When I signed up for the advanced equine medicine
elective I was expecting just a once a week lecture on something that involves
horses. Maybe I'm biased, but I don't feel like we get a lot of information
that relates to horses, it feels like a lot of small animal. But I'm sure the
small animal lovers feel like we get too much large animal. We definitely get
more equine than exotics, which is why I'm taking two exotic electives, but
I'll save that for another post.
Anyway, I expected the class to be just sitting in
a classroom listening to, I don't know, common equine diseases or nutrition or
something along those lines. Instead I was pleasantly surprised that for the
majority of our class periods, we'll actually be spending them in the teaching
hospital working on horses. And not just watching other people working on
horses like all the intro to clinics classes, but actually working on them.
Finally, some more hands on experience.
Last week it was lameness exams, and this week it
was jugular catheters and urinary bladder catheters. Lameness exams are
extremely routine in equine practice, so even if you're just interested in
horses you probably know what a lameness exam entails. Horses are always going
lame, which just means they're not walking right for one reason or another. And
if you're doing it in Oklahoma, you definitely want to be the one watching the
horse and not the one jogging it in the 100 degree heat. But basically all a
lameness exam entails is jogging the horse and trying to see which leg it's
lame on. There are a couple tricks to help- the horses head will bob up on the
lame leg if it's in the front, and the hip raises on the lame leg in the back.
Sometimes the lameness is subtle, so you can use a flexion test to try and
exacerbate the lameness and make it more obvious. For the flexion test, you
have to isolate each joint and jog the horse after each joint flexion,
otherwise it wouldn't help you narrow down which part of the leg was the
cause of the lameness. If the lameness is coming from the joint you’ve just
flexed, they will be noticeably more lame on the next job.
If the lameness is in the front legs, for the
majority of the time the problem is going to be in the feet. Even if it looks
like it’s coming from somewhere else, say, the shoulder, a lot of the time the
horse is just trying to compensate. If the lameness is in the hind legs, and
lot of the time the problem is in the hock joint (the equivalent of our ankle).
If there is lameness in both the front and the hind limbs, look at which sides
of the body they are on, and that can give you a clue as to which is the
primary lameness and which one is compensatory. If the limbs are lame on the
same side of the body, it’s more likely that the primary lameness is in the
front limb. If the horse is lame on the diagonal, such as the right front and
the left hind, it’s more likely that the primary lameness is in the hind limb.
These don’t hold true for every case, but it’s always a good starting
point. And you just have to train your
eyes to watch the entire horse as it moves to pick up the clues, as not all
lameness are obvious. Most of the time a horse is completely sound while
walking, and you might only pick it up intermittently while jogging/trotting.
That’s pretty standard procedure for horse care. If
you own a horse, at some point it will be lame. So I was pretty excited to do a
urinary bladder and jugular catheter, because that I don’t get to do every day.
Not that I do a lameness exam every day either, but when I was shadowing vets I
did quite a few of them, and I was always the one who got to jog the horse. I
got a lot of exercise those summers.
Although something new that the school was doing that I like
was using a sensor system during the lameness exam. The horse gets a little
head mask with a sensor, a sensor around the ankle, and a sensor on top of the
hips. Then when you jog the horse, it sends the information to a computer that
tells you where the horse is lame after monitoring its movements. I’m not sure
how well the system works, since this was the first time I’ve seen it used. But
I do know one downfall is the sensors can’t tell a pacer from a trotter, which
would reverse your lame leg if it was in the hind limbs, and it can’t tell if
your jogging straight or in a curve, which would affect your lameness score.
But those are pretty minor details.
To insert a urinary bladder catheter you have to
use sterile technique, which means just cleaning off the vulva before sticking
your catheter in. It’s always fun when, right after you’ve finished cleaning,
your horse decides it has to go to the bathroom. Then you get to start all
over. When you’re ready to go, you have to slide the catheter into the vulva
and try to find the little slot leading to the urethra. It feels like a little
knob, and if you poke it your finger should slide right in. I found it was
easiest to stick my middle finger in, and then slide the catheter in under my
finger a bit, before removing the finger and sliding the catheter in more. You
don’t really have to go that deep at all- as opposed to all of the artificial
inseminations I did where I was literally up to my shoulder in the mare,
placing a urinary catheter really only puts you in up to your wrist. That’s a good
check to make sure you’re not going to the wrong place. And then you just keep
sliding the catheter in until urine comes out. You should pay attention to
where you’re holding the other end of the catheter, or you may end up spraying
urine all over your shoes or shooting it at the person standing next to you,
which I almost did by accident.
For the jugular catheter, it’s the same theory as
in dogs and cats except you get a bigger vein to hit. Unfortunately, that vein
likes to fill very slowly in some horses, making it more difficult to see. You
always want to insert the catheter in the jugular groove, where there is muscle
underneath the jugular vein that helps protect the carotid artery. The very
last thing you ever want to do is hit the carotid when you’re aiming for the
jugular.
Horse skin is pretty thick, so you have to use a
good jab to get the needle going in. Then once you get the flash (blood coming
out of your catheter), you slowly advance the plastic, flimsy catheter off of
the metal needle further into the jugular vein. And that’s all there is to it.
Be prepared to get blood all over your hands though when doing this, just
because a horse is pumping a lot of blood, and you don’t have anything to stop
if from coming out when you don’t have anything hooked up to your catheter.
I love getting hands on experiences like this.
First, because it’s always so much more interesting that sitting in a classroom
just listening to the theory on how to do something. But it also stays in your
brain better once you’ve actually done it. Because you could tell me what it
feels like to insert a urinary catheter as many times as you want and how to do
it, but until I can feel that little bump and slot for myself, I’m still going
to struggle the first time I do it. So basically, I feel like I’m just
eliminating a step and getting further ahead by doing so.
I can’t wait to see what else we’ll get the chance
to do this semester.
