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Bernese Mountain Dogs - Breed Information & Education for Puppy Buyers, Owners and Breeders

Canine Hip Dysplasia

December, 2010

Authors: Pat Long, Ann Milligan,
with excerpts from the BMDCA?s Health Committee's list of health tests

Incidence of Hip Dysplasia in BMD's

The 2000 Health Survey (total 1062 dogs) showed 148/13.9% were affected with HD.
The 2005 Health Survey (total 1294 dogs) showed 135/10.4% were affected with HD.

As of December, 2010:
The BernerGarde database lists 25354 HD certifications/results for Bernese, including but not limited to OFA ratings: A BG search in "Reports" for hip certifications [http://www.bernergarde.org/dbaccess/BGquery_CertTestSearch.aspx] shows the following data: Excellent - 3072; Good - 9872; Fair - 2550; Borderline - 368; Mild - 991; Moderate - 558; Severe - 69. 283 dogs' PennHip results are also listed. Other registries' hip results are listed as well: Normal ? 4556; 554 ? almost normal. GDC results show 406 dogs with hips rated as acceptable.

The Orthopedic Foundation for Animals shows Hip evaluations records for 14801 BMD's. 16% are listed as dysplastic. Undoubtedly the percentage of dysplastic dogs is higher in that radiographs for dogs exhibiting obvious evidence of HD are not always submitted to OFA.

What is Canine Hip Dysplasia (CHD or HD)?

Canine hip dysplasia (CHD) is a heritable polygenic condition.
Environmental factors including diet and exercise can also play a role in development of CHD.

About the hip joint:

The hip joint is a ball and socket joint. Good musculature and joint integrity affect the stability of the joint. If properly constructed, the top of the thigh bone, or femoral head, is the ball that fits into the socket, or acetabulum, in the pelvis. This joint does not always develop properly. When the socket is not deep enough for the ball to fully fit into place, laxity of the femoral head ligament allows for hip subluxation (the ball is loose in the socket). This laxity, along with incongruity of the coxofemoral joint, damages the acetabular labrum and femoral head cartilage, resulting in osteoarthritis (OA), limited mobility and pain. Note: The malformation of the hip joint is called Canine Hip Dysplasia. [Dysplasia comes from the Greek words meaning bad (dys) and growth (plasia).]

Generally accepted as fact:

1. Very tight hips with a tight fit between femoral head and pelvis rarely lead to arthritis of the hip joint.

2. Very loose hips with almost no fit between the femoral head and the pelvis routinely lead to arthritis of the hip joint.

3. Arthritis [degenerative joint disease (DJD)] is the enemy.

4. Arthritic changes associated with HD are progressive and often symptoms worsen with age.

Disease Onset:

HD, in all but the most severe cases, is rarely noticeable at an early age (< 4 - 6 mos.). If a puppy is severely dysplastic, symptoms may be seen at 4 - 6 months. Regardless of the degree of malformation of the hip joint, it is not uncommon for HD symptoms to appear later in the dog?s life, after arthritic changes have occurred.

Considerations:

Each case of HD is different in terms of progression and symptoms.

1. Not all dogs affected with hip dysplasia will necessarily experience clinical signs associated with HD.

2. Some dogs with hip dysplasia will experience lameness/pain at young ages 4 -15 months, after which signs and symptoms will disappear, only to reappear later in life.

3. Degenerative joint disease (arthritis) can be caused by normal wear and tear on abnormal joints, or abnormal wear and tear on normal joints.

Symptoms of Hip Dysplasia:

"Lazy dog" - a dog that doesn't move around much
Lameness - stiff or loose movement in rear legs when gaiting
Pop or click of the joint
Hunching over the loin (when standing dog's rear legs fall under the belly)
Shuffling rear leg movement; short steps
Difficulty getting up
Unwillingness to play
Unwillingness to sit
Reluctance to climb stairs
Reluctance or inability to jump
Soreness/limping after exercise
Bunny hopping (bunny-hopping is what the dog does instead of walking or trotting. Dogs with HD will trot forward with the front legs but then hop the back legs forward together.)

None of the symptoms described above as associated with HD provide an accurate assessment of the canine hip joint.

Hip Dysplasia Diagnostics

About Hip Dysplasia Screening

NOTE: Permanent identification, such as a microchip or tattoo is recommended prior to screening.

HD screening options - two methods are available.

Method 1, PennHIP (The University of Pennsylvania Hip Improvement Program) joint laxity measurement.

Method 2, radiographs

· Method 1 - PennHIP Hip joint laxity

PennHIP screening measures joint laxity with the Distraction Index (DI). From the PennHIP website: "it is recommended that breeders choose breeding stock from the tightest 40% of the breed (meaning the 60th percentile or better), thereby maintaining an acceptable level of genetic diversity while still applying meaningful selection pressure. By breeding only dogs with hips above the breed average (60th percentile or better) the overall breed average will move toward better (tighter) hips from one generation to the next."

