Posted by Arnold Plotnick, DVM on 3/14/2008 in Scratching Post Articles
Happy cats demonstrate their happiness by kneading their paws, purring, and bunting (head-butting). A truly ecstatic cat may even drool on her owner. But drooling, while regarded as the utmost affectionate feline compliment, can also signify that something is amiss.
An excess production of saliva by the salivary glands is called ptyalism. Oral problems and central nervous system disorders are common reasons for ptyalism and subsequent drooling. Ptyalism should not be confused with pseudoptyalism, in which normal amounts of saliva – not excessive amounts – are being produced, but it overflows from the mouth due to anatomic abnormalities, such as malocclusion (abnormal alignment of the teeth) or to an inability or reluctance to swallow because of pain associated with swallowing.
The initial step in determining the cause of a cat’s drooling is a thorough oral examination. This may require sedation, tranquilization or even general anesthesia, as cats with painful mouths are often head shy and won’t allow a comprehensive exam.
Disorders of the teeth and gums are a common reason for drooling. Periodontal disease and the accompanying gingivitis, if severe, can lead to halitosis (bad breath), dysphagia (difficulty eating) and drooling. Periodontal disease is easily diagnosed during an oral examination, however, determination often requires oral x-rays. Some cats experience gingivitis or stomatitis (inflammation of the entire mouth) of such severity that they paw at their mouth, refuse to eat hard food and may drool excessively.
Biopsy of the gums or other affected oral tissues may reveal a severe infiltration of inflammatory cells. This condition, called lymphocytic/plasmacytic gingivitis or stomatitis, is usually quite painful. Treatment consists of antibiotics, anti-inflammatory medications and in extreme cases, extraction of all of the teeth.
During an oral exam, a veterinarian will evaluate if the cat can close her mouth properly. Some cats cannot, due to malocclusion. Although congenital and developmental disorders are common causes of malocclusion, oral tumors can cause misalignment of the teeth and/or jaw, leading to improper closing of the mouth and subsequent drooling. In fact, oral cancer is a very common cause of drooling in geriatric cats.
Damage or paralysis of the trigeminal nerve can lead to drooling secondary to an inability to close the mouth. Disorders involving other cranial nerves can also lead to drooling, but fortunately, cranial nerve disorders are uncommon in cats.
Oral trauma and associated pain and discomfort can lead to drooling. Broken teeth with resultant nerve exposure, a fractured jaw, and temporomandibular joint (TMJ) disorders are traumatic injuries that often lead to pain and drooling.
Kidney failure is a very common condition, especially in geriatric cats. Cats with severe kidney failure may have significant uremia (literally “urine in the blood”). These cats often develop ulcers on the gums, tongue, and edges of the lips. These ulcers are painful, and many of these cats drool foul-smelling saliva as a result. If the oral cavity is determined to be normal, other causes for drooling that should be considered include liver disease, nausea, seizure activity and drug or toxic stimulation of salivation.
Various drugs and toxins can cause hyper salivation in cats. Unpleasant tasting drugs can cause cats to salivate profusely. The antiprotozoal drug, metronidazole (Flagyl), the antihistamine, chlorpheniramne (Chlortrimeton), and the sulfa antibiotics are particularly notorious for causing cats to drool copiously if the pill inadvertently lands on the tongue during administration. These drugs require an owner who is proficient in giving pills to their cats.
Other possible causes of feline drooling include overdosing of flea and tick insecticides, secretions of various toads and the venom from a black widow spider. Various plants, including philodendron, diffenbachia, poinsettia and Christmas trees – as well as exposure to some household-cleaning products – can cause increased salivation.
A systematic approach is necessary for diagnosing the underlying cause of drooling in cats. Yes, some cats drool from happiness, but contact your veterinarian if your cat shows signs of illness, including oral discomfort, unusual behavioral changes, foul odor to the saliva, or saliva that is blood-tinged.