# Diagnosis and Management of Chronic Nonbacterial Osteomyelitis in a Dog

## TL;DR

This paper reports the first successful treatment of a rare bone condition in a dog using drugs adapted from human medicine.

## Contribution

The first documented veterinary case of chronic nonbacterial osteomyelitis managed successfully with medical therapy.

## Key findings

- A Pomeranian dog showed clinical and radiographic improvement after treatment with anti-inflammatory and immunomodulatory drugs.
- Cytological and histopathological analyses confirmed nonbacterial osteomyelitis in the dog.
- The case suggests that human treatment strategies can be adapted for non-infectious bone conditions in dogs.

## Abstract

Chronic nonbacterial osteomyelitis (CNO) is a rare inflammatory bone condition in animals. This report presents the first veterinary case of CNO successfully managed with medical therapy alone, using anti-inflammatory and immunomodulatory drugs adapted from human protocols. The dog showed clinical and radiographic improvement after treatment. These findings suggest that non-infectious osteomyelitis can occur in dogs and highlight the potential applicability of human treatment strategies in veterinary medicine.

This case presents the first documented successful medical management of chronic nonbacterial osteomyelitis (CNO) in a small dog—a condition rarely described in veterinary medicine. A 4-year-old castrated male Pomeranian dog weighing 4.6 kg was presented with a 3-week history of right hindlimb lameness. Radiographic examination revealed osteolytic lesions, periosteal reactions, and decreased muscle mass in the affected limb. Microbial and blood culture tests showed negative results, whereas cytological and histopathological analyses of the right distal femur confirmed neutrophilic inflammation and osteomyelitis, leading to a diagnosis of CNO. Clinical and radiographic improvements were observed following administration of bisphosphonates, disease-modifying anti-rheumatic drugs, and glucocorticoids. This case underscores the possibility of non-infectious osteomyelitis in dogs and suggests that adapting human treatment strategies may be beneficial. Further research is needed to clarify the diagnostic criteria and pathophysiology of CNO in veterinary medicine.