Understanding ED

We now score our Rottweilers & RBT’s

We will use a 0 grade with up to a 2 grade as long as its sire and dam is a 0 or 1 grade and not a 2 or 3 grade

we will use a 1 grade only with a 0 or 1 grade as long as its sire and dam is a 0 or 1 grade and not a 2 or 3 grade

we will not use a 3 grade

Grade I Elbow Dysplasia

Minimal bone change along anconeal process of ulna (less than 3mm).

Grade II Elbow Dysplasia

Additional bone proliferation along anconeal process (3-5 mm) and subchondral bone changes

 (trochlear notch sclerosis).

Grade III Elbow Dysplasia

Well developed degenerative joint disease with bone proliferation along anconeal process being greater than 5 mm.

 

 ELBOW DYSPLASIA THE DISEASE

ED simply describes the abnormal development of the elbow (a dog's elbow is

circled below). The term includes a number of specific abnormalities, which

affect different sites in the joint. They cause problems by affecting the growth

of the cartilage which forms the surface of the joint, or the structures around it.

These abnormalities, called primary lesions, then start a secondary

osteoarthritic process. The most common primary lesions are:

Osteochondritis dissecans (OCD or OD)

Fragmented or ununited coronoid process (FCP)

Ununited anconeal process (UAP)

There are other, more rare, primary lesions which may occur in combination

with these, or on their own. Primary lesions occur during the growth of a

puppy, and nearly always occur in both elbows to some degree.

Once the dog reaches maturity the primary lesions may stabilise. However,

once abnormal development of the joint has been started by the presence of a

primary lesion then further secondary changes occur as a consequence. Of

particular importance is abnormal wear of the joint surface and osteoarthritis

(arthrosis). These secondary lesions cannot be reversed and they are a

potential problem for the rest of the dog's life.

The elbow is particularly vulnerable to this type of disease. In construction, the

joint is like a hinge. The bones and cartilage surfaces which form each side of

the joint have complex shapes which fit closely together. The elbow is also a

high motion joint and the normal forelimb gait is more dependent on the elbow

than on other joints. Thus, a small change in the shape of one part of the joint

can have large consequences for the function of the joint, just like a small

piece of grit in a door hinge, and once elbow function is affected then forelimb

gait is altered.

An additional problem with ED is that lame dogs are only the 'tip of the

disease iceberg'. Many dogs have sub clinical disease; that is, they have

primary lesions or osteoarthritic changes in their elbows, but they do not

become lame. Fortunately these subclinical dogs can be identified by taking

radiographs (X-ray films) of their elbows.

Even though they have no lameness problem themselves, they have a high

chance of producing lame offspring, if allowed to breed.

THE CAUSES OF ELBOW DYSPLASIA

ED is a multifactorial disease, which means that a number of factors can

influence the occurrence of the condition. The most important factor, however,

is the genetic make-up of the dog. Other factors such as growth rate, diet and

level of exercise may influence the severity of the disease slightly in an

individual dog, but they cannot prevent the disease or reduce the potential of

the dog to pass the disease on to offspring. However, studies show that ED

has a high heritability confirming that a high proportion of the cause of the

disease is genetic.

As individual breeds of dog have a proportion of their genetic make-up in

common, it is not a surprise that some breeds are more vulnerable to a

heritable condition than others. In general, medium- and large-breed dogs are

considered to be vulnerable to ED.

Unfortunately ED is not controlled by a single gene or a simple inheritance. It

is a polygenic characteristic, which means that it is controlled by the

combination of many genes. One way of visualising this is to think of a normal

dog as carrying a few of the genes which can cause elbow problems; a dog

with subclinical disease will have more of these 'problem' genes, and an

animal with lameness will have a higher proportion still.

The grading system is simple

Grade Description

0 Normal

1 Mild ED

2 Moderate ED or a primary lesion

3 Severe ED

The overall grade of the dog is that of the higher graded elbow.

Eg 0-2 =2, 2-2=2, 2-1=2, 1-3=3

How is the score used?

Ideally only dogs with grades of 0 should be used for breeding, but recognising that this may result in too few animals being available the elbow dysphasia developing in their puppies. However it is still possible for 2 parents with very low elbow scores to produce puppies with elbow dysphasia, which is discouraging for the breeder.

The most helpful way of using the scoring information is in progeny testing. This means selecting parents which are known to have previously produced puppies with good elbows as well as having low elbow scores them selves. It is important to investigate the elbow scores of as many offspring of individual dogs as possible before selecting them for further breeding. It is also helpful to breed dogs whose grandparent's scores were low

What happens to the x-rays?

Diagnostic x-rays are submitted to the BVA together with the scoring fee and a part-completed certificate of grading. The veterinary surgeon submitting the x-ray certifies that the x-ray was taken on the date indicated, and may check and add the dog's microchip or tattoo number where appropriate.

The scrutineers examining the films grade them and sign the form, which is returned to the veterinary surgeon together with the x-rays. The scored x-rays are embossed with a BVA stamp.

Once a certificate has been issued the dog may not be submitted for regrading. The owner may appeal against the grade but this must be lodged with the BVA, in writing, within 45 days of grading. The same x-rays and an appeal certificate must be submitted by the vet to the BVA. The x-rays will be regraded by the Chief Scrutineer and this decision will be final.

The current BVA list includes:

Basset Hound

Bernese Mountain Dog

English Mastiff

German Shepherd Dog

Great Dane

Irish Wolfhound

Newfoundland

Golden Retriever

Labrador Retriever

Rottweiler

In certain other breeds without a current problem elbow screening is being used as a preventive measure to ensure that elbow dysplasia does not creep into the breeding population.