I agree, I don't know how any breeder can guarantee size.
Patellar subluxation can be hereditary but can also be caused by injury, especially if jumping down off the furniture on a regular basis. Also, some puppies that are raised in wire cages & don't walk on the floor or the ground can develop grade 1 or 2 patellar subluxation because they never get a chance to strengthen those ligaments (because of the wire).
http://www.porsha-distribution.com/p...ts.html#luxate Quote:
Patellar Luxation (Slipping Kneecap)
by Jennie Bullock
Patellar luxation is the dislocation (slipping) of the patella (kneecap). In dogs the patella is a small bone that shields the front of the stifle joint. This bone is held in place by ligaments. As the knee joint is moved, the patella slides in a grove in the femur. The kneecap may dislocate toward the inside (medial) or outside (lateral) of the leg. This condition may be the result of injury or congenital deformities (present at birth). Patellar luxation can affect either or both legs.
The most common occurrence of luxating patella is the medial presentation in small or miniature dog breeds. Shallow femoral groove, weak ligaments and malalignment of the tendons and muscles that straighten the joint are all conditions that will predispose a dog toward luxating patellas. Indications of patellar luxation are; difficulty in straightening the knee, pain in the stifle, limping, or the tip of the hock points outward while the toes point inward. The diagnosis of this condition can usually be confirmed (by a veterinarian) by manipulating the stifle joint and pushing the patella in and out of position.
Patellar luxations fall into several categories:
Medial luxation; toy, miniature, and large breeds.
Lateral luxation; toy and miniature breeds.
Lateral luxation; large and giant breeds.
Trauma induced luxation; various breeds
Categories 1, 2, and 3 are either hereditary or strongly suspected of being inheritable. Beyond the categorization of patellar luxation there are 4 grades of deviation for this condition:
Grade 1: Intermittent patellar luxation - occasional carrying of the affected limb. The patella can easily be manually luxated at full extension of the stifle, but returns to proper position when pressure is released.
Grade 2: Frequent patellar luxation - in some cases luxation is more or less permanent. The affected limb is sometimes carried, although the dog may walk with the stifle slightly flexed.
Grade 3: Permanent patellar luxation - even though the patella is luxated; many animals will walk with the limb in a semi-flexed position.
Grade 4: Permanent patellar luxation - the affected limb is either carried or the animal walks in a crouched position, with the limb partially flexed. Medial Luxation in Toy, Miniature, and Large Breeds Termed "congenital" because the luxations occur early in life and are not trauma associated.
Clinical indications:
1) Neonates and older puppies - display clinical signs of abnormal leg carriage and function from the time they start walking. These cases are generally grades 3 or 4. 2) Young to mature animals - usually exhibit intermittently abnormal or abnormal movement all their lives. Generally evaluated when the symptomatic gait worsens.
Most often grade 2 or 3. 3) Older animals - may exhibit sudden lameness. Usually due to further breakdown of soft tissues or the degenerative nature of joint disease. These cases are usually grade 1 or 2. Lateral Luxation in Toy and Miniature Breeds Lateral luxation in small breeds is most often seen in dogs between 5 to 8 years of age.
The skeletal abnormalities in these cases is most often obscure. Most of these cases are grade 1 or 2 and the dog tends to exhibit a more functional disability. Lateral Luxation in Large and Giant Breeds Animals usually appear to be affected by 5 to 6 months of age, with bilateral involvement being the most common presentation. The most noticed symptom is a knock-knee stance. The patella is usually reducible.
|
Most breeders will offer a vet health check before selling puppies, especially to someone who lives so far away. When puppies are shipped, the law requires an interstate health certificate done by a vet before they can ship a puppy, as this is required by law before shipping from state to state. Vets always check for patellar subluxation, heart murmurs, and other congenital defects before they will sign off on a vet health exams or an interstate health certificate.
Most of the time, grade 1 or 2 will not require surgery, but will heal up on it's own if injuries are not repetitive. I would be skeptical of any vet who talks about surgery with only a grade 1 or 2 luxation - because grade 1 or 2 often heals by itself. I have never heard of a vet doing patellar surgery unless it is a grade 3-4, which can become crippling. Discourage jumping down from the furniture, either lift your puppy up & down or build some "steps" out of cushions. You will be hard put to prove congenital versus injury as a cause of subluxation if she had a health exam done by a vet before you got your puppy.
