Links post

• Science Online 2011 is this weekend and I really wish I could be there. Luckily I can attend virtually.
• A post from this blog will be included in the 2010 Open Laboratory!

Would you cut off your dog’s leg?

Yesterday we had a lecture on osteosarcoma, a cancer of the bone. Osteosarcoma is not a good cancer, guys. It is liable to occur in younger dogs, it is extremely painful, and no matter what you do, it is almost certainly going to come back.

But there are things you can do to reduce or remove your dog’s pain, and to get more time with him (as much as a few years, sometimes). Because this tumor is so painful and aggressive, you really want to cut it out. But that is awfully hard to do as it usually appears in the long bones of the leg. So the surgical answer is almost always amputation of the limb. Alternatively, you could just do a course of chemotherapy to knock it back for a while, and deal with the pain using analgesics.

Who would want to cut off their dog’s leg? Chemo + painkillers is the obvious answer, right? And yet it is not. Chemo is much less effective than surgery, so you will have less time with your dog if you choose this option. And oral painkillers just don’t seem to help very much with this tumor, so your dog’s quality of life is likely to be pretty poor during that remaining time.

Amputation is actually a pretty good option. It just removes all the pain. And dogs do great with three legs. Dr. Glace said, with his typical deadpan delivery, “Some people say it’s like they don’t know they have lost a leg. That’s stupid. Dogs aren’t that dumb. They know they’ve lost a leg.” But they don’t care about it the way we do. They relearn to walk and then they do fine. Three legs is still one more than most of you have. I have seen three-legged dogs (“tripods”) in a flat-out run. No problems.

Dr. Glace says he won’t amputate a leg from one of the truly giant-size breeds (Great Pyrenees, Saint Bernard, Newfoundland), but noted that he amputated a leg from a mastiff (those are very big dogs!) a few months ago and the dog did extremely well. To test if the dog would manage successfully on only three legs, he employed the high tech test of picking up one leg and making the dog walk around the room on the remaining ones. Success.

The biggest problem, Dr. Glace says, is that owners really don’t want to amputate their dog’s leg. There is something viscerally upsetting about it. It’s one of those situations where your instincts might lead you wrong, leaving your dog with less time to live and more pain. Personally, I can report that I saw a tripod running an agility course, and she did just fine, even over the jumps. I direct you to this blog post about Serena, an agility tripod. Go tripods!

Everything I touch is missing a uterus, or, What is a freemartin?

Bovine procedures lab today and yesterday! (Why do they schedule these outdoor labs for the middle of the winter? Thank god for my insulated coveralls, three shirts + sweatshirt, and leggings.)

Bovine procedures lab involves actually doing lots of procedures on year-old Holstein heifers. These heifers (young cows who have not yet calved) are owned by an area farmer and lent to my school for a year or so, during which time the farmer pays for their upkeep and we get to do procedures on them. There are lots of rules about how many procedures can be done on an individual cow per day, to make sure they don’t have to put up with lots of invasive procedures (but even so my group frequently took breaks to let our heifer rest). The procedures included things like insertion of IV catheters, insertion of a stomach tube, haltering, tying up a leg, and so on. I do feel a little uncomfortable about the animal use in this lab, but I recognize the practical difficulties of spreading the procedures out over more cows. Also, I figure that once I am an all-powerful school administrator, I can find a creative solution to the problem.

These are super friendly heifers! I was surprised. One of them followed us around and solicited neck rubs. They are still pretty small, weighing in at around 700 lbs (which nevertheless felt like a lot when ours stepped on my foot).

Scratch my neck, bitches!

Late in the second day we got ready to do our vaginal exam. LPK lubed up the speculum but good and started to work it in. No go. It just wouldn’t go very deep. We called over Dr. Cole, who tried it himself, failed, said hmmm, put on a long glove (up to the shoulder), lubed it up, and did a rectal palpation. You do a rectal palpation as another method of evaluating the reproductive organs; you want to feel the cervix, uterus, and ovaries. This can tell you what stage of her cycle the cow is in (did she ovulate? is she perhaps even knocked up?). He took his arm out, looked at me, and said, “Give it a shot and tell me what you feel.”

Ah, my first bovine rectal palpation. On with the super long glove and lube. Brrr — you have to take off your insulated coverall top to do this and roll up your sleeves so your arm is bare to the shoulder; luckily it is warm inside the cow.

I got in and felt around. Lots of poop! (You have to sort of shovel that out at first. Dr. Cole had gotten most of it but I cleared out a little more. It is not cool to mistake a handful of poop for an organ.) I felt a cervix, but it was awfully tiny. And... nothing else. No uterus, no ovaries. This didn’t necessarily mean a lot, since I don’t really know what I am doing, but when I reported my findings to Dr. Cole, he replied, “That’s exactly right. She’s a freemartin.”

