Dog Won't Eat: The Clock by Age, the Pattern That Tells You Why, and What to Offer Tonight

Written by Marc Brannigan, Co-Founder & CEO of HempMy Pet. Last updated 15 October 2026.

How Long Is It OK for a Dog Not to Eat?

The honest answer depends entirely on who the dog is. This is the clock most pages leave out.

"Otherwise normal" means bright, moving around, no vomiting, no diarrhoea, normal gums, no belly pain. The moment a second sign joins the appetite loss, the clock above stops applying and it becomes a same-day question.

Read the Pattern: What the Refusal Is Telling You

The most useful observation you can make is not that your dog will not eat, but what they will not eat and what they will. The right column is the tell.

The Most Common Causes, Roughly in Order

Vets split appetite loss into true anorexia (the dog does not want food) and pseudo-anorexia (the dog wants it but cannot eat). The list looks like this.

• An upset stomach. Something scavenged, a sudden food change, a rich meal. The commonest cause by far in an otherwise well dog, usually with a day or two of loose stool. Our upset stomach guide covers the 12-hour rule and what not to give.
• Dental and mouth pain. Advanced gum disease, a cracked tooth, an abscess, a stick wedged across the roof of the mouth. The commonest cause of "wants to eat but won't," and almost never spotted by owners because dogs hide it.
• Pain elsewhere. Arthritis, back pain, a sore neck. A dog in pain eats less, and a dog who has to lower their head to a floor bowl with a sore neck may not eat at all.
• Nausea from medication. NSAIDs, antibiotics, chemotherapy, and many others. If the refusal started within days of a new drug, that is the first suspect.
• Stress and change. Boarding, a move, a new pet or baby, fireworks season, a change in who is home.
• Infection and fever. Anything from a urinary infection to kennel cough to a tick-borne disease.
• Organ disease. Kidney, liver, pancreatitis, Addison's, diabetes. More likely in a senior, more likely with weight loss or increased thirst alongside.
• A blockage. A sock, a corn cob, a toy. Vomiting, a painful belly, no stool. Emergency.
• Heat. Many dogs eat less in hot weather. Harmless if they are drinking and bright.
• Cancer. Not the first thought, but on the list in an older dog with gradual decline and weight loss.

The VCA's anorexia overview has the full clinical list, and the American Kennel Club has an owner-level summary.

What to Feed a Dog That Won't Eat

Assuming you have applied the clock and the pattern, and you are in the "watch at home" group. In rough order of what works.

What not to do: do not escalate through the fridge. A dog who refuses kibble, then gets chicken, then gets steak learns quickly, and you have created a picky eater out of a dog who had a one-day stomach upset. Do not give human medication of any kind for nausea or pain; several common ones are toxic to dogs. Do not force-feed with a syringe unless a vet has told you to; it creates food aversion in a dog who is nauseous. And do not give a dog who is vomiting anything by mouth until the vomiting has stopped for several hours.

How to Bring Back a Dog's Appetite

Once the cause is known, or ruled harmless, these are the levers.

• Treat the nausea. If a vet suspects it, an anti-nausea injection (maropitant, sold as Cerenia) often has a dog eating within hours. This is the single most effective thing in the clinic.
• Appetite stimulants. Vets use capromorelin (Entyce, the only one licensed for dogs), mirtazapine, or cyproheptadine as a short bridge while the underlying problem is treated. They are not a substitute for finding the cause.
• Fix the mouth. A dental under anaesthetic transforms appetite in an old dog more often than any supplement does.
• Fix the pain. An arthritic dog on adequate pain control eats better. See what you can and cannot give a dog for pain.
• Routine. Two meals at the same times, 15 minutes down, then up. Exercise before meals. No free-feeding.
• Rotate within reason. Some dogs do get bored. Two or three foods rotated slowly is fine; a new food every time they hesitate is not.

Where Hemp Fits, and Where It Doesn't

We make hemp products, and appetite is a subject where the marketing runs ahead of the evidence. Here is the honest version.

Where it does not fit: a dog who will not eat for a reason you have not identified. Hemp has no role in a blockage, an infection, dental pain, pancreatitis or kidney disease, and giving a dog who is nauseous anything by mouth that they do not need is unhelpful. There is no controlled canine study showing CBD restores appetite in a sick dog, and we would rather say so than imply otherwise. THC stimulates appetite; hemp products containing under 0.3% THC do not have that effect, and a dog should never be given THC.

Where it can fit: two situations, both after a vet has looked. First, an older dog whose reduced appetite is tied to ongoing joint discomfort; that is the one use where hemp has real controlled evidence (five published canine trials, four positive, one ours), and a more comfortable dog is generally a dog who eats better. Second, a dog whose appetite drops with stress: boarding, travel, a change at home; there the evidence is thinner, and it is one small part of managing the stress rather than the fix. In both cases it goes in as a daily oil over weeks, not as something to put on the food of a dog who refused breakfast this morning. Our serving guide works from body weight, and if your dog is on any medication, read CBD and your dog's medications first.

