Chronic progressive lymphoedema leads to MLD equine therapy study

Transcription

1 Vet Times The website for the veterinary profession Chronic progressive lymphoedema leads to MLD equine therapy study Author : Heather Powell Categories : Vets Date : March 1, 2010 Heather Powell discusses lymphoedema in humans and horses, and explains how she discovered manual lymph drainage therapy used in people could be effectively applied to treat equine conditions EQUINE lymphoedema is something of a Cinderella condition in Britain it is rarely described in veterinary manuals, equine journals or on websites, yet is often encountered. Lymphoedema occurs when the lymphatic system is unable to work properly. This may be for congenital reasons, such as a primary lymphoedema, or a secondary lymphoedema resulting from trauma damaging a previously healthy system or, frequently, a combination of both. Lymphoedema is proteinrich, which differentiates it from other oedemas. Large protein molecules that carry nutrients from the bloodstream into the tissues can only be removed by the lymphatic system. If not removed, these protein molecules attract water, which creates oedema and, over time, they are converted into excess connective tissue, resulting in skin thickening and fibrosis. This further damages nerves, lymphatic vessels, veins and underlying structures, causing pain and affecting function. Nutrients and waste products are no longer transported adequately in the tissues, resulting in pathological changes, and the immune system is compromised with a greatly increased risk of infection. 1 / 6

2 Research into equine lymphology and associated diseases is largely being undertaken in Germanspeaking countries, and it is through this that three familiar lymphatic oedema forms filled legs, lymphangitis and elephantiasis have been identified as similar to the stages of lymphoedema found in humans, and grouped under the designation equine lymphoedema complex (ELC). There is evidence that stage one filled legs is a primary lymphoedema (affected horses have been shown to have fewer anastomoses between lymphatic sub-collector vessels than unaffected horses), and this may cause greater vulnerability to infectious lymphatic oedemas that are stage two, such as lymphangitis. These infections obliterate lymphatic vessels and tend to recur, frequently resulting in a chronic oedema that, over time, may develop into stage-three lymphoedema or elephantiasis. Interestingly, it has been observed that infection plays a significant role in the development of stage-two ELC, whereas, in people, it is the existence of stages two and three lymphoedema that precedes an increased risk of infection 1. Research In the past few years, veterinary researchers, led by Verena Affolter at the School of Veterinary Medicine, University of California Davis, USA, and at the University of Ghent in Belgium, have been working on a newly recognised disease called chronic progressive lymphoedema (CPL) which, to date, has been found in heavily feathered shires, Clydesdale and Belgian draft breeds and, most recently, in gypsy vanners. Initially, the disease was thought to be a treatment-resistant form of greasy heel, but further research established it had an underlying cause relating to the immune system of affected horses. UCDavis describes CPL: 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 lymphoedema or elephantiasis nostras verrucosa. The condition has, therefore, been referred to as chronic progressive lymphoedema (CPL). The lower leg swelling is caused by abnormal functioning of the lymphatic system in the skin, which results in chronic lymphoedema (swelling), fibrosis, decreased perfusion, a compromised immune system and subsequent secondary infections of the skin. UCDavis researchers go on to explain that clinical signs of this disease are highly variable, and are often first addressed as a marked and therapy-resistant pastern dermatitis. Early lesions, however, are characterised by skin thickening, slight crusting and possible skin folds in the pastern area. While readily palpable, they are often not appreciated visually, as heavy feathering in the breeds covers these areas. They write: 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 horses legs and usually consist of chorioptic mange and/or bacterial infections. Pigmented and nonpigmented skin 2 / 6

3 of the lower legs are affected. Appropriate treatment of the infections (pastern dermatitis) is not successful, as underlying poor perfusion, lymphoedema and hyperkeratosis, in association with the heavy feathering, present perfect conditions for repetitive infections with both chorioptic mange as well as bacterial infections. UCDavis warns that recurrent infections and inflammation will enhance the lymphoedema, and the condition will become more chronic. As a result, the enlarged lower leg becomes permanent and the swelling is firm on palpation. More thick skin folds and large, poorly defined and firm nodules develop. They write: 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 are frequently injured during exercise. This disease often progresses to include massive secondary infections that produce copious amounts of foul-smelling exudates, generalised illness, debilitation and even death. 2 Gene related The three draft breeds in which CPL was originally identified are related. Therefore, a genetic cause to the disease is suggested. Gypsy vanners also have shire and Clydesdale blood in their breed, which supports this. Unfortunately, lack of awareness about the condition and difficulties identifying its onset mean that affected horses continue to be bred from. Research is, therefore, directed into finding an identifiable cause for CPL. The lymphatic systems of horses are very dependent on their evolution as flight animals continually on the move. Horses have few smooth muscle cells in all the lymphatic collector vessels, indicating that a further lymph transport system must be present, and it has been demonstrated that the horse s vessel composition has a high proportion (40 per cent) of elastin 3. This may be linked to the vulnerability of horses to lymphoedema, which is known to cause degenerative changes in elastic fibres, with subsequent functional consequences. Work at UCDavis has established that CPL is associated with an initially lower systemic cutaneous elastin level in affected horses, and a deposition of elastin during the progression of the disease. This results in increased levels of circulating anti-elastin antibodies in the serum, the evaluation of which may be an aid to identifying vulnerable horses, so these will not be used in breeding programmes and can be treated at an early stage. 4 Control Lymphoedema cannot be cured, but it can be controlled, and the current treatment of choice is 3 / 6