What’s a freemartin? This is a fairly rare condition. It happens when there are twin calves, one male and one female. The female is genetically normal, but as she is awash in a sea of testosterone in utero, she develops abnormally, into an intersex animal. I don’t know if all freemartins develop exactly the same way, but this one was typical in her lack of uterus and ovaries. Her vagina was a short, blind sac, which is why we could not get the speculum in.

It is freakish, I tell you. My first spay dog had no uterus, and now my first bovine rectal palpation doesn’t either. What are the chances? Am I cursed?

Living with a shy dog

I adopted a shy dog two days ago. You can see how tense she is in my house in the first picture. I’m including a second picture to prove that she isn’t like that all the time! (Also: doesn’t she look just like a domesticated fox that was dipped in yellow paint?)

 

This is Jenny. Jenny spent her first ten months on the same property on which she was born. She got to live with other dogs and knows a lot about how to interact with them. However, she doesn’t know a whole lot about interacting with humans, and we are pretty scary to her. She also doesn’t have much experience with the world in general. She’s been with me for about two days now and is just getting to the point where she’s willing to eat while I am in the room.

When Jenny is really alarmed by something I do, she pees. This is known as submissive urination; she’s sending a social cue to say “I’m harmless; please don’t eat me!” I can mostly avoid doing things to her that are this scary, but sometimes I do have to put a leash on her to get her outside, and then she is liable to pee. I’m taking various management measures to preserve my furniture, but this afternoon Jenny started being interested in eating treats that I tossed her, so I saw the opportunity to engage in some counter-conditioning with her.

The problem

When I approach Jenny purposefully and pull out a leash, she is scared, and pees.

Conditioning a new emotional response

The goal is for Jenny to see the cue (my purposeful approach, leash in hand) and feel good about it instead of scared. The solution is to break the scary cue down into cues that are smaller and less scary, and help her work through each of those with the help of something positive (treats).

It’s not just one thing that tells Jenny that I am about to grope around for the clip on her harness and attach a leash. It is my approach; the way I look straight at her; the purposeful way I walk towards her; the display of the leash in my hand. Each of these things is really a separate cue, and each should be worked on individually.

Working with Jenny

Jenny was on the couch downstairs. I wanted to be able to walk down the stairs and approach her with the leash. First, I tried it without the leash. I walked down the stairs more slowly than usual, stopped farther from her than usual, and avoided eye contact. I tossed her a treat. She thought about it, then ate it.

I repeated exactly the same sequence of events. This time, she ate the treat  promptly, suggesting that she was comfortable with the sequence.

I tried it again, and this time walked a little bit closer to her. That was okay. I tried again, making eye contact and walking faster. This scared her; she wriggled away from me on the couch. I stopped and backed up, looked away, threw a treat. She waited for me to go upstairs before she ate it. I tried again, this time backing up to something that she had previously accepted — stopping a ways from the couch and not making eye contact. This was still successful (she ate the treat without appearing alarmed). Phew. I started progressing again, but more slowly.

Counter-conditioning is extremely simple, but it can be really hard to implement properly in practice. We tend to get impatient. Why do we have to take such small steps? Can’t we go faster? Unfortunately, if the protocol you’re trying isn’t working, the answer is almost always to break the sequence you’re conditioning into smaller events and add new challenges more slowly (or maybe give better rewards; I could explore different types of treats to see if there is something more exciting for Jenny). But that is really hard for most humans. That’s the challenge of counter-conditioning and why it is often best to do it with the help of an experienced trainer until you get the hang of it.

Hopefully I will be able to teach Jenny over the next few days that the leash isn’t scary. For tonight, I stopped while I was ahead and didn’t push things too far.

Learning how to tell if a dog is in pain

I completed my second spay lab, in which third year veterinary students spay a dog from a shelter or low income family. Unlike my first spay lab dog, this dog had a uterus! (In fact, she was in heat, so I was pretty confident ahead of time that she would. My boyfriend: “How can you tell she’s in heat?” Me: “She has a vulva the size of Texas.”)

Linnea was an extremely nice dog who was extremely unhappy about being in the spay clinic for two days. She pawed at the cage door so much the first night that we gave her a sedative to take the edge off. Her spay went well, but when it is only your second spay, you still don’t trust that you haven’t done something stupid and that the dog isn’t in real trouble. (One of my classmates reports that she actually went to visit her spay patient at the shelter several days later, to make sure she was okay. My classmate pretended to be interested in adopting the dog in order to get time alone with her, so she could look at her spay scar.) So when Linnea started making a lot of noise the evening after her surgery, I was very anxious.

First I asked the anesthesia technician if he thought she needed more pain medication. He pointed out that she had been a very vocal dog before the surgery, and was almost certainly just stressed now, especially due to the after- effects of all the other medications we had given her making her feel less than mentally competent. My spay partner Lily and I looked at Linnea anxiously after letting her out to pee. Lily said: “Well, she seems to be standing sort of hunched over.” I said: “Yes, I really would like to give her more meds!”

