Chronic Progressive Lymphedema (CPL) in heavy horses.

Having had a horse myself with CPL I know that it is very frustrating and you can have multiple vets look at your horse and have blood tests or skin scrapes taken, be prescribed many lotions and potions and still not have any improvement. I can say though as well that when I went and saw an equine vet for a completely different problem, he saw that my horse had this disease and I was prescribed an injection which completely removed all clinical signs for the last 5 years of my horses life. A good equine vet is wonderful so going to a equine veterinary clinic for something which needs someone who has specialised I would say is very worth the time, effort, travel and money if you can do it, it may well save you a lot of these things in the long run.

Chronic Progressive Lymphedema is a disease which is in most draft horse breeds as well as some smaller horses and ponies with feather such as the Fell or Highland. It is still relatively unknown about, although it is becoming more openly spoken about and more veterinarians are now learning about the disease and research is being carried out to find treatments. Some people think CPL is a genetic disorder whilst others think it could be started through infection. There is currently no official treatment to heal this disease but it can be managed to varying degrees, some methods I will describe down the page. Effective management of this disease is entirely down to how quickly you catch the problem. The faster you detect a problem the easier it can be kept at bay.

What are the characteristics of CPL?

The clinical signs closely resemble a condition known in humans as chronic lymphedeme or elephantiasis nostra verrucosa. The condition has therefore been referred to as Chronic progressive lymphedema (CPL) in draft horses. It has been seen in almost all draft breeds and Gypsy Vanners and Cobs. The horse will have progressive swelling, Hyperkeratosis and fibrosis of the distal limbs. The lower leg swelling is caused by abnormal functioning of the lymphatic system in the skin. This can cause other symptoms such as a compromised immune system so the horse is open to secondary infections. This can start at an early age but may not show its self till later in life. It can lead to disfigurement and disability which then would lead inevitably to premature death so management is essential to stop it from causing further damage. 

Symptoms can start from apparent mites, leg stomping and 'therapy resistant' pastern dermatitis or "scratches". The earliest sores will have thickened skin, crusting and swollen skin folds in the pastern area. Sometimes there is a clear discharge and the skin will feel oily. They have to be felt on the horse because early lesions will not be visable because of the feathers of the horse. You should feel regularly to check your horse does not have lumps and sores under and around the pastern and take notice if your horse is stomping his rear legs. Secondary infections for example, bacterial (staphylococcus), fungal infections or chorioptic mange, start very easily once these lesions start and treatment of these are usually unsuccessful due to the poor perfusion caused by the CPL. These secondary infections cause more inflammation and the lymphedema worsens and it becomes a cycle hence it is termed as progressive. Over time the swelling worsens and can start to form large folds of skin and nodules which can encircle the leg and then cause mechanical difficulties to walking which interferes with free movement.

Management of CPL

As said before currently there is no way to heal this disease, but research is ongoing and I hope that more money will be put into finding a cure as the numbers of drafts with the disease continues to rise around the world. Management is key with this disease and although at times it can seem like a battle it can be won and your horse can have a good, long, healthy working life.

I MUST SAY THAT MOST OF THESE TREATMENTS ARE NOT LICENSED FOR USE ON HORSES AND SO IT IS VITAL THAT YOU USE A VET AND GET ADVICE AT ALL TIMES WHEN TREATING YOUR HORSE FOR CPL, CHORIOPTIC MANGE, FUNGAL OR BACTERIAL INFECTIONS.

• Injections of dectomax.

Dectomax injection is an injection licensed for the treatment of certain ectoparasites and endoparasites (mites, lice, worms) in sheep and cattle, containing doromectin which is the same family as ivermectin which is in some horse (and dog) wormers. It is used off license to treat leg mites in horses. Often horses need two injections, given 2 - 3 weeks apart. |This is a reasonably effective treatment. It is quite oily and this is the main problem with its injection in horses - it can cause a lump at the injection site, which can be painful and in the worse case could develop into an abscess, though this is very rare. It is less likely to occur when the injection is given subcutaneously, but conversely hoses usually find intramuscular injections less painful. This injection must always be done under veterinary supervision. When my horse had this injection the effect was really rather quick and all lesions went within 2 weeks. We had the injections annually and his legs looked perfect until he died of other causes 5 years later at the age of 22. All horses are different so I do not know how the effect would be for different horses but I have put this first because I wish I had found out about it 10 years earlier than I did. This was the last treatment I tried and I did not have to return to the others afterward other than maintenance of hygiene, washing drying and using sulphur powder washes. 