When to See the Vet

Today, if:

• Not eating and not drinking for 24 hours, or any refusal in a puppy, toy breed, diabetic or pregnant dog
• Vomiting more than once, retching without producing anything, or a swollen, hard or painful belly
• Lethargy, weakness, wobbliness, or a dog who will not get up
• Pale, yellow, brick-red or blue gums
• You suspect they ate something: a toy, a sock, a corn cob, a bone, a toxin
• An unspayed female who is drinking more and off her food (a uterine infection is an emergency)

This week, if:

• A healthy adult has not eaten properly for 48 hours
• The dog wants food but drops it, chews on one side, or paws at the mouth
• Appetite has been sliding for weeks, especially with weight loss or more drinking
• The refusal began within days of a new medication
• An older dog has started refusing dry food but takes wet

Bring a note of exactly what they have and have not eaten, when it started, and what else has changed. The Merck Veterinary Manual's owner section on digestive disorders is a reliable reference for what the vet may be considering.

Frequently Asked Questions

How long is it okay for a dog not to eat?
A healthy adult dog who is drinking and otherwise normal can usually be watched at home for up to 48 hours; call the vet at that point even if they seem fine. Puppies, toy breeds, seniors, diabetics and pregnant dogs have a 12-to-24-hour window, and a dog who is not drinking either has 24 hours regardless of age. Any second sign, such as vomiting, lethargy or belly pain, makes it a same-day question.

What is the most common cause of loss of appetite in dogs?
In an otherwise well dog, a short-lived stomach upset from something scavenged or a food change. In a dog who wants food but cannot eat it, dental and mouth pain. In an older dog with a gradual decline, chronic pain, fading smell and early organ disease are the ones most often missed. Nausea from a new medication is the first suspect when the timing fits.

What should I give my dog when they won't eat?
Warm their normal food with water or low-sodium broth to about body temperature; smell drives appetite. For a suspected upset stomach, small meals of plain boiled chicken or white fish with white rice, or a little plain canned pumpkin, several times a day. Offer by hand from a plate in a quiet room, take it up after 15 minutes, and do not escalate through the fridge or you will create a picky eater.

How do I bring back my dog's appetite?
Find and treat the cause first. In the clinic, an anti-nausea injection often has a dog eating within hours, and a dental under anaesthetic transforms appetite in many older dogs. Vets can also prescribe a short-term appetite stimulant such as capromorelin (Entyce) or mirtazapine as a bridge. At home: warm, wet food, a routine of two timed meals, exercise before eating, and no free-feeding.

My dog won't eat but is drinking water. Should I worry?
Less than if they were not drinking, which is the real emergency. A dog who is drinking normally, bright and not vomiting can be watched for up to 48 hours. A dog who is drinking far more than usual while refusing food is a different picture: kidney disease, diabetes, Cushing's, a fever, or a uterine infection in an unspayed female, and that is a vet visit this week with a urine sample.

My dog won't eat kibble but will eat treats. What is going on?
Their appetite is fine; this is preference, a food they have gone off, a bag that has spoiled, or a dog who has learned that refusing produces chicken. Check the kibble, stop the hand-outs, warm and wet the food, and run two timed meals a day. The exception is a dog who used to love the kibble and suddenly refuses it while still taking soft treats: that can be a sore tooth, and it wants a mouth check.

Why won't my old dog eat?
The commonest reasons are dental disease, a fading sense of smell (dry food smells of little), chronic joint or back pain that makes reaching the bowl uncomfortable, cognitive change, and the early stage of kidney or liver disease. Warm wet food in a raised bowl is the first test; bloodwork, a dental look and a pain assessment are the next. Gradual appetite loss in a senior should never be filed under "getting old."

Can hemp or CBD help a dog that won't eat?
Not for a dog whose cause is unknown, and not for illness, nausea, dental pain or a blockage; there is no controlled canine evidence that CBD restores appetite in a sick dog, and THC, which does stimulate appetite, is toxic to dogs. Where hemp has a place is an older dog eating less because of ongoing joint discomfort, which is the one use with real trial evidence, and as a small part of managing stress-related appetite loss. Both are daily, over weeks, after a vet has looked.

Should I force-feed my dog?
No, not without a vet's instruction. Syringe-feeding a nauseous dog creates a lasting aversion to food and risks inhalation. If a dog needs nutrition and will not eat, vets have better options, including anti-nausea treatment, appetite stimulants and, briefly, a feeding tube.

The Short Version

First the clock: a bright, drinking adult has 48 hours; a puppy, toy breed, senior, diabetic or pregnant dog has 12 to 24; a dog who will not drink has 24 whoever they are, and any second sign means today. Then the pattern: refusing kibble but taking treats is a preference; refusing the favourite treat is a problem; wanting food but dropping it is a mouth. Warm it, wet it, hand it over from a plate, and do not escalate through the fridge.

Hemp is not an appetite fix. It fits an older dog eating less because of joint discomfort, once the vet has looked.

Hemp for Dogs → Serving by Weight

Dog Upset Stomach Home Remedy · Home Remedies for Dog Diarrhea · Arthritis in Dogs · What Can I Give My Dog for Pain? · Sundowners in Dogs · Serving by Weight

These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease. This article is general information, not veterinary advice. If your dog is unwell, contact your veterinarian.