Margaret C

Dr Imelda McGonnell, Senior Lecturer in Anatomy and Developmental Biology, gave a fascinating presentation entitled " Analysis of Occipital Bone Development in Cavalier King Charles Spaniels."

I have written as best I can what I understood of her talk, but remember that I am not a vet so please do not take anything in these blogs as gospel.

Imelda posed the question " How do you generate changes in the skull"

The occipital skull is made up of four bones, The supraoccipital bone is a circular plate at the back of the head, it has two wings at the side( parietal bones ) and another bone ( basioccipital bone ) underneath that cups the cerebellum which among other things controls respiration & heart rate.

The occipital bone develops from tissue called mesoderm that can make lots of tissue types including cardiac muscle, cartilage and bone, some blood cells and smooth muscle.

Mesoderm derived cells first start as a cartilage tenplate. At full term it is part cartilage and part bone.

The circular supraoccipital bone has four individual growth plated which expand in four different directions at the same rate.
In the cavalier the supraoccipital bone stops growing earlier than the control group of Labradors.

In the Cavalier whelps there was a suture in the middle of the SO bone,( apparently it is unusual to find this within bone ) and that appears to close before birth ( early fusion )

The Cavaliers had less high quality bone, lots of marrow, increased blood cells.
All the whelps had disorganised structure and large blood vessels.

There are changes in the choices the mesoderm makes and the balance between cartilage, bone, smooth muscle and blood is altered.
The basioccipital bone showed the same changes but not the parietal bones ( or the leg bones )

I have noted there is reduced growth and imbalance in formation of cell types and alterations in the cerebellum and spinal cord.

The labrador whelps do not show these changes where as all the Cavalier whelps had the weak bone. ( There seems to be doubt about the number of stillborns used in the study. 71 was the number I noted but I may have misheard )

Dr McGonnell spoke of the need for other controls. She needs stillborn puppies from other spaniel breeds and I was able to suggest a contact that may be able to help obtain still born English Springer puppies.

**As a foot note I will mention here that
Dr McGonnell also mentioned they now needed bone and tissue from adult cavaliers.

Professor Nick Jeffery's Spinal Cord Study has now been completed and, although there is still a need for SM confirmed Cavaliers, the Scheme will now be helping to collect and pay for any volunteered cavaliers ( whatever their health status) to be postmortemed for tissue donation.

I will be working out the details in the next few weeks but it is thought that tissue will go to to Professor Brendan Corcoran for heart research, Dr Clare Rusbridge for genome research , Dr McGonnell and Dr Holger Volk at the RVC for the FTR, and Dr Penny Watson at Cambridge for pancreatic disease research.

Tania Ledger will be coordinating the Scheme with me.