Case Report- Belgium Draft Nurse Mare with Chronic Progressive Lymphedema

Entry, Case Study
Rachel Ruden, University of Pennsylvania

History:

Lewie presented with gross lesions on both front fetlocks and a small cluster of nodules on the dorsal surface of her left hind pastern. The affected area was clearly painful. Her fetlocks were so swollen with edema it was hard to separate individual lesions, and they readily bled when manipulated. The odor and fluid attracted flies, but upon further examination, the moist spaces were also supporting colony of maggots. Finally, movement was onerous. All of these signs indicated Lewie was suffering from Chronic Progressive Lymphedema (CPL), commonly called Draft Horse Dermatitis. This is a skin disease that causes inflammation of the legs, most commonly affecting the fetlock region. Though the original insult may be a cut, the disease becomes escalated by secondary infections that produce edematous nodules that bleed and fester. Finally, ectoparasites complicate the issue, especially in mares that should not be treated with medications like Frontline while nursing. There is no cure for CPL, and due to its progressive and debilitating nature, this disease will put an early end to a horse’s career, and often, its life.

Assessment:

Though Lewie had a valuable role as a nurse mare for a prominent breeding farm, treatment was definitely not a priority. This was a great opportunity for a budding pre-vet to have some independence in determining the following treatment plan. As an unpaid intern, I was also afforded the opportunity to allocate my time as I saw fit. Naturally, I made CPL my project for the summer. Though I could have done without the maggots, one of the veterinary technicians on staff suggested that the maggots could be beneficial by stripping the lesions of necrotic, infected tissue. Numbers noticeably diminished as the tissue became healthier, so perhaps her outlook was right on target. There is a dearth of literature surrounding CPL and its management, so all I can provide is an anecdote of my personal success in improving the quality of life of this special mare.

Treatment:

For seven weeks, I followed a strict treatment protocol. Every morning I cleansed her legs using an apricot-sulfur shampoo. I then used a manual pump sprayer, like that used for gardening, to saturate the affected region with a dilute sulfur-lime solution followed by a topcoat of fly spray. The pump sprayer was definitely the part when Lewie showed the most resistance. I imagine the solution stung upon application, and the method of application may have also been painful. However, when you are working with a stomping animal that weighs close to a ton with baseball mit-sized hooves, I decided this the safest method. I also trimmed the matted air between lesions to reduce the buildup of dirt and sweat between lesions.

Over the period of five weeks I noticed a drastic improvement in the size and smell of these nodules. They became much less tender to handling, and her mobility improved. Several times Lewie actually cantered away from me when I came to bring her for treatment. There also seemed to be a decrease in the number of individual lesions and associated maggots. The surface was significantly smoother, and after almost two months of treatment, one of the nodules fell off. This disease can never be “cured” so-to-speak, but rigorous maintenance can keep it from becoming debilitating. My personal results even suggest the potential for some reversal.