MAGGOTS IN THE FOOT... A GOOD THING?
by Dr. Amy Ehrmentraut

Usually all it takes is the word “maggot” to turn a stomach. The mere site of them causes many to flee in disgust. So how it is possible that these unattractive fly larvae can be the key to recovery for an 1800-pound Percheron gelding named Thunder? 

Thunder was seen at his home for a severe lameness of his left front leg. A thorough examination of his leg and hoof revealed a common culprit of severe lameness in draft horses- a foot abscess. An abscess is an infection that occurs when bacteria gain access to the inner tissues of the foot through defects in the white line. The abscess was treated by establishing drainage, soaking the foot in Epsom salts, poulticing and bandaging. Thunder was sound for a few weeks, but then he became extremely lame on the same leg. At the second visit, it was clear that the foot was again the source of pain. Radiographs of Thunder’s foot showed that the infection had not resolved, and in fact had gained access to the deeper structures of the foot. Deeper infections are more serious and can cause permanent lameness if left untreated.

Thunder was admitted to Great Lakes Equine Wellness Center for treatment of the infection. He was in so much pain, he did not move at all in his stall.  We were very worried about laminitis in his right front foot because he was bearing all of his weight on that limb. He was treated with intravenous antibiotics and underwent anesthesia to allow surgical debridement of the infection. An astounding amount of foul smelling pus drained from the foot! In order for the infection to be eradicated and the tissue to begin healing, all necrotic (dead) tissue must be removed. As you can imagine, extensive tissue removal is not feasible for the horse’s foot because it can cause structural damage and they need to bear weight on the foot. Aha! This is where the maggots come into play. 

Maggot debridement is a non-traumatic, minimally invasive method to remove necrotic tissue from an extensive foot infection¹. Newly hatched maggots have a voracious appetite and will happily eat away necrotic tissue.  Not only do they debride the wound, they also stimulate healing by encouraging new vessel growth. Maggot therapy had been used extensively at Rood and Riddle Equine Hospital’s Podiatry Center (Lexington, KY) in a variety of wounds and has been shown to decrease healing time significantly. Medical grade sterile maggots (500 recently hatched darlings in sterile cotton gauze) are available for overnight shipment from California. The maggot-imbedded gauze is placed directly into the foot and a light bandage is placed over the top. The foot is protected by a custom-made treatment plate that attaches to the specially-designed shoe. The plate can be easily unscrewed for inspection of the wound, maggot growth and bandage changes. The maggots stay in the wound for 5-7 days at which time they have grown significantly and no longer have an appetite. Thunder’s maggots had finished dining in his foot within five days, and by that time he was walking so well!  He was sent home with the treatment plate in place to protect his foot until the defect heals. We are happy to report that Thunder is doing well and enjoying being back at home.

¹ Morrison S.E.  How to Use Sterile Maggot Debridement Therapy for Foot Infections of the Horse   AAEP Proceedings/Vol. 51/2005

 

TUCKER’S SURVIVAL STORY
by Dr. Amy Ehrmentraut
We all hope our horses never get sick enough to need to stay in the hospital… but sometimes horses require intensive care to survive potentially fatal illness. 

This is the story of Tucker, a palomino gelding pony, who was owned by a very loving twelve-year-old boy. Tucker lived a great life at his stable in northeastern Wisconsin. He shared a paddock with a couple of good horse pals, and loved to jump and compete at shows with his owner. Unfortunately, one cold February day, Tucker became depressed and showed signs of illness. Tucker would not eat his hay or grain. His gums were pale and dry, his heart rate was elevated, and he developed diarrhea. 

Tucker’s owners and referring veterinarian knew that he was very sick and needed to be in a hospital where he could be treated and constantly monitored. I was on duty when the call came to Great Lakes Equine Wellness Center. I remember when Tucker arrived that he walked very slowly and his eyes had no sparkle. He was showing signs of being in endotoxic shock-which means that his body was having a reaction to a certain component of bacteria.  After examining Tucker thoroughly, we immediately we put an intravenous catheter into Tucker’s jugular vein and began to rehydrate him with fluids. To figure out why Tucker was endotoxic we ran bloodwork, sampled his abdominal fluid and urine, ultrasounded his abdomen, passed a nasogastric tube, and performed a rectal examination.  The laboratory tests revealed that Tucker was severely dehydrated, and had electrolyte disturbances. We continued to run fluids into Tucker’s vein…it takes a lot of fluid to rehyrate a horse!  (When horses are not feeling well, they sometimes will not drink water on their own.) 

