: A gastrointestinal blockage refers to the blockage anywhere from the stomach (gastro) to the intestines. Thankfully gastrointestinal blockages are less common in cats than they are in dogs; however, they can and do occur.
- Ingestion of poison.
- Neoplasia: Also referred to as malignant neoplasms or malignant tumours, cancer is the uncontrolled division of cells that normally should be restrictive in their growth.
- Pancreatitis: Inflammation of the pancreas which is extremely painful and can cause nausea.
- Vaccinations: They can make your cat feel a tiny bit unwell for a short period. Your cat’s appetite should return within a day or two.
When to see a veterinarian
If your cat has not eaten for more than 12 hours, seek veterinary advice. Cats can quickly develop life-threatening hepatic lipidosis. Hepatic lipidosis is caused when a cat becomes anorexic, and the body begins to use fat stores as fuel. These fat stores are sent to the liver, to be broken down to supply nutrients. Unfortunately, the liver sometimes becomes overwhelmed and is unable to process this fat as quickly as necessary, leading to a build-up of fat in the liver, which interferes with normal liver function.
The veterinarian will perform a complete physical examination and diagnostic workup. During the examination, the veterinarian will check for wounds, abscesses, internal or external masses, assess body condition and palpate the abdomen to feel the size and shape of the organs.
A complete oral examination to look for gingival or dental disease, broken teeth, check for a foreign body and tumours.
- How long has the cat not been eating?
- Are there any other symptoms?
- What diet is the cat on?
- Have you changed diets recently?
- Is the cat urinating and defecating normally?
- Is it up to date on parasite control?
- Baseline tests (complete blood count, biochemical profile and urinalysis) to check for metabolic disorders, inflammatory/infectious diseases or neoplasia.
- Abdominal x-ray and or ultrasound to check for abnormalities in organ size and shape, gastrointestinal obstruction or neoplasia.
- Thoracic (chest) x-ray and or ultrasound to check for abnormalities in organ size and shape, cardiac disease, inflammatory infections/diseases.
- Fecal exam to check for parasites.
How to encourage a cat to eat
It is so easy for a sick cat to lose his appetite, but there are ways you can try to encourage him to eat.
- Heating food can help release the odours; this can be enough to stimulate his appetite. Food should be heated up to around body temperature (think the temperature of a mouse).
- Offer the cat highly palatable food such as tuna, prawns or shredded chicken.
- Try hand-feeding him; it may be the push he needs to eat.
- Feed small amounts of food but often.
- Syringe feed. This involves removing the needle from a syringe, adding some moist food and syringing into the cat’s mouth.
- Add a little tuna juice to his food.
- Place some grated cheese on top of his food.
- Place food bowls in a position that is easy for your cat to access. A cat who is in pain, for example, may find it difficult to bend over to eat.
- Make sure the food bowls are clean.
- A blocked nose (common with cat flu) impacts the cat’s sense of smell, and if the cat can’t smell, the appetite will decline. Wipe away nasal discharge regularly and use a humidifier which can help the discharge drain from the nose.
- Ensure the cat is feeling safe and comfortable. If he is not feeling well, he may need somewhere quiet away from noises and other pets.
- If the cat requires a hospital stay, speak to the veterinarian about the possibility of visitation. I have had a hospitalised cat who wouldn’t eat for the veterinarian, but I was able to hand-feed him during visits.
- Ask about a nutritional supplement such as Nutrigel. This high-calorie product is squeezed into the mouth and can a) help to sustain the cat while his appetite is down and b) kick-start the appetite.
The goal of treatment is to find and treat the underlying cause, which is beyond the scope of this article. Supportive care is essential while the cat recovers will include:
These may be prescribed to encourage your cat to eat. Mirtazapine an anti-depressant that can also stimulate the appetite. Maropitant citrate is an anti-emetic (vomiting) medication, which can also relieve nausea, which is a common reason why cats lose their appetite. Mirtazapine and Maropitant can be used together in some cases. Other appetite-stimulating medications include cyproheptadine (Periactin) an antihistamine and corticosteroids such as prednisone.
If the above methods don’t work and your cat is still not eating, your veterinarian may have to tube feed your cat until his appetite comes back. A feeding tube is a plastic tube that is placed either through the nose (naso-esophageal feeding tube), through the skin of the neck and into the esophagus (esophagostomy feeding tube), or through the wall of the abdomen and into the stomach (gastrostomy feeding tube).
A short general anesthetic is required to insert the esophagostomy or gastrostomy feeding tubes. Soft and watery food is then placed into the feeding tube to provide adequate nourishment until the appetite returns. A cat with a feeding tube may be treated in-house, or once the tube is inserted, may be treated at home.
This can include fluid therapy to treat dehydration, analgesics to manage pain and anti-nausea medications.
If an underlying medical cause isn’t the cause, it is important to look at other possible reasons your cat is not eating. There are several possible causes, including:
Dirty food bowls:
Nobody wants to eat from a dirty food bowl, and that goes for our cats too. Not only do they pose a risk due to old food stuck to the sides becoming contaminated, but they also smell. Wash food bowls in hot soapy water at least once a day.
Sharing food bowls:
Cats are not social eaters; they prefer to eat on their own. Not only that, but a more dominant or food-obsessed cat can hog the bowl. Each cat should have its food bowl.
A sudden change in diet:
There’s a school of thought that cats should be fed the same food every day and it’s not good to swap foods around. I have always given my cats a variety of foods, including canned, dry and raw, which means they are less likely to go on hunger strike.
Cats who have only been fed one type of food can be quite sensitive to changes in diet. If you do want to (or need to) change his diet, do so over a few days. Start by adding a small amount of the new food to his regular food and slowly increase the new food while decreasing the old. A loss of appetite is often one of the first signs that your cat is feeling unwell. Always be alert and aware of how much your cat is eating and seek veterinary attention if he does stop.
Inappropriate food bowl location:
Firstly, your cat’s food and water bowls should not be located near their litter trays. Location is important. Bowls should be located in an easy to access area, but out of the way of high traffic. If your cat has to navigate three flights of stairs to locate his bowl, or pass the resident dog who bails him up, you have a potential problem.
Food left out for too long:
Fresh food (canned or raw) will go off quickly, particularly in warmer months. Don’t dump a huge mound of fresh food in his bowl and leave it there all day. If the food doesn’t smell safe, your cat won’t eat it. It is better to feed a small amount of food, more often. Remove and discard uneaten fresh food after 20 minutes.
Being bailed up by a dog, another household cat or your toddler while eating can create negative associations with feeding. Cats need to feel safe and calm during mealtimes.