There is a unique kind of panic that sets in when a professional tells you your sweet puppy has a disease you didn't even know existed. Besides being a mouthful to say, Legg-Calvé-Perthes disease is a developmental disease in small dogs where the hip bone begins to die due to a lack of blood flow.
It can be heartbreaking when your normally spunky little puppy suddenly starts painfully limping on a hind leg, and the treatment often requires surgery. Let’s take a deeper look at Legg-Calvé-Perthes disease in dogs so that you can better recognize the signs and understand the treatment.
Perthes Disease in Dogs
Whether you want to call it by its full name, Legg-Calvé-Perthes, its shortened name, Legg-Perthes or just Perthes disease, or its more scientific names, avascular or aseptic necrosis of the femoral head, the condition is the same. It’s a disease that causes a painful degeneration of the hip joint in small breed dogs under one year of age.
How Legg-Perthes Develops
The hip joint is made up of the head of the femur (the rounded end of the leg bone also known as the ball) and the acetabulum, a cupped structure in the pelvic bone commonly referred to as the socket. When healthy, this ball and socket joint smoothly rotates to allow your dog’s hind legs to move forward, backwards, and angle out.
Your dog’s hip joint doesn't just fail for no reason. This process starts deep inside, where the blood supply to the ball of the hip joint gets interrupted. Without that blood, the bone begins to starve and eventually dies. When the bone weakens, the smooth cartilage cushion that usually helps the joint glide starts to crumble. The perfect fit of the ball-and-socket joint is lost, leading to painful inflammation and limping.
Why Legg-Calvé-Perthes Happens
Sometimes necrosis of the femoral head can happen following an injury to the joint, but this disease more commonly occurs without previous agitation. Since it happens most commonly in certain breeds at certain ages, it’s thought to have a genetic component.
Age that Legg-Perthes Shows Up
Young dogs typically don’t develop debilitating lameness, except in the case of Legg-Perthes disease. This most commonly affects small breed puppies between five and eight months old but can occur in dogs of any age under one year.
Breeds Most Affected by Legg-Perthes Dog Disease
Small breeds are by far more commonly affected than their larger compatriots. High-risk breeds include:
West Highland White Terrier
Cairn Terrier
Why Small Breeds?
While it may seem like a mystery why this disease specifically targets toy and miniature dogs, veterinary science points to a literal design flaw in their anatomy.
According to research shared by the International Veterinary Information Service (IVIS), there is a distinct difference in how blood reaches the hip in small dogs versus larger ones. In big dogs, the main blood vessels (the superior retinacular vessels) are safely tucked away in deep grooves in the bone.
In miniature dogs, however, these vessels are far more exposed, crossing the hip like a "suspended bridge." This makes the blood supply incredibly fragile. Because they aren't protected by bone, these vessels can be easily "kinked" or compressed by normal growth spurts, minor joint pressure, or tiny injuries that wouldn't affect a larger dog. When that bridge collapses, the blood flow stops, and the hip bone begins to starve.
That’s not to say that larger breed dogs can’t develop Perthes disease, especially following an injury; it just isn’t as common. Certain larger breed dogs are more likely to develop hip dysplasia.
Recognizing the Signs of Legg-Calvé Perthes Disease in Dogs
Lameness in dogs seems like an easy thing to spot, but that’s not always the case, and early signs may easily be missed. Perthes disease most commonly affects only one leg but can occur in both.
Early Signs (first 2-4 weeks)
Irritability, lethargy
Mild limping or shortening of gait
Cry when extending or straightening the leg
Progressive Signs (4-8 weeks)
Moderate to severe limping
Unwillingness to climb stairs or jump up
Difficulty standing up
Atrophy (shrinking) of the leg muscles due to disuse
Advanced Signs (8+ weeks)
More pronounced muscle atrophy
Severe pain
Severe limping or not using the limb at all
What Owners Often Miss
With the way puppies tear around, minor injuries aren’t uncommon. It’s easy to think that your puppy has a minor sprain or strain when they first start limping due to Legg-Perthes disease. The problem is that minor injuries often heal within a few weeks of rest while dogs with Perthes disease only get worse. It’s also easy for owners to miss the related muscle atrophy as it’s rare that you get a good feel of your dog’s hind legs to notice the change. Immediate veterinary attention is important to help decrease your puppy’s discomfort.
