Exfoliative cutaneous lupus erythematosus in German shorthaired pointer dogs: disease development, progression and evaluation of three immunomodulatory drugs (ciclosporin, hydroxychloroquine, and adalimumab) in a controlled environment.

Abstract

Six German shorthaired pointer dogs (two females, four males) with exfoliative cutaneous lupus erythematosus (ECLE) were studied in a controlled setting until disease progression necessitated euthanasia. During investigations into the heredity of disease, five dogs received immunomodulatory drugs to alleviate clinical signs (lameness, erythema, scaling, erosions/ulcers). One dog served as a control and received only baths and oral fatty acids. Four dogs received ciclosporin (5-10 mg/kg once daily) for 4.5 months to 2 years. Ciclosporin decreased erythema and arthralgia, but did not halt worsening of lesions. Three dogs received hydroxychloroquine (5-10 mg/kg once daily) for 8 weeks, 7 months, and 9 months, respectively, with no side effects. Hydroxychloroquine appeared to slow clinical progression in two dogs on extended treatment and normalized globulin levels in all three dogs while receiving the drug. Four dogs, including the control dog, were euthanized between 1 and 4.5 years of age. Two remaining male dogs received a tumour necrosis factor (TNF)-α antagonist, adalimumab, at 0.5 mg/kg every 2 weeks for 8 weeks then weekly for 8 weeks. Serum TNF-α levels were not significantly altered nor were quantifiable changes seen in skin lesions or lameness. Subsequently, the dogs were maintained on hydroxychloroquine for another year. This is the first study to evaluate the use of a TNF-α inhibitor for canine lupus and the first to address the safety of long-term administration of hydroxychloroquine, albeit in a small number of dogs. The study documents the progression of ECLE and generally poor response to therapy.