The Orthopedic Foundation for Animals: An Overview of Canine Database Information
by Angelica Steinker, M.Ed. CBDT, CCBC

This article originally appeared in the Courteous Canine list, available on Yahoo Groups.  You may sign up by going here.

When dog people hear the phrase OFA it is synonymous to "hip rating".

In reality the OFA offers seven databases with only one being for hip dysplasia.  The remaining six include: elbow dysplasia, patellar luxation, autoimmune thyroiditis, congential heart disease, and craniomandibular osteopathy.

The Hip Dysplasia Database

The OFA hip dysplasia database is the oldest and the most popular.  Dogs can be evaluated on a preliminary basis starting at the age of 4-5 months to just under two years.  At two years and older dogs can be "certified" with a rating of "excellent" for almost perfect hips, "good" or "fair" which is considered a normal rating that is dysplasia free.  Dysplastic dogs are rated as "mild", "moderate", or "severe" based on how poor the hip joint conformation is.  A dog that is rated "fair" can be bred, but it is recommended that the dog be bred up to a "good" or an "excellent" rated dog.

A fascinating fact is that dogs that have been preliminarily evaluated as early as 4-5 months have an accuracy rate of 90% when re-evaluated at 24 months of age.

The Elbow Dysplasia Database

Elbow dysplasia is a condition similar to hip dysplasia, but obviously involving the elbow joint rather than the hip.  OFA will certify elbows on dogs that are 24 months or older.  The rating system is normal for correct elbows and a grade 1-3 for abnormal elbows.

The Patellar Luxation Database

Patellar luxation is a knee problem in which the knee cap does not track properly.  This problem is inheritable and only correctable via surgery.  OFA will assign a certified number to dogs that are 12 months or older that have been found to be free of luxating patellas by a veterinarian.  When patella luxation is found it is rated grade 1 for mild cases up to grade 4 which is the most severe form of luxation.

The Thyroid Database

Autoimmune thyroiditis is the genetic form of hypothyroidism.  Breeders are encouraged to test for thyroid no earlier than one year of age.

After that it is recommended to test every year until the dog is 9.  If the dog has a healthy thyroid by age five it is likely that the dog will continue to have a healthy thyroid for the rest of her life.

The Congenital Heart Disease Database

Congential heart disease refers to heart disease that is passed on genetically.  Dogs are required to be seen by a veterinarian that specializes in canine congenital heart disease, usually this would be a Veterinarian with a specialization in internal medicine.  Checking for a congenital heart problem is a one time thing.  Once the dog reaches 1 year or older you can have her checked one time and she will be certified congential heart disease free for the rest of her life.

The Craniomandibular Osteopathy Database

Craniomandibular osteopathy is a genetic disease which causes the jaw bone to over grow and become deformed.  The result is a painful jaw that may make eating difficult for the dog.  This disease is most common in terriers, but has also been found in Boxers, Labs, Dobermans and Great Danes.

The careful collection of data by the OFA enables both breeders and buyers of dogs to use the information to make educated choices.

Hip Dysplasia

For example the breed most effected by hip dysplasia is the Bulldog, out of all the Bulldog hips evaluated by the OFA none were rated the highest healthy rating of "excellent".  A shocking statistic is that 75.1 percent of Bulldogs have been rated dysplastic.  This means that 2 out of 3 Bulldogs have malformed hips and should not be bred.

In second place is the Pug with 59.1% being rated dsyplastic.  The remaining ten worst hips go to Dogue De Bardeaux (57.7%), Otterhound (51.4%), Clumber Spaniel (48.0%), Neapolitan Mastiff (47.3%), St. Bernard (46.7%), Boykin Spaniel (43.5%), Sussex Spaniel (47.0%), and Cane Corso Mastiff (40.5%).

It seems shocking that so many breeds have such high percentages of hip dysplasia.

