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Episodic falling or sudden collapse in the Cavalier King Charles Spaniel has been recognised within the breed for at least
20 years.
After a variable period of exercise, affected animals develop a laboured, bounding gait in the hindlimbs which appear stiff
and are partially abducted. The limbs are advanced and retracted in an exaggerated manner, resembling the hopping of a rabbit.
At the same time the back becomes arched and the animal often cries out. Following the retardation and disintegration of coordinated
movement, the dogs collapse on to the side or pitch over on to the nose.
Sometimes the forelegs also show excessive protraction; they are advanced higher and higher and when the animal has collapsed
they may be held crossed over the back of the head. There is no loss of consciousness or cyanosis and during the period of
collapse, limb tone is normal, the patellar reflex is present and conscious perception of pain is intact.
After a short interval the animal regains its feet as if nothing has happend, However, this period can often be reduced by
the owner picking the dog up. The episodes appear to be triggered by stress, apprehension and excitement.
This report is based on nine clinical cases and on reports derived from several breeders and veterinary surgeons.
The clinical cases consisted of seven females and two males, ranging in age from five and a half months to four years. In
most cases the clinical signs were first observed between three and four months of age. Under hospital conditions the collapsing
episodes could not be predicted with certainty despite a positive history, indicating that perhaps environmental circumstances
contribute to their onset. No improvement was obtained after the administration of the short acting anticholinesterase edrophonium
chloride (Tensilon; Roche) ruling out the possibility of myasthenia gravis.
There was no evidence of luxating patellae and no significant changes in haematology, plasma glucose. urea, electrolytes and
muscle enzyme levels in samples taken before and after exercise. Radiological examination of the spine was unremarkable. One
affected animal was also a `fly-catcher` (Lane and Holmes 1972)
Three cases showed slight improvement after treatment with diazepam (Valium; Roche) but this effect was not permanent. In
two cases the frequency of the episodes was increased with the use of the antiepileptic drug, caramazepine (Tegretol; Geigy).
Full post mortem examinations were carried out on a dog and a bitch, both five and a half months old. However, no gross or
microscopical changes were found in the brain, spinalcord, sciatic nerve, myocardium, liver, lung, kidney, thymus, pancreas,
adrenal, thyriod or pituitary glands, urinary bladder or eye.
Breeders reports suggest that the condition is reasonably common and the age of onset has been found to range from 14 weeks
to four years. One animal was reported to have recovered when two years old but the attacks recurred a year later. The condition
has also been reported to occur in near relatives but at present there is no definite evidence of a genetic trait.
The clinical signs are similar to those exhibited in Scottie cramp. This affects the Scottish Terrier and is provoked by an
excitatory stimulus (Meyers and Peters 1979). The latent period between the stimulus and the onset of signs can be shortened
by pharmacological compounds which decrease serotonergic function
and lengthened by compounds that increase serotonergic function. Thus the condition appears to reflect a functional deficit
of serotonergig neurons. The condition is also belived to be inherited (Meyers and others 1969)
Sudden collapse can occur in cataplexy, a condition which is brought about by fright or shock. However. in the dog, cataplexy
is often a prelude to the state of narcolepsy, a flaccid quadriplegia accompanied by sleep (Mitler and Dement 1979). Such
a sequence is not seen in the Cavalier.
It appears that episodic falling in the Cavalier King Charles Spaniel is a condition resembling Scottie cramp. it is sometimes
seen concomitantly with the `fly-catching` syndrome. We have been unable to find any clinical or pathological abnormality
to account for the behaviour, but consider that both genetic and neuropharmacological factors may contribute to its manifestation.
(C) M.E.HERRTAGE, A.C.PALMER, department of clinical veterinary medicine, Madingley Road, Cambridge.
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It saddened me greatly to read on another website that this condition is still in evidence in this breed and still nothing is being done about it. The above report was written over 20 years ago and my own bitch, born in 1978, was the one referred to as having thought to be recovered but then relapsed. I did a lot of delving and research at that time and found that there were many other cases but the majority of breeders just did not want to know. Another breeder tried to research something similar 12 years previously to this and she too gave up due to lack of breeder support. This condition is ongoing and is not going to go away but it has just been swept under the carpet. All the pedigrees and evidence that I collected was sent to Dr. Palmer. He was of the opinion that this condition is hereditary but without a research programme and the full support of cavalier breeders it was impossible to be conclusive. |
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