I am considering a 5 yo mare that a friend broke about two years ago. She’s calm, comfortable to ride, and has the height I’ve been looking for. But in the years since my friend broke her out, she’s developed an undershot bite. Her lower teeth are about 2/3 forward of her upper teeth. She has been turned out, not worked for a while, but she’s pretty fat, so her bite isn’t bothering her grain and hay consumption, at least not now. ;). But I have NO experience with this particular confirmation flaw. So, is this a significant problem for a working/not halter horse, or not? So far: I have been blessed with horses that never needed significant dental care after their 3rd or 4th year (probably because they all had good bites to start with). Is this a health/management headache in waiting, or just a matter of cosmetics?
Here’s an old COH thread on parrot mouth that will shed some light:
”‹”‹”‹”‹”‹”‹https://www.chronofhorse.com/forum/f…es-flock-to-me
I’ve known some parrot mouths – all racehorses – and they did just fine but regular dental exams are important. Hooks etc can develop more readily in parrot mouths than in normal horses due to back teeth often not alligning well either.
I’m sure this mare had the undershot jaw from birth – horses don’t suddenly start to develop this flaw when they are older (some theories suggest it’s hereditary) but the flaw can just look more pronounced as the horse ages.
Agree with danacat. I’ve only seen one, a young filly that someone bought.
I brought an OTTB home from the track to “re-home” to a local owner. A free-bee. She was a very “strange” mare, undershot jaw, and apparently an attempt to fix an umbilical hernia earlier in life (semi successful attempt- possible scar tissue and some fluid showing). VERY quiet mare. Racetrack gallop rider (a long time friend) told me, “You could take this one trail riding tomorrow, no problem”. Had one race, walked around in the paddock for saddling, walked out on post parade, stood quietly in the starting gate, stepped out- cantered around behind the race, walked back to the barn. No interest in putting out any effort at all, just NOT a racehorse in any way. Workout times in training were not good. Potential job with new owner was “trail horse/ recreational riding horse”. It seemed a perfect fit. This was the first and only undershot jaw I have seen on a horse. It didn’t bother her, she held weight no problem, perfectly healthy from what we could see. Dentistry looked after any issues with tooth wear. My small amount of research into this indicated a hormonal problem during gestation, low thyroid, I think, in her dam. Something like that, anyway. Fetal development issues caused at least these two issues (the jaw AND the hernia???), don’t know if there were more issues that were not as visible that resulted in the lack of motivation to be a racehorse??? She seemed fine enough to ride, not mentally slow, I rode her once in our arena.
We had over years of training a handful parrot mouth, overbite race horses.
We didn’t connect that with hernias, but some did tie-up:
"Equine exertional rhabdomyolysis (ER, also known as tying up, azoturia, or Monday morning disease"
Since both ran in some families, we thought for some horses at least, it may have had some inherited component to it?
The only problem would be grazing, as horses grab grass with both, upper and lower teeth and pull, so teeth need to be aligned.
Very tender green grasses, maybe the tongue can help hold to cut/pull.
More mature, tougher grasses, not so well without aligned front teeth.
Horses with a little overbite still manage, with more, not so well, unless supplemented with hay or grains, that mostly only need to be able to masticate with molars.
Umbilical hernias can be inherited, as we found out with a couple mares.
I’m reading the OP as this horse having an under bite/monkey mouth, not an over bite/parrot mouth.
Oops so sow mouth not parrot mouth?
I read it the same way, which is why I didn’t post. Seen Parrot mouths, but never the other way around, where the lower jaws juts out in front of the upper jaw. Didn’t know it had a name - so I’ve learned something new today.
You’re so right. I totally lost my reading skills this morning.
You are not the only one that just scanned quickly and went to what we are more familiar with.
I have a reason, knowing they are not excuses.
I need new glasses and cataract surgery soon.
Just have to read and re-read with more care.
To be fair for those of us who didn’t read for complete comprehension :o
The title does say ‘undershot jaw’ which to me implies parrot mouth but then original post says the mare’s lower teeth are forward of her upper teeth (opposite for me of an undershot jaw).
Yes the implication is parrot mouth. When I think ‘jaw’ I immediately think lower jaw. But on horse dental websites the jaw being referenced is the upper jaw not the lower. Undershot is a synonym for monkey mouth and overshot is a synonym for parrot mouth. Counter intuitive IMO. [h=4]SUMMARY[/h] An underbite (undershot jaw, sow mouth, monkey mouth) is a case in which the lower jaw (mandible) protrudes out further than the upper jaw (maxilla), causing the lower to protrude forward.”‹”‹”‹”‹”‹”‹
Either way, maloccusions are most often not a big problem. While I have only personally dealt with parrot mouth and have known horses with those and one sideways bite, none were problems. More frequent careful floatings and careful bitting were all that was required.
If this horse is eating well and has been accepting a bit it appears that she is doing fine. It is something to ask a vet about in a PPE. (You might get an opinion from your vet even before if you are worried it is a deal breaker)
Right, she’s “monkey” or “sow” mouthed. It is a less common malocclusion, in my experience. You don’t really see it without opening her mouth, though her head is less refined than standard for her breed.she is an Arabian, but looks more like a QH at the moment (partly because the bite is not interfering at all with her ability to eat her grain and hay, then her paddock mates’ too) …
I had a dog with this type of bite once. He was the best dog ever, but a dental nightmare (drool, awful breath, etc). But I’ve never had a horse with that issue. Thanks for the input.
I have never seen a sow mouth in person, like I have a parrot mouth. But as already noted, as long as she has regular dental visits to ensure her upper and lower front teeth aren’t getting too long (since they don’t meet as usual and will not wear properly) AND there are no other noted jaw issues (like molars that don’t line up on the upper/lower jaw), it should be fine.
While I might pass on a horse with a particularly severe case of parrot or sow mouth, a mild or perhaps moderate case (with no other jaw issues) that is easily managed would be no problem.
My current horse (nearly 29 now) had no upper front teeth at all. He stuck his nose where it didn’t belong as a youngster and they were knocked out (or so the breeder told me). He did require extra attention to those front bottom teeth, as there were no uppers for them to wear evenly. Now he has nubs for his lower front teeth (due to his advanced age) and still grazes just fine and is nice and fit all summer on just a ration balancer.
