 |
RE: [RC] [RC] Riding strategy -- mare in heat at an endurance ride - Susan E. Garlinghouse, DVMMy understanding from scads of recent reading (because I just did a lecture on it a few weeks ago) is that a lot of the rumors about estrus and tying up is because there is a higher reported incidence of recurrent exercise rhabdomyolysis (that's the early onset form) in two-year-old, nervous, goofy TB or STB fillies on the racetrack on rations sky-high in grain. So they think there *might* be some relationship to hormonal cycles, but it hasn't been clearly demonstrated, and it certainly isn't more than AT MOST a contributing factor in mares that are already prone to it. There are tons of other factors that can also cause symptoms of tying up, including exposure to viruses, diet, some specific mineral issues (including selenium), and genetic relationships in calcium channel abnormalities specifically in the TB breed, or abnormal glycogen synthesis in mostly the quarter horse breeds. Also, remember that most of the research in RER is still from the race tracks, because there's a significant prevalence of the issue on the tracks and any lameness issue means loss of potential earnings---so that's where the research money is focused. There are a lot of different factors that can all show up as "tying up" but have very different causes. Early onset tying up certainly does occur in endurance horses, but most of them still present in the PS region as the later version more related to exhausted horse syndrome. In those cases, I haven't seen any higher prevalence between one sex over another, which I suspect is similar to what Heidi has seen in the PNW. JMO. Susan Garlinghouse, DVM -----Original Message----- From: ridecamp-owner@xxxxxxxxxxxxxxxxx [mailto:ridecamp-owner@xxxxxxxxxxxxxxxxx] On Behalf Of heidi@xxxxxxxxxxxxxxx Sent: Sunday, February 10, 2008 7:23 PM To: Beth Leggieri Cc: Nancy Sturm; ridecamp@xxxxxxxxxxxxx Subject: RE: [RC] [RC] Riding strategy -- mare in heat at an endurance ride More than behavior issues, I am concerned about the physiological changes that occur which can get them into trouble if their bodies are stressed--which an endurance ride certainly does. Specifically the tendency toward azotoria seems to be connected to their heat cycles (resulting in their decreased ability to deal with excess lactic acid). I personally think this is more an individual problem than a "mare" problem. When a mare ties up, people say, "Oh, it's a mare!" When a gelding or a stallion tie up, they say, "Oh, well, he tied up..." I don't know of any evidence that they have any such decreased ability to deal with excess lactic acid--never mind that endurance horses don't tend to build up lactic acid anyway. Sure, you can fail to warm them up (regardless of gender) and slam into the first vet check and tie up--but that happens to geldings and stallions, too! Heidi =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Ridecamp is a service of Endurance Net, http://www.endurance.net. Information, Policy, Disclaimer: http://www.endurance.net/Ridecamp Subscribe/Unsubscribe http://www.endurance.net/ridecamp/logon.asp Ride Long and Ride Safe!! =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Ridecamp is a service of Endurance Net, http://www.endurance.net. Information, Policy, Disclaimer: http://www.endurance.net/Ridecamp Subscribe/Unsubscribe http://www.endurance.net/ridecamp/logon.asp Ride Long and Ride Safe!! =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
|