Bone Overgrowth in Dogs | petMD

Hypertrophic Osteopathy in Dogs

Hypertrophic osteopathy refers to an abnormal enlargement of bone due to new bone formation. It commonly occurs in humans and dogs and has been reported in dogs, horse, cow, sheep, and various other more exotic species.

In dogs the disease is characterized by swelling, primarily affecting all four limbs. Subtle in onset, it is often mistaken for early arthritis. Neoplasia is a common cause of this disease, and therefore, more common in older dogs as neoplasia is more common in older dogs.

Symptoms and Types

• Lethargy
• Reluctance to move
• Swellings at distal portions of limbs, especially forelimbs
• Painful limbs
• Edema on limbs
• Decreased movement in joints due to swelling
• Lameness

Causes

The exact cause of new bone formation is still unknown, but this condition has been seen in association with various diseases, including:

• Pneumonia
• Heartworm disease
• Heart disease
• Tumor of urinary bladder
• Tumor of liver and prostate gland
• Lung tumors metastasizing to the affected areas

Diagnosis

Your veterinarian will take a detailed history, asking you about the duration and frequency of symptoms. He or she will then perform a complete physical examination. Routine laboratory tests including complete blood count, biochemistry profile, and urinalysis will be conducted. The results are usually normal but may vary depending on the underlying disease, if present. X-rays of the bone may reveal new bone formation and help your veterinarian in localizing the disease. He or she may also decide to take bone sample for further evaluation, including investigating for the presence of tumors.