Thursday, November 29, 2012

Right to Reply

I was sent an article called ‘Right to Reply’ has been published in the recent Southern Cavalier Magazine  this month suggesting the research into certain aspects of CM and SM are flawed and  asked me to respond to it. 

The author writes:

The program (?PDE) cited that 70% of all Cavaliers over 6 years of age will have asymptomatic SM based on a study of 555 cavaliers. This study does not clarify how many of the representative sample were of that age. With an estimated population of 100,000 dogs, 555 dogs are a mere drop in the ocean.  My own personal experiences disputes this claim. We have been told that this condition is progressive and degenerative- based on a sample of just 12 dogs.

The author gives details of her own scanning experiences and some unverified anecdotal evidence of others

No publication is actually referenced but the figure ‘555 cavaliers’ quoted suggests the following:

J. E. Parker, BSc, BVSc, MRCVS1, S. P. Knowler, BSc2, C. Rusbridge, BVMS, DECVN, MRCVS2, E. Noorman, DVM3 and N. D. Jeffery, BVSc, PhD, CertSAO, DECVS, DECVN, DSAS(ST), FRCVS1

1University of Cambridge, Cambridge, UK. 2Stone Lion Veterinary Hospital, London, UK,3Dierenkliniek den Heuvel, Best, Netherlands

I don’t know where the 100,000 dogs quoted above came from but the scientific paper describes the sample population of 555 cavaliers from the UK and the Netherlands which had been MRI’d between 2004 and 2010 and screening asymptomatic dogs.

Data were analysed by logistic regression in order to determine the effects of sex and age on the prevalence of syringomyelia.  This statistical analysis first expressed the prevalence of the disease as a proportion of the entire scanned population but because symptomatic SM is more common in older dogs (Lewis and others 2010), the effect of age on the odds of a positive diagnosis of SM was then analysed.  The table below illustrates the odds of a positive diagnosis at each age and these were tested using a chi-square test for measuring the trend in odds. See table and figure below.

Only increased age was found to have a significant effect. 
The prevalence of syringomyelia was 25 per cent in dogs aged 12 months, increasing to a peak of 70 per cent in dogs aged 72 months or more.

So where is the author getting the information that are (mis)quoted to the cavalier community?   I hope this provides the actual facts given in the original scientific paper.  I will address the remaining misinformation when I have more time.

Penny Knowler (co-author of above paper)
Any further queries about this paper the contact is Professor Nick Jeffery  e-mail:

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