Hip Dysplasia in the Australian Cattle Dog

HD also occurs at the Australian Cattle Dog, is about an X-ray study compulsory from the age of 12 months in Austria. It may only be bred dogs with HD A (normal) and B (nearly normal). B x B is not permitted in Austria, C (HD light) dogs are excluded from breeding.

The hip dysplasia or hip dysplasia (HD) is a disorder of the hip joint. This affects all breeds, with larger breeds the disease develop more frequently. For the first time she was diagnosed at the German Shepherd and is therefore wrongly mainly been associated with this race, despite the fact that other races are affected. The frequency of occurrence (prevalence) is depending on the race four to about 50 percent. The HD is largely genetically determined, so many breed associations, the high-demanding freedom for breeding approval. Since the wrong diet and attitude formation and may promote the progression of the disease is a multifactorial (dependent on many factors) Done. Clinically, the HD shows in the increasing restriction of movement and pain caused as a result of pathological remodeling of the hip (Coxathrose). In advanced stages, can only bring about the removal of the hip joint with or without a hip replacement, a significant improvement. This is not possible, can be a long lasting pain often maintain an adequate quality of life.

 

The expression of clinical symptoms of HD vary depending on the age and stage of disease. In relatively young animals, aged six months to a year, it comes to pain, because the femoral head by the acetabular margin (acetabulum) is only insufficient support and its abnormal mobility pain registering nerve fibers of the periosteum of the glenoid rim are irritated. Older animals are more likely from pain due to progressive degenerative changes (arthrosis) of the hip joint.

A beginning HD manifests itself in increasing pain when walking, the dog no longer wants to run far more often sits down, screaming and playing occasionally shows an unstable response. When giving the hind limb in the direction of the pelvis submitted in the limb is moved sideways (LSÜ-twist). With movements of the joint, a pops, clicks or grinding of the joint may be heard. Upon discovery of a Symthome of the immediate transition to the vet is advisable.

 

X-ray
A reliable way to detect the severity of the disease, the X-ray. In this case, the joints are hyperextended, causing severe pain in the presence of HD. Therefore, it is performed under Kurznakose. Requirement for a detailed diagnosis, the exact positioning of the animal in the supine position with straight, parallel and perpendicular to the thighs supported beam screwed kneecap.



 
A key evaluation criterion is the Norberg Winkel. It is defined as the angle that is between the line connecting the centers of both femoral heads and the front edge of the socket is removed (see illustration). With an HD-free animal, he should be more than 105 degrees (yellow lines). Further evaluation criteria are the congruence of the femoral head and acetabulum, the width of the joint space, the pan contour, the contour of the femoral head and the presence of evidence of athrotische processes such as drum-shaped thickening of the femoral neck, bead-rings on the socket, in, under the cartilage located compaction of the bone socket region and the addition of bone (osteophytes) at the base of the joint capsule (Morgan Line). The Morgan line is a sensitive early marker of instability in the hip joint. The breeding evaluation of HD recording is only from the race breed associations approved appraisers possible to the vet a contribution of the X-ray images.

Severity is usually distinguished between five different degrees of severity.
 


HD-Heavy Grade A HD-free joints inconspicuous in all respects, Norberg angle 105 ° or more. Sometimes even when the A1 pan edge even further embraces the femur.
B HD-suspected femoral head or acetabulum are slightly uneven and the Norberg angle is 105 ° (or more), or Norberg angle is less than 105 ° but uniform femoral head and acetabulum.
C Light HD femoral head and acetabulum are uneven, Norberg-angle 100 ° or smaller. Any slight osteoarthritic changes.
D Medium HD femoral head and acetabulum are markedly irregular with partial dislocations. Norberg angle greater than 90 °. This leads to arthritic changes and / or changes to the glenoid rim.
E Heavy HD Conspicuous changes in the hip joints (for example, part contortions), Norberg angle below 90 °, the acetabular rim is flattened considerably. There will be various arthritic changes.

Sometimes the grade AD will be split into A1 and A2, B1 and B2, C1 and C2 and D1 and D2.