Tuesday, September 28, 2010

Women in veterinary medicine

Men make up around 12% of the students in my veterinary school. Yesterday, a guest lecturer commented on that, and noted that in another school, a recent year had no male students at all. I posted a while back about the contributions of improved large animal sedation to the introduction of women into veterinary medicine, which was once a male-dominated profession. Commenters have noted that other factors were almost certainly in play as well. But improved sedation methods in large animals aren’t going to explain why women are starting to dominate this profession rather than being content with half of it.

Interestingly, women do not dominate human medical schools in the same way. Johns Hopkins reports that their classes are made up of 50/50 male and female students. There has also been some commentary in the blogosphere recently about how many fewer female science bloggers are out there, with notes that women are as likely as men to get PhDs, but less likely to stay in academia.

So why are there more women becoming veterinarians these days than men? I don’t think anyone knows. I have two personal theories:
  • Vet med is often seen as a caretaking profession, something that may appeal strongly to more women than men.
  • Why vet med and not human med? One difference is that vet med pays a lot less. Are women more tolerant of low pay than men?
Any other ideas?

Monday, September 27, 2010

Veterinary fact of the day: Itchy dogs

A few weeks ago we started our Clinical Dermatology class, and next week is the first test. It’s been a particularly useful class for me on account of my itchy golden retriever. Jack has always itched from September through November, on his belly, armpits, feet, and face. My dermatology notes taught me: he probably has atopic dermatitis, or non-contagious, itchy inflammation of the skin. Atopic dogs very often show this exact distribution of itchiness (or pruritis, to use the technical term). Many atopic dogs are allergic to dust mites, and many benefit from shampooing to remove allergens. (I literally put down my notes, got up, vacuumed my bedroom floor, and put Jack’s bedding in the wash. It is amazing that I know for sure that I am allergic to dust mites — I’ve been tested — and yet it takes learning that my dog may just possibly be allergic to them to get me to vacuum.)

There are lots of other approaches to managing an atopic dog; cleaning up dust mites is just the easiest, and a good approach in a dog that is not all that itchy. Anti-histamines may or may not help, but are very safe to try in case they do help. Their main side effect is to make your dog sleepy — which in Jack’s case is probably the main mechanism whereby they take care of the itching. Atopic dogs can scratch their fur off (alopecia) and have thickened skin (lichenification), along with other problems.

I hesitated at first to write this post for fear that people would try to fix their atopic dogs on their own. You guys wouldn’t do that, would you? You will of course call your vet for advice before trying to give any medication to a dog, even something safe like an anti-histamine. And if you think your dog is uncomfortably itchy, don’t just vacuum — take him to a vet, starting with a general practitioner and moving on to a dermatologist if you need to.

What I did today: Today was one of the dreaded “eight hours of lecture” days. Two hours of anesthesia, two hours of dermatology; lunch (during which I went to a talk about research on whales in the Arctic, very cool, but that made it nine hours of lecture); two hours of large animal medicine/surgery; two hours of ethics. Phew!

Sunday, September 26, 2010

Veterinary fact of the day: measuring the scrotal circumference of a bull

Two weeks ago we started a new class, Theriogenology, about the medicine of reproduction. (What do you do if she has trouble getting pregnant? What do you do if she has trouble during her pregnancy? Etc.) So far it has all been about cattle, though we will get into other species soon. Much of the veterinary work for the dairy industry specifically is about timing pregnancies, making sure cows get pregnant promptly, and managing herd health reproductive problems.

We had six hours of lecture on cows, and finished up with two hours on bulls. The Society for Theriogenology has guidelines on how to perform a breeding soundness exam on the bull. Is he physically healthy enough to mount a cow? Is the circumference of his scrotum large enough to suggest that he has plenty of sperm (more important for his ability to service multiple cows sequentially than for his ability to get lots of sperm into a single cow)? Are his sperm well-formed and mobile, and mobile in the right direction (forward, not backward)?

Bull scrotums contain vertically oriented testicles, so it is actually useful to wrap a measuring tape around them. (The circumference should be a minimum of 30 cm in a bull of breeding age.) This sort of measurement is not useful in horses, dogs, pigs, or humans, whose testicles are oriented in a different direction.

