Hypertrophic Osteodystrophy and Concurrent Presumptive Autoimmune Disorders in a Jindo dog - Successful Treatment

Background: Hypertrophic osteodystrophy is an orthopedic disorder that primarily affects rapidly growing dogs. Although the exact etiology remains unclear, an autoimmune origin has been proposed. This condition is usually self-limiting and treated with non-steroidal anti-inflammatory drugs to alleviate pain and inflammation. It is rare for hypertrophic osteodystrophy to occur with other autoimmune diseases, and established treatment protocols for these concurrent conditions are lacking, complicating management. This report details the clinical observations and successful treatment of a patient with hypertrophic osteodystrophy along with concurrent ischemic dermatopathy and lymphoplasmacytic enteritis.Case: A 1-year-old neutered male Jindo dog was presented with a 2-month history of lameness, chronic diarrhea, and repeated ulcerative skin lesions with delayed wound healing. On the gross examination, multifocal cutaneous signs, including alopecia, crusts, and ulcers, were observed on the ear pinnae, nose and elbow. Soft-tissue swelling was identified in right carpi and severe pain were elicited on palpation, flexion, and extension of right carpi. Radiographic examination revealed multifocal hypertrophic osteodystrophy and a pathologic fracture of the distal right radius with angular limb deformity, leading to its surgical correction. Additional skin biopsy confirmed ischemic dermatopathy, and endoscopic gastrointestinal biopsy confirmed lymphoplasmacytic enteritis. Initially, the treatment included immunosuppressive therapy with prednisolone and cyclosporin. However, the response to this treatment was insufficient. Consequently, the treatment was adjusted to incorporate a hydrolyzed diet specifically designed to manage lymphoplasmacytic enteritis, and oclacitinib to address ischemic dermatopathy. After this adjusted treatment strategy, the clinical symptoms totally improved over 4 weeks. The patient remained clinically stable throughout the six-month follow-up period, with no reported side effects or recurrence of symptoms. Discussion: In veterinary medicine, reports of concurrent autoimmune diseases are occasionally noted, but the coexistence of hypertrophic osteodystrophy with autoimmune diseases is very rare. To date, only two cases of hypertrophic osteodystrophy with concurrent autoimmune diseases have been reported, making this the first documented instance of hypertrophic osteodystrophy with lymphoplasmacytic enteritis and ischemic dermatopathy. Management of hypertrophic osteodystrophy typically involves symptomatic treatment and immunomodulatory therapy. However, in this case, glucocorticoid treatment showed no effect over six months. Instead, an individualized approach targeting each condition led to full resolution of lesions, and the patient maintained a stable condition. This suggests that disease-specific treatment strategies may be effective, although hypertrophic osteodystrophy’s self-limiting nature indicates the possibility of spontaneous recovery of concurrent conditions such as ischemic dermatopathy, and lymphoplasmacytic enteritis. Thus, treatment approaches for hypertrophic osteodystrophy with concurrent autoimmune diseases should consider both disease-specific strategies and the potential for spontaneous recovery. Further studies are required to deepen our understanding of the etiology and treatment options for hypertrophic osteodystrophy and concurrent autoimmune diseases.