IN the early days of my career, anaesthesia of dogs was a pretty risky business.

You have to bear in mind I am talking about more than 40 years ago. mind you. I know, it’s hard to believe, isn’t it? Ah, those balmy days of luxurious, wind-swept hair, eating all you can eat with no thought of weight gain, running without pain. I know now why I feel like a grown up…because I groan every time I get up. 

But enough nostalgia. Where was I? Ah, yes. Anaesthesia of dogs. As I say, once upon a time it was far from without its risks. Induction and maintenance were achieved by the use of intravenous thiopentone, which was a severe irritant if it leaked under the skin. One injected a carefully calculated quantity of said liquid, and hoped for the best.

There were no in dwelling intravenous cannulas, so a simple syringe with a needle attached was used. It was all more of an art than a science. Or maybe it was better described as 'a wing and a prayer'. Patients slept for a couple of days post-operatively, before eventually staggering out of the surgery.

Gradually, over the years, the situation improved. Anaesthetic machines became the norm and the intubation of dogs allowed for proper oxygenation. The use of gaseous anaesthetics started with ether, which was highly explosive, and quickly progressed to halothane. It, in turn, was superseded and replaced by isoflurane and sevoflurane.

Every change brought about easier, safer and more reliable maintenance, along with a smoother and faster recovery. Induction agents also evolved, so that modern drugs have been metabolised long before patients wake up, meaning that there is little or no ‘hangover’ period.

But more recently, anaesthesia has become more dangerous again. The risks associated with it have increased, and vets and nurses everywhere approach it with more care, concern and trepidation than ever before.

The reason, of course, is simple. It has nothing to with drugs, training, tubes, cannula, or equipment. It has everything to do with the explosion in popularity of the brachycephalic breeds.

These guys, who include pugs, French bulldogs, English bulldogs and boxers, can suffer from a number of conditions that must be taken into account if anaesthesia is to be successful.

First and foremost is the presence of brachycephalic obstructive airway syndrome (BOAS), which results from the aggregation of various issues. Stenotic (blocked) nostrils, floppy soft palates, narrowed windpipes, wrinkled noses and extra tissue in the larynx all conspire to reduce pre-anaesthesia oxygen levels and limit our ability to preserve lung function.

Additionally, brachycephalics tend to suffer from increased reflux from the stomach and regurgitation, leading to an increased risk of aspiration.

Those bulging eyes may be appealing but they are also more likely to ulcerate due to dryness and biochemical changes that can occur during surgical procedures.

And then there is the fraught recovery period, when very close monitoring is required right up to and long after the removal of the endo-tracheal tube. Indeed, in our practice, one-on-one attention is given until patients are able to stand.

Insofar as safety is concerned, it almost feels like a step back in time.