August 2019 - Equine Nutrition
With so many supplements and grain options, how should you know what to feed? Join us this month as our expert, Dr. Alison Cornwall answers your questions concerning equine nutrition.
Click here to read this month's questions and answers.
Dental Care for Your Horse
- I have a 28-year-old Friesian, which when sedated for a dental float, is ataxic while still alert. Is there a sedative used for senior horses that helps to alleviate this issue? (View Answer)
A good and important question!
I used to struggle with this, but a board certified anaesthesiologist helped me out and those disastrous old-horse and anxious-horse sedations rarely occur now for me. Anxiety in these horses, usually due to a combination of moderate to severe long-term oral pain plus the smart old horses usually acquire, causes release of chemicals in their bloodstream which help them override the sedative drugs typically used. You may have seen these horses seem, alert, while they are ataxic. I suspect you’ve also seen them become very sleepy and probably more ataxic when the vet stops working in the horse’s mouth. I use this technique with most of the anxious horses in my practice.
The answer for me has been to
1-administer diazepam, xylazine, butorphanol and acepromazine intramuscularly twenty minutes before the vet plans to begin his or her dentistry. I usually administer this “pre-anaesthetic” in a paddock handy to where we’re working and then leave the horse in the paddock, (safe from other horses) but without stressing it, for the next 20 minutes. I use this time to set up my portable stocks and get my gear out. The diazepam is an anti-anxiety drug, which seems to keep the horse from working themselves up and overriding the other drugs.
2-Quietly lead the horse to the stocks and administer xylazine and butorphanol intravenously, at a low dose. I am happy to speak with your veterinarian if they wish, regarding doses.
** It’s important to take your time and not stress the horse at any time.
This will give you the longest-lasting sedation time, allowing the vet to complete their work.
I have found the horses given this sedation regimen appear awake but are rarely ataxic. However, they don’t seem to care what you’re doing, usually very different from doing it without the diazepam. Elizabeth Thompson, DVM, MANZCVSc (EqDent), Blue Mist Equine Veterinary Centre, New Zealand
- I have a miniature donkey that quids. He stores food in the side of his mouth and has choked three times since starting this habit. I'm sure it's tooth-related. But how, exactly? (View Answer)
Thank you for your question. By quidding, I take it you mean dropping feed or hay? Choke frequently occurs when a horse isn’t chewing its food properly, resulting in wads of long hay or grass stems that get stuck in the oesophagus. The underlying issue here is likely oral pain. When there is disease in the mouth, horses tend to pack partially chewed feed material between their cheeks and cheek teeth. Whether or not they do it on purpose to protect their cheeks from the sharp enamel points on the buccal, or cheek, side of their cheek teeth, or not is up for debate.
The pathology, or dental disease list that can cause problems like this includes (but isn’t limited to):
- Sharp enamel points and overgrowths of teeth (from lack of “odontoplasty”, or tooth floating, or insufficient floating causing pain and ulceration of the inside of the cheeks (buccal mucosa)
- Periodontal disease, which progresses in earnest with the help of the bacteria and acid-containing packed-in feed wads
- Fractured or loose tooth or teeth
- Missing tooth or teeth with overgrowth of the teeth opposing the missing-teeth-gap. This restricts the normal lateral (sideways) jaw movement and may progress to the extent of the overgrown tooth actually protruding into the soft tissue (or even the bony tissue) of the opposite jaw
- “mesial shift” of teeth after loss or extraction of a tooth and neglecting the six monthly-for-life requirement of “odontoplasty”, or tooth floating.
- Pulp exposure and pain causing incorrect chewing of feed materials
- Foreign body in the back of the mouth or tongue (stick, piece of wire, etc.) preventing donkey from chewing correctly.
- Supernumerary (extra) teeth, which are usually not opposed by teeth in the opposite jaw, leading to over growths (as above)
- Any other disease which causes oral pain
- There are other conditions that may cause choke, which your veterinarian can rule out, including neurological dysfunction
- And as always, be sure any pelleted feed you’re feeding him has been appropriately soaked to manufacturers specifications (e.g. sugar beet)
- You didn’t mention this mini’s age, but due to their breeding, they tend to retain their deciduous (baby) teeth, so it’s important they are checked every year by a highly qualified equine dental veterinarian.
Truly, though, most of this may be prevented by at least yearly veterinary dental examination and as-needed therapy. Unfortunately, when we breed equids, we’ve not been selecting for poor tooth occlusion, or bite, so we need to take care of them. Elizabeth Thompson, DVM, MANZCVSc (EqDent), Blue Mist Equine Veterinary Centre, New Zealand
- How can dention affect a horses eyes? I have an older mare that seems to have an infection/blockage in her nasolacrimal duct in only her right eye. She has no swelling or tenderness in her mouth and she eats well on both forage and grain. Can any kind of dental issue (major or minor) cause an infection or blockage of the nasolacrimal duct? And, if so what are the mechanisms for this? (View Answer)
Yes, dental disease can affect a horse’s eyes, but a much more common cause of blockage of a nasolacrimal duct is from inflammation/ infection of the duct from bacteria and contaminated material moving down the duct from that right eye itself. Has your veterinarian flushed the nasolacrimal duct? I would do this first, then treat with ophthalmic antibiotics for several days to clean up whatever infection may have been in there. Some horses will continue to block up.
