In general, the Canaan Dog is possibly one of the healthiest breeds around, with no known hereditary problems. As breeders we have a responsibility to ensure that the breed remains so, not just for today but for future generations. To help us with this, we use every tool that is available today, including testing all our dogs for hereditary problems such as HD and PL, and looking at inbreeding coefficiencies. Of course this still doesn’t guarantee the perfect dog, but it does give us much more information to base our decisions upon than just the phenotype (looks) of the dog.
Here I go through some things which have apparently, at one time or another, been seen in the breed. Of course there may be others that I do not know about. If you know of other issues, or can expand upon what I have written here, perhaps you could let me know.
Hypothyroidism, Epilepsy, Progressive Retinal Atrophy (PRA), Cryptorchidism, Hip Dysplasia (HD), Osteochondritis Dissecans (OCD)
In his book “Control of Canine Genetic Diseases”, George Padgett lists the above diseases as having been seen at one time or another within the Canaan Dog. His research took place in the USA and, as far as I am aware, epilepsy and pra have only been seen within the breed in the USA.
Hip Dysplasia (HD)
Having had a very bad experience some years ago when having our first Dalmatian hip-scored, we were obviously very wary of having another dog tested and going through a similar experience. Therefore we did not have Evie scored before breeding from her. It was nothing to do with “not believing in it”, as some have said, because we did, we were simply frightened of the possibility of losing her under anaesthetic. However, having gained more knowledge on both HD and hip-scores since then, together with the fact that dogs can nowadays be merely sedated to x-ray, we now hip-score all our dogs.
Whilst, to my knowledge, hip dysplasia has not been seen to be expressed in this country, there are dogs with very poor hip-scores (radiographical hip dysplasia). Because we have a very small genetic pool, it is important that these dogs are not simply excluded from the gene pool, so as to help with diversity. But it is equally important that the stud dog (or brood bitch) be chosen very carefully, having a good hip score and, if it has had progeny, that the progeny also have good scores.
We therefore believe that it is important to test all dogs, especially those used for breeding, to ensure that high scores do not persist, and HD does not become an expressed problem in the future. Indeed, in an article he wrote for The Canaan Dog Club newsletter a few years ago, Dr Malcolm Willis, well known geneticist, advised this.
Patella Luxation (PL)
We first heard about PL the hard way, when a puppy we bred and sent to America was diagnosed with bi-lateral patella luxation. The vet who performed surgery believed it was probably congenital (present at birth), but we unfortunately have no way of knowing at this time whether or not it was inherited or merely a mutation.
Patella luxation is strongly suspected of being inherited, but it can also be caused by trauma. When the luxation is from trauma, something has occurred that has caused the knee to be forced out of normal alignment. Usually the traumatic injury occurs when the dog’s leg gets caught somehow and he struggles to pull free. Or during an overly enthusiastic playtime when the playmate grabs the foot and holds tight while the excited puppy tries to get away. Any other similar accident can permanently injure this small joint.
If the luxation is believed to be of a genetic nature, it is due to an abnormal development of the leg. The possible mode of inheritance is at present undetermined, but it is believed that it may be a polygenic threshold trait. This means that any number of genes may be involved, and that dogs are not “carriers”, but it is merely an unfortunate specific combination of certain genes from the parents that produce patella luxation.
As with all polygenic traits, affected dogs should not be bred from as the risk of producing puppies with patella luxation would then be increased.
On making further enquiries within the breed, we found out that there were a few cases some years ago in Holland and Israel. However, there have been so few cases that it was not really possible to analyse, although they appeared to be quite random and therefore more likely to be simply unfortunate instances rather that an inherited problem.
Since then, all our dogs have been tested clear for PL, and each litter is also tested at the age of 8 weeks before leaving for their new homes.