While reading up on CECS in border terriers, I happened upon a condition called ‘Scottie Cramp’. I was keen to learn more, and found the article “Hyperkinetic episodes in Scottish Terrier dogs” (and, more importantly, the reproduction of its text on the Scottish Terrier Club of America website).

Scottish terriers. Photo courtesy of Argowan Scottish Terriers. (Photo for illustration purposes – these dogs do NOT have scottie cramp.)

What is ‘Scottie Cramp?’

‘Scottie Cramp’ is the popular term for hyperkinetic episodes in scottish terriers. This is a central nervous system problem that causes the hindlegs of effected Scottish Terriers to ‘cramp up’ so they kind of ‘skip’ with their hindquarters.

This condition is often brought on by excitement or exercise, and gets worse as exercise progresses. Generally a walk of 90m-600m was enough to bring about symptoms in affected dogs in this study. (However, there was one badly effected dogs who displayed symptoms after 10m.)

Usually a dog will exhibit symptoms before 18 months of age, and this condition does not seem to affect the dog’s lifespan.

What does it look like?

The paper does a pretty good job of describing this disorder. So here’s what they say with some added emphasis from me:

During exercise, the onset of a hyperkinetic episode was usually indicated by a slight abduction of the front legs, resulting in an arclike motion of the limbs while extending.  The back then became arched in the lumbar region, and the hind legs were quickly over­flexed and then swiftly returned to the ground.  This motion has been appropriately described as a “stringhalt” gait.

The front legs became increasingly stiff, and while walking were quickly ex­tended then flexed. In rare cases where the back was not arched, the dog walked with a “goose step” gait. Forward movement was usually hindered, and in severe cases was completely absent, resulting in the dog walking in place. Facial muscles did not ap­pear to be affected at this time…

Occasionally, when the younger dogs were running, the hindquarters would suddenly and strongly become elevated, often to such a degree that the dog somersaulted. If the inducing stimulus was continued, the hind legs became increasingly resistant to flexion, which finally resulted in a pillarlike stance, with the dog unable to walk. If the dog fell down, it would curl into a ball with its head, limbs, and tail tucked in; breathing would ap­pear to cease. The severe seizure would last approximately 15 seconds, after which the dog appeared relaxed and panting. During or just preceding a severe episode, the facial muscles were often affected, and the dog was unable to open its jaws.

None of the dogs lost consciousness during an episode, nor did they appear to be in pain. A short period of rest would alleviate the hyper­kinetic episode in most dogs, but the signs would quickly reappear if the inducing factors were not eliminated.

Here’s a video showing a scottie with this cramping disorder, and a ‘normal’ scottie:

What causes it?

This was a small study of only 10 dogs, but the results seem to indicate: “Excitement and fear facilitated the hyperkinetic episodes, whereas anxiety and apprehension were often inhibitory”. (Personally, I am not sure that fear and anxiety are different enough to form this kind of conclusion.)

They also found that amphetamine sulfate, when injected intramuscularly, caused symptoms within 15 minutes.

There was a lot of variation between dogs and symptoms, but it seemed that frequent exposure to the trigger, the dogs tended to build tolerance. However, no dog ‘recovered’ (i.e. ceased to display symptoms).

What fixes it?

As this is a Central Nervous System problem, drugs that target the CNS, naturally, are effective.

Symptoms can be alleviated by some drugs (such as chlorpromazine, acepromazine, and diazepam) injected intramuscularly. In the case of chlorpromazine, injection intramuscularly during a seizure caused cessation of symptoms within 15 minutes.

Diazepam worked to stop dogs seizing, and also to prevent seizures (given twice daily to affected dogs).

While Vitamin E has been anecdotally suggested as a preventative, this study did not find it to be effective.

How is Scottie Cramp diagnosed?

3 criteria for scottie cramp:

1) abnormal gait or seizures during excitement,

2) injected amphetamine should induce an episode, and

3) administering diazepam or promazine during a seizure should cause prompt remission.

Reference:
Meyers KM, Lund JE, Padgett G, & Dickson WM (1969). Hyperkinetic episodes in Scottish Terrier dogs. Journal of the American Veterinary Medical Association, 155 (2), 129-33 PMID: 5816228