Chance has always been fighting “scratches” on his back legs.  Frustrating, painful, and never seem to completely go away.  Could scratches have caused this?  My thoughts- scratches allowed bacteria to enter the leg, the infection settled on the DDFT sheath and caused the current flare up.  Below is some research I found on possible conditions due to scratches that caused similar symptoms Chance had been experiencing.

CHRONIC PROGRESSIVE LYMPHEDEMA (CPL) due to Scratches

A condition characterized by progressive swelling, hyperkeratosis and fibrosis of distal limbs has been characterized in Shires, Clydesdales and Belgian Draft horses and unfortunately affects numerous horses within these breeds. The disease has also been recognized in Gipsy Vanners; however, only a few horses have been evaluated at this point of time. This chronic progressive disease starts at an early age, progresses throughout the life of the horse and often ends in disfigurement and disability of the legs, which inevitably leads to the horse’s premature death. The pathologic changes and clinical signs closely resemble a condition known in humans as chronic lymphedema or elephantiasis nostras verrucosa. The condition has therefore been referred to as chronic progressive lymphedema (CPL). The lower leg swelling is caused by abnormal functioning of the lymphatic system in the skin, which results in chronic lymphedema (swelling), fibrosis, decreased perfusion, a compromised immune system and subsequent secondary infections of the skin.

The clinical signs of this disease are highly variable. It is often first addressed as a marked and “therapy-resistant” pastern dermatitis (scratches). The earliest lesions, however, are characterized by skin thickening, slight crusting and possible skin folds in the pastern area. While readily palpable, these early lesions are often not appreciated visually as the heavy feathering in these breeds covers these areas. Upon clipping of the lower legs, it becomes obvious that the lesions are far more extensive than expected. Secondary infections develop very easily in these horse’s legs and usually consist of chorioptic mange and/or bacterial infections. Pigmented and non-pigmented skin of the lower legs are affected. Appropriate treatment of the infections (pastern dermatitis) is not successful as underlying poor perfusion, lymphedema and hyperkeratosis in association with the heavy feathering present perfect conditions for repetitive infections with both chorioptic mange as well as bacterial infections. Recurrent infections and inflammation will enhance the lymphedema and hence, the condition becomes more chronic. As a result, the lower leg enlargement becomes permanent and the swelling firm on palpation. More thick skin folds and large, poorly defined, firm nodules develop. The nodules may become quite large and often are described as “golf ball” or even “baseball” in size. Both skin folds and nodules first develop in the back of the pastern area. With progression, they may extend and encircle the entire lower leg. The nodules become a mechanical problem because they interfere with free movement and frequently are injured during exercise. This disease often progresses to include massive secondary infections that produce copious amounts of foul-smelling exudates, generalized illness, debilitation and even death.

TREATMENT/MANAGEMENT

Please keep in mind that none of these treatments listed below will “heal” chronic progressive lymphedema (CPL). However, a rigorous management following our suggestions below will assist you to slow down the process and even make some of the nodular lesions disappear. Your horse will need this management the rest of its life.

• Clipping of the feathers
Long and dense feathering makes management of lymphedema more difficult. We highly recommend clipping the feathers and keep them short, if horses are not presented at shows. If you have a show horse, we still recommend to clip the feathers to initiate a rigorous treatment. As the skin condition improves and the edema is reducing – you may have a better chance to keep the horse’s legs in better condition by. careful repetitive treatment, while the feathering is growing back. The feathers are usually back to their original length in about 10-12 months.

• Treatment of skin infections
Progression of lymphedema is also associated with deposition of fibrous tissue and formation of fibrotic nodules.. As a result, these horses have a poor blood circulation and immune response in the skin of their legs. They tend to built up a thick keratin layer. The long feathering further occludes the skin surface, which then remains humid. These factors provide the perfect culture environment for infectious pathogens. This explains why horses with CPL constantly battle recurrent infections with mites (Chorioptic mange) and bacterial infections (Staphylococcus, Dermatophilus).

Horses with CPL should consistently be treated against reinfestation of mites and bacteria:

Topical treatments:

• Careful washing, cleaning and drying of the legs on a routine basis is essential. Horses with long feathering may require blow-drying of their legs. We recommend using a product manufactured by HydroSurge Inc. ( http://www.hydrosurge.com ) called Apricot Sulfur Skin Treatment Shampoo.

• Frontline spray to treat chorioptic mange (do not use Frontline on pregnant and nursing mares)

• The best and most economical topical treatment is to find a source of wettable sulfur powder (“flowers of sulfur”). This can usually be found through a vineyard supply or at your local nursery (certain “rose dust” preparations). Mix this powder with mineral oil in to form a creamy paste. You can mix a moderate amount in a plastic lidded container or glass jar so that you have enough to last 2-4 weeks at a time. Apply this mixture to the ulcerated and/or affected areas of skin daily. This preparation is the best and most economical topical treatment we have found. You can use it indefinitely. Sulfur is safe to use in pregnant mares.

Systemic antiparasitic treatment: Frequent ivermectine treatment will also assist to keep the mites away.

• Exercise
Regular exercise is crucial. It will increase the circulation and the lymph drainage.

• Manual Lymph-drainage
Manual lymph-drainage is regularly used in humans with lymphedema as long as there is no inflammation present within the tissue. MLD has been successfully used in horses with more acute lymphedema, but has not been established yet in horses with progressed CPL. A massaging coldwater stream may assist a massage. It is important to dry the skin before applying anything else after massage and rinsing. If the feathers were not clipped this may take a long time and you may have to use a hair dryer. Your horse may become more compliant to this treatment as swelling reduces over time

• Bandaging and stockings
We have some limited experience with using special bandages developed for people with lymphedema. For horses, which always move around, “short-stretch” bandages should be used (example: Rosidal ®). Short stretch bandages have been successfully used in three horses with clipped feathering; but bandaging was not as successful on horses with long feathers. Of course it is crucial to have very good padding and keeping the bandages fairly tight. If tolerated, the best results will be achieved by keeping the bandages on 24/7. Of course they need to be redone at least every other day – better every day to control the legs. At first, there will be oozing from the lymphedema through the skin – so the bandages will get wet and have to be changed every day. With the reduction of the edema – this will stop. If the horse is only walked quietly the bandages can be left on for the exercise; very likely the legs have to be rewrapped after the exercise as the swelling will somewhat reduce. For more exercise it may be better to take the bandages off, use working bandages and then switch back to the short–stretch bandages after work. Again make sure the skin is dry when you rewrap.

After the edema has been reduced by using bandages – stockings are used for people to maintain avoid recurrence of lympedema. The use of such stockings in horses are currently under investigation.

It should be noted that horses suffering from CPL often are susceptible to reapeated bouts of “Thrush”. Consequently, thorough and routine foot trimming care is an essential part of the health care management for these horses.