Chronic Progressive Lymphedema or CPL, is a condition
now noted in all Draft Horse breeds, including Gypsy
Horses. It is a problem of which we should all be aware.
Sadly,much of the time, it goes unnoticed by owners until
the disease has reached advanced stages.
The condition is characterized by progressive
swelling, hyperkeratosis and fibrosis. CPL often starts at an early
age, progresses throughout the life of the horse, mostly ending
with horrible disfigurement and often an early death for the
animal. The disease closely resembles the condition known in humans
as chronic lymphedema or elephantiasis nostras verrucosa.
We have been doing ongoing research into this problem and
have heard from many dealing with it daily in their horses. It is
devastating and heartbreaking for their owners and difficult for
the horses involved. Dealing with it, is an everyday problem.
Is it hereditary? Some think it is - others are not sure - yet.
Personally, I don't believe it "is" hereditary but that all heavily
feathered breeds have a predisposition to the problem "because" of
their feathers. I was speaking to a lady in another Draft Horse
breed the other day, and she feels that in her breed, as many as 90%
might be affected.
I offer some links below, which
will give you some idea of what it entails. You will note that the
problem in Gypsy Horses is "not" mentioned, but other Draft Horse
breeds are. However, please know it "is" widespread within the Gypsy
Check your horses' feather each and every week, parting the hair down
to the skin all down and around each leg from the hock down.
Feel his flesh to see if you feel skin folds or grape-like bumps.
Grape-like bumps under the skin are another part of this evil thing.
They are often very apparent under the flesh above the line of
feather. Even if your horse does have it, the sooner you discover it,
the better off you will be. Educate yourselves regarding this
and let's not put our heads in the sand by not discussing or learning
about it. It might be the life of your horse if not dealt
For the last few months, I have been doing much ongoing
research into the CPL and related problems. I have
been forwarded a great deal of interesting material on the
subject, by many very knowledgeable people and from many
different areas of the world and some of those in the field
of Veterinary medicine. A friend in the breed in England,
has a Veterinary Surgeon in that Country. She is doing much
research into the subject and as soon as I receive her permission
to post her findings here - I will.
With this at my disposal, I "have" formed some opinions of my own.
As I mentioned earlier, I don't believe it is hereditary
but that all heavily feathered breeds have a propensity to
the problem "because" of their feathers. Most especially those
kept in constant wet conditions throughout their lives and
lacking in good animal husbandry by their owners. However, horses
kept in dry areas with vigilant owners can also show early signs of
The lady Vet in England seems to also agree that this "is" the start of
Personally I do believe that the condition now known as CPL,
is seen almost without question, in those horses, who are heavily
feathered and have been pastured for many years or kept in
constantly damp conditions. Such horses are not always brought in
for inspection - let alone grooming, for years at a time. Some
never. Such horses, having been in wet conditions without the
benefit of good animal husbandry, probably started off with a
simple case of Scratches/Mud Fever, which went unnoticed and
untreated. Unchecked, over time, this produces sores, scabs,
long horizontal cracks and skin folds. Later, as the problem
progresses, fungal infections are found. Tiny mites infest in
huge numbers, to feed on the dead and decaying skin. Further
infections such as Staphyloccocus and Dermatophilus set in and
eventually the horse has the condition we now see as full-blown
CPL. One can only guess at just how much these horses suffer
for years and years, before they are found dead in their field!
Think I'm being dramatic? No - I now know of several well
So what does this possibly tell us? Well it "does" tell us
that we should be extremely vigilant in the care of our feathered
They should be checked weekly for signs of anything unusual.
All feather should be parted, down to the skin from the knees
and/or hocks, to the heel and inspected carefully, for any
signs of a problem. After bathing, feather should be dried
completely - preferably with a hair dryer. Any horse showing the
first signs of a problem should be removed to a dry area and
treated until the condition has completely cleared up. Bedding must
also be kept clean and dry and free of mites. There are many
remedies for early cases of scratches but for problems which have
progressed beyond that, then a course of Antibiotics and/or Anti-
inflammatory drugs, should be prescribed. This of course in
addition to topical preparations and care.
