Suggested French Bulldog Breed Health Testing
Lori Hunt, DVM
As breeders, we are keepers of our chosen breed. We are responsible for the health, temperament, and type we create and share with others and that we pass down to future breeders. When you really start to think about it, we are genetic engineers, planning breedings and twisting genes to achieve that look, personality, movement, and so on that we desire. This is a heavy burden and one we shouldn’t take lightly. Health tests are a tool, individual pieces of a larger puzzle. We can then use that information to make the best decisions possible moving forward. The breeder’s job is to take the health test results, and consider them in the larger picture of breed type and temperament and try to make the best decision they can and attempt to not double up on less than ideal results in hopes to better the breed!
I am going to touch on several phenotypic and genetic tests available for the French bulldog and what the results mean. When possible and to keep things simple, I will use data and statistics from the Orthopedic Foundation for Animals (to be referred to as OFA from hereon out) as it is probably the most noted registry for breeders. There are several others, depending on location, so please check with your local French bulldog and/or all breed clubs to see which is best to use.
All breeds can have their hips radiographed and are assigned a “rating” by various registries. An explanation of how the OFA grades hips is available here as well as a comparison to several other registries: http://www.offa.org/hd_grades.html. As of the writing of this article, the OFA has 1050 Frenchies in their hip database and frenchies rank 21 of all breeds with at least 100 evaluations for the amount of hip dysplasia in the breed. Frenchies currently have 1.5% excellent rankings and 29 % dysplastic. Another way to put it is one in every 3 frenchies has hip dysplasia.
This is a frenchie specific test that is in its pilot stage and requires lateral and ventrodorsal images of your frenchie’s spine from the first cervical vertebrae to the last lumbar one. Dr. Keller is working on determining if there is a pattern to the placement of abnormal vertebrae. So far, no relationship between vertebral anomalies, aka hemivertebrae, and intervertebral disc disease has been noted. In 2004, there were 245 spines evaluated through OFA. Dr. Keller found that thoracic hemiverterbae were the most frequent, and that 81% of French bulldogs had 5 or less hemivertebrae. In a recent conversation with Dr. Keller, there are now over 1000 spines submitted to the study and these percentages are relatively unchanged. Full results of the initial spine report from 2004 can be found here: http://frenchbulldogclub.org/wp-content/uploads/2010/10/French-Bulldog-Spine-Database.pdf
While we are still in a state of determining what French bulldog spines mean, we will only find out if we continue to look at them! Having this information is invaluable and the cost for this reading is a mere $20, which as I say, is the cheapest radiologist’s opinion available. An application to submit your frenchie’s spine to the database is available here: http://www.offa.org/pdf/spineapp_bw.pdf
For patellas, OFA acts just as a keeper of the data. They have a process (http://www.offa.org/pl_grades.html) by which patellas should be graded but any competent veterinarian can do the test itself. But this is where we as a breeder are tested. You can choose to only submit the “good” ones, or all. I challenge everyone to submit all results, so we can get true statistics on this issue in frenchies. OFA currently has 1363 frenchies with only 5.3% affected with luxating patellas, but I believe this is seriously skewed by the lack of submitting non-passing grades.
CERF/OFA eye exam
This is an exam done by a veterinary ophthalmologist, either through the Canine Eye Registry Foundation (CERF) or most recently OFA. The veterinarian will dilate your frenchie’s eyes and search carefully for things like cataracts, lens issues, persistent pupillary membranes, corneal issues, distichiasis, entropian, retinal folds and many more. Some are inherited and this information can be very helpful when planning breeding. A recent discussion with the CERF secretary showed that of all the frenchies tested over the last decade, 15% had heritable abnormalities. More information can be found here: http://www.offa.org/eye_genetics.html
Cardiac disease is definitely beginning to rear its ugly head in frenchies. Pulmonic Stenosis (PS) and Ventricular Septal Defect (VSD) are the diseases seen most often. There are several ways to check a frenchies’ heart. Start with auscultation, meaning have a qualified veterinarian listen to your dog’s heart, in several places and in a very quiet place. Any noted murmurs should be explored before breeding. If you have a dog from a line with known heart disease, I suggest having an echocardiogram performed prior to breeding. As with patellas, I believe the OFA database is skewed due to lack of submission of abnormal results. Do the breed a favor and submit them. They can still remain anonymous, but let’s try to maintain an open database. More information can be found here: http://www.offa.org/cardiac_exam.html
Congenital Deafness (BAER) testing
