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Anorexia in Dogs - Causes, Diagnosis and Treatment

Cristina Pascual
By Cristina Pascual, Veterinaria. Updated: January 29, 2024
Anorexia in Dogs - Causes, Diagnosis and Treatment

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Consultations related to anorexia in dogs are among the most common reasons for visits to the veterinarian. The fact that a dog stops eating or eats less than usual is a cause of concern for its owners. Most cases of anorexia in dogs are due to an underlying medical condition. We can remedy this by accurately diagnosing the underlying disease, targeting it, and offering our dog a more palatable diet to increase their appetite.

The following AnimalWised article explains what anorexia in dogs is and the possible causes, diagnosis, and treatment.


  1. What is anorexia in dogs?
  2. How to know if a dog suffers from anorexia?
  3. Causes of anorexia in dogs
  4. Diagnosis of anorexia in dogs
  5. Treatment for Anorexia in Dogs
  6. How to make food palatable for dogs with anorexia

What is anorexia in dogs?

The term anorexia is often used to refer to a dog that is not eating, without assessing whether the lack of food intake is complete or partial. Strictly speaking, anorexia refers to the loss or complete lack of interest in food. Most cases of anorexia in dogs are due to an underlying disease.

In cases where the dog eats its usual food but eats less than the amount required to meet its energy needs, it should be referred to as hyporexia. Dysrexia, on the other hand, is the term used for a dog that completely refuses its usual food but eats other types of food.

Decreased appetite or complete lack of appetite is a clinical sign that can be relatively common in older dogs. If you find that your older dog is not eating as much as they used to, you might be interested in this other article, where we explain all the possible reasons why your old dog is not eating.

How to know if a dog suffers from anorexia?

Since anorexia has already been classified as a clinical sign and not a disease, we cannot talk about the symptoms of anorexia in dogs. We know that a dog is suffering from anorexia when it refuses to eat at all. If your dog's lack of appetite lasts longer than a few days and is not due to an acute illness, you as a pet owner are naturally concerned.

Dogs do not carry the stigma of anorexia as humans do, but the condition can be similarly complex. There can be several factors, both physical and emotional, that contribute to the development of anorexia. While hunger (a physical drive) may be present, appetite (a mental drive) may be decreased, causing your dog to refuse or avoid eating.

The consequences of this loss of appetite depend on its duration. The longer the anorexia lasts, the more severe its negative effects. Therefore, it is important that you consult a veterinarian as soon as you notice that your dog is not eating.

Sometimes we find that our dog refuses to eat but drinks a lot of water. If this is the case with your dog, continue reading this other article on "Why does not my dog eat but drinks water", where we explain the possible reasons and pathologies that could cause this behavior.

Causes of anorexia in dogs

Anorexia is a very non-specific clinical sign, which means that it can occur in the context of various pathologies. Below, we explain the main pathologies and pathological situations, both physical and psychological, in which we can observe anorexia in dogs:

  • Fever: the Hypothalamic Regulatory Center (HRC) acts as a "thermostat" to regulate body temperature. When the HRC detects an increase in body temperature, it attempts to reduce the body's heat production by (among other things) curbing appetite. For this reason, any cause that triggers fever (both infectious agents and non-infectious causes) can cause anorexia.

  • Pain: Any process that causes pain or discomfort in a dog can cause anorexia. We must pay special attention to abdominal pain, pain in the spine (especially due to herniated disks in the neck) or pain of the musculoskeletal system.

  • Neuronal diseases: The absence of signals that are sent from the brain can be factors that cause anorexia in a dog. This happens when the animal suffers from a tumor or a neuronal disease that prevents it from feeling the sensation of appetite.

  • Stress: Stress and anxiety, for example due to loneliness or separation from their caregivers, can be a cause of anorexia in dogs.

  • Digestive disorders: Any disease affecting the gastrointestinal tract can cause anorexia, starting with changes in the oral cavity (lesions of the oral mucosa or dental pathologies). Periodontal disease is a common cause of anorexia in older dogs. Megaesophagus and chronic gastritis are common causes of anorexia in adult dogs.

  • Hepatobiliary pathologies: The first signs to appear in liver diseases such as chronic hepatitis or portosystemic shunts are non-specific signs such as anorexia.

  • Pancreatitis: Inflammation of the pancreatic tissue causes severe abdominal pain, which in turn can lead to anorexia.

  • Chronic Kidney Disease (CKD): Patients with CKD usually suffer from anorexia as a result of uremia (accumulation of uremic toxins in the blood) and anemia. We must consider CKD as a possible differential diagnosis, especially in anorexia in older dogs.

  • Endocrine pathologies: such as hypoadrenocorticism (Addison's syndrome), hyperparathyroidism or diabetic ketoacidosis.

  • Anemia: in anemic dogs we can observe general clinical signs such as anorexia, lethargy, and weakness.

