One of the most unusual yet incredibly interesting tools I use in my work with foundered horses is Maggot Debridement Therapy (MDT).
In 2005 I attended the Laminitis Conference in West Palm Beach, Florida and listened to Dr. Scott Morrison present on using Maggot Debridement Therapy to treat infections in the horse's foot. This is an article published by Fran Jurga in Hoofcare and Lameness Magazine Issue No. 78 on Dr. Morrison's work:
One of the most devastating complications of laminitis is hoof infection. Due to the amount of necrotic tissue in the foot and damage to the circulation, a horse with laminitis can develop a foot infection which can be very hard to fight off. Infections like those pictured here can be very common:
There are many different approaches to working on resolving these infections between the farrier and veterinarian: drawing poultices and soaks, antibiotics, debridement of infected tissue, anti-microbial hoof soaks, and topical cleaning materials are commonly used with varying degree of success.
In 2005 when I listened to Dr. Morrison I was dealing with a chronically foundered horse who had a hoof infection that was difficult for me and the veterinarian to resolve. I was intrigued by the idea of using maggots to debride the infected tissue. I spoke with my veterinarian who was in favor of the idea and contacted Dr. Morrison who walked me through the application process. I quickly realized I was going to need to be creative in my application as typical methods involved a metal shoe with a hospital plate which was not desirable in this case. Working with Dr. Morrison and the lab who cultivates the maggots for medical use, Monarch Labs in Irvine CA, I figured out a protocol that would work without a hospital plate. Here are the supplies needed:
- Maggots from Monarch Labs: prescription from a veterinarian required
- Creature Comforts Chiffon Gauze: also from Monarch Labs, contains the maggots in the area, yet is breathable for the maggots
- Elasticon: to keep the Chiffon Gauze in place
- Composite bar shoe or other protection: designed to keep the horse from crushing the maggots when the foot is weight bearing
- Disposable Diaper: to absorb the maggots exudate so they don't drown
- Vet Wrap: to hold diaper in place
- Duct Tape or Hoof Boot: to protect the bandage
Since 2005 I have used Maggot Debridement Therapy, in conjunction with other supportive therapies and veterinarian guidance, on over 100 hooves with tremendous success in resolving chronic hoof infection in the laminitic horse. In 2011 I won an award for a Scientific Poster I presented at the Laminitis Conference on my method of application, which is inexpensive and can be applied at home by the farrier, veterinarian or even horse owner successfully. My message was that MDT can be affordable, easy, and should be more accessible for treatment of chronic infections for the laminitic horse.
The idea of maggots eating away at the foot may really turn you off. If so, I understand. Keep in mind these maggots are specifically designed to only eat necrotic tissue, not live healthy tissue. They are also sterile, so they will not reproduce. Their saliva and exudate further break down infection, and the maggots stimulate new cells to grow and keritanize, which is critical to healing. They are amazing critters! I admit I have a bit of a love affair with them, at least when intentionally put in the foot for therapeutic purpose.
Here are some examples of horses I've helped using MDT and what to expect:
This QH mare was chronically foundered for years with a horrible foot infection. The current vet and farrier felt she should be euthanized, however the idea of Maggot Debridement Therapy gave us another tool to give her a chance. Here is her foot when I first met her:
With any therapy, success is largely dependent on managing the multitude of factors impacting the given situation. In this horse's case, we had a lot of room for improvement with the trim alone. We trimmed her to the protocols I've mentioned in pervious blogs like this one here, and also worked with the veterinarian to rule out any metabolic or other underlying issues.
Just trimming alone wasn't enough to resolve the infection, so MDT was applied:
After two courses of MDT she was much more comfortable and the infection had resolved:
Her foot after corrective trimming and MDT:
Here is another example of a badly foundered horse with a chronic foot infection. I typically see quick resolution of the infection and growth of new keritanized sole using MDT:
Recently I've been privileged to help a wonderful horse named Maeve, a 28-year-old TB mare who developed laminitis with sinking of P3 in the hoof capsule on her left front foot. When I first saw her she had active drainage at the coronary band, and from her sole:
After initial evaluation and discussion with the veterinarian and owner, the coronary band pinching was relieved with grooving, and the sole was carefully debrided to allow access for MDT. Initial debridement for MDT, first photo, and further debridement for second course of MDT, second photo:
Maggots mature around 3-7 days and grow to approximately 1cm in size. They start with a black dot on their head, and grow a brown stripe down their back. When the stripe reaches their tail they are mature. Their instincts cue them to seek ground to turn into flies and they will stop eating, so can be removed.
Maeve's sole after the second course of MDT, looking much more keritanized and infected material much more localized:
Everything is drying up and keritanizing well. This progress was made in about 2 weeks time. We just applied one more course of MDT to help resolve the last bit of infection:
I feel very fortunate to have a tool like Maggot Debridement Therapy to help resolve chronic foot infections for laminitic horses. I hope you will consider using MDT when dealing with a horse with a chronic hoof infection, or bring the idea up to your farrier or veterinarian if your own horse is dealing with this issue!
If you would like more information on my method of application, or a copy of the Scientific Poster "Easy Application of Maggot Debridement Therapy To Treat Chronic Abscesses in Laminitic Horses" please contact me.