Losing Appetite in Dogs

Why is my dog losing appetite?

What is Losing Appetite?

While a loss of appetite is not unusual in dogs, it can mean that there is an underlying health condition, whether physical or psychological, present. A lack of appetite can be a symptom in numerous conditions to include:

  • Anxiety/stress (to include separation anxiety)
  • Upset stomach
  • Depression
  • Gum and teeth issues
  • Parasites
  • Heart disease
  • Poisoning
  • Being near a female that is in heat
  • Cancer
  • Lung disease
  • Irritable bowel syndrome

The seriousness of your dog’s loss of appetite is dependent on why it is occurring. Some situations will be relatively minor, like if your dog ate something that has spoiled and his stomach is upset. Others, like heart or lung disease, will be more concerning.

Why Losing Appetite Occurs in Dogs

The reason for your dog’s disinterest in eating will depend upon its cause. For example:


One of the most common reasons for a lack of appetite in dogs is separation anxiety. This can occur when your dog is left at home alone for too long or if he has been abandoned. Your dog may experience anxiety as a result of moving or new additions to the house (human or animal). Big noises may cause anxiety in your dog and lead to his not being interested in eating for a few days.

Upset Stomach

If you notice your dog vomiting or having diarrhea, it is likely his stomach is upset and that will lead to a loss of appetite in your dog. This will typically resolve on its own, though if vomiting, diarrhea and a lack of appetite continue, you will want to contact your veterinarian.


A dog that is experiencing depression will often not have any interest in eating. The depression may be due to a recent loss, a health issue or a chemical imbalance. Often, dogs that are struggling with depression don’t drink any water. Medication and therapy are options to help your dog overcome the condition.

Gum and Teeth Issues

If your dog is experiencing tooth decay or gum disease, it will be painful and lead to a disinterest in eating. 


Being infected with parasites, for example intestinal worms, can lead to your dog losing is his appetite. Other symptoms include lethargy, weakness and vomiting.

Heart Disease

Heart disease can result in your dog losing appetite. A dry cough and unsuccessful attempts at vomiting are other symptoms of heart disease. Examples of heart disease include myocarditis (swelling of the heart muscle), mitral valve disease (the valve degenerates and starts to leak) and dilated cardiomyopathy (the heart muscle weakens causing it to struggle to contract and pump blood).


Dogs that get into the garbage or sample plants are at risk of experiencing poisoning. Symptoms of poisoning include a lack of appetite, vomiting and lethargy.

Being Near a Female in Heat

If your dog is a male, he may refuse to eat if he is near a female who is in heat. Once the female is no longer in heat, the male dog should again have his appetite. 


Should your dog have cancer, it may lead to a change in his metabolism, which can impact his appetite. If your dog’s spleen in enlarged, it can push against his stomach and make him feel full.

When undergoing treatment for cancer, the medication may cause appetite loss and/or upset stomach.

Lung Disease

Conditions that can impact your dog include asthma, bronchitis, pneumonia, lung cancer, canine pulmonary fibrosis and chronic obstructive pulmonary disease.

Irritable Bowel Syndrome

Known as canine IBS, the condition occurs when the walls of your dog’s gut become inflamed. This can be caused by primary and secondary bacterial species, parasites, tumors, injury or an obstruction. How severe the condition is will be connected to the type and location of the lining that is impacted.in the small intestine; typically, in the stomach. The condition can also be classified by the type of inflammatory cells in your dog’s gut (lymphocytes, eosinophils, neutrophils or fibrous tissues).

What to do if your Dog is Losing Appetite

If you notice that your dog is not interested in a meal, you will want to keep a close eye on him and consider whether he has recently vomited or had diarrhea, as well as whether there are psychological issues that can be impacting his appetite. Should his lack of appetite not resolve and a few meals are missed, you will want to contact your veterinarian and set up an appointment for your dog to be examined. As loss of appetite is a symptom for numerous medical conditions, some minor and some significant, it is important that medical attention is obtained to help your dog’s health. 

Your veterinarian will conduct a full physical examination of your dog (including his mouth) and ask you for information regarding the symptoms he has displayed, when they began and what changes you have observed. You will likely be asked about your dog’s diet, any medications or supplements he is taking, and whether there have been any changes in his circumstances that may lead to his disinterest in food.

Depending on what is seen during the physical examination and the symptoms you have observed, your veterinarian may request additional tests, to include a complete blood count (CBC), urinalysis and fecal analysis. Further testing may be necessary depending on the results. If irritable bowel syndrome is suspected, for example, your veterinarian may recommend conducting a biopsy, endoscopy and/or radiography to confirm the diagnosis.

Prevention of Losing Appetite

You can help your dog avoid getting an upset stomach due to eating spoiled food by keeping him on a leash when you go out on walks and keeping your trash where he won’t have access to it. Preventative dental care is important in order to avoid gum disease and tooth decay (and the pain that comes with it). Regular exercise is important for your dog’s physical and psychological health. An annual check-up with your veterinarian will help ensure that any problems your dog is experiencing are caught early and can be treated before the issue worsens in severity.

Cost of Losing Appetite

The average cost of treatment for a dog losing appetite is $1,000; however, this cost can vary greatly based on the reason for your dog’s lack of appetite. For example, should your dog be uninterested in eating as a result of an upset stomach, this is something he can overcome on his own or with minimal, inexpensive treatment. If he is suffering from irritable bowel syndrome, the average cost of treatment is $2000 and will depend on the location where you reside and the cost of living.

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Losing Appetite Questions and Advice from Veterinary Professionals


Australian Shepherd




5 Months


0 found this helpful


0 found this helpful

My pet has the following symptoms:
Separation Anxiety
Lack Of Appetite
My 5 month old Australian Shepherd puppy is struggling with not eating time to time. She is not displaying any symptoms that would correlate with any medical issues (she is on flea prevention and heartworm prevention), however she does seem to have separation anxiety. She barks when she is put in her crate even in short increments, she no longer sleeps in her crate due to the fact she would not sleep because she would be concerned about everyone else around. We have tried multiple types of feeding options with bowl selection, and seems to enjoy the taste of her food.

Dec. 7, 2017

0 Recommendations

Bexley may just be a fussy eater or may not want to eat when you put food down; however there are different conditions which may explain a loss of appetite which include dental disorders, hormonal conditions, parasites, stomach upset among other causes. You should keep an eye on Bexley and her body condition score so see if she is losing weight. Regards Dr Callum Turner DVM

Dec. 7, 2017

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German Shepherd




8 Years


2 found this helpful


2 found this helpful

My dog has stopped eating and vomiting also.. A nearby doctor has given him Xone injection, vomikind and pan iv from past 3 days but still till now no difference

Sept. 14, 2017

2 Recommendations

There are many different causes for a loss of appetite in dogs and may be caused by infections, hormonal issues, parasites, foreign bodies, other obstructions, spoiled food among others; try feeding a different food or giving boiled chicken and rice so see if he is tempted or can keep it down. If there is no success, then further investigation would be needed to help determine a cause. Regards Dr Callum Turner DVM

Sept. 14, 2017

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