What to Do When Your Dog Won't Eat

Kelly Roper
Dog refusing to eat

A loss of appetite, aka anorexia, is one of the most common issues that worries dog owners. Anorexia can be caused by a variety of health concerns ranging from minor anxiety or stomach upset to much more serious conditions. Find out when to call the vet.

Common Reasons a Dog Stops Eating

According to PetMD, psychological issues, as well as physical issues, can cause a dog to stop eating. Here are a few examples of both.

Psychological Issues

  • Anxiety - Anxiety-related problems are among the many reasons a dog might stop eating. Separation anxiety is a common cause of poor appetite in dogs. Many dogs that suffer this form of anxiety will refuse to eat while their owner is away, be it for an hour or a week. Others suffer anxiety with thunderstorms, fireworks or other loud events that trigger an attack of nerves that can affect the appetite for days.
  • Depression - This is another common reason for dogs to lose the desire to eat. Depression in dogs follows much the same path as it does in humans, often heralded by lethargy, moodiness, and loss of appetite. Depression can be triggered by an event such as the loss of a beloved family member or a move from one home to another, or, as in humans, a chemical imbalance can be to blame. Long-term depression symptoms should be assessed by a veterinarian. Treatment options are available that can help your furry friend recover his spunk.
  • Breeding activity - In male dogs, appetite loss can often occur if there is a female in heat nearby. A male can sometimes become so obsessed with the scent of the female that he will not engage in normal activities, such as playing, sleeping or eating. Weight loss is sometimes quite severe during such a spell and causes a lot of worry. Generally, the situation will resolve itself as the female passes out of her heat cycle, but if your dog has lost a dramatic amount of weight, it may help to tempt him with foods he is not usually allowed to have.

Physical Issues

  • Minor conditions - A dog will sometimes stop eating over very minor physical problems such as a temporarily upset stomach, a mouth injury or dental problems. Under these circumstances, changing to a mild, soft diet and seeking help for the underlying condition will usually make the dog feel comfortable enough to start eating again.
  • Indigestion - A sudden loss of appetite could be a symptom of a more serious health problem. If your dog is fond of sneaking into the garbage pail, this can cause a condition commonly called "garbage gut" that can range in severity from a day or two of vomiting to a serious poisoning incident or an intestinal blockage that can be fatal. It's a good idea to call your vet if your dog stops eating after a midnight garbage raid. That way you can be sure that your faithful companion has not eaten something that could have disastrous effects.
  • Worms - Intestinal worms are another common health issue that can cause a lack of appetite in dogs. A worm infestation can cause dogs to stop eating, and it's often accompanied by lethargy, weakness and a bloated abdomen. A dog with these symptoms should be seen by a veterinarian to diagnose the particular parasite involved for effective treatment.
  • Vaccinations - Some dogs can have a minor reaction to vaccinations which may lead to a lack of appetite for a short period of time. Usually, this lasts no more than a day or two but if it lasts longer, you should contact your veterinarian.
  • New environment - Dogs that have moved, or are traveling with you, may stop eating due to the stress of their new surroundings, but also physical issues surrounding these life changes such as motion sickness. Your veterinarian can prescribe medication for the stomach upset and for anxiety as well.
  • Major health problems - Serious conditions that can cause a drop in appetite include thyroid problems, heart disease, pulmonary disease, and cancer, among many others. You may not notice accompanying symptoms in the beginning stages of many of these conditions, so take any decline in appetite with no obvious cause seriously.
  • Major dental problems - In addition to minor dental issues such as a sore tooth, dogs can refuse to eat if they're suffering from major dental issues including canine periodontitis or a tumor in the mouth. Bring your dog in for a check-up right away if you notice any bleeding or growths in your dog's mouth.

Additional Causes for Canine Anorexia

In addition to the causes mentioned above, other issues that can make a dog stop eating include:

What to Do for a Lack of Appetite

If your dog seems normal with no other symptoms, there are a few things you can do to encourage him to eat.

  • Try to determine if this is a passing phase that will go away on its own. Some dogs skip a meal but are enthusiastic eaters the next time.
  • Try a change of food. Some pets get tired of the same taste day after day.
  • Warming the food before serving can entice a picky eater to eat.
  • Withhold food for 12 to 24 hours. Allow your dog to become hungry and see if that encourages him to eat.
  • Keep plenty of fresh water available at all times. A thirsty dog may not want to eat.
  • Monitor your dog closely to determine if he is eating something he shouldn't.

When to Be Concerned Your Dog Is Not Eating

Many dogs will occasionally skip a meal. Some will even skip two meals. You should contact your vet if your dog skips three meals or has gone more than 36 to 48 hours without eating. You should also see your vet immediately if your pet displays other symptoms, including:

Dog being examined by the vet
  • Fever
  • Constipation
  • Diarrhea
  • Vomiting
  • Refusing to drink water
  • Showing obvious sign of pain or discomfort such as limping, difficulty moving, panting or labored breathing or restlessness
  • Drinking more water than usual (polydipsia) which could be due to kidney disease, diabetes or Cushing's disease
  • Unusual lethargy, which may indicate congestive heart failure, liver disease or diabetes.
  • Unusual behavior for your dog such as hiding, shyness, trembling, confusion or anything that seems "unlike" himself or herself

Puppies and Not Eating

Puppies who will not eat are a particular source of concern as they are in their initial growth stages where eating and putting on weight are essential to their development. If you have a puppy who is six months or younger, check with your veterinarian if your puppy has not eaten in 24 hours.

You Know Your Dog Best

No one knows your dog's eating habits and other behaviors as well as you do, so use that knowledge to help your pet. If you know your dog is a picky eater, there might not be an immediate cause for alarm. If you know he's normally a hearty eater, this sudden change in behavior may be a cause for concern. Don't hesitate to call your vet for advice if you feel there's truly a problem.

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What to Do When Your Dog Won't Eat