Horses heavy in mane, should also be checked very carefully,
down to the skin, under the mane and weekly. Such horses, kept
in damp conditions, are prone to rainrot which should also be
I think if all were to practice good animal husbandry, it
quite well might be that this terrible problem could become a
thing of the past.
Have any of you seen foals with it? No.
It only shows up in older horses who have not had the care
they deserved! Imagine if you will, what would happen if you kept
your head and hair, under water or thoroughly wet for years. There
is no doubt that you would have similar problems. At this point,
I cannot believe this is hereditary. Remember "we" have bred
horses with feather. Those in the wild do not have it and would
not have survived harsh conditions, if they did. Some still are
not convinced it's not an Immune problem. Maybe it is - but I
believe the Immune system is compromised "only" after the problem
has gone unnoticed and untreated for a very long time.
Don't for a moment think that a horse stamping his feet constantly
is just badly mannered. He's probably itching or hurting.
If you notice your horses scratching their legs on any available
object start looking beneath the feather!
If you notice horses in large herds, who have been kept out in
pasture their entire lives, suddenly start becoming bad tempered
or even dangerous to handle - consider that they might be in
When you sell a horse or foal, do the owner and the breed a
favour, by explaining in great detail, the care these horses need
and deserve. Make sure that new owners are fully committed to
taking care of them properly.
As always, these are my own thoughts on the subject, but
only after putting together tons of information I have received
from many knowledgeable people.
Please note that many Vets are not familiar with the
disease at all so it's up to you to do your homework, check your
horses and if necessary - educate your Vets!
This (below) also makes reference to the fact that the skin of heavy horses is different from light horse breeds as I was speaking of in another post on our forum recently.
Experimental work has now shown that when mites are fed on skin scale from heavy horse breeds they will flourish in a "test tube" laboratory environment. Identical mites fed a diet of thoroughbred skin quickly die. There must therefore be factors within the skin of these heavy horses that act to enhance growth and multiplication of mites; as yet these components remain undetermined.
Interesting isn't it!
Chorioptic mange in the horse.
Mange in the horse can be caused by a variety of different parasites. However Chorioptic mange which is caused by infestation with the mite Chorioptes bovis, is the disease most commonly identified by owners and Veterinarians. Although this parasite can cause irritation on any part of the horse's body it is colloquially known as "foot mange","leg mange" or "itchy leg" due to it's tendency to effect the lower limbs.
Chorioptes mites are microscopic ectoparasites that are 0.3 - 0.5mm in length. They feed on the most superficial layers of the skin and are found particularly on the lower limbs of heavy horses, especially those with feathered heels.
The mite life cycle
It takes two to three weeks for the newly laid Chorioptes egg to develop through to a mature adult. Although the mite can survive in the environment, the life cycle can only be completed on the horse. Under ideal conditions of dark, warmth and relatively high humidity the mite, according to some sources, can live for more than two months in the environment. Mites can also survive off the horse in skin debris, such as dried crusts and scabs. Therefore when a case of Chorioptic mange is identified on a yard there is a real danger not only of contagion from any infested animal but also from the horse's immediate environment which of course will include grooming equipment and tack, for up to two months.
Eggs laid by the female mite hatch into the larval stages within four days. The larvae develop into nymphs then adults over the following few weeks. Larvae, nymphs and adults are all capable of feeding actively only twenty-four hours after hatching. The time from egg laying to feeding and disease can therefore be as little as five days.
Mite populations are usually highest in cold weather. During the cooler winter months the mites burrow down underneath the hair particularly around the heels. The thick hair coat of the heavy draught breeds provides perfect conditions for mite development. Cosseted within this niche the mites can survive extreme environmental temperatures due to their own hidden warm, humid microclimate under the protective barrier of hair. Mite numbers drop dramatically in the summer and as they do many of the signs of mange may also appear to abate. However even though the horses may no longer show signs of disease, mites can still be identified in samples taken from around the coronary band by an experienced investigator. Such asymptomatic horses, that remain untreated at the end of the winter, will act as carriers of mites and provide a new focus of infestation later in the year as the temperature drops. There is no doubt that features other than hair coat predispose heavy breeds to mite infestations. Even in working horses whose fetlocks remain clipped and well-groomed mites can thrive on the lower legs.
