Why Do Dogs Sometimes Not Want to Eat?

Most dogs treat dinner like the best event of the day. So when yours sniffs the bowl and walks away, it is hard not to worry. Sometimes the reason is simple, like a hot afternoon or too many treats. Other times, a missed meal is the first clue that your dog is sick or in pain.

Here is how to tell the difference, how long you can safely wait, and what you can try at home.

Not eating vs. eating less

Veterinarians use three terms that help explain what you are seeing:

• Anorexia: the dog will not eat at all.
• Hyporexia: the dog eats, but much less than normal.
• Pseudo-anorexia: the dog wants to eat but cannot, often because of mouth pain. You may see it approach the bowl eagerly, then drop food or give up.

Watching closely for which one fits your dog gives your vet useful information.

When to call the vet

Call your vet right away, without waiting, if your dog stops eating and also:

• Vomits, has diarrhea, or seems to be in belly pain
• Is weak, very tired, or hiding
• Will not drink, or is drinking much more than usual
• Has a swollen belly or tries to vomit without bringing anything up, which can mean bloat in large dogs
• May have eaten something toxic or a toy, sock or bone
• Has diabetes or another ongoing illness

If your dog otherwise seems normal, these are common guidelines from veterinary sources such as PetMD:

• Puppies: call within about 12 hours, sooner for very young or toy-breed puppies. Puppies can develop low blood sugar quickly.
• Small and toy-breed adults: call after about 24 hours.
• Healthy adult dogs: call if your dog has not eaten for 24 to 48 hours. Do not wait longer than 2 days.
• Senior dogs: call sooner, since older dogs are more likely to have an underlying illness.

Medical reasons dogs stop eating

Appetite loss is a symptom with many possible causes. The common ones include:

• Dental pain. Broken teeth, gum disease and mouth infections make chewing painful. Signs include dropping food, chewing on one side, drooling, bad breath, and pawing at the mouth. Many dogs show no obvious pain at all, which is why a vet exam matters.
• Stomach and intestinal upset. Eating garbage, a sudden diet change, infections, parasites and pancreatitis can all cause nausea.
• A blockage. A swallowed toy, sock or corn cob can block the gut. This is an emergency.
• Kidney or liver disease. Failing kidneys allow waste to build up in the blood, which causes nausea and dulls taste and smell. Signs often appear only after much of the kidney function is gone.
• Pain elsewhere. Arthritis, back problems or an injury can make a dog too uncomfortable to eat.
• Fever and infection. Like people, dogs often lose their appetite when they are sick.
• Medicines. Some antibiotics, pain medications and other drugs can upset the stomach.
• Cancer and other serious illness, especially in older dogs.

Everyday reasons that are usually harmless

• Too many treats or table scraps. A dog that got snacks all afternoon may not be hungry at dinner. Veterinary sources note that dogs who learn that refusing food brings something tastier will keep holding out.
• Free feeding. When food is always available, dogs never get properly hungry, and many become picky.
• Hot weather. Dogs often eat less in summer. They burn fewer calories keeping warm and tend to be less active. Eating more in the cooler evening is a good sign that heat is the cause.
• Stress and change. A move, a new baby, a new pet, boarding, travel or a change in routine can put a dog off its food for a day or two. Some dogs will not eat when their owner is away.
• After vaccines. A mild drop in appetite for a day or so after shots is common. Vomiting, facial swelling, hives or trouble breathing are not normal and need a vet right away.
• A new or different food. Some dogs simply dislike a new flavor or texture. Switch foods gradually over about 7 to 10 days.
• Female dogs in heat may eat less for a few days.
• The bowl or the spot. A noisy metal bowl, a busy hallway, or another pet hovering nearby can make some dogs reluctant to eat.

Senior dogs and appetite

As dogs age, their senses of smell and taste can fade, and food becomes less exciting. A slow, mild drop in appetite can be part of normal aging. A sudden or large change is a reason to see the vet, since older dogs are more likely to have dental disease, kidney disease or cancer. Your vet may recommend blood and urine tests to check kidney and liver function.

How to encourage a dog to eat

These tips are for healthy dogs that are just being picky, or for dogs your vet has already checked:

1. Warm the food. Warming wet food to about body temperature boosts the smell. Microwave in short bursts, stir well, and test the temperature before serving.
2. Add warm water or broth. Pour a little over dry kibble. Use only low-sodium broth with no onion or garlic, which are toxic to dogs.
3. Mix in some wet food or a vet-approved food topper.
4. Set meal times. Offer food for 15 to 20 minutes, then pick it up until the next meal. This builds a healthy appetite.
5. Cut back on treats between meals.
6. Feed in a quiet place, away from other pets and foot traffic.
7. Try a different bowl, such as a flat plate or a quieter ceramic dish.
8. Use a puzzle feeder or hand-feed a few pieces to make eating more interesting.
9. Offer a bland meal if your vet recommends it, such as plain boiled chicken and white rice, for a day or two.

Never try to starve a dog into eating its food, and do not give human medicines to settle its stomach. Many are dangerous to dogs.

Keep a simple log

If you need to see the vet, bring notes on when your dog last ate a normal meal, how much it is drinking, any vomiting or diarrhea, changes in energy, and anything new in its life or diet. A photo or video of how it acts at the bowl can help too.