Most amusingly, the product used to measure the scrotal circumference, with a feature that lets you see if you’ve wrapped the tape too tight, is called ReliaBull. That made me giggle.

Wednesday, September 22, 2010

Links post

Meta science blogging


Sunday, September 19, 2010

How to learn how to (not) spay a dog, Part 3: Surgery

Surgery day. This was one of the most emotionally (and physically) challenging days I’ve had in vet school, which has made it hard to write about. However, the dog did not die, and I did not faint, so let us say that overall it was a success.

The previous day, I had performed anesthesia while Lily spayed “her” dog. Today, she would perform anesthesia for me while I did surgery on mine. My dog was a very nice adult, much calmer than the puppy assigned to Lily, and giving her the premedication was a lot easier. We left her alone to let the sedative take effect while we got our operating table ready and made sure we had all our equipment set out.

I should have known that my luck was going to be bad this day when I looked outside and realized it was bucketing down rain, and that I had left my car doors open. I was already in full operating room gear, with booties and mask and head covering, but Lily (bless her) ran out in the pouring rain to close my car’s windows.

We walked my dog in to the operating room, lifted her on to the table, and Lily put in an intravenous catheter and induced general anesthesia, then intubated her. While Lily was setting up all the monitoring equipment, I shaved the dog’s belly and scrubbed it clean with disinfectant. I checked one more time for a spay scar; we had no history on this dog, who was a stray, but she did not appear to have been already spayed.

During this time, the dog was failing to breathe on her own, and Lily was using the anesthesia machine to give her breaths with the breathing bag. The intern who was helping out explained that it would not at all be unusual for a dog to never breathe on her own for the entire surgery. Thankfully for Lily’s sanity, this dog did start breathing on her own eventually, so Lily could concentrate on learning how to monitor her properly.

I left the room, scrubbed in (hand washing! putting on gown and gloves without touching anything! getting yelled at for getting too close to various unsterile items!), returned, and it was time. I put the scalpel on the dog’s abdomen and pressed down.

Opening the dog was disturbing in a very different way from dissecting a cadaver, which I did a great deal of during my first year of school. Cadavers are cold and sort of sad. Live dogs are warm and not sad, but scarier: I kept worrying that I would hurt her, even though I knew she didn’t feel what I was doing.

The initial incision went smoothly (skin; clean the subcutaneous tissue with scissors; then cut into the body wall, along the fibrous white linea alba, careful not to cut too deep so that you hit organs). I got my spay hook ready to go fish for her uterus, but the intern hollered “Put that away!” and had me stick my bare hand down into the dog’s abdomen.

I pulled out a ureter (cutting the ureter is contraindicated, though it does happen, and I can now verify that it does look like a uterine horn), some jejunum, even some colon. The intern hunted as well. Eventually I asked “Is it supposed to be this hard?” Other classmates had reported failing to find the uterine horn on their own, but I figured the intern should be able to do it. The intern called over the surgery resident and explained that this dog had already probably been spayed, and we needed to be sure. And then the surgery resident had a go.

Eventually the resident doubled the size of the dog’s incision and put in a Balfour retractor to hold the sides of the abdomen open so that she could better look around. I got a nice tour of the inside of a living abdomen. And finally she found it: the little uterine stump. The dog had been spayed previously, and I had just performed my first abdominal explore. But I would not be spaying a dog that day.

So I had to close the dog up. The incision looked huge to me. Closing this sort of incision is done in three steps: first you close the body wall, then the subcutaneous tissue (“the subcu”), then the skin. I sewed the body wall. And sewed and sewed. Sometimes I would realize I had gotten off the fibrous linea alba onto muscle (painful for the dog after she wakes up), and would pull out some stitches and back up. Sometimes the intern would point out I had gotten some subcu, and I would pull out the stitches and back up. Finally the body wall was closed, and I called the resident over. She took a look, declared my stitches too loose, and pulled them all out, every one.

I started over (and she helped). It felt as though I had been sewing linea alba for an hour. I was becoming frustrated, and my initial adrenaline rush was fading. As a result, I was starting to become aware of my body again: I was hypoglycemic, dehydrated, exhausted, and my back was spasming from the hours on my feet leaning over a table. When I am that hungry and tired, I am usually careful not to make important decisions or to do anything requiring manual dexterity until I have eaten and rested, yet here I was placing stitches in the body wall of a dog of whom I had become somewhat fond.

