Orthopedic Issues



As a large breed of dog, Greater Swiss Mountain Dogs are at a higher risk for the orthopedic problems that plague big, fast-growing dogs.  Most people are familiar with Hip Dysplasia to some degree.  But Swisses are also prone to Elbow Dysplasia and Osteochondrosis (OCD), particularly in the shoulder joint.

All breeding stock should be free of these diseases.  The Orthopedic Foundation for Animals maintains a database of all dogs who have been x-rayed free of these diseases.  It is standard operating procedure for all reputable breeders of GSMDs to obtain Hip and Elbow clearances (which results in a unique number issued to each dog) on all breeding stock.  Because Hip and Elbow Dysplasia are often non-symptomatic, there is no way to know a dog is free of these diseases unless they are x-rayed.  If you research a dog in the OFA database and find that they may have a hip number, but NO elbow number, you should assume that the dog could not get an elbow number...unless the breeder can prove otherwise.  If a breeder is taking their two year old dog in for x-rays, to obtain their clearances, they don't merely x-ray the hips and "forget" to do the elbows (or vice versa).   Please keep in mind that non-passing results only show up in the database if the owner of the dog checks a special box, allowing failing results to be published.  If they do not check that box, and the dog fails his hips for example, no hip results at all will show up in the database for that dog. 

Because OCD is almost always symptomatic and will show up before a dog is a year old, it has been much easier for breeders to identify and eliminate dogs with OCD from the breeding pool.  Therefore, shoulder clearances have not been standard procedure in this breed.  Also, it wasn't until relatively recently that the OFA even started maintaining a database for shoulder clearances.  We are now starting to see more and more breeders obtain official shoulder clearances from the OFA.  However, if a dog does not have a shoulder clearance in the OFA database, it should not automatically lead to the conclusion that the dog could not get a shoulder clearance.  Instead, speak with your breeder and ask them if the dog ever suffered from any chronic front-end lameness, if the dog's shoulders needed to be x-rayed for that reason, and whether the dog was diagnosed with or suspected of having OCD at any time.

Canine Hip Dysplasia

Canine Hip Dysplasia (CHD) is a hereditary disease that affects the hip joints of dogs. The word "dysplasia" itself means abnormal development or growth of tissues, organs, or cells. Hip dysplasia is characterized by a looseness in the hip joint that causes abnormal wear and tear on the femoral head (the ball portion of what is a ball and socket joint) and the acetabulum (the socket). This wear and tear leads to malformation of the ball and socket, which can lead to arthritis. Hip pain is generated by the abnormal arthritic bones rubbing against each other.

Because not all dogs with hip dysplasia are symptomatic, and some clinical symptoms may have a cause other than CHD, the only way to diagnose CHD is through radiographs.  Almost all puppies are born with normal hip joints, but over time the looseness will often cause the joint to develop abnormally as the dog is growing.  In rare, more severe cases, hip dysplasia can be seen in some dogs as young as five or six months of age. In other dogs, signs do not develop until after the dog matures. This is why the Orthopedic Foundation for Animals (OFA) will not give a final rating of hips until a dog is two years old.   

OFA Excellent Hips

OFA ratings fall into three categories:  Normal (Excellent, Good or Fair), Borderline, and Dysplastic (Mild, Moderate, Severe).  All dogs with Excellent, Good or Fair rated hips are issued a number by the OFA.  When we say that a dog has his obtained his "hip clearances," this means that the dog has an OFA number indicating his hips fell within that normal range.  A Borderline result indicates that the OFA saw some potential for changes to still develop and would like to see that dog x-rayed and submitted again six months later before making a final determination.  The photo to the right is an example of an OFA Hip radiograph with superior hip conformation (rated "Excellent" by the OFA).  Dogs who are dysplastic (Mild, Moderate or Severe) may or may not ever show clinical signs, although the symptoms and the severity of symptoms can be exacerbated by various environmental factors.  Therefore it's recommended that any dog with a diagnosis of CHD be kept as lean and fit as possible.  In more severe cases, CHD can be surgically, and although costly, total hip replacments have had a good success rate in large breed dogs.

Approximately 19% of all Swissies evaluated by the OFA since 1974 have been graded as Dysplastic. While there is a higher incidence of CHD in many other breeds (from Pugs and Norfolk Terriers to Newfoundlands and Golden Retrievers), breeders should do everything possible to reduce the incidence of CHD by breeding only dogs with Normal hips (Excellent, Good or Fair). The majority of Swissies who have CHD are rated as Mild, and while many of these dogs may never show clinical signs, Swissies are large, heavy dogs and the potential for arthritic pain as the dog ages is very real. The OFA has shown that as the incidence of Dysplasia increases, so too does the severity. So by trying to reduce the incidence of CHD through careful breeding of ONLY X-RAYED CLEAR (Fair, Good or Excellent) DOGS, hopefully we can also drive down the number of severe cases.

Breeders may now use PennHip to evaluate their dog's hips, rather than OFA (note: PennHip only evaluates hips, NOT elbows or shoulders).  PennHip is not a pass/fail method of grading hips, but rather a numerical evaluation of the hips' Distraction Index (DI), which measures joint laxity.  They will also note any presence of Degenerative Joint Disease.  For an explanation of Distraction Indices and their implication for breeding dogs, visit www.pennhip.org. In addition to the Distraction Indices, the PennHip evaluation will also state in what percentile, for the breed, the hips fall.  Penn Hip recommends that only those dogs in the top 50% or better, with no DJD, should be bred.  Since the PennHip database is CLOSED, the only ways interested parties have access to PennHip DIs on Swissies is to ask the OWNER for a photocopy of the report (see sample here) or for the OWNER to submit the PennHip results to the GSMDCA for inclusion in the GSMDCA Health Database, which is an OPEN database now residing on the GreaterSwissDotCom.com website (after it was scrapped by the GSMDCA).

