Equine Exertional Rhabdomyolysis

Or tying up, as it is most commonly referred to. "The most common cause of ER is an imbalance between the animal's diet and his workload, especially when he has a high-grain diet." I think you all know that I have been worried about his feet and wondering if he had the precondition for laminitis, but now I wonder if his right haunch has been the issue the entire time. 

Friday night was not such a good night. Since Wednesday of last week, when I was thrown, I have been working Ashke in the round pen. I haven't worked him hard, but I have worked him until he was warm. It has been walk, trot and canter in both directions, walked down and rinsed off to cool him, then let him graze or wander around until time to go back to his stall. It has gotten really hot here and often Ashke is warm, but not sweaty, when he is in his stall. I have been grooming him regularly, and he has been shedding violently, and we can tell he is itchy. He rubs his chest on his feed bin (leaves nice parallel lines of black on his chest and neck), his neck and shoulders on the ball we have in his stall (especially where his mane lays - leaving huge patches of black skin where he has rubbed off the hair) and his tail dock (leaving a bird's nest of broken hair standing up on the top edge of his tail).

He nickers at me and leans into the brush when I am scrubbing him down. His neck and shoulders have developed some nice muscle.

I also braided his mane with a "french" braid. He has rubbed and pulled it some (it looked so good right after I finished it) but it has served the purpose of getting it off his neck and helping keep him cooler.

He really likes it when his sides and haunches are scratched. We've definitely moved from "I don't really want to be groomed" to "Oh, please, don't stop!"

So, our time line since I was thrown was to groom, saddle and work in the round pen. Friday it was over 90 during our work out, Saturday it was over 90 and Sunday it was over 90. Monday, Ashke was turned out into the pasture since I wasn't able to get to the barn (T has trombone lessons that take priority). He was worked on Tuesday night and the temp was in the mid-80's. Ashke was turned out on Wednesday and then not worked at all on Thursday. During that time he was still being fed the same amount of food as he has been since he moved into the barn. Friday, I groomed (pics above), tacked him up and took him to the round pen.

He started at the walk and then moved to the trot. There didn't seem to be any issues and he seemed to be favoring his front feet less than in the past.

I asked him to move into a canter, which he did willingly, and moved easily around the pen in the clockwise direction. I was pleased, since this is the direction he usually fights me.

Ashke was attentive and responsive, but not shaking his head or arguing with me. He slowed when asked and worked well at the gait I requested. He only did three or so circuits before I asked him to stop. I didn't want to overwork him, since it was so hot and he had had the past couple of days off.

Here you can see he is relaxed and responsive.

Getting him adjusted to turn in the opposite direction.

There didn't seem to be any issues when we started. Ashke was listening well and moving easily. I had him work a couple of rounds at the jog and then asked for the canter. On his first circuit around the ring, he suddenly threw up his head and it seemed like his haunches went out from under him. He was limping heavily immediately after. I had been watching his feet. I thought maybe he had hurt a tendon or overflexed his pasturn. He stopped moving immediately.

I checked all of his legs. There didn't seem to be any swelling or heat in the tendons or joints.

I couldn't find any nicks from where he might have over reached with his hind feet. I couldn't see anything that told me what had happened. I, (stupid me) asked him to move forward. In retrospect, and after doing a bunch of research, it was the worst thing I could have done.

He moved a little stiff at the walk, but was stiffer at the trot. He stopped moving after half a circuit. I was still trying to figure out what was wrong and asked him to move forward again (at this point I was still thinking hock, tendon, pasturn, fetlock).

He did, sweet boy, because I asked, but it was almost immediately obvious that something was really wrong. He was moving in a rocking horse movement and not using his right hind leg. He stopped immediately when I asked.

This time I was able to decipher the problem. Ashke had a charley horse (what I would call it if it happened to me) in his right haunch. It was about the size of my fist. I checked his left haunch to make sure it wasn't "normal", which it wasn't. I tried rubbing it, but it was really tight.

Ashke has gotten so good at backing that when I went to untie the reins he felt the pressure on his bit and immediately backed up.

We walked back to the stable and untacked. I walked him out to the wash area and rinsed him off (it was still in the nineties). Then I walked him back to the grooming area and rubbed the knot (which had gone down) with liniment until it was just a slight ridge in his muscle. Ashke went from acting a little uncomfortable when I started, to leaning into the massage before I was finished.

After he was put away, I went home and did some research.

This condition is known as Equine Exertional Rhabdomyolysis and is both hereditary and behavior based. It occurs most frequently in Thoroughbreds, Saddlebreds and Arabians. It is caused by feeding a high grain diet with inconsistent workouts. Basically, because I had been working Ashke regularly and then he had three out of four days off without adjusting his grain ration, and I worked him again, he tied up. The most significant part about this is that in horses the "Charley horse" causes the muscle to die. If the condition worsens the horse can go into renal failure and die because their kidneys can't handle processing the dead muscle.

Talk about complete mental freak out.

According to the University of Minnesota Equine Center:
Sporadic exertional rhabdomyolysis occurs most commonly in horses that are exercised in excess of their level of conditioning. This happens frequently when a training program is accelerated too abruptly, particularly after an idle period of a few days, weeks, or months. Endurance competitions held on hot, humid days may elicit sporadic exertional rhabdomyolysis in susceptible horses because of high body temperatures, loss of fluid and electrolytes in sweat, and depletion of muscle energy stores.

So, in other words, working Ashke after the days off, without reducing his grain ration, in the heat, caused him to tie up. And I am pushing him too fast. J thinks my being thrown was a blessing in disguise, because it has had the effect of making me slow down and reevaluate what I am asking Ashke to do.

The best way to combat the condition is to decrease the amount of carbohydrates the horse gets (cut the grain) and increase the amount of fat and forage in their diet. The diet should also include selenium, potassium and vitamin E. Ashke should be getting the vitamin E from his hay, and we rushed out to buy Amplify (by Purina) for him. The Amplify pushes his fat content up (30%) and decreases the carbohydrates. I talked to the barn manager (actually the owner) about cutting the grain ration to .5 lb per feeding and supplementing with .5 lb of Amplify. After three days, I will have Grace cut the grain out completely and increase the Amplify to #1 per feeding. I also want to talk to her about increasing his forage with additional grass hay instead of the grain. By increasing the forage and fat and decreasing the carbs and sugars and adding the mineral supplements, it should help reduce the conditions that cause sporadic ER. If the option of increasing the forage with the feeding of grass hay isn't available, then I will have them use the beet pulp, since it will increase is forage without increasing sugars.

 Additionally, I am going rest the horse until there is no sign of soreness, and then start the exercise program slowly and consistently. Hand walking is a good start. Going to plan it out over several weeks until we are back where we were two weeks ago. Going to continue grooming and handling and working from the ground. Walk him around the area. Condition slowly. Hope this is a one time occurance and doesn't happen again.