Appetite Loss in Pets: Why it Happens and What to Do


(by Dr. Iuliana Mihai, DVM)

In veterinary clinics, dog or cat owners frequently come and simply say - My dog or cat no longer eats! Very often, this manifestation is the only symptom. The owners do not notice any change other than the loss of appetite (and gradual weight loss, which is a consequence).


In dogs and cats that are fed two or more times a day, this modification in their behavior is easily noticed by their owners. In contrast, in cats that are free-fed with dry food (they have food at their discretion), it is much harder to notice because the rate at which the food ‘disappears’ from the bowl is very low.


Even as a vet, I can panic when my pet loses its appetite or refuses to eat. You’re not alone! So let’s take a minute to explore appetite loss in pets – why does it happen and what to do.


What is Appetite Loss in Pets, Medically Speaking?


We all like to see our pets healthy and happy, but there are moments, perhaps seemingly out of the blue, when they start eating less and less. In some cases, they may even suddenly stop eating.

Pet owners should take the scenario seriously when their pets are having a reduced or absent appetite, as this symptom usually hides health problems that could be life-threatening for them.


A poor appetite or a decreased appetite is represented by a reduced desire to eat, which is known in the medical world as hyporexia or inappetence.


On the other hand, the lack or loss of appetite is called anorexia - not to be mistaken with the eating disorder, anorexia nervosa. Anorexia can be partial or complete. In partial anorexia, your pet will only eat some types of foods, but never enough for a healthy organism.


In pets, there are two types of anorexia: pseudo-anorexia and true anorexia.


In pseudo-anorexia the pet is hungry and would want to eat, but due to certain health conditions, it will be unable to do so. It will take the food in its mouth, will chew it, sometimes it will spit it out or swallow small bits of food, etc. Therefore, pseudo-anorexia is a false anorexia that doesn’t have the lack of appetite as the main symptom.


In true anorexia the pet isn’t hungry and wouldn’t want to eat, and it’s caused by a variety of health conditions, which will be listed in the following lines.


Why Appetite Loss Occurs in Pets?


Sometimes pets can get tired of the food they are constantly fed. No matter if you feed dry, wet or canned, or home-cooked food. They feel the need from time to time for a variation in their diet, or maybe they just don't like the taste and refuse that particular food from the start. We call these pets picky. If you have a picky pet, changing up their diet from time to time is an acceptable way to solve their appetite loss, if they do not have any other medical problem.


However, if your pet is diagnosed with pseudo-anorexia, this condition usually occurs in problems of the oral cavity, which cause pain or discomfort locally, such as


  • Gingivitis
  • Tartar/periodontal disease (with teeth loss)
  • Mouth lesions (ulcers, eosinophilic granuloma in cats)
  • Cancer (mouth, tongue, tonsils, salivary glands)
  • Pain in the chewing muscles
  • Mandibular problems
  • Salivary gland problems (cysts)


Pets could also be dealing with neck and/or back pain or chronic pain anywhere in the body, an abscess behind the eye, nervous system problems that affect chewing and swallowing, high environmental temperatures, etc.

In other words, the pet will want to consume food, but due to certain health conditions or other factors, the act of chewing and/or swallowing is painful.


When it comes to true anorexia, there are many underlying causes that could be the issue, such as:

  • fever
  • systemic diseases (kidney disease, diabetes, liver disease, etc.)
  • intoxication (poisoning)
  • gastric problems (nausea, stomach ulcer)
  • intestinal ulcer or blockage
  • cancers (all types of cancer lead to anorexia)
  • immune imbalances
  • psychological conditions (stress, depression, or anxiety – sometimes they can lead to overeating)
  • side effects of some drugs




What should you do if you notice appetite loss in your pet?

Usually, loss of appetite is a sign that something ‘else’ is happening inside the pet's body.

As a veterinarian, my main advice is to make a visit to your current doctor for a check-up as soon as you noticed that your pet's eating behavior has changed! It’s critical to rule out any of the aforementioned illnesses, injuries or diseases that could be preventing your pet from enjoying his or her meals.


Your veterinarian will need to determine the type of anorexia (pseudo- or true) to approach a proper therapeutic conduct.


Your veterinarian will ask you in detail about your pet's health history (anamnesis) - if your cat/dog has had such episodes before; if you have noticed any other changes in your pet health condition in addition to the loss of appetite; etc.


It will then subject your pet to a thorough clinical examination, which will include:


- a physical examination to determine if there is a physical explanation for its appetite loss (pseudo-anorexia - for example, the pet may have a tumor in its mouth that prevents it from chewing or swallowing);


- abdominal ultrasound to detect kidney, liver diseases, and so on.


- blood tests (blood count and blood biochemistry);


- Feline leukemia virus (FeLV) and Feline immunodeficiency virus (FIV) testing in cats, parvovirus and coronavirus testing in dogs, etc.


- radiography (especially in intestinal blockage);


- and in some cases, endoscopy and/or biopsy, depending on what is found at the previous tests.


The treatment of appetite loss differs from case to case and is established according to the primary condition. Usually, when the animal is not eating, doctors will start treating it with IV fluids to rebalance the body's functions.


It is important to remember, especially for cat owners, that if their cat does not eat food for more than three days, they can develop hepatic lipidosis or fatty liver disease. In this disease, the liver function is compromised, and the prognosis of anorexia becomes poorer.



What if I Just Have a Chronically Picky Eating Pet?


If you are sure your pet is healthy and you are dealing with a picky eater, here are some tips that might do the trick:


  • If you are feeding your pet cooked food or canned food that comes directly from the fridge, it is recommended to heat it to body temperature (100° F/38° C).


  • If your pet consumes only dry food, try adding wet/canned food over it to enhance the flavor and make it more palatable.


  • You can add chicken, beef, or vegetable broth (no salt) over your pet’s food to enhance the flavor. For cats, you can add the liquid that comes from the canned tuna (in water) over their food to stimulate their appetite.



  • You can also prepare a home cooked meal for your pet according to your veterinarian’s directions.


  • For cats, you can also try replacing the food they eat with a different texture (for example, pieces instead of pate/mousse or vice versa). As well, you can try to "tempt" your cat with pieces of turkey or tuna (cooked and without salt) or sprinkle their food on top with catnip - they will be attracted by it and may want to eat it, and they can start eating the food too.



  • There is also the option of feeding with a syringe (force feeding), but this method can cause aversion to the pet for food because it can be stressful (especially for cats). This method should only be used by a veterinarian to be applied so that the animal can feel the taste of the food in its mouth and try to eat on its own.


  • There are also appetite stimulants that can be prescribed by your veterinarian.





What is important to remember?


  • Lack of appetite poses a great risk to their health.


  • The longer your pet stays without food, the greater the chances of developing hepatic lipidosis (in cats), and the less likely it is to want to eat in the coming days.


  • Even if you may think that your pet is healthy, at the first signs it shows (the pet is not eating as it used to), it is advised to take your dog or cat to the vet immediately! Don't wait for your pet's appetite to completely disappear before taking him to the vet!




Dr. Iuliana Mihai, DVM, Masters In Small Animals And Equines Pathology

Iuliana graduated from the University of Agronomical Sciences and Veterinary Medicine in 2012, Romania. She has a Master’s degree in Small Animal and Equines Pathology and a strong affinity for Veterinary Parasitology and Laboratory. In 2013 she started her Ph.D. in epithelial cancer in dogs and cats. She volunteered at the faculty’s clinic at her 3rd year of study, and continued her career in small animal pathology and laboratory. She has one cat and eleven rats. Her interests outside of work include traveling, writing, and crafting.






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