The short answer: A dog that suddenly stops eating is usually not feeling well. Sometimes it is temporary: heat, stress, being in season or too many treats between meals. But a reduced appetite is also one of the most common early signs of illness, from toothache and gastritis to infection or problems with the liver and kidneys. If your dog refuses all food for a day, or is also lethargic, vomiting or has diarrhoea, contact a vet. If it eats a little and is otherwise bright, you can often start by looking at the routines at home.
Not eating at all, or just eating less?
Vets distinguish between two things. Refusing food altogether is called anorexia. Eating less than usual is called inappetence2. The difference matters. A dog that refuses all food is often nauseous or has a sore stomach2. A dog that sniffs the food, eats half the portion or only takes the treats4 may be heading the same way, but it may also simply be full or fussy.
Think about what is normal for your own dog, too. Small breeds in particular can have a weak appetite and nibble a few pieces of kibble now and then. If the dog eats the amount stated on the pack and keeps its weight, it does not have a poor appetite, even if the daily portion looks small to us2. What should catch your attention is the change: a dog that usually loves its food suddenly leaving the bowl1.
Seven common causes
1. Nausea or a sore stomach. Gastritis, a stomach bug or something the dog ate outdoors often causes nausea, and the appetite disappears1. Often it is an ordinary stomach upset that passes quickly2.
2. A sore mouth. Gum disease, a cracked tooth or a sore in the mouth. With moderate pain the dog usually wants to eat but hesitates. Signs to look for are gulping without chewing, dropping food or chewing only on one side. Such a dog often eats soaked or soft food happily2.
3. Infection or disease of internal organs. Loss of appetite can be linked to an infection or to reduced function of, for example, the liver or kidneys. There are then often other signs too, such as fever, vomiting, diarrhoea or increased thirst2.
4. Something is stuck. Plastic, bone or a toy in the stomach or gut can make a dog stop eating1. Often together with vomiting.
5. Hormones. A bitch in season or with a false pregnancy may eat less. Entire males can also lose their appetite when bitches nearby are in season. It usually passes once the hormones settle. Some diseases can show up precisely during a season, though, so if she stops eating when she normally would not, contact a vet2.
6. Stress and change. Kennels, a dog sitter, moving house or an event that frightened the dog can dampen the appetite and upset the stomach2. Hot weather and new routines can be enough4.
7. Habits and fussiness. A dog that has learned something tastier arrives if it waits, will wait. The same goes if the food is always served with something nice on top. But be careful with that conclusion. Some dogs with chronic stomach problems seem fussy because they can only face food that is extra tasty, even though their stomach hurts2.
Key insight: Ask yourself whether your dog wants to eat but cannot, or can but does not want to. The dog that goes to the bowl but hesitates often has a sore mouth. The dog that ignores food completely is often nauseous. And the dog that takes treats but not its food may be fussy, but may also have a sore stomach. If it has gone on for a while, you cannot tell the difference from home.
When to see a vet
As an emergency if your dog has a swollen, tight belly and tries to vomit without anything coming up, cannot swallow, drools heavily or is markedly lethargic4. The same applies if it vomits repeatedly, vomits blood or may have swallowed something.
Within a day if your dog has eaten nothing at all for a day, or also seems ill, out of sorts or tired1. A healthy dog can often manage two to three days without food, but that does not mean it is normal or that you should wait that long1. For small dogs the margin is smaller. They can get low blood sugar if they go too long without food, so do not try to wait out a small dog2.
Within a few days if the appetite has been reduced for more than one to two days, or if your dog is drinking poorly, has diarrhoea or seems to have difficulty chewing4.
Book an investigation if your dog has recurring periods of poor appetite or is losing weight. The vet will want to know how long it has lasted, whether it has happened before and what other signs you have noticed. A diary of what the dog has eaten and how it has been is valuable2.
What you can do yourself
This advice applies to a dog that is bright, drinking and has no other symptoms.
Look in the mouth. Red or swollen gums, loose teeth, something stuck. If you suspect pain, contact your vet3.
Serve at set times. Put the bowl down and take it away after a short while if the dog has not eaten. Trygg-Hansa suggests 15 minutes and AniCura half an hour. Then wait until the next meal32. Do not leave food out all day.
Stop treats and snacks. For a small dog, a slice of cheese can be the equivalent of a hamburger for us2. That is often enough to make sure the dog is not hungry when it is time for proper food.
Make food appealing without bribing. Warm wet food slightly so the smell comes through, put the bowl in a calm spot and try small, frequent portions4. A little boiled chicken or stock without salt, onion and garlic can spark interest, but do not let it become the main course4.
Get your dog moving. A longer walk, some training with the food as a reward or letting the dog search for its food can wake the appetite3.
Change food slowly. If you want to try another food, mix it gradually into the old one. Sudden changes can irritate the stomach4.
Never give human medicines to boost the appetite4.
We do not recommend a supplement here. A dog that has stopped eating first and foremost needs an explanation, and that comes from the vet.
Frequently asked questions
How long can a dog go without food?
A healthy adult dog can often manage two to three days, but it is not normal. Contact a vet if it has not eaten for a day. Small dogs tolerate a shorter time without food.
My dog eats treats but not its food. Why?
Either it has learned that something tastier comes if it waits, or it is not feeling well and can only face what is extra tasty. Stop the treats for a few days. If it still does not eat, it is time to contact a vet.
My dog drinks but will not eat. Is that dangerous?
Drinking is good, but it does not remove the need to find out why your dog is not eating. If a day has passed without food, contact a vet.
Should I change the food?
If your dog is healthy but seems to have tired of its food, another food may be worth trying, mixed in gradually. Do not switch back and forth between many kinds. That teaches the dog to wait for the next one.
That was the short answer. If you have a question about your own pet, email us at info@herbiovet.se. We reply within one working day.
Read more:
Sources
- Agria Djurförsäkring, Dog that will not eat (in Swedish).
- AniCura, Dog that is not eating (in Swedish).
- Trygg-Hansa, My dog will not eat, what do I do? (in Swedish)
- Sveland Djurförsäkringar, Reduced appetite in dogs (in Swedish).