An important sign of mouth pain is a change in
eating behavior. A dog with a tender mouth eats
slowly and selectively, dropping food that is particularly coarse and large. A
dog with pain on one side of the mouth often tilts her head and chews on the
opposite side. With an extremely painful mouth, the dog stops eating
Excessive drooling is common in all painful mouth diseases. It is often
accompanied by bad breath. Any form of
halitosis is abnormal. Periodontal disease and
gingivitis are the most common causes of halitosis in dogs.
Difficulty opening and closing the mouth is characteristic of head and neck
abscesses, nerve damage, or jaw injuries.
Cheilitis (Inflammation of the Lips)
Cheilitis usually results from an infection inside the mouth that extends to
involve the lips. In hunting dogs, chapped lips can be caused by contact with
weeds and brush. Dogs with canine atopy may irritate their
lips by constantly rubbing and pawing the face.
Cheilitis can be recognized by the serum crusts that form at the junction of
the haired and smooth parts of the lips. As the crusts peel off, the skin becomes raw and denuded
and is sensitive to touch. Involvement of the hair follicles produces a
Treatment: Clean the lips daily using benzoyl peroxide shampoo (OxyDex or Pyoben), or hydrogen
peroxide diluted 1:5 with water. Then apply an antibiotic-steroid cream such as
Neocort. As the infection subsides, apply petroleum jelly or aloe to keep the
lips soft and pliable. Chapstick may also be used. Periodontal disease or
canine atopy, if present, should be treated to prevent recurrence.
Lacerations of the lips, gums, and tongue are common. Most occur during fights
with other animals. Occasionally a dog accidentally bites her own lip or
tongue, usually because of a badly positioned canine tooth. Dogs can cut their
tongues picking up and licking sharp objects, such as the top of a food
An unusual cause of tongue trauma is freezing to metal in extremely cold
weather. When the tongue pulls free, epithelium strips off, leaving a raw,
Treatment: Control lip bleeding by applying pressure to the cut for 5 to 10
minutes. Grasp the lip between the fingers using a clean gauze dressing or a
piece of linen. Bleeding from the tongue is difficult to control with direct
pressure. Calm the dog and proceed to the nearest veterinary clinic.