Ask the Vet: Dental Care for Your Horse

Answered by, Elizabeth Thompson, DVM, MANZCVSc (EqDent), Blue Mist Equine Veterinary Centre, New Zealand

Question: 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? 

 Answer: 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.

Question: 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? 

Answer: 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.