Even the most careful breeders who only breed dogs with normal hips, from pedigrees that have strong depth for hip clearances, can and will produce dysplastic dogs. The odds are lower, of course, but it can and does happen. There is no genetic test to determine if a dog may develop CHD or produce it, so all we can do is eliminate dysplastic dogs from our breeding programs based on hip phenotype, as identified by radiographs. At the same time, great caution should also be given when breeding a dog who may have excellent rated hips if several of his littermates were diagnosed as having CHD.

For more information on Canine Hip Dysplasia, please visit the Orthopedic Foundation for Animals website:  www.offa.org

Elbow Dysplasia

Elbow dysplasia is a general term used to describe malformations in the elbow joint.  These malformations may appear in three different areas, and may occur together or independently.  The three etiologies which may constitute elbow dysplasia are:

  1. Ununited Anconial Process (UAP).  The anconial process is a small piece of bone at the upper end of the ulna.  In a puppy, this piece is made of cartilage that gradually ossifies into bone and unites with the ulna.  If that union does not take place, the result is an ununited anconial process.
  2. Fragmented Coronoid Process (FCP).  The coronoid process is a small piece of bone on the ulna that articulates with the humerus.  This bone also starts as cartilage in puppies and eventually turns to bone as it fuses to the ulna.  If that fusion does not occur, or if chipping or fragmenting occurs after it fused to the ulna, this is called a fragmented coronoid process.
  3. Osteochondrosis (OCD) of the humerus.  OCD, can occur in many joints, including the elbow.  In this case, OCD is a vertical fracture of the articular cartilage of the humerus, which leads to a flap of cartilage in the joint.

Dogs with elbow dysplasia may or may not exhibit lameness.  Therefore the only true way to diagnose ED is through radiographs.  As with Hip Dysplasia, the Orthopedic Foundation for Animals does certify elbows at two years of age.  The ratings are either Normal (if there is no evidence of any dysplasia), in which case the OFA will issue and Elbow number, or Dysplastic -- and ratings of Grade 1, Grade 2 or Grade 3 will be issued, depending on the extent of changes observed in the radiographs.

In some ways, Elbow Dysplasia is a tougher disease than Hip Dysplasia.  The elbow is a more complicated joint, and if the ED is symptomatic, surgery is not simple and often not totally effective.  Dogs with hip dysplasia have an easier time compensating to relieve pressure on their hip joints.  The front end assembly of a dog, on the other hand, bears significantly more weight and there is no real way around this for the dog. 

Heredity definitely plays a role in Elbow Dysplasia, as there is a tendency for the problem to occur more often in certain breeds.  While it is also true that ED tends to plague larger, fast-growing breeds, it's clear that genetics are certainly a major factor, which is why two very similar breeds in size, such as Rottweilers and GSMDs (both fast growing), can have a vastly different incidence of ED -- over 40% of Rottweilers versus just under 12% of Swissies.  This data suggests that, to an extent, Elbow Dysplasia has been bred into Rottweilers.  Today, most  Rottweiler breeders have no real choice but to breed dogs with dysplastic elbows.  GSMDs are much more fortunate in that we have the luxury of eliminating dogs with ED from our breeding program. 

Some breeders choose to breed Swissies with Grade 1 Elbow Dysplasia.  Others, like me, will not -- even if the dog has never exhibited clinical symptoms.   The bottom line is this:  symptomatic or not, dogs with Elbow Dysplasia have a higher likelihood of producing Elbow Dysplasia.  And as the overall incidence increases, so too does the likelihood of more severe elbow dysplasia.   Read more about this at the OFA website.

OCD (Osteochondrosis) of the Shoulder

Osteochondrosis, or OCD, is a relatively common and painful orthopedic issue in large, fast-growing breeds of dogs.  Although OCD can occur in many joints, from ankles to elbows, in Swissies it most commonly occurs in the shoulder joint.  OCD is characterized by abnormal cartilage-to-bone transformation (ossification) which leads to the development of a loose piece or flap of cartilage in the joint capsule.  This flap of cartilage, in the joint, often causes moderate to severe discomfort until it is treated or, in some rare cases, heals on its own.  If untreated, this loose cartilage can give rise to secondary degenerative joint disease. 

Most dogs affected with OCD will develop clinical signs (lameness) before twelve months of age, as this disease most often strikes during rapid growth periods in a puppy's development.  It can occur unilaterally, or in both the left and right joints.  Depending on the size and location of the cartilage flap, there is a chance that with extensive crate rest a dog with OCD can heal itself, and this has been reported in some Swissies.  That said, it is usually more expedient and humane to treat OCD with surgery, to remove the cartilage flap.  This type of surgery has a very high success rate and most dogs go on to live perfectly normal lives with no pain in the affected joint. 

It is also best to keep young Swissies as lean and fit as possible while they are growing, and minimizing strain and impact to the joints.  While this does not remove any genetic tendency a dog may have toward OCD, it may help suppress the expression of that predisposition.  At the very least, should OCD occur, an overweight, out-of-shape puppy will most likely suffer more and be slower to heal.

The best prevention for OCD it to not breed dogs who have it.  OCD is believed to be inherited, though the exact mode of inheritance is unknown, so dogs with OCD should not be bred.  This is why it is so important to insist on shoulder clearances when investigating the parents of any prospective litter.  

 

 

 

 

 

    

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