Rusbridge Newsletter: head shape study

[Karlin]

What a lot of the breeders have been wondering is if a change in the shape of the head that breeders themselves were selecting in the 80s conributed to a more severe form of SM; eg somehow also seleceted for more sever forms of the malformation or a shape that especially obstructed CSF flow and caused syrinxes... the 80s are a time when some like Bet who remember the heads from well back, think there was a noticeable shift. Not all agree and researchers have so far said they see no correlation in head shapes, when they do lots of measurements on MRIs.

If it were linked to head shape it would make it a lot easier for breeders to take some decisions that might immediately help to breed away from severer forms, so a lot have been disappointed that this small initial study didn't show a connection.

[sellnee]

Unfortunately, the most obvious reason is rarely the answer.

[Jen]

Unfortunately, the most obvious reason is rarely the answer.

and so frustrating that it's not.

[Karlin]

Well, there is a certain element of direct connection -- researchers have only seen this type of SM in brachycephalic (short nosed) dogs so it does seem in some way connected to changes to dog head shape. One Swedish study connects it as well to dogs with a steeper occiput (back of skull). But not apparently in the more obvious way people had hoped. Nonetheless one of the key researchers on the DNA project thinks there may be some connection to changes inhead shape in the 80s when certain sires also became very popular and the gene pool narrowed.

More research and scans needed, as always!

[sellnee]

We have to be so careful that this connection with the 80's isn't a red herring. I suspect it is.