San Miguel de Allende, GTO, MX, August 22, 2014 – For the past several weeks I’ve been spending some time at the local animal shelter. I usually go on Thursday, and I see cases and do surgeries with the vet there. She thinks I’m some kind of surgical genius because I can spay a dog that’s in heat with minimal bleeding; I’m not telling her otherwise. On my first day I successfully suppressed an overwhelming urge to run into the street and away, never to return. I’ve had my share of rough days in my seven years as a vet, but seeing three dogs die in the space of 30 minutes was almost more than I could take.
The vet on staff there is a very nice woman, who cares a lot for her patients and their owners and is doing an admirable job considering the facilities and supplies that she has. I am fairly certain the x-ray machine was built by Marie Curie herself.
They taught me lots of things in vet school, many of which I promptly forgot right after national boards, including the twenty-three causes of diarrhea in neonatal pigs. But I very well remember being told that there is no such thing as “safe” anesthesia. You are giving dangerous drugs that depress the respiratory, cardiovascular, and nervous systems, and even in healthy patients things can go wrong. Your training is focused on how to administer these substances at what we know to be the safest dosages in the safest combinations, and what to do if the animal’s body reacts aberrantly.
On my first day at the rescue I was putting my stuff away and I saw an injectable drug bottle on the top of the refrigerator. The manufacturer’s label was somewhat obscured by the hand-lettered word “ANESTHESIA”, and this is how the clinic staff referred to it, as in “give me ½ ml of ‘anesthesia’”. The bottle actually contained a combination of two drugs. The one that truly provides anesthesia is xylazine, a drug that I have almost never used. It’s very widely used to knock out horses and cows and other such creatures but we have drugs in this class, known as alpha-2 agonists, that were developed especially for small animals. In this combination the xylazine was mixed with another drug similar to Valium, which provides some sedation and muscle relaxation. The rescue typically gives the drug combination in a muscle, and is used for everything from mild sedation for an orthopedic exam on a painful patient to abdominal surgery and dental cleanings.
Not to get too geeked-out on the veterinary stuff, but the majority of American vets would never perform abdominal surgeries using injectable anesthesia only. It’s unreliable, and frequently patients start to wake up during surgery and have to be re-dosed. This means if the patient starts to wake up five minutes before you’re finished, once you re-dose them you can expect them to be anesthetized an hour or so longer. Gas anesthesia is by far the preferred method, as it provides a rapid way to change the depth of anesthesia, i.e. how asleep the patient is, as well as gives you a way to deliver oxygen directly into the trachea via the tube that is placed there to deliver the gas. This tube also occludes the airway, so that fluid cannot get into the lungs. This can easily occur during dental cleanings, or if the animal regurgitates stomach fluid during recovery.
But machines that deliver gas anesthesia and the assorted accoutrement that goes along with them are expensive, and it is unlikely that most vets in Mexico have them, much less any rescue organizations. In addition there is a definite shortage of skilled veterinary technical staff, so most staffers probably wouldn’t even know how to use these machines if they had them. So, they’re using injectable drugs to anesthetize patients.
OK, xylazine. I’ve known small animal vets who used it and were very comfortable back in the day with it. It’s a good drug when used properly. The main reason vets use alpha-2 agonists is because they provide deep, reversible sedation. Reversible, meaning there is another drug that is given once the sedation is no longer desired, and the act of giving the second drug makes the animal wake up. We use drugs like this in my clinic to do things like suture lacerations in otherwise healthy animals. Give the first drug, dog goes to sleep. Fix up the mess. Give the second drug, dog stands up and goes home. It’s a beautiful thing, and in a healthy animal with a good heart it’s a good choice.
But the rescue doesn’t have the reversal agent, for reasons I’m not yet clear on. I don’t know if it’s not available in Mexico, or if Mexican vets just aren’t trained to use it. This is especially surprising in a situation such as this, where there is limited staff of varying skill levels and less-than-ideal monitoring capabilities. And by “less-than-ideal” I mean “none”. No heart-rate monitors, no pulse oxygenation levels, certainly no EKG or blood pressure. We can see that they are breathing, and look at their gums to see that they are pink. If we’re not performing a sterile procedure we can certainly listen to their hearts and lungs, and feel their pulses. So our patients wake up when the drugs wear off. At least, we hope they do.
