Health and Certifications
OFA - Hip Registry

General | CERF | Bouvier Reports
OFA: Overview | Cardiac | Elbows | Hips | Thyroid

• Purpose
• What is Hip Dysplasia?
• How Common is Hip Dysplasia?
• What are the trends in Hip Dysplasia?
• What can breeders do to help reduce Hip Dysplasia?
• What should I check before purchasing a Bouvier?
• AVMA Positioning Required
• Does OFA require chemical restraint (anesthesia)?
• Should bitches be radiographed around a heat cycle?
• Radiographic Criteria
• Film Copies
• What's a "Prelim"?
• Categories
• How do I interpret the OFA Hip Registry numbers?
• How does OFA hip scheme compare to FCI classifications?
• Fact or Fiction?
• Does OFA have a website?
• How to contact OFA

Purpose

The purposes of the registry are:

• to provide a standardized evaluation for hip dysplasia; and
• to serve as a database for control of hip dysplasia through selective breeding.

To date, the OFA maintains the world's largest database on hip conformation.

What is Hip Dysplasia?

Canine Hip Dysplasia (CHD) is an inherited trait involving multiple gene pairs which results in a spectrum of radiographic conformations. CHD is a developmental disease. All dogs apparently are born with normal hips but in affected individuals the radiographic signs of CHD can become evident within several months to several years. Therefore, the accuracy of diagnosis increases with age to about 95% at 24 months of age. OFA preliminary evaluations (dogs evaluated between 4 and 23 months of age) are about 90% accurate when compared to repeat studies at 2 years of age.

How common is Hip Dysplasia?

The incidence of dysplasia in any given breed is unknown. The majority of dogs evaluated by the OFA are submitted by breeder clientele concerned with controlling canine hip dysplasia. Therefore, the OFA data, while biased toward normal due to prior screening by referring veterinarians, can serve as a benchmark for the frequency of CHD in the breeding population (seeTable 1).

What are the trends in Hip Dysplasia?

The incidence of CHD is breed dependent and improvement depends on responsible breeding practices. It has been demonstrated that the frequency of CHD can be reduced by responsible selective breeding practices (seeTable 2).

What can breeders do to help reduce CHD?

• Breed normals to normals.
• Breed normals with normal ancestry.
• Breed normals from litters with a low incidence of CHD.
• Select a sire that produces a low incidence of CHD.
• Replace dogs with dogs that are better than the breed average.

What should I check before purchasing a Bouvier?

Do your homework!

Prospective buyers should check pedigrees for OFA numbers prior to purchasing a dog. If an OFA number cannot be verified, do not assume the dog to be dysplastic-free.

AVMA Positioning Required

The OFA requires a ventrodorsal radiograph with the pelvis symmetrical, femurs parallel to one another and approximately parallel to the table, and with the patella on the midline. The radiographic technique should be sufficient so that the trabecular bone pattern and the dorsal rim of the acetabulum can be seen.

Does OFA require chemical restraint (anesthesia)?

Chemical restraint (anesthesia) is not required by OFA, but chemical restraint to the point of muscle relaxation is recommended. With chemical restraint, optimum patient positioning is easier with minimal repeat radiographs (less radiation exposure) and a truer representation of the hip status is obtained.

Sometimes, it might depend on the experience of the veterinarian in processing radiographs, and the personality of the dog being radiographed. Consult with your veterinarian.

Should bitches be radiographed around a heat cycle?

Observations suggest that female dogs not be radiographed 3 to 4 weeks before or right after a heat cycle, or 34 weeks after weaning a litter of puppies. Apparently, hormonal fluctuations in female dogs can influence the radiographic appearance of subluxation.

Radiographic Criteria

All radiographs are screened for positioning and technique upon arrival. If the radiograph is not diagnostic it is returned to the referring veterinarian.

Acceptable radiographs are then evaluated independently by three (3) board certified veterinary radiologists and a consensus derived.

The hips are evaluated for subluxation, shallow acetabulum, femoral head/neck remodeling, acetabular rim/edge changes, and degenerative joint diseases. With the introduction of optical archiving and remote viewing from magnetic media, the average report time is now 15 days with 87% of the evaluations finishing in less than 20 days.

Film Copies

Due to optical archiving, the OFA can no longer supply copies of films. If a copy is necessary, be sure to ask your veterinarian to insert two (2) films into the cassette prior to making the exposure. This normally requires an approximate 15% increase in the "kVp" to make an exact duplicate of the radiograph which will be sent to OFA.

What's a "Prelim"?

Dogs must be at least 24 months old before they can register the hips and elbows evaluations. However, preliminary evaluations can be performed as early as 4 to 5 months of age, and OFA evaluations can be up to 90% accurate when compared to follow-ups at 24 months of age.

Categories

Excellent Good Fair	Normal ~ Receive OFA Numbers
Borderline	Recommend repeat study in 6-8 months
Mild Moderate Severe	Dysplastic
Normal hips on individuals 24 months or older are assigned a breed registry number and will periodically be reported to the parent club and AKC.

How do I interpret the OFA Hip Registry numbers?

Here's an example:

Another example:

How does OFA hip scheme compare to FCI classifications?

Fact or Fiction?

• There are currently no proven environmental factors which cause canine hip dysplasia (CHD).
• There is currently no scientific evidence supporting that megadoses of vitamin C or any other supplement is beneficial in reducing the effects from or preventing hip dysplasia.
• High caloric intake resulting in rapid growth may exacerbate changes in dysplastic hips, but will not create hip dysplasia (more studies are still in progress).
• Exercise, running, jumping up and down, and slick floors will not cause hip dysplasia.
• Prior injuries to the femurs and/or pelvis may be detected radioraphically, and are taken into account when evaluating hip status.

You can get more info by visiting OFA's official website.

Contact OFA directly for specific information on the OFA registries:

Orthopedic Foundation For Animals
2300 E. Nifong Blvd.
Columbia, MO 65201-3856
phone (573) 442-0418
fax (573) 875-5073

Dr. R.A. Weitkamp ~ President
Greg Keller, DVM, MS ~ Executive Director

email ofa@offa.org

Health and Certifications
OFA ~ Hip Registry

General | CERF | Bouvier Reports
OFA: Overview | Cardiac | Elbows | Hips | Thyroid