Hip Dysplasia in Cats

Feline hip dysplasia involves abnormal hip joint formation where the ball and socket do not fit together properly, leading to joint instability, pain, and eventually arthritis.

Although less frequently diagnosed in cats, this disease can significantly impact their quality of life, causing discomfort, decreased mobility, and altered behavior. 

This article covers the causes, preventions, and solutions to hip dysplasia in cats for concerned owners.  

What are The Causes of Feline Hip Dysplasia?

Several factors contribute to the development of hip dysplasia in cats, primarily:

• Certain breeds of cats are more likely to have hip dysplasia
• Overfeeding in kittens can lead to rapid growth which contributes to hip dysplasia
• Excessive exercise can cause damage that leads to hip dysplasia

Genetics:

Certain breeds are more genetically predisposed to developing hip dysplasia, including Maine Coon, Persian, and Himalayan breeds. Studies have indicated a significant hereditary component, suggesting that the condition can be passed down through generations.

Nutrition:

Overfeeding and rapid growth during kittenhood can exacerbate the development of hip dysplasia. Excessive weight gain can place additional stress on the developing joints, leading to malformation and instability.

Activity Level:

While moderate exercise is beneficial, excessive or inappropriate physical activity can lead to joint damage and increase the risk of developing hip dysplasia.

Hip Dysplasia Prevention Strategies

Preventing hip dysplasia involves a combination of the following nutritional and environmental strategies aimed at minimizing the risk factors associated with the development of this condition:

• Diet and supplementation can help prevent symptoms
• Controlling weight and monitoring extreme exercise are important
• Staying in touch with your veterinarian and creating a prevention plan can be very helpful

Proper Nutrition

Providing a balanced diet during a cat’s growth phase is crucial. Avoiding overfeeding and ensuring that kittens receive appropriate levels of nutrients can prevent rapid growth and excessive weight gain, which are risk factors for hip dysplasia. Specialized diets formulated for growing kittens can help maintain an optimal growth rate and support healthy joint development.

Weight Management

Maintaining an optimal body weight throughout a cat's life reduces the stress on hip joints. Preventing obesity through controlled feeding practices and regular monitoring of body weight is essential. For adult cats, regular exercise and portion-controlled feeding can help maintain a healthy weight and support joint health.

Controlled Exercise

Appropriate exercise is vital for developing strong muscles that support the joints. Providing a balance of activity that promotes muscle development without overexerting the joints is important. Controlled play and avoiding high-impact activities can help prevent joint damage during the critical growth periods.

Regular Veterinary Check-Ups

Regular veterinary check-ups can help detect early signs of hip dysplasia. Early intervention and management strategies can be implemented if any abnormalities are detected, potentially mitigating the progression of the disease.

Symptoms to Look for in Your Cat

The clinical signs of hip dysplasia in cats can vary widely, ranging from subtle to severe. In some cases, cats may exhibit no obvious signs, making diagnosis challenging. Common clinical signs include:

• Limping and intermittent lameness are signs of the discomfort and pain of hip dysplasia
• Reduced activity could signal hip discomfort
• Changes to gait and stiffness in the legs are also signs

Lameness

Lameness is one of the most common signs of hip dysplasia in cats. Affected cats may exhibit a limp or favor one hind limb over the other. The lameness can be intermittent or persistent and may worsen after physical activity or prolonged rest. Cats with hip dysplasia might also show reluctance to bear weight on the affected limb(s), leading to noticeable limping or altered movement.

Pain and Discomfort

Pain and discomfort are significant signs of hip dysplasia. Cats may vocalize when their hip area is touched or manipulated. They might also show signs of discomfort when performing activities that involve their hind limbs, such as jumping or climbing. Some cats may become less tolerant of handling and grooming, particularly around the hip region.

Decreased Activity

A reduction in activity levels is often observed in cats with hip dysplasia. Cats that were previously active and playful may become more sedentary and less willing to engage in physical activities. They may begin avoiding exercise, climbing stairs, or playing with toys. This decrease in activity is often a response to the pain and discomfort associated with the condition.

Stiffness and Reduced Range of Motion

Stiffness, particularly after periods of rest or upon waking, is a common sign of hip dysplasia. Affected cats may have difficulty rising from a lying position and may move more slowly and cautiously. The range of motion in the joints may be reduced, making it challenging for the cat to perform normal activities that require flexibility and mobility. 

Altered Gait

Cats with hip dysplasia often exhibit an altered gait. This can include a swaying or "bunny-hopping" motion of the hind end, where the cat uses both hind legs together rather than in a normal alternating pattern. The altered gait is typically a compensatory mechanism to minimize pain and discomfort in the joints. Observing a cat’s movement from behind can help identify these gait abnormalities.

Behavioral Changes

Behavioral changes can be an indirect sign of hip dysplasia in cats. Affected cats may become more withdrawn, irritable, or less interactive with their pet parents and other pets. They may also display changes in grooming habits, such as reduced grooming of the hindquarters due to pain or difficulty reaching those areas. Some cats may also exhibit changes in litter box habits, such as avoiding the box if it requires climbing or stepping up.

Muscle Loss

Over time, chronic pain and decreased use of the affected limbs can lead to muscle atrophy. This is the wasting away of muscle mass, particularly in the hindquarters. The loss of muscle tone and mass can further exacerbate the instability of the hip joints and contribute to the progression of the condition.

Grinding or Popping

In advanced cases of hip dysplasia, veterinarians may detect crepitus, which refers to a grinding or popping sensation, and joint laxity during physical examination. Crepitus occurs due to the abnormal contact between the femoral head and acetabulum, leading to joint degeneration. Joint laxity, or looseness, is a hallmark of hip dysplasia and can be assessed through specific manipulation techniques during the examination.

