Perhaps there has been a thread on this before, but for those who have done PennHip, do you use the same caution in scheduling around a bitch's heat cycle in case of the hormonal impact relaxin might have on laxity? In talking with a PennHip vet, he said there is no validated studies to indicate a need to avoid PennHip films around or during estrus. Thanks!
If you talk to the folks at OFA they will also tell you there is no known correlation between heat cycles and an increased laxity. Their recommendation to avoid radiographs for hip clearances during heat cycles I believe is as "just in case" (ie, one less thing to complain about in dogs that don't pass). I have done a number of dogs in the middle of their heat cycles and have had them pass.
I think it's just one of those things that people try to avoid.
Since many folks who bring dogs to me for PennHIP also want to send to OFA I don't think I've done any PennHIP on an in heat bitch.
What about pregnancy/whelping and x-ray for PennHIP? How long after whelping a litter should you wait before x-raying for PennHIP (bitch already has OFA's).
Dr. Keller at OFA backed up in a phone call a few years ago what is/used to be on OFA literature, that one would expect laxity around a heat cycle but especially around pregnancy and lactation. I delayed my in-season girl's hip films, and we later got an Excellent. The opinions of some at OFA may have changed. However, the official view is still on the website:
http://www.offa.org/faq.html#22
"Can I have my female radiographed while she is in season, pregnant, or nursing?"
"Some female dogs exhibit additional subluxation when radiographed during these times. The OFA recommends radiographing three to four weeks before or after the heat cycle, and three to four weeks after weaning a litter of puppies."
My PennHip repro vet said that PennHip feels that laxity increases with lactation and pregnancy This includes lactation during false pregnancy. Relaxin, well, in a lay explanation, relaxes the ligaments to allow passage through the birth canal, and is what the relaxin dog pregnancy tests detect.
This is also on PennHip's website:
Based on measurements that Penn took on NINE (not ninety) dogs, breeds not named, they disagree with Dr. Keller of OFA concerning the heat cycle's effects. Nine is not statistically significant sample in the number of dogs that PennHip has studies, so I find this statement at least a bit unscientific. It may yet prove to be true. I find that dogs in season have a greater chance of joint injury, in my own small gene pools of more than nine dogs and a few breeds over the years.
I do note, as a woman, that my own ligaments loosen and tighten during my cycle. Pregnancy, wow, that did a lot, and nursing, somewhat. That is statistically a sample of only one human, and anecdotal. Slightly less scientific than only NINE PennHip dogs out of thousands!
I do think that PennHip, combined with OFA, can be a great tool. Just use common sense and maybe caution on opinions. There are politics and biases in the medical community and vet med publishing fields, as I, a veteran editor can attest. Humans are, well, human!
