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White Shaker Dog Syndrome (WSDS) manifests in a fairly specific, generalized tremor pattern usually affecting the head and body of the dog. It can be mildly inconvenient for the dog or totally incapacitating, depending on the severity. WSDS was given this name because it was historically recognized in small breed white dogs such as the Maltese, West Highland White Terrier and poodle, although dogs with all coat colors are now recognized as being susceptible.
Because of the response to steroids and the recognition of this syndrome in breeds other than those with a white hair coat, this disease is also referred to as Steroid Responsive Tremor Syndrome. Another name for the disease is Idiopathic Cerebellitis [inflammation of the cerebellum (part of the brain) with unknown cause].
Signs and Symptoms
The primary sign of WSDS is tremors which can range from mild, causing incapacity, to severe. The dog may shake for prolonged periods. Shaking can worsen with movement (intention tremor), and ease with relaxation or sleep. In breeds other than Samoyeds, it usually starts in dogs under three years old. Head tilting, limb weakness and seizures are occasionally associated with the syndrome. Mild to moderate hypermetria (limb movements miss their target) is sometimes evident. Commonly there are rapid, random eye movements as well.
Note: There is research being done on tremors in Samoyeds caused by hypomyelination. These tremors are seen in very young (several weeks old) puppies. This is not WSDS, but for further information, look at the Current Research section below.
It is not known why WSDS occurs. It has been speculated that the tremors are due to an immune reaction targeted against tyrosine-producing cells.
There is also conjecture that it can be congenital in some breeds.
WSDS is diagnosed by excluding other possible causes for tremors, and by looking for a response to corticosteroid treatment.
The things to be eliminated are primarily, but not restricted to;
- Ingestion of chemical or plant toxins such as organophosphates, hexachlorophene and bromethalin
- Congenital diseases that cause insufficient myelination (hypomyelination) in the CNS
- Ingestion of mycotoxins (toxins produced by fungi)
- Side effects from existing drug therapies
- Bacterial and viral encephalitis, which may be caused by canine distemper virus, adenovirus, parvovirus, herpes virus and tick-borne diseases. Cerebrospinal fluid is evaluated for cytology as well as titers for the suspected agent.
A complete physical, neurological and orthopedic examination should be performed. A CBC and chemistry panel is performed to evaluate body systems and look for metabolic dysfunction. A cerebrospinal fluid tap may be performed. The cerebrospinal fluid analysis in WSDS often reveals a mild lymphocytic pleocytosis (increased white cells), indicative of inflammation. It may however be normal.
Note: Treatment of animals should only be performed by a licensed veterinarian. Veterinarians should consult the current literature and current pharmacological formularies before initiating any treatment protocol.
Most dogs respond to an immunosuppressive dose of cortico-steroids (prednisone), or to diazepines. Sometimes both drugs are given. Tremors generally resolve the first week or two after starting therapy. The dose is then decreased or discontinued completely. Should the tremors return, the therapy is restarted at the initial dose until the tremors are controlled, then decreased again. Some dogs respond quickly to treatment and do not need additional treatments. Other dogs need to stay on low dose treatment to keep the tremors under control.
White Shaker Dog Syndrome is a disease usually found in smaller breeds of dogs. For a Samoyed to be diagnosed with this is very rare. Exercise, stress or excitement can cause the shaking to start. In an active Samoyed it is difficult to limit exercise and they are often excitable.
The disease is usually controllable, and rarely fatal, but sometimes not curable. It can be incapacitating.
Parker, A.J. 1995. “Little white shakers” syndrome: generalized, sporadic, acquired, idiopathic tremors in adult dogs. In J.D. Bonaguara and R.W. Kirk (eds) Kirk’s Current Veterinary Therapy XII Small Animal Practice. pp. 1126-1127. W.B. Saunders Co., Toronto
Bagley RS. Diseases of the Cerebellum. Page 31 in: Principles of Neurologic Evaluation: Evaluation of Dogs and Cats that Look and Act Funny.
There does not appear to be a support group specifically for this. However, some of the ‘small white dog’ groups would seem to be of service.
General information is included in the following sites for other breeds;
Westie Foundation: White Shaker Disease Syndrome