🦴 Legg-Perthes Disease in Dogs: Vet-Approved 2025 Guide to Hip Pain, Surgery & Recovery 🐾

By Dr Duncan Houston BVSc

🔍 What Is Legg-Perthes Disease?

Legg-Perthes disease—also called Legg-Calvé-Perthes disease or avascular necrosis of the femoral head—is a condition that affects the hip joint of young, small-breed dogs. It causes the “ball” of the hip joint (the femoral head) to die due to poor blood supply, leading to pain, lameness, and loss of joint function 🦴.

This condition typically appears between 5 to 8 months of age, although it can affect puppies up to a year old. Toy breeds and terriers are the most commonly affected 🐶.

📉 What Happens in the Hip?

The hip is a ball-and-socket joint. In Legg-Perthes disease, the femoral head loses blood flow, causing:

• 🧠 Bone tissue death (avascular necrosis)
• ⚠️ Collapse of cartilage and bone in the joint
• 🐾 Pain and limping in the affected leg

Over time, the hip joint becomes malformed and non-functional. In most dogs, the disease affects only one hip, but about 15% of cases may involve both sides 🩺.

🐶 Breeds at Risk

Legg-Perthes is seen mostly in small breeds and terriers. These include:

• 🐾 Yorkshire Terrier
• 🐾 Miniature Poodle
• 🐾 Chihuahua
• 🐾 Pomeranian
• 🐾 Jack Russell Terrier
• 🐾 Boston Terrier
• 🐾 Miniature Schnauzer
• 🐾 Affenpinscher, Bichon Frise, Pug, Westie, and more

While trauma may play a role in rare cases, genetics is believed to be the primary cause 🧬.

📋 Signs of Legg-Perthes Disease

Early symptoms usually appear in one hind leg and include:

• 🚶 Limping or favoring one leg
• 😖 Crying when bearing weight
• 🛌 Reluctance to move, play, or go for walks
• 📉 Loss of muscle mass in the hip or thigh
• 😟 Difficulty stretching or extending the affected leg

If untreated, dogs may stop using the leg altogether and develop secondary muscle atrophy or joint contracture.

📸 Diagnosis

Diagnosis is made via X-rays of the hips. Early changes may show:

• 🔍 Loss of bone density in the femoral head
• 🦴 Flattening or deformation of the femoral head
• 🔄 Changes to joint space or socket shape

Veterinarians may also test range of motion and pain response during physical exams 🩺.

💊 Is Medical Treatment an Option?

Anti-inflammatories and pain medications may provide short-term relief, but they do not stop disease progression. Surgery is the only definitive treatment 🛠️.

🔧 Surgical Treatment: Femoral Head and Neck Ostectomy (FHNO)

The recommended surgery for Legg-Perthes is a Femoral Head and Neck Ostectomy (FHNO). This involves removing the diseased femoral head and neck, eliminating bone-on-bone contact that causes pain 🎯.

Why This Works:

• 💪 Surrounding muscles still support the hip
• 🧽 A scar tissue “false joint” forms over time
• ✅ Dogs return to normal function—especially small, lightweight breeds

Though it sounds extreme, this surgery is very effective. The leg remains fully functional, and most dogs are pain-free within weeks 🐾.

📈 Post-Op Recovery

Recovery includes:

• 🛏️ 1–2 weeks of rest
• 🚶 Encouraging gentle use of the leg to prevent stiffness
• 🏋️ Physical therapy to rebuild muscle

Timeline:

• 📅 Days 3–7: Some weight-bearing begins
• 📆 Week 2: More confident walking, less pain
• 🧠 Week 4–6: Most dogs using the leg normally

Veterinarians often recommend physiotherapy or controlled exercise like leash walking, incline walking, or swimming to support muscle rebuilding 🧠.

📲 Ask A Vet About Surgery or Recovery

Worried about limping or hip pain in your small dog? Visit AskAVet.com to speak with a licensed vet 🐶💬.

• 📋 Help understanding X-rays or diagnosis
• 🔧 Guidance on FHNO and recovery
• 💬 Daily support during post-op care

📱 Download the Ask A Vet App to connect with Dr Duncan Houston or another vet anytime from your phone 🐾.

💚 Final Thoughts

Legg-Perthes disease may sound scary, but with early diagnosis and surgery, most dogs recover fully. The false joint formed after FHNO is functional, pain-free, and allows dogs to live active, happy lives 🐕.

Need help understanding your options? Reach out at AskAVet.com today or open the app to start your pup’s recovery journey 🐾.