Out of the total 132 breeds listed in the database the ten breeds least likely to have hip dysplasia are:

Other popular breeds such as the Austrialian Shepard rated 11.2%, Border Collie 12.3%, Chow Chow had a higher rating of 20.5%, German Shepard, who are known for hip problems rated a surprising 19.4% dysplastic.  Golden Retrievers only have 20.9% of their breed come back dysplastic.  Labrador Retrievers, another breed know for hip problems, also rated a low 13.0% dysplastic.

An interesting fact is that many of the toy breeds were not represented in the statistics.  Yorkshire Terriers, Papillion, and Miniature Pinschers were all absent from the list of breeds.  This means that either hip dysplasia is not common in these breeds, breeders are choosing not to screen, or the OFA limits of a minimum of 100 xrays had not been met.  OFA states that only breeds that included a minimum of 100 xrays were included in these statistics.

The OFA has also kept track of trends in selected breeds that have been screening hips for long periods of time.  When examining hip scores of dogs in two groups of the same breed of dog, one group being born 1972-1980 and the second being born 1994-1995, it is possible to examine trends with in a given breed.

For example it was found that when comparing Golden Retrievers born 1972-1980 to Golden Retriever born 1994-1995, that the number of dysplastic Goldens is decreasing and the number of "excellent" rated Goldens is increasing.

This same dynamic was found across the board in all of the breeds that have been evaluating hips since 1972.  The number of "excellent" rated hips are increasing and the number of dsyplastic hips are decreasing.  Of all statistics this is the one that makes it most clear that screening hips works!

Elbow Dysplasia

Elbow dysplasia is another serious joint disease that can have three genetically based causes, ununited anconeal process, fragmented coronoid process, and osteochondrosis (OCD).

As with the hip database only breeds that had submitted a minimum of 100 xrays are included in the statistics.

The ten breeds that are most likely to have elbow dysplasia are:

The ten breeds most likely to not have elbow dysplasia are:

Other breeds of interest are listed at the following: Australian Shepard 4.9%, Bloodhound 16.3%, Golden Retriever 11.6%, Poodle 2.2%, and Sheltie 3.3%.

Patellar luxation is another heredity joint problem.  This database has been added more recently, so OFA is providing information for breeds that have registered 50 or more dogs.

The three breeds most likely to be effected by patella luxation are:

Some surprises were that several large dogs are listed as having patella luxation, such as Akita (2.8%), Australian Shepard (2.9%), Flat Coated Retriever (3.2%), Keeshond (12.8%), and Rottweiler (3.5%).  It was my understanding that luxating patellas were really more of a small dog problem, but this clearly does not seem to be correct.

Not surprising was to see that small dog breeds like Bichon Frise (10.2%) had high percentages of the disease.  It may be that some statistics could be off because all sizes of Poodle are included in the "Poodle" breed statistic of 9.5%, no category was created for toy, miniature or standard Poodles.

OFA requires that dogs be screened by a Veterinarian.  Dogs will only be certified if they are a minimum of 12 months of age or older.  It is recommended to have the patellas rechecked later in life as sometimes luxations do not appear until the dog is older.  OFA will accept preliminary patella info if the dog is under 12 months of age, and they recommend preliminary certification if the dog is going to be bred.

Animals that show to have patella luxation are classified as grade 1 (intermittent patellar luxation), grade 2 (frequent patellar luxation), grade 3 (permanent luxation with torsion of the tibia and deviation of the tibial crest of 30-50 degrees), grade 4 (the tibia is medially twisted and the crest may show deviation between 50-90 degrees).

OFA explains that while the luxation may not be present at birth the anatomical deformities that cause the luxation will be present and are responsible for the subsequent luxation.  This is the inheritable form of the disease, however trauma can also cause patella luxation and this form of the disease is not inheritable.

