50 Saber Tails Fall 2017

Petit Basset Griffon Vendéen Club of America

It has been two and a half years since the discovery by Dr. Catherine Mellersh and colleagues at the Animal Health Trust 

of the gene mutation that leads to primary open angle glaucoma (POAG) in the PBGV. This breakthrough has already 

had an enormous impact on our breed. At this time, it would be helpful to take a look back at the events leading up to 

this discovery and consider the effect on future generations of PBGVs.

Glaucoma is traditionally thought of as a plumbing problem. The normal eye has cells that produce fluid and the drain-

age of this fluid from the eye must match its production in order to maintain normal pressure within the eye.  When 

drainage is blocked, the increased intraocular pressure damages the optic nerve and results in pain and impaired vision. 

Sometimes the blocked drainage is due to a structural problem that reduces the rate of fluid outflow from the eye. This 

is known as primary closed angle glaucoma, a condition that can be detected by a veterinary ophthalmologist using a 

technique called gonioscopy.

PBGVs are not predisposed to the closed angle form of glau-

coma; instead, they develop the open angle form. Until 2015, 

there was no way to foretell if your dog was going to develop 

open angle glaucoma; instead, you discovered this when your 

dog developed painful symptoms and went blind.

Twenty years ago, glaucoma didn’t seem to be a major problem 

for the breed. In fact, it was barely on the radar screen. The 2000 

health survey revealed that 16.4% of PBGV owners thought that 

eye disease was a great concern for the breed, but that was not 

due to glaucoma. Fifty-seven dogs out of 640 (8.9%) had persistent pupillary membranes while 17 (2.7%) had cataracts. 

Only 4 of 640 dogs (0.6%) reported glaucoma; the same percentage reported lens luxation. The 2010 health survey 

showed that 11.6% of our dogs had some eye problem, making eye problems the most common disease on the list. 

Again, the most common problems were persistent pupillary membranes and cataracts. Glaucoma was reported in 4 

dogs out of 302 (1.3%). 

Glaucoma was present in the North American PBGV population but from health survey evidence it didn’t seem to be a 

serious problem for our breed. We must keep in mind, however, that the numbers derived from a health survey are only 

accurate if a representative cross-section of the population participates. Nevertheless, there were a few PBGV owners at 

that time who insisted that the problem was worse than the health survey indicated. And we became aware that there 

were clinicians and researchers who were interested in investigating POAG in PBGVs.

In 2012, glaucoma was a main topic at the 3rd BGV World Congress in the UK, which was attended by several PBGV-

CA members, including Helen and Charlie Ingher, Nick Frost, Jeff Pepper and Jan Zigich. We learned that Dr. Andreas 

Komáromy (Michigan State University) was collecting PBGV DNA samples in collaboration with Dr. Catheryn Mellersh 

(Animal Health Trust, UK), who had been successful in finding the POAG gene mutation in other dog breeds and had 

turned her attention to the PBGV. Her work received incredible support from Vivien Phillips (BGV Club, UK) and Dr. Peter 

Bedford (Veterinary Ophthalmologist, UK). The PBGVCA Health Committee arranged for Dr. Komáromy to present semi-

nars, examine eyes, and collect blood at the 2013 PBGVCA National in Houston, TX, and the 2014 National in Camp Hill, 

PA. Throughout this time, we were hearing about more PBGVs developing glaucoma.

We rejoiced when, in 2015, Dr. Mellersh identified the gene defect leading to POAG in PBGVs. The mutation is in a gene 

called ADAMTS17. This mouthful stands for A Disintegrin-like And Metalloprotease with ThromboSpondin type1 motif 

POAG UPDATE

By Laura Liscum, Assistant Chair to the Health Committee

CLEAR

: Your dog inherited good genes with no 

mutations from both parents. S/he will not develop 

POAG and will not pass the disease to offspring.
CARRIER

: Your dog inherited a good POAG gene 

from one parent, but a bad POAG gene from the other 

parent. S/he will not develop POAG but can pass the 

defective gene to offspring.
AFFECTED

: Your dog inherited bad POAG genes 

from both parents. S/he will develop POAG and will 
pass the defective gene to all offspring.