[GalomyOak]

PennHip makes the recommendation that breeders use animals that are within the tightest half of their breed population (lowest distraction/laxity number); this is more reliable obviously, if there is a large population tested for the breed. PennHip begins providing numbers against a control group for the breed, once 20 dogs have been tested within a breed.

PennHip research has shown that dogs who test at .30 or below have virtually no chance of developing HD (only one dog of thousands ever has). Conversely, dogs close to or over .70 are almost guaranteed to develop HD. Between .30 and .70, there is an increasing chance to develop HD. GSDs tend to develop HD at lower numbers than other breeds. Pennhip hypothesizes this is because of the "tucked under" structure of a GSDs rear legs...but maybe not? Maybe it's in genetics.

PennHip makes 3 xrays. One is the same as that used for OFA in the US, or standard testing in Europe. PennHip evaluates this film for signs of HD - if it is normal, they tell you, or if there is disease, they tell you, but they don't give it a "grade" of having a little HD or a lot of HD - only yes or no to presence of the disease. At this point, I don’t think PennHip is totally reliable for our breed; but since the film is made that is the same for OFA, it costs only an extra $30 to send a second copy to OFA. Two tasks and types of research (one for now, for owners who wish to breed soon, and one for the future, that can be used with the PennHip method) can be done with the same xrays.

Once a large enough population is established, PennHip has been shown to be quite effective in decreasing (and even eliminating) HD within closed populations, if high pressure on selection for hips is used. One example is the Seeing Eye Labradors. It’s more effective because a quantitative result is used – a measurement of the laxity (elasticity, or “stretchiness”) of the ligament that makes hips tight/fit correctly, or loose/not fit correctly (HD) - rather than qualitative. It is probably not as effective to use qualitative results, since some dogs with genetics prone to developing HD never get the disease…but still pass the gene to their puppies. It could be hypothesized that these dogs have a higher laxity of the ligament – if bred to another dog with a recessive gene prone to high laxity, they could produce puppies with HD.

All of the 9 CSVs tested so far (including one in Holland, mentioned above, who has the healthiest results) have come from a variety of genetic backgrounds. So far as I know, our highest numbers have been in the high .40s, but I think it’s possible we might have a higher number now - one who shows a lot of evidence of disease. Not all of the tested dogs were selected from parents with good selection for hips…so we do have a variety at this point. Its PennHip’s goal to have an open database of tested dogs (voluntary for the owner), and they are currently working on this.