But the vet seems extremely comfortable with using this drug combination in many circumstances. On my first day at the rescue we started to see patients shortly after I arrived. One was a puppy with parvo (a highly contagious gastro-intestinal virus that causes vomiting, severe diarrhea, and decimation of white blood cells) that’s had been in the hospital all night. He was supposed to be getting intravenous fluids but his catheter failed. Overall he was doing pretty well, though. He was being cared for in the shelter’s isolation ward, along with several very loud cats and kittens with ringworm, who clearly felt fine and wanted out.
Later in the morning a teenaged boy left a middle-aged poodle-ish dog with us. I understood from the vet’s explanation that she saw the dog last week, and that at that point he had just returned home from being missing for three days. At the time his tongue was black, his mouth full of ulcers and abrasions, and he wasn’t eating. She had given antibiotic and anti-inflammatory injections, but the dog was back today, still not doing well, not eating, and clearly not feeling well.
We were able to examine the dog and see that the entire end of the tongue was black and dying. This looked extremely painful and infected, and was very likely the primary reason why the dog wasn’t eating. We speculated about the possibility of electrocution (dogs will bite onto electrical cords and get these types of lesions in their mouths) or chemical burns. There didn’t seem to be any fractures to the jaw or any pain elsewhere.
The shelter vet felt that we could anesthetize the dog, remove the dead tissue from the tongue, and this would help him to feel better and hopefully start eating. I couldn’t disagree with this theory, since there were no other diagnostics to support any other troubles. He went quietly down with his anesthesia dose and we cleaned up the mouth. Throughout this procedure his heart rate was stable and his breathing was normal.
Noting that he still had his testicles I wondered aloud if his owners realized that he would probably stop running away and getting into trouble like this if he were neutered, and the rescue vet agreed. She laughed and said they probably wouldn’t even notice if we neutered him today, and I laughed too, until I realized that she was serious. Before I knew it he was given more “anesthesia” and was shaved and scrubbed for surgery.
Now, this would likely never, ever happen in the U.S., or at least not at my practice. At home, this is malpractice plain and simple; performing a surgical procedure without the owner’s knowledge or consent. But clearly, I’m not at home anymore, and the vet in charge believed that this was reasonable. The clinic doesn’t obtain informed consent for anything they do; they are providing free or very low cost care and basically the owner provides information about what is going on with the animal and leaves it, hoping to get call later that its better. The clients seem to trust that the vet knows best, and it’s up to her to do what she thinks is necessary.
During the neuter, the dog’s vital signs again stayed in the normal range, although the heart rate came down a little more, and afterwards we placed an IV catheter and started fluids. I gave him to the technician to continue his recovery in the isolation room. Final check of his vitals: still good, but he was still completely anesthetized.
Are you outraged at me? Because I’m fairly outraged at myself. Why didn’t I speak up and say you can’t do this procedure on this dog, you don’t have informed consent? Why didn’t I stop everything and go look up appropriate dosing guidelines for xylazine, like how soon after a first dose can you give a second dose? Why didn’t I say that I didn’t think it was a good idea to give an obviously dehydrated animal more anesthesia than necessary, especially not xylazine, which is contraindicated in animals with cardiovascular compromise?
I don’t know why I didn’t say anything. I suppose the vet seemed very confident in her actions, and I am certainly a stranger in a strange land is so many ways, that I just didn’t feel right saying anything, and I was really hoping everything would be alright. And quite honestly I did think the dog would be OK; he was doing well the entire time we were working on him and based on the information I had to hand I had no reason to think it wouldn’t be alright. But in the end it wasn’t. It went completely and horribly wrong.
I’ve got lots more to say about my experience that first day, and on those that followed. Since Google tells me the optimal blog post is 1900 words long, I’m going to end this post just over that, and continue tomorrow.