STUNG! by Ken Keckler DVM 3/16/2014
Waiting on the hotdogs and burgers to come off the grill, I had a feeling things were about to get weird. An unexpected thunderstorm had just blustered through, chasing the youth from the community pool to dry places under the shelter house. And then my phone rang. It’s the answering service with an emergency. Attempting to chaperone a church group when I’m on call is never a good idea…
Apparently, an extended Amish family had been enjoying the summer day as well. Somehow the storm had missed their barbeque at a community park, but a natural disaster of another kind had struck. Having tied their horses to trees just inside the woods, they had gone off to prepare the grill and toss a baseball around. As one horse pawed the ground, looking for a tasty morsel, he disturbed a nest of very angry ground hornets.
He was found pretty quickly; his face still engulfed by furious insects, covering his muzzle and up inside his nostrils. Hornet stings release pheromones, drawing the other members of the hive to the victim. Wasps can sting multiple times, injecting venom with every attack. Rapidly their poison took effect.
When I arrived, the Standardbred gelding (let’s call him “Buzz”) was standing, his extremely lumpy, fluid filled head hanging down, eyes swollen mostly shut, and his body gently swaying. The men had somehow chased the hornets from his face, but they were afraid to do much with him. Although he looked completely out of touch with reality, when they touched his face, he exploded with furious striking. Then he’d sink back to a severe depression. Aggressively reaching back toward his right side every few minutes, he looked like a sleepy, puffy horse reacting to painful abdominal spasms. In his delirium, I think he didn’t know how to react to the discomfort.
A quick physical exam showed a low body temperature and an extremely low heart rate. Normal heart rate in a resting horse should be “less than 40 beats per minute”. That’s my typical answer when asked. However, rarely do I find rates less than 28. This poor equine had a heart rate of 18 per minute. That’s astonishingly low. Frighteningly low. Like it may want to stop, low. Cautiously, since he was responding with violent striking, I gently elevated the thickened upper lip and revealed gums that were chalky: no hint of pink. The hundreds of sting swellings had coalesced, leaving his face distorted and misshapen. Swollen inside and out, his nostrils fluttered raggedly as he struggled to breathe. Multiple welts were raised on his neck and body as well. Shock had obviously set in, and the body was sending fluid to the injury sites in an attempt to “flush” the poison away. The vast quantity of toxin was likely directly responsible for the diminished heart rate. Time was of the essence in treatment.
Quickly I drew up coricosteroid injections: a whopping dose of Solu-delta-cortef (very fast acting) and dexamethasone. An antihistamine injection was given. Bute and Banamine (non-steroidal anti-inflammatories) were also given IV. Placing an IV catheter, I then began to run bags of saline to increase his body’s fluid volume. DMSO was added to some of the fluids, as it is a good anti-inflammatory as well. Over the next thirty minutes, Buzz began to look slightly more alert, but still very unsteady on his feet, wavering with any movement.
Since this horse had pulled a buggy to the park, the Amish gentlemen had to find someone with a horse trailer to retrieve him and carry him home. When a ride was secured, I left them with plans to see Buzz the next day.
Buzz made it home all right, and remained depressed, sluggish and inappetant through the night. When I arrived the next afternoon, Buzz had eaten a little, but was still despondent, and his face still somewhat swollen. In addition, he was still occasionally reaching his head back to touch his right side, and intermittently would have a spastic head shaking reaction. His bottom lip would flop loosely, and then his lips would twitch and ripple as his muscles spasmed. (See the video here). His heart rate had come back to normal, and he was no longer aggressively throwing his front legs at anyone who touched him. He was getting better, but I had no way to know how long he would be uncomfortable, or if he would be left with residual problems.
Continuing the anti-inflammatories for a few more days, Buzz’s strange head jerking, muzzle twitching gradually went away. I can only assume that the toxins left by the hundreds of hornet stings caused irritation to nerves promoting this odd, involuntary reaction.
Luckily, Buzz survived this episode, but it was touch and go at the beginning. An aggressive attack by hornets is frightening, and unfortunately, there’s not much you can do once it begins. The mob mentality and stimulation/attraction of the rest of the hive can cause large amounts of toxin to be “injected” into the victim. Best advice is to stay on the trails through the woods, and watch for any obvious insect activity, as it could indicate a nest. In the event of enough stings that the horse becomes depressed, call for help as soon as possible, as the condition may worsen. Hopefully there won’t “bee” any more attacks in the coming months…