The veterinary intern came by around that time, for evening rounds, and I explained how Linnea looked painful to us. (It is veterinary jargon to say an animal is “painful” rather than “in pain,” and I have seen this usage really annoy non-veterinarians. I am not sure why we say it that way, but that is how it is.) Now, Lily and I had recently completed our anesthesia course, which had several lectures about how to tell if dogs are painful, but of course in the heat of the moment we had completely blanked on this. The veterinary intern simply put her hand gently but firmly on Linnea’s spay incision. Linnea didn’t even blink; she didn’t turn her head or growl or flinch. The intern said confidently, “She doesn’t appear to be painful,” and this time, I believed it.

Dogs do sometimes vocalize when they are in pain, but it is not the best way to tell. Many dogs in pain do not vocalize, and there are tricks of body language that you can use to tell what is going on in their heads. We had some fascinating lectures on that, unfortunately far too image-filled for me to reproduce here.

I learned from this experience. When you’re not sure how to proceed, take a deep breath and think back to what you were taught in class. We actually have received a very good foundation for clinical work, but it can be really hard in the moment to pull the appropriate fact out of the mass of information packed into our brains after three years of veterinary school!

How to learn how to do ... lots of procedures

Recently I had my Small Animal Procedures lab, in which my classmates and I learned how to perform dentistry, take skin biopsy samples, do trans-tracheal aspirates, take bone marrow biopsies, and a raft of other procedures. I wouldn’t feel comfortable doing any of these procedures unsupervised yet, but I did get to actually do them with my own hands rather than just pick “do a trans-tracheal aspirate” as a multiple-choice answer on a test.

In the past I have described learning on shelter animals that need low-cost procedures, or ex-research dogs that are living at the school until they can be rehomed. This lab used the bodies of animals who had been euthanized at our hospital, and whose owners had agreed to allow us to use them. It is always somewhat disturbing to spend several hours with a dead dog, but this is the one use of animals for teaching that I am one hundred percent happy about. Learning on live animals is never perfect, although my school does its best to find constructive ways to obtain animals for us to use. We had to do so many procedures for this lab, and such invasive ones, that it made sense to use cadavers.

The trans-tracheal aspirate is a particularly interesting procedure to do. The idea is that an animal has some sort of infection in its lungs, and you want to know exactly what. So you thread a catheter into its trachea and down into its small lower airways, pump some fluid in, suck the fluid back out, and test it for bacteria. Okay, but if you thread that catheter in through the mouth, it is going to be contaminated with all kinds of bacteria that you’re not actually interested in, right? So how do you get the catheter in to the trachea without getting mouth bugs all over it?

You stick a big needle in through the outside of the dog’s throat directly in to the trachea, and thread the catheter through that. This means when you stick the needle in, you have to know when its point is inside of the trachea. You can’t see where the point of the needle is, obviously, and that’s why it’s a learning experience. This procedure was particularly hard for me. I kept sticking the needle in, being convinced it was in the right place because I felt a “pop” as it passed into the trachea, and then not being able to thread the catheter in. A tech told me patiently, “if the catheter won’t thread, that means it’s not in the trachea.” Goddammit. I tried again. And again. And eventually it worked.

This was a really enjoyable lab. Four of us worked on one dog cadaver. There were also a few cat cadavers for multiple groups to share. It felt good to do some of the procedures we had learned about, but scary to imagine doing them on living patients in the near future.

Veterinary fact of the day: feeding guinea pigs

We are having some of the final lectures for our zoo medicine course, and today’s was about pet rodents — guinea pigs, rats, chinchillas, mice, and gerbils. Coincidentally, we also covered many of the same animals in our lecture on laboratory animals, earlier in the day. Both lecturers emphasized the fact that guinea pigs require vitamin C supplementation. Unlike most other species, they can’t make it themselves, and if you don’t provide it in their diet, they will get scurvy. Some owners, we were told, are so dedicated in their C supplementation that they actually provide too much, which can also be problematic.

A lot of our zoo medicine course has covered good feeding and management practices. It seems like a large part of practicing on exotic pets (a term which includes things you might not think of as exotic, like rats and rabbits) includes making sure that people are managing their pets right. Basic husbandry is something that is rarely covered in our small animal medicine course, which is about cats and dogs. We assume that people know how to feed them and what temperatures to maintain them at. I think the really good small animal veterinarians, though, are asking their clients about all kinds of management issues and offering advice, not just waiting for a problem to crop up. Maybe vet school should prepare us more for that.

What I’m up to: I am sliding in to the last few weeks of the semester, and don’t have a lot of extra emotional energy for blogging. I miss it and will certainly be writing more when final exams are over. Next week is my second and final spay lab. Wish me luck for getting a dog with a uterus this time!