Complete Treatment Journey: Diagnosis Through Recovery
Though Perthes disease may be debilitating, it can be treated, the earlier the better.
Diagnosis
With any luck, you’ll catch your puppy’s limping while it’s still mild, but if it progresses in severity, the diagnosis is going to include an exam by your veterinarian along with x-rays. Even in the early stages, changes to the femoral head are noticeable via x-ray. The x-ray and exam will also help your vet rule out other causes of lameness.
Treatment
Occasionally, and especially in the early stages, your vet may recommend anti-inflammatories and rest to help relieve the inflammation. However, this conservative approach is rarely curative.
A groundbreaking 2024 study published in Open Veterinary Journal found that in the "dead" areas of the hip, there is zero natural bone reconstruction occurring. While a typical broken bone sends in "builder cells" to bridge a gap, this research shows that the body’s repair system simply fails to show up in the necrotic area of the hip. Because the bone is literally starved and unable to rebuild, the joint will eventually collapse under your puppy's weight. This is why surgery is almost always necessary.
The procedure is called a femoral head ostectomy (FHO) and ultimately involves removing the blood-starved end of the femur bone. This creates a false joint where instead of a bone-on-bone connection, the hip joint is stabilized with the surrounding muscles. Since there is no longer a misfit of bone making up the joint, inflammation and pain are greatly reduced or completely cured.
Most puppies recover well and quickly from an FHO but lifelong weight management and exercise are essential to prevent further stress on the joint, and joint supplements and regular checkups are important to maintain joint health and prevent arthritis.
The Financial Cost
Of course, conservative management is going to cost less than an FHO. You’re looking at a difference of $60-$150 per month for medications versus $1,200-$3,000 per hip for surgery.
Because Legg-Calvé-Perthes is a hereditary condition, many owners worry it won't be covered. The good news? Most top-tier pet insurance providers (like Embrace) cover hereditary and congenital conditions as long as they weren't diagnosed before your policy started.
While surgery costs a lot up front, the success rate is much higher and coverage with health insurance for dogs can help with the cost.
However, the surgery is only the first step. Embrace is one of only a few pet insurance companies that covers complementary treatments as a standard part of their accident and illness policies. This is vital for recovery, as it helps cover the costs of:
Hydrotherapy
Physical Therapy
Laser Therapy
Without this coverage, pet parents often face high out-of-pocket costs for the very therapies that make the surgery successful:
Treatment Type | Estimated Cost (2026) | Typical Frequency |
|---|---|---|
Initial Rehab Eval | $180 – $225 | One-time |
Hydrotherapy | $75 – $175 | 2-3 sessions / week |
Physical Therapy | $100 – $200 | Weekly for 8-12 weeks |
Laser Therapy | $40 – $100 | 1-2 sessions / week |
These treatments ensure your small breed puppy rebuilds the muscle they need to return to a life of pain-free zoomies.
Prevention and Risk Management
There are many health issues that you can prevent in your dog through regular veterinary care, a proper diet, and exercise. Unfortunately, Perthes disease can’t be prevented in all cases, but there are things you can try.
Risk Reduction Strategies
Some cases of Perthes disease start with an injury to the hip. This means that making sure your puppy plays safely and gets regular exercise may help.
Breeding Considerations
When a disease has genetic backing, selective breeding becomes very important. Ensure that your puppy comes from a reputable breeder that doesn’t use animals with unhealthy track records. Before bringing a puppy home, ask to see the OFA Hip Evaluations for both parents to ensure they have healthy joints.
Don't be afraid to be direct: Ask if there is any history of Legg-Perthes in their bloodline. A responsible breeder will provide a health guarantee for hereditary conditions.
Speak to your veterinarian for further guidance.
Regular Veterinary Care
Getting your puppy into the veterinarian on a regular basis can help ensure that they are growing and developing normally, and that you’re feeding and exercising them properly. Your vet should be your go-to for all questions regarding your puppy’s activities and any health concerns. Investing in a wellness plan for dogs can help budget for the costs of these routine visits.
Legg Calvé Perthe Disease
Legg-Calvé-Perthes is a debilitating condition affecting the hip joint in young, small breed dogs. It likely has a genetic component, so selecting a puppy from a reputable breeder is a key in preventing this issue. Regular veterinary care also goes a long way in recognizing this condition early on and getting treatment so that your puppy suffers the least amount possible.