• Clipping the feathers.

If your horse has lesions already clipping the feathers will make the infections easier to treat and topical lotions, pig oil and sulphur or any of the other applications are able to get to the skin easier. I hated to clip my horses feather because I thought they would protect the leg but in the end it does make treatment far easier and cost effective.

• Manual lymph drainage massage.

Specfic massage strokes are designed to facilitate the movement of the lymph. The lymphatic system is a network and so has the capacity to absorb redirected fluid from the areas that are flooded into areas that are not therefore reducing the swelling. This must be carried out correctly because it is important to massage the lymph in the correct direction. There are people trained to carry out lymph massage. Please contact your vet for more advice.

• Compression bandages.

In humans with the equivalent condition bandages are used to reduce the swelling. It is based on the idea that the lymph fluid is pushed from the area and leaves the system by being urinated out. short stockings made specifically for this job can be helpful, they need to be changed regularly because they will get damp from the discharge from the sores and so to keep the area clean and to stop further infection these must be changed regularly. Bandages can be helpful to reduce the swelling and make treatment easier. A vet can advise you more on how to carry this out. It is important to do this correctly so as to not cause damage. 

• Exercise.

Exercise is very important to move the fluid around the body and encourage the fluid to leave the system. Plenty of exercise and grazing is important.

•  Regular hoof trimming and cleaning.

Many horses with CPL get thrush regularly compared to those without and so regular cleaning and trimming is vital to make sure infection is kept at bay and that the frog is kept working efficiently to keep blood movement in the legs and body as good as it can be.

• Treatments to stop secondary infection and the re-infestation of mites.

Horses with CPL need constant treatment to stop or cure infestations of mites, and or bacteria. To do this the legs must be regularly washed and dried thoroughly. A castile soap (100% olive oil soap) is recommended by many as it is non drying but also oil based and does not contain chemicals if it is a true castile soap. 
When drying the feathers they should be dried using wood flour or sawdust. Not rubbed into the skin which could cause sensitivity with any lesions but gently thrown around the leg from above to dry thoroughly the hair on the legs. 
Pig oil and sulphur can stop mite infestation and keep scratches and pastern dermatitis at bay please click the link to the page what is pig oil? for more information on this. As most mites are also found in the mane and tail these areas should be treated too.
There are washes now available which were not when my horse had CPL. These are licensed products for use for horses and should be tried first and are available through your vet to be used under veterinary guidance. Sometimes these may not be deemed a suitable treatment. This treatment involves using a benzoyl peroxide shampoo to break down the scurf and then applying a dilute lime sulphur to the legs. The horse may be too sore to allow shampooing or have stopped allowing touch to the legs due to CPL, in this case the treatment can be sprayed onto the legs - this does dye white feathers yellow and smells like bad eggs due to the sulphur. This should be applied once weekly for 4 weeks. There are also some washes which are off license and these too should be used under veterinary guidance and involves applying an Ivermectin solution mixed with propylene glycol mixture then applying the solution to the legs. 
Keeping a regular worming routine can stop mites. It has been reported that oral Ivermectin based wormers which active ingredient is Ivermectin can be effective (worming the horse at a standard dose as with usual worming based on the weight of your horse and after reading all the advice on age and usage of that particular wormer- if in doubt please contact your vet for advice). This is using a drug which is known to be safe and is licensed to be given to horses but for a purpose for which it is not intended and so may not be effective. 
Application of a spray containing fipronil (Frontline spray) to all legs as indicated by your vet can kill mites. It can be costly, difficult to apply properly and is also not its licensed use although in studies there have been no side effects found so far. I found personally that this did not make much improvement but symptoms also did not worsen so it may have stopped the legs from getting worse secondary infections. I would advise to wear a mask when applying this as well as covering arms and leaving your horse tied for around an hour after application because horses with CPL will bite at the legs with their teeth and this was my main worry after application.


I will update this page if and when I have more information to bring to you.

For further reading and for further advice please click on the following links:

http://www.thehorse.com/articles/15923/whats-brewing-under-those-feathers

http://www.harlequinfarmsgypsyhorses.com/ChronicProgressiveLymphedema.html

http://equinemld.com/

http://issuu.com/fourinhand/docs/the_horse_report_cpl_in_draft_horses