Hip Joint Disease in Very Young Dogs (Legg-Calvé-Perthes Disease)

  • Occurrence: rarer
  • Location of disease: Legs
Author: Dr. med. vet. Gisa Löwe | Last modified: 11.08.2026
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When to visit the vet?

Non-urgent see a veterinarian within 2–3 days

?

If the condition worsens / symptoms persist, consult a veterinarian.

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Definition

Legg-Calvé-Perthes disease, also known as femoral head necrosis, is an orthopedic condition in dogs caused by insufficient blood supply to the femoral head, leading to breakdown of bone tissue and ultimately deformation of the femoral head.

The most important facts at a glance

Legg-Calvé-Perthes disease in dogs is a condition in which blood supply to the femoral head is disrupted, resulting in aseptic necrosis of the femoral head. This disease occurs mainly in young dogs between 4 and 12 months of age, particularly in small breeds such as Yorkshire Terriers and Miniature Poodles. The exact cause is unclear, but genetic factors appear to play a role. Traumas or mechanical stress can also trigger the disease by impairing blood supply to the hip. Symptoms include lameness, pain during movement, reluctance to move, and muscle atrophy. Diagnosis is made through clinical examination and X-ray images showing changes in the femoral head. Early diagnosis is crucial to slow disease progression and improve treatment success. Treatment varies depending on severity and can range from conservative therapy with pain medication and physiotherapy to surgical interventions. A common operation is femoral head resection, in which the damaged femoral head is removed. After surgery, careful follow-up care is important to support recovery. The prognosis is generally good with timely treatment, and many dogs can lead a normal life. Prevention is difficult, but maintaining a healthy weight and selecting healthy parent animals can help reduce the risk.

Causes

The scientific basis of Legg-Calvé-Perthes disease involves disruption of blood supply to the femoral head, leading to aseptic necrosis. This condition typically occurs in young dogs between 4 and 12 months of age, particularly in small breeds such as Yorkshire Terriers, West Highland White Terriers, and Miniature Poodles. The reduction in blood supply causes bone tissue in the femoral head to die, leading to weakening and progressive deformation of the bone.

The exact causes of Legg-Calvé-Perthes disease are not fully understood, but genetic factors are believed to play a role. Studies have shown that the condition occurs more frequently in certain dog breeds, suggesting a hereditary component. Additionally, traumas or mechanical stress on the hip could contribute to the development of the disease by further impairing blood supply.

Another possible factor is the development and growth of the bone. Since this disease often occurs in rapidly growing dogs, an imbalance between bone growth and blood supply during the development phase could play a role. Environmental factors and nutrition could also influence the occurrence and course of the disease.

Symptoms

Rare symptoms:

The symptoms of Legg-Calvé-Perthes disease are often subtle and develop gradually. One of the first signs is mild lameness of the affected leg, which initially occurs only occasionally but becomes more frequent over time. This can be caused by pain resulting from necrosis of the femoral head and subsequent inflammation.

Affected dogs may also show decreased activity and be less willing to run or jump. In advanced stages of the disease, lameness may become more pronounced, and the dog may have difficulty bearing weight on the affected leg. Examination may also reveal atrophy of the thigh muscles, as the dog favors the affected leg.

Additionally, restricted hip joint mobility may be noticed, and the dog may show pain when the joint is moved. In some cases, cracking or clicking may be heard when the hip joint is moved. These symptoms often indicate that the femoral head is already significantly damaged.

Therapy

Treatment of Legg-Calvé-Perthes disease depends on the severity of the condition and the age of the affected dog. In mild cases, conservative treatment with pain medication, anti-inflammatory drugs, and physiotherapy may be attempted to relieve symptoms and improve hip mobility.

In many cases, however, surgical intervention is required to relieve pain and improve hip joint function. The most common operation is femoral head resection, in which the affected femoral head is removed. This prevents the damaged bone surfaces from rubbing against each other and causing pain. After surgery, a fibrous pseudojoint forms, which allows hip mobility.

Post-operative care is crucial for treatment success. It typically includes physiotherapy and controlled exercise to strengthen muscles and promote joint mobility. The dog may need to be kept on a leash for several weeks to avoid excessive stress on the hip.

Prognosis and follow-up care

The prognosis for dogs with Legg-Calvé-Perthes disease varies depending on the severity of the condition and the treatment performed. With early diagnosis and appropriate treatment, especially surgical intervention, the prognosis is generally good. Many dogs can lead a pain-free life after surgery and resume normal activity.

In cases where the disease is not treated in time or no surgery is performed, permanent impairment of mobility and chronic pain may result. The dog’s quality of life can be significantly affected, and there is a risk of secondary arthritis in the affected joint.

Long-term follow-up care and regular veterinary check-ups are important to monitor the progress of recovery and to detect possible complications early. Even after successful treatment, dog owners should ensure that their animal maintains a healthy weight and that excessive stress on the hip is avoided.

Prevention

Since the exact causes of Legg-Calvé-Perthes disease are not fully understood and genetic factors play a role, prevention of this condition is challenging. One of the best preventive measures is to pay attention to the health of the parent animals when selecting a puppy and choose breeders who test for genetic diseases.

It is important for dogs, especially those of breeds that are susceptible to the disease, to maintain a healthy weight in order to minimize the stress on the hip joints. A balanced diet and regular, but not excessive, exercise can help maintain joint health.

Although there are no specific measures to completely prevent the disease, early preventive examinations by the veterinarian can help to recognize the first signs and respond accordingly. An attentive approach to the dog’s musculoskeletal system, combined with good veterinary care, can reduce the risk of complications and the progression of the disease.

