What this means
Dogs hide pain, so a change in chewing can be one of the first signs. You may see food dropping from the mouth, your dog tilting its head to one side, or gnawing a toy only at the side when it did not before.
Write down which side it chews on, whether it pauses while chewing, whether it eats more slowly, and whether it picks softer food. Also note the breath, any drooling, bleeding, or swelling on the cheek.
Difficulty chewing is not caused by the teeth alone. The jaw joints or chewing muscles can hurt too, so only a vet can tell where the problem lies. Do not wait until your dog stops eating altogether.
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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A painful or broken tooth
Your dog protects the sore side and chews on the other. A broken tooth or a swollen gum may be visible.
About the condition: Dental and gum disease -
Dental deposits and gum disease
Deeper changes in the gums and teeth hurt when chewing. The breath may be unpleasant.
About the condition: Dental and gum disease -
A foreign object in the mouth
A piece of bone or a stick wedged between the teeth or across the palate makes a dog chew on the other side. Drooling and champing may follow.
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Inflamed chewing muscles
Inflamed muscles make chewing painful or hard. Your dog may struggle to open its mouth or the face muscles may look shrunken.
About the condition: Masticatory muscle myositis -
Changes in the jaw bones
In growing puppies of some breeds the jaw bones can change and swell. Chewing becomes painful.
What else to watch for
These observations help your vet build the picture faster. Note down what you saw and when.
- Which side your dog chews on and when it started
- Whether food falls out of the mouth
- Whether your dog picks softer food
- Whether the breath or drooling has changed
- Whether the cheek or jaw is swollen
- Whether your dog can open its mouth wide
When to book a routine visit
Book a visit if your dog has chewed on one side for more than a couple of days, eats more slowly or has bad breath. If your dog refuses all food, cannot open its mouth or the face is swollen, 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.
- Masticatory muscle myositis Nerves and muscles Masticatory muscle myositis is an autoimmune disease in which a dog's immune system attacks the chewing muscles on the head. The inflamed muscles are painful and swollen, and over time they can waste away and stiffen, making it harder and harder for the dog to open its mouth. The sooner a vet sees the dog, the better the chance of keeping the jaw moving.
- Craniomandibular osteopathy (lion jaw) Bones and joints Craniomandibular osteopathy is a disease of growing puppies in which extra bone builds up irregularly on the lower jaw and on some bones of the skull. The thickened bone is painful, and changes near the jaw joint can make it hard for the dog to open its mouth wide, chew and eat. The condition is thought to be inherited, and its course and how much it has affected the jaw are for a vet to assess.
Body systems: Digestion and liver Nerves and muscles Bones and joints