I wondered if this experience was showing me that I was not physically up to the demands of a veterinary internship. Maybe I was only good for research and never meant to practice. I was so hungry. I was so tired. I was so depressed at the idea that this was all for nothing: the dog didn’t need the surgery, and I wasn’t going to get class credit for it, because I wasn’t doing an actual spay. We sewed and sewed, and then I did the next two layers, and finally the surgery was done. All that was left was a pile of paperwork, four hours of lecture, and continued care of my dog until she was discharged 25 hours later.

A few days after the experience, I feel a lot better about it, but it was an emotionally rough day. I felt very bad for the dog. She had a much larger incision than she would have if she had been spayed, because we had to be sure that there was no uterus before we closed her up. And she had incompetently performed sutures, which I am sure are more painful than they would have been if someone who knew what they were doing had put them in. And she didn’t need the surgery in the first place.

So do I now think that it is a bad idea for veterinary students to do their first spays on shelter dogs? Absolutely not. These things happen. This dog would have received an unnecessary surgery no matter what, since the standard of care does not dictate waiting for a dog to go into heat before spaying her. It was inconvenient for me, but the inconvenience is worth it. The program is a good one, and no one did anything wrong.

I did not actually spay a dog, but I did learn a great deal about anesthesia and about surgical procedures. I did open and close a dog, which was very important experience. All students at my school are required to complete two spays during their third year, so I will go through this lab two more times. That won’t leave me an expert on spaying a dog, but there will be lots of other opportunities to practice during my clinical year. I can’t quite say that this particular lab was a good experience for me, but I can say that the program is well designed, finding a good balance between students’ needs for experience and ethical issues.

[How to learn how to spay a dog, Part 1: Basic skills]
[How to learn how to spay a dog, Part 2: Anesthesia]
[How to learn how to spay a dog, addendum: uterus removal]

Saturday, September 18, 2010

How to learn how to spay a dog, Part 2: Anesthesia

Monday evening, at 5 pm, eight of us arrived at the spay clinic. The anesthesia tech who is in charge of the clinc hadn’t arrived yet, but we found that each of the eight dogs in the clinic had one of our names on the front of her cage. We took our dogs outside to let them stretch their legs and pee. Mine was a sweet mid-size dog of a few years of age. My partner, Lily, was assigned a six month old who had the normal energy level of a six month old puppy — she was a handful. Lily was scheduled to spay her puppy (we quickly started referring to them as “our” dogs) on the first day of the lab, and I was scheduled to spay my dog on the second. I would perform anesthesia for Lily on the first day, and she would perform anesthesia for me on the second.

The anesthesia tech and veterinary intern arrived, and helped us draw blood on our dogs. (This was my third time drawing blood. I am still terrible at it.) We tested the blood to make sure that all the dogs were good surgical candidates. Any dog with any medical problem at all would be ineligible for the spay lab program; that dog would need to be spayed by someone with more experience.

Then we gave our dogs physical exams and wrote up our SOAPs (Subjective/Objective Assessment and Plan). We presented our dogs to the veterinary intern. A typical presentation would sound something like: “This is a two year old intact female dog, presenting to the spay clinic for ovariohysterectomy. Her heart rate was...” And so on. The intern was helpful, explaining things to me like “don’t say you found a lesion on her tail, say you found an area of alopecia on the dorsal caudal aspect of her tail.”

Around 7:30 pm we were done. We fed our dogs. Lily and I agreed that I would handle the 9 pm walk that night. I went home, fed my own animals, fed myself, and came back in for the 9 pm walk. I put a note on Lily’s dog’s cage to make sure that no one else gave her more food, since she was scheduled for surgery the next day. Home again, I calculated the drug dosages for Lily’s dog for the next day (since I would be handling her anesthesia), and went to bed.

