by Carol Beuchat PhD

The list of canine genetic diseases seems to get longer every day, and you have to wonder if this is "normal".  Of course, all animals have inherited disorders, but is the dog typical of other animals?

One of the best online resources for information about genetic traits in mammals and birds is OMIA - Online Mendelian Inheritance in Animals.  It contains information on both domestic and wild animals, and even a few birds and fish.  Displayed are the total number of traits or disorders they have information for, as well as the particular gene or mutation if known.

By Carol Beuchat PhD

I ran into a paper about primary lens luxation in dogs today, and the phrase "widespread among dog breeds" in the title caught my attention.  Naturally, I wondered exactly how widespread we're talking about here.  To get right to the meat of things, have a look at this table, which reports carrier frequencies by breed.  (These are data for US dogs, but the reported numbers for dogs in the UK are very similar; I've included the entire table at the bottom of the post, and note that there additional affected breeds listed below.)

American Hairless Terrier - 4%

Chinese Crested - 26%

Jack Russell Terrier - 35%

Miniature Bull Terrier - 51%

Parson Russell Terrier - 22%

Rat Terrier - 38%

Sealyham Terrier - 36%

Tibetan Terrier - 28%

Toy Fox Terrier - 29%

Welsh Terrier - 36%

With the single exception of the American Hairless, these numbers are shocking.  Carrier frequencies are all in the double digits for every other breed, and for a disorder that (might) be autosomal recessive there are plenty of opportunities to unwittingly produce homozygous (i.e., eventually blind) puppies.  Almost 30% of Tibetan Terriers are carriers, and for Minibulls fully half have the gene.

by Carol Beuchat PhD


Myopathies are diseases that impair the function of muscle.  There are many different kinds, and there is one called centronuclear myopathy (CNM) that is on its way to becoming a real problem in Labrador Retrievers. 

CNM in Labradors is caused by an autosomal recessive allele and first popped up in a research colony in France a few decades ago.  In the years since, dogs with phenotypically similar myopathies have being reported in the USA, UK, Australia, Canada, and elsewhere in Europe.

Now, the source of the disease has been nailed down to a mutation in a single famous stud dog that has been copied thousands of times in his descendants, which are now distributed all over the world.

Centronuclear myopathy can be gravely disabling.  Puppies appear normal when born, but they fail to develop normal muscle strength and are exercise intolerant.  They can have a normal lifespan, but activity is compromised because the muscles of affected dogs atrophy, especially in the hindquarters.

There is so much genetic research being published these days that it's actually become hard to keep up.  The problem is being able to find these papers, which end up in journals that range in topics from evolution to molecular genetics, veterinary medicine to conservation biology.