What it means and why it's important

By Amanda Preston

Have you ever brought your horse in from the pasture, or out of the stall, and he was just not right?  To anyone else who didn’tpreston1 know your horse, he would have seemed fine, but you know your horse, and you know he’s not right. 

Having this relationship and knowing your horse’s personality and habits can be of incredible value, especially if he’s sick or injured.  So let’s talk about your horse’s “baseline” and how it can save his life. 

The “baseline” is your horse’s normal vitals values at rest, pulse, respirations, temperature, weight and physical make up. 

Temperature:  Let’s get right to the business end… (yes, bad pun) There’s only one way to get an accurate reading on a horse and you have to get friendly.  My own recommendation is the old-fashioned analog thermometers.  Yes, you can use the digitals but through my own experience, they are not as sensitive as the analogues, and you’d never have to worry about batteries dying.  In order to get an accurate rectal temperature, you need to make sure the thermometer is in as far as it will go (a string on the end is very practical) and make sure it’s resting against the colon wall.  It needs to stay in for 2.5 – 3 minutes, 3 minutes being ideal for an accurate reading.  I would recommend having a pair of rubber gloves and some water-based lubricant handy when you’re doing this, keep things “pleasant” on all ends. Horses normally run from 99.5 – 101.5 degrees F, 36.6 – 38.3 degrees C.

Respirations: Easy enough and straight forward right?  Well, not always.  Certainly it’s more of a challenge if your horse is searching you for cookies, anxiously looking for his BFF or practising for Arab halter classes.  Ideally you should check respirations at rest (when your horse is nice and relaxed) by watching behind his ribs.  Watch the rise and fall for 30 second and just multiply by 2.  There should be no noises, nasal discharge and no straining or effort to breathe.  Normal respirations are 12 – 20/minute. 

Weight:  No problem!  Pick up the horse, stand on your bathroom scale, read, put the horse down, stand on the scale withoutpreston heart girth your horse and subtract the difference.  Right on!  Ah if only it were that easy.  You could try taking your trailer to the dump and weighing the rig with and without the horse inside, but I’ve got a much easier technique for you.  Sure weight tapes work, and they’re usually accurate to within 10%, but here’s an old cowboy formula that is accurate to within 4%.  Heart girth x heart girth x length divide by 330.  If your horse is quite leggy and lean, like a youngster, then divide by 305. 
Heart girth is the widest part of the horse’s barrel, right up over the withers, behind the elbow.  Length is the length of your horse’s body, not the way you measure a blanket.  What you want to find is the length from the point of shoulder to point of buttock, one straight line, no bending or wrapping of the measuring tape. This information can be vitally important when dosing dewormer or medications. 

Heart Rate:  Another incredibly important value to know is your horse’s pulse, but man sometimes it’s really had to locate those pulse points.  Here’s one reason why:  Normal heart rate for a horse is between 30 – 40 bpm.  That’s only one beat every 2 seconds! 
I run through 3 different locations on horses when land marking for pulse points. The first is the posterolateral (that’s the back outside) corner of the pastern.  If you have access to a laminitic horse, you will be able to find pulse points without issue since they have increased blood flow in their extremities. 
The second landmark is between the cheeks of the jaw. Please have your vet or first-aid instructor help you find this landmark.  It’s further forward and higher up than I thought it was.  Some horses are very hard to locate, some are very easy. 
The third is the femoral artery.  I like this one best, but I’m not comfortable with just any horse to check it on.  The femoral artery runs on the inside of the thigh on the inside, the equivalent of the groin region.  Feel around on the leg for a cord about the thickness of your pinky finger.  Just relax and count. 

These vitals are very easy to take when you do your routine deworming or once every month or so for good measure. 

Now, why are they important?  Here’s a scenario: Your 19-year-young gelding decided (for whatever reason) to lay down in the trees and gets cast.  You and your buddies find him in the morning while enjoying your Timmies and get him unstuck and on his feet.  You’re not sure how long he’s been down for, but you suspect colic.  You check your horse’s tummy sounds and don’t hear much.  You check him for skin turgor (tenting) and capillary refill on the gums.  He is dehydrated.  He is off his feed and looks uncomfortable.  Before you bring out the mineral oil and start walking, you want to get your vitals and let your vet know what’s happening.  He’s going to ask you…. you guessed it!  What’s his temperature?  He’s reading 100.5 degrees F.  Well, that’s nothing to worry about, right?  Not necessarily, his baseline temp may be 101.3.  He goes down to roll, you put him in the trailer (what’s the first thing horses will do in the trailer? POOP!) but he does not move his bowels.  15 minutes has elapsed so you check his temperature again.  100 degrees, still within normal range, but if we know his baseline, we may know he’s hypothermic and going into shock already.  Yes, this was a real-life experience that I was participant to.  Very sadly this horse did not make it through his colic but we were able to give the vets very specific information regarding his vitals and the times they were taken.  The vets were able to be set up for the horse before he stepped foot in the clinic and start his treatment faster. 

In my travels as a first-aid instructor, I met a lady who had a horse who was drooling one day.  He was still eating, although he would chew off to the side of his mouth.  She didn’t know to check his vitals but called her vet out for him regardless.  They sedated the horse and opened up his mouth and found a 4 inch bit of wire impaled into his tongue!  He recovered just perfectly but that owner knew that behavior was unusual for her horse. 

Don’t underestimate knowing your horse.  Truly it can save his life!

Amanda Preston operates Shimmer-E Equestrian and is a certified equine first-aid instructor with Equi-Health Canada. She travels throughout Alberta teaching first-aid and trick-horse clinics (usually separately) and enjoys meeting new people, horses and learns as much as she teaches.