My alarm went off at 4:45 am the next morning. I was at school by 6 am. We walked our dogs, did another physical exam, and wrote up another SOAP, which was very similar to the previous SOAP from twelve hours before. I fed my dog. Then Lily and I premedicated her puppy. This was difficult, as the puppy didn’t want to hold still, and I had to put a very large needle into her back and inject the premedication cocktail into her muscle. But I managed. The puppy started getting drowsy in a few minutes, while we took care of necessaries before surgery, like food, water, and toilet breaks. By 8 am she was ready and so were we, so we carried the sleepy puppy in to the operating room and put her on the table.

To induce anesthesia, we used an injectable solution. First I put in an IV catheter. This is the second time in my life that I have had to thread a catheter into an animal’s vein; the first time, I almost passed out. I did not even get woozy this time. (Thank you, adrenaline.) Then I injected the anesthesia solution, and the puppy got very sleepy. Good puppy.

Next I put an endotracheal tube down the puppy’s throat. I had been nervous about this, but it was easier than it looks. You can actually see the vocal cords and thread the tube right between them. It helps if the puppy is “deep enough” under anesthesia; we gave her a little more juice after my first try.

Next I hooked her up to the anesthesia machine and started the oxygen and anesthesia gas flowing. We had induced anesthesia with an injectable solution, but maintained it with gas. Gas is a lot easier to control; if you want to change anesthetic depth, you can easily turn it up or down. An injectable solution is out of your hands once it’s in the animal.

Next I added several more monitors and started recording information. Every five minutes, I recorded her heart rate (a machine provided that number), her systolic blood pressure (I took it with a cuff, just as the doctor does it to you), her respiration rate (I counted breaths by watching the breathing bag), and her anesthetic depth (I looked at her eye to see the position of her eyeball, and tested her jaw tone; an eyeball rolled down is a good depth, and a loose but not too loose jaw is also a good depth). If I had time left over, I sometimes listened to her esophageal stethoscope (a stethoscope threaded down her esophagus to lie close to her heart), which let me make sure that her heart was actually echoing the sound I heard on one of the monitors.

Every fifteen minutes, I assessed how much fluid had gone in via her IV catheter, recorded her oxygen pressure, and recorded her temperature. How hard could it be to record a temperature? I had to crawl under the surgical drape and try to see the rectal thermometer. This required a flashlight and lots of craning.

Periodically, the anesthesia tech handed me more meds (pain killers or antibiotics) with instructions on how to administer them. At one point I had three medications stacked up, to be administered “four hours after induction” (in an hour), “when your partner closes the linea alba” (watch partner), and “an hour after the first antibiotics dose.” I had to write down the various times so I didn’t forget them, since I was balancing a few other things in my head at the same time.

The surgery went smoothly. When my partner was done, I turned down the gas and let the puppy breathe pure oxygen for five minutes. Then we unhooked her from the machine, unhooked all the monitors, and carried her back to her cage. When she had swallowed twice (after about ten minutes), I pulled out her breathing tube. We covered her with warm blankets and checked on her frequently while doing paperwork. She did exactly what she was supposed to: went back to sleep after the tube was out, and got steadily warmer.

I had a few minutes to have lunch, then went to four hours of lecture. After lecture, at 5 pm, I walked my dog and helped with clinic cleanup. We planned for Lily to cover the 9 pm walk. The next day I would spay my dog. I was tired, but it felt good to be halfway done, and to have not done a bad job so far.

[How to learn how to spay a dog, Part 1: Basic skills]
[How to learn how to spay a dog, Part 3: Surgery]
[How to learn how to spay a dog, addendum: uterus removal

Wednesday, September 15, 2010

How to learn how to spay a dog, part 1: Basic skills

As my advisor once asked: “How many times do you want a veterinarian performing surgery on your dog to have done that procedure before?” My answer is “a thousand.” But there is a first time for everyone. How do vet students learn how to spay female dogs (a procedure that many vets will do commonly during their careers)? This is real surgery, in which you go into the animal’s body cavity. It is serious stuff and animals could potentially die. So who do we learn on? (Take a moment to think about how you would design the perfect spay learning experience. I would be curious to hear how it compares with my school’s approach.)

At my school, spay lab is scheduled at the beginning of our third year. We are given videos to watch (how to scrub in to surgery, how to suture and knot, how to induce general anesthesia, and how to perform the actual ovariohysterectomy, or spay). And our anesthesia course is front-loaded for the first few weeks. During the second week of classes, before most college students have returned to school, we have a practical exam of several of these skills.