Outlook on current research

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Legg-Calvé-Perthes disease is aseptic necrosis of the femoral head, meaning death of bone tissue in the femoral head due to disrupted blood supply. In veterinary medicine, it primarily affects young dogs of small breeds. Research today focuses mainly on why blood supply breaks down. Genetic predisposition, local vascular disorders, mechanical stress, and bone remodeling disturbances are discussed. A single cause valid for all cases has not yet been confirmed. (merckvetmanual.com, pubmed.ncbi.nlm.nih.gov)

An important research outlook lies in earlier diagnosis. Conventional X-ray images often show changes clearly only when structural damage has already occurred. Therefore, earlier staging, more precise imaging, and better functional assessment of the hip are gaining importance. This could help identify patients earlier in the future and select therapy more specifically. (pubmed.ncbi.nlm.nih.gov)

A second focus is therapy optimization. So far, surgical treatment dominates in small animal medicine for advanced cases, such as femoral head-neck resection. In the future, it will be crucial to determine which patients benefit most from which method, and whether joint damage can be slowed earlier. (merckvetmanual.com)

Overall, the outlook is cautiously positive: Research is evolving from pure description of the disease toward earlier detection, better clarification of causes, and more individualized therapy planning.

Frequently Asked Questions (FAQs)

1. What is Legg-Calvé-Perthes disease?
Legg-Calvé-Perthes disease is aseptic necrosis of the femoral head in young dogs of small breeds. Due to circulatory disorders, bone tissue in the femoral head dies, the bone collapses, and the hip joint becomes deformed. This leads to pain and lameness.
2. Which dogs are affected?
Typically, dogs of small and toy breeds weighing less than ten kilograms are affected, especially West Highland White Terriers, Yorkshire Terriers, Jack Russell Terriers, Miniature Poodles, and Chihuahuas. The average age at onset is between five and eight months. Males and females are affected approximately equally.
3. What is the cause?
The exact cause is not fully understood. Local circulatory disorders of the femoral head epiphysis, hereditary factors, and hormonal influences during growth are discussed. A hereditary component is particularly likely in West Highland White Terriers and terriers in general.
4. What symptoms does an affected dog show?
Dogs usually develop gradually increasing hind limb lameness that becomes progressively more pronounced over weeks. The thigh muscles atrophy, and the hip is painful during passive movement. Usually only one side is affected; in about ten to fifteen percent of cases, both sides are affected.
5. How is the diagnosis made?
The key finding is the pelvic X-ray image, which shows irregular bone density, deformation and flattening of the femoral head, and joint space changes. In early stages, MRI can visualize circulatory disorders before radiographic changes appear.
6. How is the disease treated?
In mild, early cases, conservative treatment with rest, weight reduction, physiotherapy, and pain medication may be attempted. When joint changes are significant, surgery is the treatment of choice. The standard procedure is femoral head resection, in which the deformed femoral head is removed and a fibrous pseudojoint forms.
7. What is the prognosis after surgery?
In small dogs with timely surgery, the prognosis is very good. Most animals become pain-free again within three to six months after consistent physiotherapy. A loading deficit often does not persist, occasionally with minor muscle atrophy.
8. What role does physiotherapy play?
Physiotherapy is crucial for treatment success. Targeted muscle building, passive movement exercises, underwater treadmill, and controlled exercise training accelerate the return to normal loading. Without physiotherapy, functional mobility often remains limited.
9. Is total hip replacement an option?
In very small dogs, femoral head resection is usually sufficient due to low joint loading. Total hip replacement is considered in larger dogs or in bilateral disease with pronounced functional impairment. It provides functionally somewhat better results but is significantly more complex.
10. How can it be prevented?
There is no certain prevention. Weight-appropriate, not overly energy-rich puppy nutrition and moderate, joint-friendly exercise during growth probably reduce the risk. When familial predisposition is known, affected dogs should not be used for breeding.

Literature

  • Aguado, E., & Goyenvalle, E. (2021). Legg Calvé Perthes disease in the dog. Morphologie, 105(349), 143–147. https://doi.org/10.1016/j.morpho.2020.11.011
  • Cardoso, C. B., Rahal, S. C., Mamprim, M. J., Oliveira, H. S., Melchert, A., Coris, J. G. F., & Mesquita, L. R. (2018). Avascular necrosis of the femoral head in dogs — Retrospective study. Acta Scientiae Veterinariae, 46, Article 1537. https://doi.org/10.22456/1679-9216.81845
  • Jankovits, D. A., Liska, W. D., & Kalis, R. H. (2012). Treatment of avascular necrosis of the femoral head in small dogs with micro total hip replacement. Veterinary Surgery, 41(1), 143–147. https://doi.org/10.1111/j.1532-950X.2011.00925.x
  • Vasseur, P. B., Foley, P., Stevenson, S., & Heitter, D. (1989). Mode of inheritance of Perthes’ disease in Manchester terriers. Clinical Orthopaedics and Related Research, 244, 281–292. https://doi.org/10.1097/00003086-198907000-00031
  • Pidduck, H., & Webbon, P. M. (1978). The genetic control of Perthes’ disease in toy poodles—A working hypothesis. Journal of Small Animal Practice, 19(12), 729–733. https://doi.org/10.1111/j.1748-5827.1978.tb05564.x
  • Mickelson, M. R., McCurnin, D. M., Awbrey, B. J., Maynard, J. A., & Martin, R. K. (1981). Legg-Calvé-Perthes disease in dogs: A comparison to human Legg-Calvé-Perthes disease. Clinical Orthopaedics and Related Research, 157, 287–300.
  • Isola, M., Zotti, A., Carnier, P., Baroni, E., & Busetto, R. (2005). Dual-energy X-ray absorptiometry in canine Legg-Calvé-Perthes disease. Journal of Veterinary Medicine Series A, 52(8), 407–410. https://doi.org/10.1111/j.1439-0442.2005.00746.x