Tucker had to stay in the isolation barn at GLEWC due to his diarrhea. Sometimes diarrhea in horses is caused by contagious pathogens such as Salmonella bacteria, so we had to keep Tucker separate from other horses to be safe.  We submitted samples of Tucker’s manure to be tested for Salmonella, and his paddock mates were tested as well. 

Overnight, Tucker spiked a fever and his blood work showed that he had very low white blood cells. His diarrhea became worse, and we needed to act fast to keep Tucker alive. In order to keep his head and limbs from swelling with fluid, Tucker needed large volumes of plasma and hetastarch (products that help keep the fluid in Tuckers blood vessels because he had lost most of his natural proteins throuh diarrhea). He was given antibiotics, anti-inflammatory medicine, anti-diarrheal products, and probiotics. His feet were iced and padded with Styrofoam to prevent laminitis, which can occur secondary to diarrhea and endotoxemia in the horse. Tucker was feeling much too sick to eat and he was losing weight.

Over the next six days, Tucker was visited often by his owners and he continued to receive intensive treatments for his condition.  Fortunately, things started to turn around for Tucker. He and his paddock mates tested negative for salmonella, and he did not develop laminitis. He began to have more solid manure and even nibble on hay and grass!  We were overjoyed to see him feeling better.  After one week in the hospital, Tucker was cleared to go home on some medication. He continued to do well and made a full recovery. Tucker is now back to being a horse and doing what he loves. 

 

 

STUCK IN A RAVINE
by Dr. Rob Blohowiak
It was late June of 2005 and I was enjoying a lazy, hot Tuesday afternoon with few appointments. Then the call came in... "Horse Stuck in Ravine". I didn't even know that we had ravines in Wisconsin. As I listened to the information, I started a mental list of the things that I may need – rope, chains, sling, helicopter, tractor, more muscles, shovels, skid steer, crane, someone else to take this call! I gathered 2 technicians and an intern and as many of the things I could imagine needing and headed off, not knowing exactly what to expect at the scene.

Upon arrival, all I could see was a group of people down near the middle of the property. They motioned for me to drive down, and sure enough, there was a large ditch. I got out of the truck to look over the situation and what I saw was absolutely amazing. InstaMary, a 7-year-old Trakehner, was buried in mud and stuck up against this ravine, approximately 12 feet deep. She had gotten out of her pasture with a few other horses, and while running freely, forgot to cross the ditch at the driveway and flipped into it. She was all done fighting at this point and was exhausted and in shock. We immediately began to treat Mary in the hopes of stabilizing her as we made a plan to get her out.

An IV catheter was placed and she was given steroids, non-steroidal anti-inflammatories, antibiotics, hypertonic saline and then fluids. In attempt to deliver faster fluids, we discussed a second catheter, but Mary was holding her own, and we needed to get her out as soon as possible!

Her heart rate was 72, respiration 20, temperature was 101.9. She was sweaty and exhausted. As her fluids ran in, we began to dig for her legs and assess her musculoskeletal system and look for fractures or other open wounds. I decided that the safest way to get her out was to anesthetize her and pull her out by her legs with the tractor.

By this time, we were all in our socks as the mud had sucked off our shoes. We found all of her hooves and they appeared to be attached to the rest of her body! After 20 liters of fluid, I anesthetized Mary with ketamine and valium. We placed hobbles on her legs and attached them to a tow rope and slowly pulled her out with the tractor.

I carried her head so it would not drag along the tall grass and we dragged her to an open field. I probably dragged her further than necessary, but I wanted to ensure that she didn't wake up and fall back into the ravine.

She lay in the field for almost an hour and a half! Finally, she stood up! I examined her while my technician rinsed out her eyes and held her steady. We made our way back to the barn, slowly, and set Mary up with fluids spiked with DMSO and KCl in her stall.

I made daily trips out to the farm over the next 3 days. Mary made a spectacular recovery. No serious injuries except the loss of sight in her right eye. She improved daily and actually was bred in July for a June 2006 foal.

This was no doubt a remarkable event. A tragedy with a wonderful outcome thanks to the quick action of a team of folks dedicated to patient care. It truly is all about the health of the horse.