Age: PennHIP screening can be done as early as 4 months

Age recommended: after 12 months for optimal results.

PROVIDERS/HOW TO:

For PennHIP information see: http://research.vet.upenn.edu/pennhip/LocateaPennHIPVet/tabid/3539/Default.aspx.

BERNER-GARDE: Copies of the PennHIP results should be submitted to Berner-Garde.
[http://www.bernergarde.org/home/forms.aspx]


__________________________________________________________________________


· Method 2 - Radiographs

IMPORTANT CONSIDERATION: screening for HD should be done by a veterinarian experienced with positioning requirements for the procedure.

ADDITIONAL NOTE: Dogs can be radiographed under anesthesia or not. Consult the attending veterinarian for further information.

Age: > 6 months

Age recommended: after 24 months

PROVIDERS/HOW TO:

OFA (Orthopedic Foundation of Animals)

Radiographs are mailed direct by the attending veterinarian to OFA using this form: http://www.offa.org/pdf/hdappbw.pdf.
Important note on completing this form: If you choose to share the results, be sure to initial the section "authorization to share abnormal results." If you overlook this and wish to have the results shared, OFA has a form to enable you to make the change: http://www.offa.org/pdf/databasechange.pdf

OVC Ontario Veterinary College (OVC)
Howard Dobson, DVM
University of Guelph
Guelph, Ontario, E1G 2W1
Canada
Phone: (519) 823-8800 x 4000
Website: http://www.ovc.uoguelph.ca (Ontario Vet College)

BERNER-GARDE: OVC results must be submitted to Berner-Garde.
[http://www.bernergarde.org/home/forms.aspx]

Correlate/compare different systems/methods of diagnosing hip joint conformation

Worldwide many registries and systems are used for hip certification. Please see the Hip Ratings Comparison Chart for insights.

GENERAL INFORMATION
Hip Evaluations - Radiographs:

OFA tells you whether or not your dog has hip dysplasia, but does not predict whether your dog will develop HD. PennHIP tells you the chances your dog might develop hip problems, but does not provide an absolute yes or no answer. A PennHIP evaluation tells you if the dog has DJD or any other hip joint abnormalities they can specifically identify. PennHIP: the Bernese Mountain Dog breed median DI is 0.56.

There are BMD?s who have tight hips according to PennHip and are rated by OFA as having moderate hip dysplasia. And there are BMD?s who have good OFA rated hips, but lower than the breed average DI values according to PennHip.

It may be safe to assume that a PennHip DI score in or above the 80% percentile for the breed has little to no chance of developing HD.

PennHIP evaluations consist of three separate radiographs: the distraction view, the compression view and the hip-extended view. The distraction view and compression view are used to obtain accurate and precise measurements of joint laxity and congruity. The hip-extended view is used to obtain supplementary information regarding the existence of osteoarthritis (OA) of the hip joint. (The hip-extended view is the conventional radiographic view used to evaluate the integrity of the canine hip joint.) The PennHIP technique is more accurate than the current standard, and it has been shown to be a better predictor for the onset of OA. Below are sample radiographs showing positioning (hip-extended) for OFA. For more information on positioning for PennHIP radiographs see: http://research.vet.upenn.edu/pennhip/GeneralInformation/WhatisPennHIP/tabid/3232/Default.aspx

hip x-rays Bernese

Medical Management of Hip Dysplasia

Conservative management - Non-surgical methods for treating hip dysplasia

Pain medications - such as NSAIDS and adequan (*Consult a veterinarian ? do not mix herbal/holistic preparations with pharmaceuticals without developing a complete understanding of potential interactions.)

Dietary supplements - Glucosamine, Chondroitin, MSM

Weight loss/weight control programs

Proper controlled exercise (rigorous, forced exercise is not advised. Ramming, slamming play can easily injure growing BMD?s.)

Physical therapy (hydrotherapy, massage, acupuncture, chiropractic)

Stem cell therapy may prove beneficial. (See link below.)

Surgical methods for treating hip dysplasia

*Comment ? surgical correction of hip dysplasia is a serious undertaking. HD surgery(s) can be very expensive ($1500.00>$3500.00 per hip); post surgical rehabilitation may take 4 -12 months. HD surgery may or may not work to alleviate all symptoms associated with HD. HD surgery should only be considered when other less invasive forms of medical management are unsatisfactory or unsuccessful.

