Excessive Production of Saliva in Cats

Ptyalism in Cats

Saliva is constantly produced and secreted into the oral cavity from the salivary glands. Production of saliva increases because of excitation of the salivary nuclei in the brain stem. Ptyalism is a medical condition characterized by the excessive flow of saliva, also referred to as hypersalivation. The stimuli that lead to the over production of saliva are taste and touch sensations involving the mouth and tongue. Higher centers in the central nervous system can also excite or inhibit the salivary nuclei, and lesions involving either the central nervous system or the oral cavity can cause excessive salivation as well. Diseases that affect the pharynx, esophagus, and stomach can also stimulate excessive production of saliva. Ingestion of a toxin, caustic agent, or foreign body can also lead to ptyalism. Conversely, normal saliva production may appear excessive in animals with an anatomic abnormality that allows saliva to dribble out of the mouth, or are affected with a condition that affects swallowing. Pseudoptyalism (i.e., false ptyalism), on the other hand, is the release of excess saliva that has accumulated in the oral cavity.

Young cats may be more likely to have a form of ptyalism caused by a congenital problem, such as portosystemic shunt. Under normal conditions, the portal vein enters the liver and allows toxic components of the blood to be detoxified by the liver. When a shunt is present, the portal vein is inappropriately connected to another vein, which causes blood to bypass the liver. Enlargement of the esophagus is hereditary in Siamese cats.

Symptoms and Types

• Loss of appetite - seen most often in cats with oral lesions, gastrointestinal disease, and systemic disease
• Eating behavior changes - cats with oral disease or cranial nerve dysfunction may refuse to eat hard food, not chew on the affected side (when the lesion is unilateral), hold the head in an unusual position while eating, or drop food
• Other behavioral changes - irritability, aggressiveness, and reclusiveness are common, especially for cats with a painful condition
• Difficulty swallowing
• Regurgitation - in cats with esophageal disease
• Vomiting - secondary to gastrointestinal or systemic disease
• Pawing at the face or muzzle - cats with oral discomfort or pain
• Neurologic signs - cats that have been exposed to causative drugs or toxins, and those with hepatic encephalopathy following consumption of a meal high in protein

Causes

• Conformational disorder of the lips
• Oral and Pharyngeal Diseases
  • Foreign body (e.g., ingestion of a linear foreign body, such as a sewing needle)
  • Tumor
  • Abscess
  • Gingivitis or stomatitis: inflammation of the lining of the mouth, secondary to periodontal disease
  • Leukemia infection
  • Viral upper respiratory infection
  • Immune-mediated disease
  • Kidney disease
  • Ingestion of a caustic agent or poisonous plant
  • Effects of radiation therapy to the oral cavity
  • Burns (e.g., from biting on an electrical cord)
  • Neurologic or functional disorder of the pharynx

• Salivary Gland Diseases
  • Foreign body
  • Tumor
  • Sialoadenitis: inflammation of the salivary glands
  • Hyperplasia: over proliferation of cells
  • Infarction: area of necrotic tissue caused by loss of adequate blood supply
  • Sialocele: salivary-retention cyst

• Esophageal or Gastrointestinal Disorders
  • Esophageal foreign body
  • Esophageal tumor
  • Esophagitis: inflammation of the esophagus secondary to ingestion of a caustic agent or poisonous plant
  • Gastroesophageal reflux
  • Hiatal hernia: stomach bulging up into the chest
  • Megaesophagus: enlarged esophagus
  • Gastric distension: bloating of the stomach
  • Gastric ulcer

• Metabolic Disorders
  • Hepatoencephalopathy (higher incidence in cats) - caused by a congenital or acquired portosystemic shunt, where the liver is not able to remove harmful substances from the blood, and the toxins are diverted to the brain
  • Hyperthermia: high fever
  • Uremia: kidney failure

• Neurologic Disorders
  • Rabies
  • Botulism
  • Tetanus
  • Dysautonomia: disease of the nervous system
  • Disorders that cause dysphagia, or difficulty swallowing
  • Disorders that cause facial nerve palsy or a dropped jaw
  • Disorders that cause seizures
  • Nausea associated with vestibular disease

• Drugs and Toxins
  • Caustic/corrosive toxins (e.g., household cleaning products and some common house plants).
  • Substances with a disagreeable taste (cats tend to react by drooling)
  • Substances that induce hypersalivation.
  • Animal venom (e.g., black widow spiders, Gila monsters, and North American scorpions)
  • Toad and newt secretions
  • Plant consumption may cause increased salivation (e.g., poinsettia, Dieffenbachia)

  

Diagnosis

There are many different causes for excessive salivation. You will need to give a thorough history of your cat's health, including vaccination status, current medications, possible toxin exposure, a background history of symptoms, and any other possible incidents that might have precipitated this condition. Your doctor will need to distinguish between hypersalivation associated with a condition that is causing difficulty swallowing, from hypersalivation associated with nausea by looking for signs such as depression, lip smacking, and retching. Your doctor will also want to perform a complete physical and neurologic examination on your cat, with special attention paid to the oral cavity and neck. Diagnostic tools may include x-ray and ultrasound imaging to determine whether there is a problem in the structure of the liver, or in any other internal organs. If an immune-related disorder is suspected, your veterinarian may also want to conduct a biopsy of tissue and cells.

Treatment

Your veterinarian will treat the underlying cause of the ptyalism, once it has been effectively diagnosed. Although it is generally not necessary, your doctor may also treat the outward symptoms to reduce the flow of saliva. Nutritional supplements may be recommended if your cat has been suffering from ptyalism for any length of time and has not been able to eat properly.

Living and Management

Depending on the underlying cause, your veterinarian will want to monitor your cat as often as necessary to make certain that the treatment plan is effective.

---