How to learn how to ultrasound a dog

I’ve seen a bunch of ultrasound images (still and moving) throughout vet school. Lecturers will flash up a picture and say things like “and that’s what a pyometra looks like on ultrasound.” And what do I see? MASS OF GREY AND BLACK.

[Image source: Imaging 2003;15:72-78.]

Today we had our first lab in which we got to actually handle ultrasound machines. When you’re driving, everything makes a little bit more sense.

The procedure

Take a dog. Sedate it. Put it on its back (padded to stay in place). Slather gel on its belly. Watch as someone who knows what they’re doing shows you how to find the liver, gallbladder, and kidneys with the ultrasound probe.

The liver isn’t so hard: it’s tucked up under the rib cage, so you put your probe at the end of the rib cage, right in the middle of the belly, and look around. The round black circle that is the gallbladder tells you that you’ve found the right spot. The liver is all around the gallbladder, and once you know that, you can see that it is indeed a slightly different color and texture of grey than all the grey around it. Move the probe back and forth along the dog’s belly, following that particular grey texture until it disappears. You have imaged the liver!

The kidneys are a lot harder to find, as they are not so near the surface of the dog’s body, and they don’t have as clear a landmark. When you do find them, they are super cool to look at, though. The liver is a plain mass of grey, but the kidneys have a pattern to them that looks exactly like a kidney looks when you cut it in half in gross anatomy lab. It convinces you that what you’re looking at is for real and not just made-up images on a computer screen.

Try again with the urinary bladder. That’s easy to find, a nice big black circle. You can change its shape by pushing down with the ultrasound probe. As you are being pleased with how easy this is, the radiology resident comes over and asks if you want to try to find the prostate.

The prostate is hard to find, I tell you what. The resident had to find it for me (I held on to the probe while he moved it, so that I could feel where to put it), and when he pointed it out to me, I was like, “That’s a thing? A thing I am supposed to be able to recognize later? It doesn’t look like anything!”

Wipe the gel off the dog. Call someone to give him his reversal agent to counteract the sedative. Wrap him in a warm blanket and cuddle him while he wakes up.

Success! You saw a liver, gallbladder, urinary bladder, and prostate!

The students

There are two labs for the class of 82 students, so this lab had 41 students in it. There were 5-6 students per dog, 6 students in my group; we took turns with the probe. The dogs were sedated for about 80 minutes, which didn’t feel too long to me.

The instructors

The instructors included: a private practice veterinarian; two radiology residents; a representative of the ultrasound equipment company (who may or may not have been a vet, I wasn’t clear, but certainly knew how to ultrasound a dog).

The equipment

A manufacturer of ultrasound equipment lent us the equipment for the day, so that we could have several ultrasound machines in use at once. They did this out of the kindness of their hearts, and perhaps with the idea that we would think well of them and perhaps purchase some of their equipment some day.

The dogs

The dogs came from my school’s teaching colony. These are ex-research dogs. The research laboratories can’t place the dogs directly in homes once their stint as research animals is over, so they give them to my school, which socializes them for a few years and uses them in procedure labs like this one, then adopts them out. They retire to pet homes for the rest of their lives. I also learned how to do a neurology and cardiology exam on these dogs, among other non-invasive procedures.

The dogs represent a complex moral question for me. Is it acceptable to use them like this? They are cared for well, but they live in kennels rather than homes, and they do have procedures like this done on them, which while non-invasive must be at least a little stressful. However, my school is doing a good thing by helping them to transition from a research environment to pet homes. And the alternative would be that I would learn ultrasound techniques on patients, animals who were actually sick, and perhaps less able to tolerate my bumbling around. In the end, I like this solution.

So thank you to the dog who let me practice on him (although it was not his choice). Thank you to the people who taught me. Thank you to the company who lent the equipment. It was a good lab.

Links post

• Scared or feral: How do you know? (Pet Connection)
• Repost: The ethics of snail eradication (Adventures in Ethics and Science): “Plenty of people are happy just to get the food without knowing the details of its provenance. I’d rather shoulder the responsibility of doing my own dirty work here. The karmic costs of my food are not hidden out back in the fields behind the farm stand.”
• Canine Cogniton and Pointing Gestures – An Update (The Other End of the Leash)
• Vaccination, Confirmation Bias, and Knowing Your Audience (The Thoughtful Animal): on effective communication of science
• Enrichment in Captive Cephalopods (Cephalove)

More on women in veterinary medicine

Some while back I wrote a post asking why there are so many more women than men in veterinary medicine. Recently, that post received a comment from Anne Lincoln, whose research into exactly that subject has just been published. Her findings are summarized at Eurekalert. You should read that summary, but in short:

Women now dominate the field of veterinary medicine — the result of a nearly 40-year trend that is likely to repeat itself in the fields of medicine and law...That's the conclusion of a new study that found three factors that appear to be driving the change: the 1972 federal amendment that outlaws discrimination against female students; male applicants to graduate schools who may be deterred by a growing number of women enrolling; and the increasing number of women earning Bachelor's degrees in numbers that far exceed those of male graduates, says sociologist Anne E. Lincoln.