1. Triple Pelvic Osteotomy, or TPO. This procedure is best done before any degenerative changes occur.

AGE: TPO surgery is most effective for dogs under the age of one year

2. Total Hip Replacement (THR). The femoral head is replaced by a prosthetic ball, and the acetabulum is replaced by a prosthetic socket. AGE: dogs over the age of one year, or after degenerative changes of the hip have begun.

NOTE: There are two types of prosthetics for the femoral head, a fixed head unit, and a newer version modular system. There is a 95% rate of achieving normal or near-normal function for the fixed head prosthetic, while the modular system equals or betters that. Surgical complications can include infection, dislocation, femoral fractures, and sciatic nerve damage. Although the risk of infection is rare, it is probably the worst of the side effects, since the whole prosthesis must be removed - including scraping out all of the cement.

3. The Femoral Head Osteotomy (FHO) involves removing the femoral head and allowing scar tissue to develop to create a new ball. This procedure is not generally used for big dogs. This is a procedure of last resort, once the FHO has been done, there are no other options. This is sometimes even used in large breeds if the THR has been unsuccessful or has become infected.

4. The Intertrochanteric Osteotomy involves cutting the femoral head in order to force it to fit better into the acetabulum. The procedure is most effective for dogs weighing less than 50 pounds and before any degenerative changes occur.

5. Juvenile Pelvic Symphysiodesis (JPS) is a relatively new procedure for the treatment of canine hip dysplasia. The procedure is done in young dogs that screen positive for hip laxity. JSP is a minimally invasive procedure done to correct or limit the development of initial forms of canine hip dysplasia and therefore reduce secondary osteoarthritis. During JPS surgery, electocautery is applied to the growth plate of part of the pelvic bone inducing pubic fusion which results in angular changes to the pelvis. These changes allow for a better fit of the ball and socket joint. JPS surgery employs no orthopedic implants. Typically, the procedure is short in duration, involves an over night stay in the hospital; and most dogs experience minimal discomfort. Compared to traditional procedures for hip dysplasia, the costs for JPS surgery are considerably less expensive.

Breeder notes...

FACT: The genes for hip dysplasia are widespread through families of BMD's.
Anyone who claims otherwise is fooling themselves.
FACT: Even two dogs with perfect hips can produce dysplastic puppies.
FACT: If you are actively pursuing breeding BMD's, sooner or later you will produce dogs with hip dysplasia.

Consider: Breeding from families of Bernese and/or dogs with 'unknown hip status'* puts any dog breeder at greater risk of producing dogs that may be affected with HD. [* Please remember a dog may be affected by HD and show no clinical symptoms. A young breeding dog that has malformed hip joints may show no signs and symptoms of HD at 2 years of age, but the dog could well become lame and crippled by arthritis later in life.]
Consider: All Bernese Mountain Dogs that you plan to use as breeding stock should be evaluated for hip dysplasia.
Consider: Pet owners with whom you place pups can help you to ensure the future health of the breed by evaluating their pets? hips ? full litter hip evaluations provides you with feedback to guide your future breeding decisions. HD evaluation can also help pet owners by letting them know if they need to be cautious with managing their dog?s diet and exercise so as to not exacerbate problems caused by faulty hip joints. Management tactics for dogs prone to develop HD make a noticeable difference in the progression of the arthritic disease process. Lean dogs with poor hips do better than overweight dogs. HD affected dogs should be provided with opportunities for consistent, moderate exercise. Proper exercise helps keep joints flexible and adds muscle mass which provides additional support for faulty hips.

The BMDCA Health Committee - Info on genetic management of HD

Recommended practices for Bernese breeders ? BASIC Breeding Principles Apply

Breed normals to normals when possible.
Breed close relatives of affected dogs only to unaffected dogs in as few cases as possible.
DO NOT BREED AFFECTED TO AFFECTED.
Breed normals with normal ancestry (straight line pedigree; parents, grandparents, great grandparents...)
Breed normals from litters (lateral pedigree; sibs, or half sibs) with a low incidence of HD
Remove from breeding programs or 'breed away from' (refrain from line breeding on) dogs with a track record for producing multiple or high %'s of dogs affected with HD.
To establish a viable breeding program choose dogs and families of dogs that have a track record for producing dogs with better HD test results than the breed average.

Additional Hip Dysplasia Articles - LINKS:

Doctor's FOSTER & SMITH
http://www.peteducation.com/article.cfm?c=2+2084&aid=444

- HD article at Working Dogs.com
http://www.workingdogs.com/vchipdysplasia.htm

- CHF podcast
http://traffic.libsyn.com/akcchf/CCL_and_HD-Kraus.mp3

- Stem cell Therapy
http://www.vet-stem.com/uploads/casestudies/3154926_CanineCaseStudy-DegenerativeJointDisease.pdf

- See an OFA/PennHip comparison and discussion article for more in depth information at:
http://workingdogs.com/ofa_penn.htm