Experimental work has shown that when mites are fed on skin scale from heavy horse breeds they will flourish in a "test tube" laboratory environment. Identical mites fed a diet of thoroughbred skin quickly die. There must therefore be factors within the skin of these heavy horses that act to enhance growth and multiplication of mites; as yet these components remain undetermined.
Clinical signs of mange
The author recognises a whole range of different clinical signs in horses affected with Chorioptes. Some horses can carry large numbers of mites, usually concealed deep within the hairs of their leg feathers, without ever manifesting signs of disease. Other horses present with very severe mange and harbour only a few mites. This latter group of animals manifesting a grossly exaggerated response to mite feeding activity is probably allergic to the mites.
Whichever parts of the horse's body is affected the first apparent sign of mange is intense itch. The lower legs are common sites of infestation in heavy horses. The horse will nibble accessible areas and commonly foot stamping is observed. Some of these animals show such marked signs as they pick up their feet and flex their legs that they can be misdiagnosed as having strange neurological diseases such a "stringhalt". Foot stamping in Chorioptic mange is a sign of severe discomfort and irritation as well as the horse's frustration at not being able to reach an area of intense itchiness. The whole body is often effected in young foals possibly due to their lower immune status. These animals will rub along suitable surfaces in the stable or paddock and can be mistakenly identified as having allergies. The feeding activity of the mite leads to the characteristic changes in the skin. Where mites feed over extensive areas, the body of the horse can be covered in a fine "oatmeal like" scale. Localised sores on the legs appear as areas of thicken crust, which mats the hair. Trauma to the site from the horse further enhances these changes and produces a compressed protective covering of debris that adds to the mite's microenvironment.
Chorioptic mange should be considered as a possible cause of any itchy disease in the horse, especially those involving the legs.
As the mites feed it is not uncommon for them to introduce infection into the skin. Ringworm (dermatophytosis) and bacterial infection with such organisms as Staphylococcus and Dermatophilus can complicate the picture. Even if mite infestations are identified and treated adequately, sores may show only a partial or temporary improvement if the infection is not recognised and addressed.
How do we find the mites?
Mites can be identified by taking skin scrapings, which can be mounted in either mineral oil, or potassium hydroxide Your Veterinary Surgeon should be able to sample any potentially affected areas and assess skin for the presence of mites. Alternatively the advice of a Veterinary Dermatologist with knowledge of equine skin disease, may be sought. In fractious and uncomfortable horses techniques such as skin scraping can be difficult. Scraping scabs off the legs of a stamping Shire horse with a sharp scalpel blade can lead to the collection of more than horse skin! Tape strippings can also be performed to collect mites. Clear adhesive tape placed repeatedly onto the skin can be mounted and examined microscopically.
How do we kill the mites? Where possible not only should an infested animal(s) be treated but all in contact animals and the environment. Therapy can be difficult to apply and can necessarily be expensive in a large horse. Both oral drugs, given by mouth; and topical therapy applied directly to the skin can be used. The biggest problem encountered by any Veterinary Surgeon treating mite infestations in the horse is the limited availability of what are considered to be licensed products. No drug is currently licensed to the author's knowledge to treat Choroptic mange in the horse in the U.K. Many different therapies have never-the-less been shown to be effective but should be used under Veterinary supervision in the light of a specific diagnosis. Ivermectin, which is available as a general equine wormer, can be given following specific protocols by mouth or applied as a solution directly to the legs. Some of the insect repellents more commonly used for conditions such as Sweet itch, particularly those containing permethrin, cypermethrin and benzyl benzoate can be used. However the author would strongly advise against the use of products used for cattle and sheep which can be irritant to the more sensitive equine skin. Sulphur containing solutions including selenium sulphide are highly effective mitacides, although they can be labour intensive and messy to use. The most recent veterinary literature has identified a small animal flea preparation containing fipronil, which has excellent efficacy against mites. This is an expensive form of therapy but as a non-aerosol spray can be applied directly to the legs.
In summary, Chorioptic mange is common in heavy cobs and draught horses. These horses are highly predisposed to developing and maintaining mite infestations, not only because of the conformation of their legs but also because of more subtle factors relating to their skin type. Identification and treatment of the mite can be achieved by an experienced Veterinary Surgeon.
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