I still have questions! If veterinary medicine, medicine, and law are all changing, why is veterinary medicine changing first? Why are more women earning bachelor’s degrees than men these days? Enquiring minds want to know. Hopefully Dr. Lincoln is continuing research in this area.

I also recently encountered Science IS Sexist, in which Alexandra Jellicoe asks, Do you think that women are more intuitively than logically intelligent and do you think that as scientific research has been designed to only include this logical, evidence based approach, it alienates women? She concludes that the female brain is likely to find the existing scientific research approach dull, dull, dull.  It is too narrow and systematic and does not maximise the use of the hive of activity going on in a female brain.  Men approach problem-solving from a task-oriented perspective while women typically solve problems more creatively.

What I find particularly interesting about this idea is that my friend LPK and I have observed that in vet school, dominated by women as it is, we tend to have different approaches to problems than most of our classmates. We tend to approach problems more intuitively and creatively; our classmates are more likely to approach problems more systematically. LPK and I also differ from most of our classmates in that we spent significant time out of school, in non-veterinary careers, before entering vet school. (Five years for her, more like 12 for me.)

So is vet school the place for women to go who think like men? Did it take me so long to realize I wanted to become a veterinarian because (in part) I had to overcome the obstacle of having different approaches to problems than the rest of the veterinary community?

Food for thought. I usually like to leave you with an opinion, but I don’t have one here, just questions.

New comments policy

I just turned on moderation for comments. I hate to do it, but lately I have been getting a lot of spam comments (put in by real people who can pass the spam filter, but with links to commercial pet supply sites — I have heard about this on other dog-related blogs). I will do my best to approve real comments promptly. I know this is inconvenient for all; sorry!

Veterinary fact of the day: is it the brain or the heart?

This morning as I was walking out the door on the way to Lottery Day, I looked over at my golden retriever Jack and observed that he was having a small seizure. Jack does this from time to time and these days I don’t consider it a big deal (though of course when it first happened it was a very big deal, and I visited several vets about it). I sat with him until it was over, and then he was fine. Dogs are great; I would have been distressed for hours afterwards. (As I headed off to Lottery Day, now slightly late, I thought to myself: “This is the best excuse for being late ever! I should have thought of it years ago.”)

So, you are an emergency veterinarian, and a young woman brings in her newly-adopted golden retriever who, she reports, had a seizure this morning. Do you accept this at face value and explore only things that could be wrong with this dog’s brain? Or might another system be at fault?

In fact, it could be the heart. Some heart problems can cause collapse (“syncope”) which can look very much like a seizure. In both cases, the dog can collapse on its side, lose consciousness, and urinate or defecate. So how do you tell the difference?

Seizures can last several minutes. They usually don’t seem to be triggered by any particular activity, but the dog sometimes seems to be able to predict them (the “pre-ictal period”) and may act differently. During the seizure, the dog is likely to move its limbs in classic “tonic-clonic” motions, drool a lot, and possibly chew on its face (you know how with humans, they warn you to secure the tongue if you have a chance?). Afterwards, recovery can take a few more minutes in which the dog is not quite right (the “post-ictal” period).

In contrast, syncope is shorter, usually more like 30 seconds. It may be associated with exercise or a coughing fit. You are not going to see “tonic-clonic” limb motions during syncope; you are more likely to see the dog go limp. The dog is unlikely to drool or chew on its face. Recovery is a lot faster.

Jack’s seizures are extremely mild; he does not even lose consciousness. (A vet once told me that it can be hard to tell if dogs lose consciousness during a seizure and that I was probably mistaken. I replied that I had once attempted to take Jack’s favorite toy away during one of these episodes, and that he had managed to take it back, even with all his muscles contracted so that he had real trouble moving.) But they are clearly seizures.

So if your dog has a collapsing episode, now you know what to pay attention to so that you can help your vet figure out what’s going on.

What I did today: Lottery day! I got most of what I wanted, but not everything. Now my schedule is set for my core rotations from March 21, 2011 to March 5, 2012. After that I have two months of elective time until graduation (there is also some elective time built in to the preceding year). I have such fun electives planned, you guys! I am really enthusiastic about them. I don’t want to jinx them by reporting them here too early, but I’ll let you know how they go when they happen.

[ETA: A friend comments:


Be careful!  You say, “you know how with humans, they warn you to secure the tongue if you have a chance?”  This is an old wives’ tale.

“Do not try to stop the seizure.  Do not hold or restrain the person, nor put anything in the person’s mouth.  Care for a person who has had a seizure the same way you would for an unconscious person. …  Do not try to place anything between the person’s teeth.  People having seizures rarely bite their tongues or cheeks with enough force to cause significant bleeding.  However, some blood may be present.”

— American National Red Cross, First Aid/CPR/AED for Schools and the Community, 3rd ed., 2006; p. 156.

P.S. Everyone should get basic first aid and CPR training…]