Leukocytoclastic pastern vasculitis: classification and thermal hydrotherapy

Abstract

Background. Leukocytoclastic pastern vasculitis is a still poorly understood condition in equines with a guarded prognosis, facing veterinarians and owners with serious treatment and management difficulties. Currently, treatment routinely consists of corticosteroids. However, since they are regarded as a banned substance by the FEI, can come with serious side effects and do not prevent the condition from reoccurring, it is worth investigating possible different treatment options. Thermal hydrotherapy might be one of them. Hot washing protocols are already carried out in several clinics while claims about remarkable results are being made.

Aim. The aims of this study were (1) to give an overview of the prevalence of vasculitis in equines with dermatoses presented to an equine referral hospital in the Netherlands; (2) to propose a new classification system for leukocytoclastic pastern vasculitis; (3) to describe a hot washing protocol for patients with leukocytoclastic vasculitis; and (4) to evaluate treatment outcomes of equines with this condition that underwent the protocol to help evaluate its effectiveness.

Method. Patient files from equines presenting from March 1st of 2022 until December 1st of 2024 at the internal medicine department of Utrecht University’s equine referral hospital were accessed. Records from 7 equines with (suspected) leukocytoclastic pastern vasculitis that received a hot washing treatment according to a protocol described in this study were reviewed retrospectively and a questionnaire was sent out to their owners.

Results. In the researched period, 104 equine dermatology consults took place at the clinic. 15 patients were diagnosed with or suspected from vasculitis; in 12 patients, this concerned lower leg vasculitis. Of the 7 equines included in this study that received a hot washing treatment, complete remission occurred in 3 patients (43%), while an additional horse (14%) experienced almost complete remission. 5/7 owners (71%) indicated the condition improved in the period after the treatment, with 4/7 (57%) stating to be satisfied with the treatment’s outcome. Furthermore, this study presents the Equine Leukocytoclastic Pastern Vasculitis Activity Score (Eq-LPVAS) that was developed and describes its use to score the condition’s progression and severity objectively and quantitively.

Conclusions. These findings support hot washing as a promising treatment for equine leukocytoclastic pastern vasculitis. Further research including a larger number of patients is needed to scientifically prove its effectiveness and compare outcomes of hot washing to currently routinely used treatment strategies.