The practical exam (which was one of the more relaxed of the exams given at my school, perhaps to balance the extreme stressfulness of the actual spay) is in four parts. This is how it goes.

Prove that you  can gown up: pretend to scrub your hands and arms, showing that you know how to hold your arms so that the dirty water doesn’t run onto the clean parts of your hands; show that you know how to crawl inside surgical gloves and gowns without contaminating yourself.

Next, pick out your tools from a massive pile of them. Be able to tell apart different hemostats (clamps) and scissors; there are lots of different kinds. Put together your “spay pack” of appropriate tools.

Next, prove that you can suture and knot. Do not panic when the surgeons ask for suture patterns that the syllabus said you didn’t have to know.

Finally, show that you know how to write a SOAP (Subjective Objective Assessment and Plan). A surgeon rattles off information about a case. You write down the physical exam findings, your assessment of the dog (what is probably going on with her? What are your rule-outs?), and your plan (what diagnostics would you do if this were your patient?).

Students who pass this exam (and so far as I know, all of us did) are theoretically ready to perform their spay. Where do the spay dogs come from? One option is to purchase dogs, usually purpose-bred animals, perform a spay and possibly some other surgeries, and terminate them at the end of that use. My school has gone a different route. We have a relationship with local area shelters; students perform their spays on shelter dogs or dogs from low income families, under the watchful eyes of surgeons to make sure that we don’t screw up. It’s not ideal; the dogs will be under general anesthesia for longer than if someone with more experience performed the surgery, and they will be more painful when they wake up, again because of our inexperience. But I think it’s the best solution there is, given the situation.

Each student is assigned a partner, and each student is assigned a dog. On the first day, one student spays one dog, while their partner performs anesthesia. On the second day, their roles switch for the other dog. Both jobs are stressful; anesthesia entails monitoring a lot of parameters, and all the little tasks are hard to do at once. Moreover, it is easier to kill a dog with anesthesia gone awry than with a surgical mistake, at least in this surgery. Small groups of students are assigned dates for spay lab throughout the semester; the entire class can’t do the lab all at once, obviously. My spay day happened recently. I’ll report on it in detail in the next posts in this series.

[How to learn how to spay a dog, part 2: Anesthesia]
[How to learn how to spay a dog, part 3: Surgery]
[How to learn how to spay a dog, addendum: uterus removal

Friday, September 3, 2010

Veterinary fact of the day: changing the face of large animal medicine

A few days ago in anesthesia lecture, Dr. Drile announced, “Now we are going to learn about xylazine. All of you in the audience who are women, or men under 200 pounds, can be thankful for this drug.” She then plunged into her lecture on xylazine, and it took several minutes for her to get around to explaining why I should be thankful for it, during which time I was mostly distracted by what a weird introduction that had been.

Eventually we got to a slide depicting a small woman leading an enormous draft horse, and Dr. Drile explained. Xylazine is a really excellent sedative/tranquilizer, used primarily in large animals (although also sometimes in small animals). Before we had xylazine for chemical restraint, we had to physically restrain these enormous animals in order to do simple procedures on them. This was difficult and dangerous, and if you were a small person, you couldn’t easily do it. Xylazine hit veterinary medicine around the 1970s, which coincides with an increasing influx of women into the field. The estimates vary for women in veterinary medicine now, but we decidedly dominate numerically. In my first year class, there were 70 women and 12 men. My school recently spent a hefty chunk of change to remodel the anatomy building’s changing rooms, to increase the space in the women’s room at the expense of the men’s. There are, of course, lots of reasons why there are so many more women in veterinary medicine now than there used to be, but this was one I hadn’t considered before.

Thanks to xylazine, veterinary medicine is no longer a wrestling match. I am, accordingly, grateful.

What I did today: Quiz in zoological medicine (not supposed to be hard, and wasn’t). Gym! Two hours of dermatology lecture (new class, very engaging guest speaker). Lunch! (Went to meeting about how the lottery for scheduling our clinical rotations will work.) One hour of small animal medicine lecture (vaccines). Out super early.