4 combined decongestive therapy (CDT). This has been used successfully in human patients for decades and is available in Britain on the NHS. CDT is based on a highly specialised form of massage called manual lymph drainage (MLD) a very gentle, painless, totally non-invasive, but highly effective technique that stimulates the activity of the lymphatic system. It works with the network of superficial lymph collectors in the dermis and can speed the delivery of lymph to local lymph node groups or, where lymphoedema is present, across regional watersheds to functioning areas of the system. CDT consists of an intensive course of MLD daily which reduces oedema, softens fibrotic tissue, improves skin condition and supports the immune system followed by compression bandaging to continue its effects. Once maximum oedema reduction is achieved, the results are maintained through the use of compression garments, skin care and exercise. Compression stockings for horses are also available. I am a fully qualified MLD practitioner trained to use this technique to treat humans with lymphoedema, but also have a life-long involvement with horses. In common with most enthusiasts, I had never heard of horses developing this condition. However, because of MLD s ability to quickly reduce congestion and inflammation, I felt (correctly, as it turns out) that it could be an effective auxiliary treatment for equine conditions, such as laminitis and tendon injuries, and was determined to find a way of using it with horses. This led me to train with leading German lymphologist Dirk Berens von Rautenfeld, founder of the European Seminar For Equine Lymph-Drainage, created to teach equine manual lymph drainage (EMLD) to vets and therapists. MLD is very effective with people, but even more so with horses. In the horse, it is possible to use MLD techniques to stimulate contraction of both the superficial and the deep collector vessels, which are normally not accessible in humans. The high proportion of elastic fibres in all parts of the collectors are also thought to play an important role in MLD and compression treatment. MLD in horses may stimulate collectors outside, as well as inside the area, where the technique is applied due to a pacemaker activity by myofibroblasts within the lymphatic vessels. 3 It is established that EMLD can be very effective when used with the early stages of lymphoedema, and justified even with elephantiasis, when degenerative tissue changes are permanent, to reduce oedema and as a preventive against further infection. However, because of the lack of awareness, it is at this late stage, when all else has failed, that the EMLD therapist is likely to be approached. Other work has shown that EMLD can be effective as an auxiliary treatment with a growing number of other conditions for example, the lymphatic anatomy within the horse s tendon enables EMLD to substantially speed up its recovery from acute tendon injuries and encourage correct alignment of collagen fibres. 4 / 6

5 EMLD is also effective when used with acute and sub-acute laminitis. By stimulating the deep collector vessels through which the hoof drains, pressure is reduced and blood and toxins are quickly removed, slowing necrosis, reducing damage and speeding recovery. Study I have followed UCDavis internet updates on its research into CPL with interest and, at the start of 2009 had the opportunity to meet Dr Affolter, who explained their researchers thoughts had been turning to ways of helping affected horses. They were aware of compression bandaging (and had used it with varying degrees of success), and also of MLD treatment in humans, but were unaware it had been developed for equine use. This quickly led to a proposal for a small study into the use of EMLD in horses affected by CPL. As a result, a pilot study is currently taking place at the UCDavis School of Veterinary Medicine, expected to run for approximately two to three weeks, despite there being no funding for the study. UCDavis CPL research budget has ended, and while it may be able to help with the cost of the specialised short-stretch bandages required, and owners of affected horses have kindly offered their animals for the study, there is a lack of funding sources for non-veterinary qualified researchers, such as myself, to help with basic expenses. It is my hope, through the study, we will encourage greater appreciation in the UK of the existence of CPL. It cannot go unnoticed that three of the four breeds known to be affected are British, and we have been made aware of horses in this country with the disease that we would be happy to include in the study. For further information about research into CPL at UCDavis, visit edu/elephantitis/about.html and If you are interested in the study or would like to know more about EMLD visit or I can be contacted on References 1. Berens V, Rautenfeld D and Fedele C (2005). Manuelle Lymphdrainage beim Pferd, Pub Schlütersche 10: UCDavis, 3. Fedele C, Berens V and Rautenfeld D (2007). Manual lymph drainage for equine lymphoedema-treatment strategy and therapist training, Equine Veterinary Education 19(1): van Brantegem L, de Cock H E V, Affolter V K, Duchateau L, Hoogewijs M K, Govaere J, Ferraro G L and Ducatelle R (2007). Antibodies to elastin peptides in sera of Belgian 5 / 6

6 Powered by TCPDF ( draught horses with chronic progressive lymphoedema, Equine Veterinary Journal 39(5): (4). 6 / 6