With regards to the dental issue, has she had a thorough oral and head examination, including a tooth-by-tooth probing for pulp exposure? Percussion of her sinuses? Thorough examination of the upper 11’s (furthest back cheek teeth), etc, etc? To affect the bone-covered nasolacrimal duct, it would have to be a major infection, (ie, sinus infection), probably one which could deform the bone around it due to the pressure build-up in the sinus. Elizabeth Thompson, DVM, MANZCVSc (EqDent), Blue Mist Equine Veterinary Centre, New Zealand
- My 24-year-old horse has a fractured “molar” discovered at last dental examination and had been quidding his food. Initially, he had swelling, which disappeared with sulfa medication and has not returned. He is eating smaller mouthfuls of hay at a time so I believe compensating for structural chewing issues that do not seem to be pain related. The quidding is not very prevalent. He has no problem with grass (obviously more pliable). I plan to have him examined assuming chew changes will create mouth imbalances. His teeth are floated every year, but has lost weight over the winter. I plan on feeding a senior feed protocol next winter, which may involve moving to a different facility as the current stable does not offer herd separation in order to allow him time to consume a senior diet. He is currently bullied from the hay pile. He does have a stall but he does not like being alone. I wondered if extraction of the fractured tooth is an option or would make matters worse. If he has no infection, wouldn’t it be better to leave what remains to “hold” the neighboring teeth from caving in? Is it possible that the fractured tooth could erupt/grow faster to the height of the other teeth? (View Answer)
It would be a good idea to have your veterinarian X-ray your horse’s teeth. The pulp, or the live, painful part of the tooth may be only 2-6 millimeters beneath the surface or sides of a tooth, so in all likelihood, there will be pulp exposure and pain. If the tooth fracture extends into live, painful, tissue, there will be infection and pain. That’s why he’s eating small bites. And quidding. If he indeed has a fractured tooth, it should probably be extracted as soon as possible, unless it’s just a tiny chip off the outside. The fractured tooth will probably not erupt faster, in fact, probably less, as it will likely die (may already be dead). The fact he’s an older horse means his teeth are not as likely to be able to seal off the live portion of his tooth to try to keep it alive (not as good a blood supply as in a young horse).
Re: Horses and Showing Pain
Horses are prey species, which means they are preyed upon (eaten) by predators. There is ZERO selective advantage in showing when you’re weak, or in pain, as it would just encourage the predators. Your horse may not be surrounded by hungry wolves or other predators, but the horse’s defense mechanisms have evolved over millions of years. A few hundred years of our keeping the wolves away hasn’t changed that. Sometimes it’s hard to see when they’re in pain, but believe me, a fractured tooth will be causing him pain every time he chews. Please advise your dental veterinarian to look at the horse as soon as possible.
Re: Post-Extraction Requirements of Owners
Extraction of a tooth (or tooth loss) in a horse means that the opposing tooth will no longer have anything to grind against... and will continue to erupt. It will become an overgrowth, which causes severe problems to your horse, unless floated at least every six months, when it “grows” into the opposing jaw. Not a nice situation for the horse. If it’s left too long, one cannot reduce (grind away) the full excess length without exposing the pulp, or live portion of the tooth, so please schedule your veterinarian for those six-month floats before they leave your place. Elizabeth Thompson, DVM, MANZCVSc (EqDent), Blue Mist Equine Veterinary Centre, New Zealand
- I have a 3-year-old Friesian filly that I will soon be starting next summer. I have been given (and read) conflicting opinions as to whether or not to have her wolf teeth removed and, if so, at what time is best to do it? I have one horse that never had his removed and have not had issues with the bit. I would like to avoid an unnecessary procedure if possible. I plan to ride her with a bit, but for pleasure riding only, no intense dressage or the like. (View Answer)
Thank you for your question as it is one that is asked frequently. Unfortunately, the answer to your question depends upon the size and location of the wolf teeth, and whether or not they are in a position that could endanger them if a bit is pulled hard back against them. Often when this happens (even during pleasure riding as unexpected things will happen) a wolf tooth (premolar one/ 1-405) is contacted and damaged. Your horse is 3-years-old, so whatever wolf tooth development will occur has likely already occurred (by six months).
1-A wolf tooth can break, exposing pulp and resulting in inflammation and infection, or 2- it may become loosened, or 3- a combination of both. All of these choices will result in pain and if not noticed, may contribute to training and attitude changes.
Regarding the occasional lower (mandibular) cheek tooth, whether or not they have erupted [tooth showing above the gums (gingiva)] or unerupted (tooth still hidden beneath the gums), I always remove them. They are usually situated further forward (rostral) to the cheek teeth than the upper (maxillary) wolf teeth, a huge problem in a bitted horse. Unerupted mandibular wolf teeth may be lying flat on top of the bone or directed slightly outward toward the cheeks. As you might imagine, the tender gingiva overlying these teeth is traumatized whenever the bit hits them and this would cause no end of grief for your horse. Your veterinarian should always feel (palpate) the gap between the incisors and the cheek teeth (the diastema) with their fingers to ensure 1-no mandibular cheek teeth are present and 2-to check for any pain in the area. Unerupted mandibular wolf teeth are often invisible to the eye but easy palpable with the fingers.
Personally? I remove my own horses’ wolf teeth prior to any bitting, unless they are palatal (situated on the inside of the first cheek teeth). I have seen enough problems created by them to last me a lifetime.
I will be publishing a book for horse owners later this year if anyone would be interested, please join my Lizzi Tremayne Author mailing list at https://lizzitremayne.com/vip-dent-owner/ to learn when it becomes available. Elizabeth Thompson, DVM, MANZCVSc (EqDent), Blue Mist Equine Veterinary Centre, New Zealand