French Bulldogs are also prone to color related as well as a heritable form of deafness. Deafness is most common in pieds, and can be easily masked by the dog if the deafness exists in only one ear, but it does exist in all colors. Brain Auditory Evoked Response (BAER) testing is a simple ten-minute exam done by a certified veterinarian where small 25 gauge needles are placed through the skin and electrodes are attached. Sound is played into the dog’s ear and the brain’s response is measured through the electrodes. This test can be performed on animals as young as 4-5 weeks once the ears have opened and is easily done on whole litters before they go to new homes. These results can then be sent in to OFA. More info on congenital deafness can be found here: http://www.offa.org/deaf_genetics.html
Juvenile Cataracts (JC)
Cataracts are a clouding of the lens and affect vision. This test is a simple cheek swab and an autosomal recessive gene. Dogs are either affected, carrier or clear. By breeding affected or carrier dogs to clear dogs, none of the offspring would be affected and in a generation or two, one could have an entirely clear line, if so desired. All testing labs are reporting close to 30% of frenchies as either carriers or affected. Several labs do testing for this and some offer a discount if several tests are submitted together. More information can be found here: http://www.horsetesting.com/canine/hc.htm
This is done by radiograph of the chest of dogs at least 12 months of age and helps us see whether tracheal diameter is sufficient for breathing. More information can be found here: http://www.offa.org/th_eval.html
Frenchies can also be hypothyroid. Signs of low thyroid hormone include but are not limited to irregular estrus cycles, obesity, thinning and/or dry and dull coats, pruritis, scabs or scaling of the skin. A simple blood draw can check thyroid levels to determine if this is an issue. More information here: http://www.offa.org/thy_class.html
Degenerative Myelopathy (DM)
This is a devastating disease of the spinal cord resulting in progressive paralysis in many breeds of dogs. Recently, it is coming to light that French bulldogs are carrying this gene. At several labs, including OFA and Animal Genetics, frenchies are coming back with close to 60-70% testing as either “At Risk” or “Carrier”. At Risk dogs are carrying two affected copies of the gene but will not necessarily become clinically affected by the disease. Currently the laboratories are working from information in the genes they have from other breeds, i.e. Corgis, German Shepherds, and Boxers. These breeds have had more samples submitted (as it does require spinal cord tissue from affected dogs to confirm it and thus far, only one has been submitted to the University of Missouri). OFA is currently cautioning that although any dog can be tested, some breeds have genetic backgrounds that may prevent at risk dogs from developing the disease. So for us in frenchies, an at risk test result does not necessarily mean that they will develop DM, but the genes are there, hence the moniker “At risk” and not “affected”. This is a fairly inexpensive cheek swab DNA test and the information is extremely useful, as just like JC, it is an easy recessive gene that can be carefully bred away from if so desired.
Cystinuria is a genetic disorder in the domestic dog that leads to recurrent urolith (bladder stone) formation. Cystinuria is an inherited autosomal recessive disorder and is characterized by the formation of cystine stones in the kidney, ureter, and bladder. There is hope to have a DNA test commercially available soon through University of Pennsylvania researcher Dr. Paula Henthorn.
I have attempted to lay out most of the currently available tests for French bulldogs as well as introduce a few more that are new and up coming. It’s up to each and every breeder to decide what they feel is important to test for and to use that information to plan breedings. It’s also up to the entire frenchie community to share results openly and not judge other breeders’ results, all in the name of “bettering the breed”!
Suggested French Bulldog Anesthesia Protocol
Lori Hunt, DVM
No food for 12 hours before surgery. This is crucial. If the dog eats the morning of surgery, cancel the surgery for that day. Vomiting and aspiration can have devastating effects in a Frenchie. In an emergency, it’s possible your dog may have eaten. PLEASE tell your vet this info, as often it may affect how they recover your frenchie.
Use with Caution
Do Not Give Frenchies
(These would be in addition to the optimum anesthetic protocol listed above and are recommended for longer procedures)
EVERY brachycephalic dog that goes under anesthesia should have an endotracheal tube (ET) placed in his or her trachea. Always! The airway must be protected at all times. The endotracheal tube should be left in until the dog is awake. Use intravenous propofol (or one of the other satisfactory drugs listed above) to induce anesthesia (which puts them under) and allows sufficient time to place the ET tube. From then on, anesthesia is maintained with sevoflurane or isoflurane.
Brachycephalic breeds, such as Frenchie, should NEVER be masked down with anesthesia. Masking down is when a mask is placed on an awake or mildly sedated dog’s muzzle. The mask is held in place by restraining the dog. The inhalant, which has a bad smell, is given at high levels. As the dog breaths more and more, he/she gets sleepy. The problem with masking down Frenchies is that they can become very anxious, fight the mask and not breath well. Most Frenchies have problems breathing in the first place, this just makes it worse, which results in lower oxygen levels. Ideally, injectable sedatives are used and an endotracheal tube placed which is then attached to an anesthetic machine. This gives them the optimum oxygen supply.
Lori Hunt, DVM