More changing faces

First generation cross

Dad

Henry (Brittany Spaniel)

Mum

Smudge (Cavalier King Charles Spaniel)

Daughters

Blottie (F1 Brittany/Cavalier)

Bumble (F1 Brittany/Cavalier)

A follow on from the blog Changing faces that I done a couple days ago, images of our first Brittany cross Cavalier girls we bred in April 2015 Smudge has nine little Hudges 
You can see improvement in the skull shape. A lot of people think the problem with flat faced dogs or dogs with shorter muzzles such as the Cavalier, the problems are just caused by the shortening of the nose. Hence why many do not understand why Cavaliers are classed as brachycephalic, having the disease Brachycephaly. This is because of confusion with the Craniofacial ratio (CFR) and the Cephalic index as I discussed on the blog Heads and heartache. The CPR includes the measuring of the muzzle, but the Cephalic index is the ratio between the width (side to side) and length (front to back) of its cranium (skull), not including the muzzle. So this is why Cavaliers, although they have a bit of muzzle, are in the extreme brachycephalic catergory, because the length of the cranium is shorter than the width, giving the top and sides of the cranium a round shape, often referred to as 'apple-head'. In 2012 a study of Brachycephalic Airway Obstruction Syndrome (BAOS) surgery on 155 Australian dogs, the cavalier was the most common breed (29 dogs, 18.7%). The researchers found: "All CKCS had an elongated soft palate and accounted for 41% of the laryngeal collapse ​cases." Cavaliers are with no doubt extreme brachycephalics, don't let the length of the nose fool you.  
David Sargan who heads the BOAS Research Group - University of Cambridge Veterinary School tells us in a comment on the CRUFFA Public Group | Facebook page, why CFR is not used, as the problems with BOAS are more likely to be caused by the shortening of the cranium. "If you look at the sites within the airway where we know there may be obstructions within the brachycephalic breeds, the nostrils and alar folds are within the face; but the turbinates and soft palate are almost completely under the cranium; the larynx is more or less under the back of the head, and the trachea is really behind the head. Considering the internal anatomy meant that that several of these structures will actually be more cramped when the cranium is shorter, (and for a given facial length, shortening the cranium will of course increase the ratio of face to cranial length). So we were not too surprised when our measurements on over 600 dogs suggested that CFR is unlikely to be a useful guide in the three breeds we looked at."
He then goes on to make this comment, "If BOAS is genetic but it is caused by genes that also cause the short skull then getting rid of the short skull will reduce or eliminate BOAS. Even though single genes code (in general terms) for single proteins, changes to them do not often have only single consequences. For example genes that when mutated reduce the production of strong cartilage or increase its conversion to bone can show their effects on skull or spine shape or by producing soft collapsing tracheas, or more likely show both effects. Breeding away from the short skull might then also breed a dog with a stronger trachea by reducing the frequency of these mutations." Let's hope they can proof this to the blind brachy breeders sooner rather than later.
I understood a long time ago that the key to the Cavaliers head problems are the not only to lengthen the nose, but the skull needs to be lengthened. Just look at x-rays of a dog with extreme brachycephaly compared to one without. Look how the brain and everything else is squashed up, due to the lack of length in the cranium. The skull has been distorted to such an extent, the x-rays almost look like two different species of animal. 

German Shepherd with a dolichocephalic (long) skull.

Pug with a brachycephalic skull.

So we are trying to improve not only nose length, but more importantly, cranium length. The Brittany crossed with the Cavalier does both of these things, and in 2018, we hope to breed our next generation on from our first cross Brittany/Cavaliers with our F1b 3/4 Cavalier, 1/4 Poodle Ernest. This we hope will produce a nice lap sized family spaniel, still capable of days in the field.