What this means
Ulcers are hard to spot in a dog's mouth because the dog rarely allows a long look. The first signs are usually indirect: drooling, unpleasant breath, reluctance to eat, champing, or less interest in chewing toys.
If you can safely look, note where the ulcer is: next to a tooth, on the tongue, inside the cheek or on the palate. An ulcer beside tartar looks different from ulcers in several places at once alongside general tiredness or other body signs.
Write down whether your dog is drinking more than usual, vomiting, or has lost weight. Mouth ulcers can be one sign of a wider illness, so your dog's whole condition, not only the mouth, is important information for the vet.
Possible causes
These are things that can cause this sign. It is not a diagnosis, and they are not equally likely for your dog.
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Dental deposits and gum inflammation
Deposits irritate the gums and the cheek beside them, where small sores can form. The breath may be unpleasant.
About the condition: Dental and gum disease -
An injury in the mouth
Bone splinters, sticks or sharp toys can cut or damage the lining. The damage is usually in one place.
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Kidney disease
When the kidneys are not working properly, ulcers can appear in the mouth and a distinctive smell can develop. Your dog may also drink and urinate a lot.
About the condition: Kidney disease -
An immune system disorder
Some autoimmune diseases damage the mouth lining and cause painful ulcers. Skin changes may appear as well.
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An irritating substance or plant
If a dog tastes or bites something irritating, the lining of the mouth can redden and develop sores. Heavy drooling can go with it.
What else to watch for
These observations help your vet build the picture faster. Note down what you saw and when.
- Where in the mouth the ulcer is and whether there is more than one
- Whether your dog drools or champs its mouth
- Whether the breath has changed
- Whether your dog drinks more than usual
- Whether your dog is vomiting or has lost weight
- Whether it could have chewed or swallowed something
When to book a routine visit
Book a visit if you can see ulcers in the mouth, your dog drools, avoids eating or the breath is strong. If your dog refuses all food, is vomiting, is very weak or the bleeding will not stop, go straight away.
Related conditions
Conditions whose entries mention this sign. The list is somewhere to read on, not a way to reach a diagnosis.
- Dental and gum disease Digestion and liver Dental and gum disease starts with plaque that hardens over time into tartar, and the bacteria multiplying beneath it cause inflammation of the gums. Left alone, the inflammation can damage the tissues and bone that hold the tooth in place, so teeth loosen and fall out. A sore mouth troubles a dog every day, and infection in the mouth can affect other organs too.
- Kidney disease Kidneys and bladder The kidneys filter the blood, remove waste from the body and help keep the balance of fluids and salts. When they are damaged suddenly, for example by poisoning or infection, or weaken gradually over a longer time, substances they should remove start to build up in the body. Long-term kidney changes can go unnoticed for a long time, because the healthy part of the kidneys takes over the work for a while.
- Autoimmune disorders Blood and immunity This is an umbrella term for conditions in which the immune system, instead of defending the body against germs, starts attacking the dog's own tissues. The skin, blood cells, joints or internal organs can be affected, so these diseases can look very different from one another. What the condition is and what caused it is for the vet to determine.
Body systems: Digestion and liver Kidneys and bladder Blood and immunity