  • Tumors: some tumors can cause very non-specific signs such as anorexia and weight loss. Therefore, we must consider tumors as a possible differential diagnosis, especially in anorexia in adult dogs.

  • Chemotherapeutic treatments: Antitumor drugs act not only against cancer cells, but also against healthy cells of tissues that are very actively proliferating, as is the case with the gastrointestinal epithelium. As a result, some chemotherapeutic drugs exhibit gastrointestinal toxicity and cause anorexia.

  • Other treatments: Some medications such as NSAIDs (non-steroidal anti-inflammatory drugs), amiodarone, methimazole, or uric acid-forming agents such as ammonium chloride can cause anorexia as a side effect.

As you can see, anorexia in dogs can be due to either physical or mental problems. If your dog is healthy think your dog might be stressed and that's why he's not eating, read this other article where we talk about 10 signs that your dog is stressed.

Diagnosis of anorexia in dogs

As we have already mentioned, anorexia is a clinical sign that we can observe in various canine diseases. Therefore, when a dog suffers from anorexia, it is necessary to determine the cause of it in order to correct it. The diagnostic protocol for a dog with anorexia should include the following:

  • Medical history: your veterinarian will ask you a series of questions to determine the possible causes of your dog's anorexia.

  • Complete physical examination: including inspection, palpation, percussion, and auscultation. It is especially important to look for the presence of pain points and the presence of fever.

  • Complementary tests: depending on the possible differential diagnoses, your veterinarian may perform various complementary tests, including laboratory diagnostic procedures (blood or urine tests, microbiological diagnosis, etc.) and diagnostic imaging procedures (X-ray, ultrasound, CT or MRI).

When a dog loses so much weight that fat and muscle are broken down, it means that it is facing a significant health problem. This type of weight loss is called cachexia. If you want to know more about this condition, continue reading our other article about cachexia in dogs.

Treatment for Anorexia in Dogs

Once the specific cause of anorexia has been diagnosed, specific treatment must be determined. Thus, the treatment of anorexia depends on the specific cause or pathology that causes it and may be pharmacological or surgical, depending on the cause. If such a cause is present, etiological treatment is initiated. If it is not present, you must limit yourself to symptomatic treatment to control the clinical signs of the disease in question.

In addition to specific treatment for the pathology causing the anorexia, there are several things veterinarians and pet owners can do to address the behavioral and emotional components of anorexia in their dog. Below, we explain some of them in more detail.

Change eating environment and situation

  • Change the container; avoid plastic, which can give off its own odor

  • Find a place where your dog does not feel distracted

  • Take the food away and present it again to arouse your dog's curiosity, because dogs are most interested in food when it is first presented.

  • Experiment to find out what time of day your dog is most likely to eat food.

  • Heat food up


  • Stimulate your dog's appetite with a walk, work or play.

How to make food palatable for dogs with anorexia

To remedy anorexia in dogs, we must try to increase the palatability of the food as much as possible. The more attractive and appetizing the food is, the more likely the dog will eat it. To increase palatability, we can use several strategies:

  • Wet food: dogs tend to show a greater interest in wet food than in dry food. So you can try to offer them their usual wet food to increase their interest in the food. In this other article, we will help you to choose the best wet food for dogs.

  • Home-cooked food: dogs that are used to commercial food show special interest in home-cooked food. You can offer home-cooked food, but you should consult a veterinarian specialized in animal nutrition beforehand to avoid undesirable consequences. We show you a video with a very simple recipe suitable for digestive problems, to which we recommend adding animal protein to make it more complete.

  • Increase the fat or protein content of the food: in general, a diet rich in fat and protein is tastier for dogs. However, remember to consult your veterinarian before changing the amount of these nutrients in your dog's diet, as this can have very negative consequences in case of kidney disease or pancreatitis.

  • Change the brand of commercial food: sometimes we can make the food more palatable for our dogs by offering premium or gourmet brands or even cat food.

In any case, we must keep in mind that stress is one of the causes of anorexia in dogs. Therefore, it is important that we do not force food intake in animals with decreased appetite, as we can cause stress that will worsen the anorexia.

If the anorexia does not subside with treatment and a more palatable diet, assisted feeding via a nasogastric tube or an esophagostomy, gastrotomy, or jejunostomy tube is required.

In the video below, we give you some extra tips on how to increase your dog's weight naturally.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to Anorexia in Dogs - Causes, Diagnosis and Treatment, we recommend you visit our Other health problems category.

  • Davidson, MG, Davidson, MG, Else, RW, Lumsden, JH (2000). Manual of clinical pathology in small animals. Ediones S.
  • Nelson, R.W., Couto, C.G. (2014). Small Animal Internal Medicine . Elsevier.
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Anorexia in Dogs - Causes, Diagnosis and Treatment