Hip Dysplasia (Pead) Flashcards
How can simple heritabile sex linked disease be managed?
Cull the carriers
How does polygenic disease differ from simple sex linked disease with carriers etc.?
- can only be expressed as a risk or liability
- range from normal, subclinical disease and clinically affeced
How are risks of polygenic disease transmissioin minimised?
- detect carrier aniamls (by radiogaphic signs etc.) in CLINICALLY NORMAL DOGS
- detects the 1* disease (ED, HD)
- detects the 2* OA
- has no relevence to clinical problemin that individual (ETHICS)
What is the best way of minimising breeding affected dogs?
- beed from individuals not clinically affects and with no radiographic signs as MOST likely to be furthest away related from affected animals (still doesnt r/o disease)
What aspects of the pathogenesis of hip/elbow dysplasia can be seen to help with timeline?
> ligament hypertrophy - slack ligaments > subluxation (partial luxation/dislocation, which is usually traumatic) - ball and oscket not together - destruction of cartilage - change of shape of joint surface > 2* OA - bony and fibrous > pain on hip extension early on
What does the funny gait seen with hip dysplasia due to?
- dog trying to prevent subluxation by keep femurs underneath the pelvis
What 2 main ligaments are associated with the hip?
- capsular ligament
- ligament of the head of the femur
Is subluxation painful
not always
Where should the head of the femur sit?
Acetabulum of pelvis
Outline physical changes associated with hip dysplaisa
- microfx of subchondral bone of acetabulum
- flattening of joint and femoral head
- becomes “cup and saucer” rather than ball and socket
> new bone formation (most common/obvious radiographic sign)
What is tx usually based on?
Clinical exam NOT radiographic changes
- but rads usually useful for prognosis, to see degree of subluxation and bony changes
What tes can be used to measure subluxation?
> Alterlany test
- push down on knees, abduct legs to measure angle of reduction
- bigger angle of reduction, slacker the joint capsule
- push back = angle of subluxation
- depending how close angle of subluxation to angle of reductin = measure of shallowness of acetabulum
OUtline signs and pathophysiology @0-6mo, 6-16mo, and 16mo+ of hip dysplasia
> 0-6 - subluxation - abnormal gait > 6-16mo - subluxation - abnormal gait - sublux - damage and inflam - pain - lameness > 16mo+ - abnormal joint - 2* OE - pain - lameness - *muscular/fibrous stablisation* -> pain free but restricted range
Why does 9-16months rpesent a danger zone for joint disease?
- skeletally mature @9mo
- NOT muscularly mature until 16mo
- Joints not stabilised so vulnerable to damage
What problems generally cause the issues afer 16mo?
- mostly OA
- all muscular stabilisation likely complete at this stage
