Great Swiss Mountain Dog Club - Health
THE GREAT SWISS MOUNTAIN DOG CLUB
CANINE HIP DYSPLASIA

Hip dysplasia is a condition that primarily affects large and giant breed dogs.  It is associated with abnormal joint structure and a laxity of the muscles, connective tissue, and the ligaments that would normally support the joint.  As the laxity develops, the articular surfaces of the two bones lose contact with each other.   This causes pain which in turn causes the affected animal to limp. The result is osteoarthritis.

Overweight dogs are more prone to the condition.  Rapid growth in puppies from 3 - 10 months can also have a higher incidence of hip dysplasia.  Exercise can also be a risk factor with over-exercised puppies showing increased incidence.
  
There is a strong genetic link between parents that have hip dysplasia and the incidence in their offspring.  For this reason the best way to prevent hip dysplasia is through selective breeding and careful monitoring of diet and exercise.

Only low scoring dogs and bitches should be used for breeding. 

See the comparison table below:-




Canine Elbow Dysplasia

Elbow dysplasia is a generic term meaning arthritis in the elbow joint.  Elbow dysplasia can cause lameness in young large-breed dogs and is commonly found in both elbows. There are four developmental causes of elbow arthritis in dogs:

o    osteochondritis dessicans

o    ununited anconeal process

o    fragmented coronoid process

o    elbow incongruency

Osteochondritis dissecans (OCD)
OCD is a condition in which a piece of cartilage becomes partially or fully detached from the surface of the elbow joint.  This results in inflammation of the lining of the joint and pain. This can  communally be caused through trauma. See further information below.

Fragmented medial coronoid process
Fragmented medial coronoid process is a condition in which a small piece of bone on the inner side of the joint has broken off of the ulna bone. This piece of bone irritates the lining of the joint and grinds off the cartilage of the adjacent humerus (similar to having a pebble in your shoe).

Ununited anconeal process 
Ununited anconeal process is a condition in which a fragment of bone on the back side of the joint has failed to unite with the ulna bone during growth.  Normally this bony process fuses with the ulna bone by 20 weeks of age.

Elbow incongruency
Elbow incongruency is a condition in which the joint does not have perfect conformation, and the cartilage of the joint wears out rapidly.  In simple terms the joint does not fit together well and the final result is progressive arthritis. 

For elbow evaluations, there are no grades for a radiographically normal elbow  The only grades involved are for abnormal elbows with radiographic changes associated with secondary degenerative joint disease.

ED - 0 (Free)

ED - 1 (Grade I Elbow Dysplasia)
Minimal bone change along anconeal process of ulna (less than 3mm).

ED - 2 (Grade II Elbow Dysplasia)
Additional bone proliferation along anconeal process (3-5 mm) and subchondral bone changes (trochlear notch sclerosis).

ED - 3 (Grade III Elbow Dysplasia)
Well developed degenerative joint disease with bone proliferation along anconeal process being greater than 5 mm.


Osteochondritis Dissecans (OCD)

Osteochondrosis is a disease that affects cartilage formation; the cartilage, due to an abnormal thickening, is unable to receive a normal supply of nutrients from the joint fluid, causing it to become weaker and more susceptible to damage.  Cartilage provides a protective gliding layer between the bones in a joint, and when it is injured and lesions form, the dog will experience pain, lameness, and arthritis.  Lesions may occur on one or both sides of the body.

In all animals, osteochondrosis can affect many different joints, but in the dog, the most common sites of disease are the shoulder, elbow, stifle or knee joint, and tarsus or hock. Generally, osteochondrosis occurs in young, large to giant breeds, although it is also seen in mixed breeds.

Clinical Signs:

  • Lameness
  • Pain 
  • Swelling of the affected joint(s).

Description:

Osteochondrosis, or OCD, is a disease of cartilage formation that results in weakened cartilage.  Because cartilage is the contact layer between bones forming a joint, joint pain, lameness, and progressive arthritis result when the cartilage is damaged.  A form of the disease called osteochondritis dissecans (OCD) occurs when a weakened layer of cartilage forms a flap that becomes elevated because of joint fluid dissecting between it and the surrounding cartilage and bone.  Mineralization can occur when the flap breaks off and floats around in the joint.  This complication, called a joint mouse, can result in a "pebble-in-the-shoe" feeling of irritation for the dog, as well as intermittent or persistent lameness.

Osteochondrosis can affect any joint, but generally, there are four commonly affected joints in the dog:

  • Shoulder osteochondrosis, or shoulder OCD, causes a lesion to develop on the head of the humerus, which is the bone in the upper front leg.  Although this condition occurs while the dog is growing, some animals will not show signs of disease until they have matured fully and more advanced disease is present.  However, the majority of animals show lameness early on, between the ages of five and 10 months. generally, both shoulders are affected.  The lameness is usually one-sided and tends to improve with rest.  With exercise, though, the lameness recurs.  Pain is seen on extension of the shoulder.  The amount of arthritis present depends on the size and duration of the lesion.  Because osteochondrosis is often bilateral, it is necessary to take x-rays of both shoulders to evaluate the extent of the disease.

  • Primarily occurring in large to giant breed dogs, elbow osteochondrosis is one of three diseases that are grouped under the term elbow dysplasia.  (See separate heading for Elbow Dysplasia).   With elbow osteochondrosis, the lesion is usually seen on the inside of the humerus.  Most dogs with elbow osteochondrosis are presented for lameness at less than one year of age.  As with the shoulder form of the disease, some animals may not be seen until they are much older, after the onset of significant arthritis.  The lameness may be intermittent or persistent, tending to improve with rest and worsen with activity.  Because it can be difficult to differentiate between elbow and shoulder osteochondrosis, x-rays of both joints may need to be taken.  Even with x-rays, though, it can be difficult to detect a lesion in the elbow.  Exploratory surgery may be needed in some cases before arrival at a definitive diagnosis.

  • Stifle osteochondrosis, which occurs in the knee joint, affects the same breeds and types of dogs that develop shoulder and elbow osteochondrosis, but it is much less common.  Dogs with this disease usually show a slow onset of lameness that worsens with activity.  The lesion will occur on the femur, the large bone in the thigh usually on the outer part of the bone.  The degree of arthritis depends on the size and duration of the lesion.

  • Tarsal or hock osteochondrosis occurs in large dogs.  Hind-limb lameness and a straight-hocked stance are the most common signs.  The joint will appear thick and will be painful on manipulation.  With this form of the disease, arthritis tends to develop more rapidly and become more severe.

Cause 

The cause of osteochondrosis is unknown, but because the disease is primarily seen in large and giant breed dogs, a genetic component is suspected.  Other factors, such as a high calorie diet, and diets that promote rapid growth, are also thought to be significant.  Trauma can also be attributed, especially if present after a known injury and only one limb is affected.

Prevention

Prevention generally includes avoiding calorie-dense diets in large to giant breed dogs. Puppies should be fed adult diets or giant breed growth formulations, and vitamin over-supplementation should be avoided.  Maintaining a lean body condition also seems to decrease the risk of osteochondrosis.  Exercise should also be moderated during the growth stages. 


Please note this is an approximate guide only....
The official KC recognised UK Breed Club for GSMD's.