Is buying a horse who has had a wind operation still a risky bet — or have better, more targeted surgical techniques refined the management of upper respiratory tract disorders? Andrea Oakes investigates

The dilemma of whether or not to buy a horse who has undergone wind surgery is a common one, especially given the trend for the rehabilitation of racehorses for alternative careers.

No other discipline puts a horse under such pressure as racing. The airflow through the “tubes” is thought to be a lot less in other sports, such as endurance, point-to-pointing and even four-star eventing. The speeds involved speak for themselves. The 2000 Guineas is raced at around 17 metres per second (mps), while horses travel at 9.5mps on average around Badminton’s CCI4* cross-country track.

Once a horse’s racing days are over, he’ll most probably be working well within his athletic capacity — yet how much of a gamble is it to take on such a horse for other disciplines?

Geoff Lane FRCVS has performed numerous upper respiratory tract operations and recommends first considering the nature of the surgery.

“Wind surgery covers a wide spectrum, from the least invasive tightening of the soft palate by cautery, to tie-back and tie-forward procedures,” he explains.

“The latter operations are both major, while the Hobday sits somewhere in the middle. In racehorses, soft palate malfunctions are many times more common than all other wind entities put together.”

Each procedure has the ability to correct airway problems in the racehorse, yet ongoing health and management issues can be a concern.

diagcopy

“The benefits of soft palate cautery generally last around 12-18 months, so if the horse continues racing, a repeat operation may be necessary at some stage to tighten the tissues,” says Geoff. “While four-star event horses occasionally have soft palate problems, the level of exertion is much less, as the horse will never again gallop at true racing speed.

“If done properly, a Hobday generally lasts for life. There is a small chance that the sutures or attachment points in a tie-forward could give way, but the procedure can be repeated if needed.

“I would not worry too much about a horse who’d had soft palate cautery, a Hobday or a tie-forward, subject to a satisfactory endoscopy.”

With a tie-back, however, difficulties can arise. Fixing the left, flap-like arytenoid cartilage in a permanently open position means the horse’s windpipe is no longer protected when he swallows. This increases the chance of upper respiratory tract infection.

“Even if the horse has a good post-operative record and seems clear of complications, a change of management, however subtle, could tip him off the tightrope,” says Geoff.

“I would be particularly wary with a horse who is coughing after surgery,” he adds. “Nasal discharge might indicate food material in the windpipe and could be a red light that complications have occurred.

“If the tie-back has failed and the windpipe is no longer open, a second surgery is probably not worthwhile. Removing the tie-back sutures can resolve clinical signs, but you’re just reinstating the original condition.”

Tailored treatment

State-of-the-art techniques, such as overground dynamic endoscopy (pictured top), now allow airway changes to be monitored during exercise — a huge improvement on the standing endoscopic examination that was once the norm. But is surgery any more successful or longer lasting?

“The introduction of the tie-forward procedure in 2003 was a big step forward,” says Geoff. “But while the accuracy of diagnosis has advanced hugely, the techniques available for surgery have changed very little.

“We know that tie-back surgery has limitations. Developments are under way to use electro-stimulators [to stimulate correct functioning of the arytenoid cartilage] instead, but this procedure is not yet freely available.

“Laser surgery is increasingly common for certain wind problems, but its use remains controversial,” he adds. “On the plus side, the horse does not require general anaesthetic, which is always a risk to use, and there is no incision to keep clean while it heals.”

The minimally invasive nature of laser surgery and other modern techniques may mean that a potential buyer is unaware that a horse has been operated on. The only clue may be an absent or “hoarse” whinny.

“During a pre-purchase exam (PPE) vets should look for scars from Hobday and tie-back procedures,” says Geoff. “At a normal vetting they would not find evidence of soft palate cautery — and probably not even a tie-forward.”

View of a horse's larynx through a videoscope

View of a horse’s larynx through a videoscope

Exposing limits

If you know that the horse you’re considering buying has had wind surgery, it is wise to take some common sense measures.

Consider requesting an endoscopic exam as an add-on to the PPE, so the vet can assess any scar tissue. If possible, reproduce what you plan to do with the horse during the exercise phase of the exam, to expose any limits.

If he is being sold on for anything other than racing, the purchase price is unlikely to be reduced.

“If you buy a horse with a wind anomaly or a history of wind surgery, try to find out what has been done and have him endoscoped to see if the site has healed properly,” Geoff concludes. “Provided that further examinations are satisfactory, he should be capable of a less arduous pastime.”

Further reading

www.horseandhound.co.uk/tag/respiratory-problems

Ref: Horse & Hound; 3 September 2015