It was disappointing to see that Jack Russell Terriers were not listed at all.  The Jack Russell has a high percentage of Patella Luxation and to require that breeding dogs be listed in the OFA Patella database would be a good start to reducing the number of dogs effected.  I own three Jack Russells and all three have Patella Luxation, one dog required surgery.

Hypothyroidism

Another common inheritable disease is hypothyroidism.  OFA has three categories: autoimmune hypothyroidism, idiopathic hypothyroidism, and equivocal. Autoimmune seems to be the most common.  The idiopathic form of the disease seems to be relatively rare.  Idiopathic means of unknown origin, so it seems that most of the time it is know that the source of the disease is autoimmune.

The autoimmune hypothyroidism is most common in the following breeds:

The dogs least effected by autoimmune hypothyroidism are:

The idiopathic hypothyroidism was much less likely to effect dogs.  Many breeds and 0% listed as number of dogs effected.  The breeds most likely to be effected by idiopathic hypothyroidism are:

Of all the databases, the thyroid one was the only one to list "equivocal" results.  This statistic seemed very high ranging from 30.9% to 8.2%.  This seemed like a very high number of dogs to be listed "questionable" results.  Dogs that are rated as "equivocal" are recommended to repeat the test in 3-6 months.  Even dogs that are certified as having healthy thyroid levels are recommended to recertify at age 2,3,4, 6 and 8.  There is no charge for recertification.

Congenital Cardiac

This certification requires an examination by Veterinary Internist, or a Cardiac Specialist.  Again, dogs are found to be normal - clear of congential heart problems or are rated from grade 1 to 6 depending on the severity of the heart problem.

Grade 1 is for dogs with a soft murmur.  Grade 2 the murur is readily evident, grade 3 is a moderately intense murmur, and grade 4-6 are reserved for the most severe murmurs.

Because this is a more recent database, breeds with 50 or more dogs registered were listed in the database.

The breeds most commonly effected by Congenital Cardiac Disease were:

There were many breeds listed that had a clean slate when it came to congential heart problems.  The following breeds all were 100% free of any congenital heart disease:

Austrialian Shepard
Bloodhound
Border Terrier
Curly Coated Retriever
Doberman Pinscher
French Bulldog
German Shepard Dog
Novia Scotia Ducktolling Retriever

As with the thyroid database, the congential heart database also listed results that were inconclusive and would need to be repeated.  These percentages ranged from 0.0% to 4.8% for various breeds.

Genetic Databases

In the future, we will hopefully have blood tests for all congenital diseases of the dog.  Currently there are only a handful of diseases that have been DNA databases available for only a handful of breeds.

Currently there are DNA databases for:

Von Willebrand's disease - Scottish Terrier, Manchester Terrier, Doberman Pinscher, Shetland Sheepdog, Poodle, and Pembroke Welsh Corgi.

Progressive Retinal Atrophy - Irish Setter, Cardigan Welsh Corgi, Cheasapeak Bay Retriever, Labrador Retriever, Portuguese Water Dog, English Cocker Spaniel.

Copper Toxicosis - Bedlington Terrier

Cystinuria - Newfoundland

Phsophofructokinase Deficiency - English Spring Spaniel, Cocker Spaniel.

Congenital Stationary Night Blindness - Briard

Pyruvate Kinase Deficiency - Shih Tzu, Lhasa Apso, Soft Coated Wheaton Terrier.

Hopefully in the future tests can be developed for other disabling diseases such as Epilepsy, Collie Eye Anomaly, and many more.

If you are considering breeding your dog the costs of these genetic tests, or certifications are considerable.  Any breeder that does it "right" will be spending more money than they will be making as the result of the sale of the pups.  Proper breeding truly is a labor of love.

Angelica Steinker, M.Ed. is a motivational trainer and owner of Courteous Canine, Inc., a dog training school that specializes in dog behavior, problem solving, clicker training, and agility.  Angelica has a Master's degree in counseling from George Mason University and actively uses behavior and learning theories in her work with dogs and their owners.