Dog not eating? Causes and what to do in each case

You set the bowl down, your dog sniffs it, looks at you and walks away. When your dog is not eating, the reason can be as simple as too many treats or a hot afternoon, or as serious as a painful tooth, nausea or an illness that hasn’t shown other symptoms yet.

Skipping a single meal usually isn’t a big deal for a healthy adult dog. What matters is everything else: whether your dog is drinking, acting normal, vomiting or losing weight, and how long it’s been going on. This guide helps you tell a sick dog from a picky one, explains how long it’s reasonable to wait, what you can try at home and what your vet will do.

Not eating at all, eating less, or unable to eat?

Not every dog who “won’t eat” has the same problem. Watch your dog at the bowl for a few minutes and compare with this table:

That third situation is easy to miss. A dog with a fractured tooth, heavy tartar or a piece of stick wedged between the molars is hungry, but chewing hurts. If you also notice a bad smell, take a look at our guide to dog bad breath: the two problems often share the same cause.

How long can a dog go without eating?

There’s no single number. It depends on your dog’s age, size and health, and on whether there are other symptoms.

Toy-breed puppies such as Chihuahuas and Yorkies have very little stored glucose. When they stop eating they can develop hypoglycemia (low blood sugar), which shows up as weakness, trembling, wobbliness and even seizures. That’s an emergency.

Medical reasons a dog stops eating

• Mouth problems: tartar and periodontal disease, broken teeth, abscesses, ulcers, objects lodged in the roof of the mouth or between teeth, oral tumors.
• Nausea and digestive trouble: gastritis, pancreatitis, swallowed objects, parasites, constipation. Many nauseous dogs lick their lips, drool or swallow repeatedly without actually throwing up. If your dog is vomiting too, see what to do when your dog is vomiting.
• Pain anywhere in the body: joints, back, belly or ears. Dogs are good at hiding it, so learn the signs your dog is in pain.
• Fever and infections, including respiratory ones: a dog with a stuffy nose can’t smell food well and loses interest. Here’s how to tell if your dog has a fever by taking their temperature correctly.
• Chronic diseases: kidney or liver disease, heart disease, hormonal disorders or cancer.
• Poisoning from foods, plants, cleaning products or medications.
• Side effects of some veterinary treatments.

Non-medical causes: food, routine and environment

When your dog is active, drinking normally and has no other symptoms, the cause is often in their surroundings or how they’re fed:

• Unappealing food: kibble that’s stale, rancid, expired or left in an open bag for weeks, or a bowl that smells of old grease.
• Too many treats or table scraps. Your dog shows up to dinner already full and learns that if they turn down the kibble, something better eventually appears.
• Too much food. The feeding charts on the bag tend to be generous, and neutered, senior or less active dogs need less. Work out how much you should feed your dog based on weight and activity: sometimes “not finishing” simply means the portion is too big.
• Hot weather. Many dogs eat less in summer, especially in the middle of the day.
• Stress and change: a move, a new pet, a family member away, construction noise, fireworks, or a bowl in a busy hallway.
• Heat cycles. Females in heat, and intact males who smell one nearby, may lose their appetite for a few days.
• Age. Senses of smell and taste fade over the years, so food becomes less exciting.

Warning signs: when to see the vet

How to get a healthy dog to eat again

If your vet has ruled out a medical problem, or your dog is active, drinking and has no symptoms at all, these changes usually work within a week or two:

1. Check the food. Smell the kibble; if it smells off, replace it. Keep it in its original bag, rolled shut and placed inside an airtight container, and wash the bowl daily.
2. Set a schedule. Offer the meal for 15–20 minutes, then pick up whatever’s left until the next feeding. Free-feeding all day makes food less interesting.
3. Cut the extras. No scraps or between-meal treats while you fix the problem; afterward, keep treats under 10% of daily calories.
4. Boost the aroma. Add a splash of warm water to the kibble or warm wet food to about body temperature. Never serve it hot, and stir well if you use the microwave.
5. Pick a quiet spot, away from other pets and household traffic. Don’t hover or coax.
6. Make mealtime more interesting. Some dogs eat better from a food puzzle or a snuffle mat.
7. Schedule a calm walk before meals. For large, deep-chested breeds, leave at least an hour between hard exercise and eating.

Also resist switching brands every few days. Besides upsetting the stomach, it teaches your dog that refusing food pays off. If you do decide to change food, do it gradually over 7–10 days.

What your vet will do

Your vet will start with a full exam, paying close attention to the mouth, belly, temperature and weight. They’ll score your dog’s body condition on a 1-to-9 scale that reflects fat reserves, along with muscle condition, since muscle loss can signal disease even when the scale barely moves.

Depending on the findings, they may recommend blood work, a urinalysis, X-rays or ultrasound. Treatment targets the cause: a dental cleaning or extractions, treatment for nausea or pain, a more palatable or prescription diet and, when needed, appetite-stimulating medication that your vet prescribes. In serious cases where a dog hasn’t eaten for days, a feeding tube may be placed for a while.

Loss of appetite in senior dogs

With an older dog, it’s tempting to blame a poor appetite on age, but there’s often a treatable cause behind it: dental disease, kidney disease, arthritis pain or a fading sense of smell. Weigh your senior dog once a month, feel along the ribs and spine, and note any change in how much they eat and drink.

Wet or warmed food, smaller meals spread through the day and a raised bowl for dogs who struggle to bend down can make a big difference. Our senior dog care guide has more tips for this stage of life.

Frequently asked questions

Is it normal for my dog to not eat but still drink water?

Drinking is a good sign because it lowers the risk of dehydration, but it doesn’t rule out a problem. An active adult who drinks normally can be watched for a day or two. If your dog is drinking much more than usual and not eating, though, it can point to kidney disease, diabetes or, in unspayed females, a uterine infection. In those cases, call your vet soon.

Why won’t my dog eat kibble but will eat treats or people food?

It’s almost always learned: your dog has figured out that waiting brings something tastier. If they have normal energy, a stable weight and no other symptoms, stick to set mealtimes and drop the extras for a few days. If they refuse even the tastiest food or start losing weight, it’s no longer pickiness and your vet should take a look.

Do dogs eat less in hot weather?

Yes. In the heat, many dogs eat less because they move around less and burn less energy. Offer meals early in the morning and in the evening when it’s cooler, and make sure fresh water is always available. If your dog is also listless, panting heavily or vomiting, think heatstroke and act fast.

Can a dog stop eating because they’re sad or miss someone?

Yes. A family member leaving, a move or the loss of another pet can dampen appetite for a day or two. Sticking to the usual routine of walks, play and meals usually helps. If the poor appetite lasts more than 48 hours or other symptoms appear, don’t chalk it up to mood alone; check in with your vet.

Should I switch dog food if my dog won’t eat it?

Not as a first step. Rule out a health problem first and check the food’s freshness, the portion size and the treats. Switching brands every time your dog turns up their nose usually makes things worse, because your dog learns to wait for something new. If you do switch, mix the old and new food over 7–10 days to avoid stomach upset.

Sources

• WSAVA Global Nutrition Committee: guidelines for the nutritional assessment of dogs and cats.
• Merck Veterinary Manual: digestive and oral disorders in dogs.
• American Veterinary Dental College (AVDC): information on periodontal disease in dogs.
• American Kennel Club (AKC): why dogs stop eating and when to worry.