How is Feline Hip Dysplasia Diagnosed?

Diagnosing hip dysplasia in cats involves a comprehensive approach combining clinical evaluation, imaging techniques, and sometimes advanced diagnostic tools. The goal is to accurately assess the structure and function of the hip joints to determine the presence and severity of the condition as follows:

• Veterinarians will conduct a physical examination
• They will likely take X-rays and conduct advanced imaging tests to better diagnose the issue

Physical Examination

The initial step of diagnosis is a thorough physical examination by a veterinarian. During this examination, the veterinarian will:

Observe Gait and Movement: The veterinarian will observe the cat’s gait, posture, and movement to identify any signs of lameness, altered gait, or discomfort. Observing how the cat walks, runs, and jumps can provide valuable insights into the severity and impact of the condition.

Palpation and Manipulation: The veterinarian will palpate the joints and surrounding muscles to assess for pain, swelling, or muscle atrophy. Manipulating the hips through various ranges of motion can help identify joint laxity and crepitus (a grinding or popping sensation). Specific tests, such as the Ortolani sign, can be performed to detect joint instability and subluxation.

Assessing Range of Motion: Reduced range of motion in the joints is a common sign of hip dysplasia. The veterinarian will gently extend and flex the hind limbs to evaluate the ease and extent of movement.

Radiographic Imaging (X-ray)

X-rays are a crucial tool for a definitive diagnosis. They provide detailed images of the joints, allowing the veterinarian to assess the structure and alignment of the ball and socket joint. Key aspects of radiographic evaluation include:

Standard Views: The most commonly used radiographic views for diagnosing hip dysplasia are the ventrodorsal (VD) hip extended view and the lateral view. The VD hip extended view involves positioning the cat on its back with the hind limbs extended and the knees rotated inward. This view provides a clear image of both hip joints.

Assessment of Joint Congruity: Radiographs allow for the evaluation of the fit between the ball and socket joint. In hip dysplasia, there is often a shallow acetabulum and a flattened or irregular femoral head, leading to poor joint congruity.

Measurement of Angles: Specific angles, such as the Norberg angle, can be measured to quantify the degree of hip dysplasia. The Norberg angle assesses the coverage of the femoral head by the acetabulum, with smaller angles indicating more severe dysplasia.

Evaluation of Secondary Changes: Radiographs can also reveal secondary changes associated with chronic hip dysplasia, such as osteophyte formation (bone spurs), joint space narrowing, and subchondral sclerosis (increased bone density).

Advanced Imaging Techniques

In some cases, advanced imaging techniques may be required to obtain more detailed information about the hip joints and surrounding structures. These techniques include:

Computed Tomography (CT): CT scans provide cross-sectional images of the joints, offering detailed views of the hip bone and soft tissue structures. CT is particularly useful for evaluating complex cases and planning surgical interventions.

Magnetic Resonance Imaging (MRI): MRI is the gold standard for imaging soft tissues and can provide detailed information about the cartilage, ligaments, and muscles around the hip joint. It is useful for assessing the extent of joint damage and identifying any concurrent soft tissue injuries.

Diagnostic Procedures and Tests

Additional diagnostic procedures and tests may be employed to further evaluate hip dysplasia in cats:

Joint Fluid Analysis: In cases where there is significant joint swelling or effusion, joint fluid analysis can help rule out other conditions such as infectious arthritis or immune-mediated joint disease. This involves aspirating a small amount of fluid from the joint and analyzing it for signs of inflammation or infection.

Genetic Testing: For breeds with a known predisposition to hip dysplasia, genetic testing can be a valuable tool for identifying carriers of the condition. Genetic testing can help breeders make informed decisions and reduce the incidence of this ailment in future generations. 

How to Treat Your Cat's Hip Dysplasia

The treatment of hip dysplasia in cats depends on the severity of the condition and the individual cat's overall health. Treatment options can be broadly categorized into conservative management and surgical interventions as follows:

• At home management and physical therapy are options to significantly help symptoms
• If symptoms are advanced enough, surgery may be required

Conservative Management

Conservative management aims to alleviate discomfort, improve joint function, and enhance the cat's quality of life. This approach may include:

Weight Management: Maintaining an optimal body weight is crucial to reduce stress on the joints. Weight loss in overweight cats can significantly improve the signs.

Exercise Modification: Controlled exercise routines that avoid high-impact activities can help maintain muscle mass and joint flexibility without exacerbating the condition.

Pain Relief: Your vet may prescribe anti-inflammatory medication and other pain relievers to manage pain and inflammation. Regular monitoring and adjustments are necessary to avoid side effects.

Nutritional Supplements: Joint supplements containing glucosamine, chondroitin, and omega-3 fatty acids may support joint health and reduce inflammation.

Physical Therapy: Physical therapy, including hydrotherapy and specific exercises, can improve muscle strength and joint mobility.  

Surgical Intervention

In cases where conservative management is insufficient, surgical treatment may be considered. Surgical options include:

Femoral Head and Neck Excision (FHNE): This procedure involves removing the femoral head and neck, creating a false joint. It can effectively alleviate pain and improve function, particularly in smaller and lighter cats.

Total Hip Replacement (THR): THR is a more advanced surgical option that involves replacing the diseased hip joint with an artificial one. It can provide excellent outcomes but is typically reserved for severe cases due to its complexity and cost.

Juvenile Pubic Symphysiodesis (JPS): JPS is a preventive surgical procedure performed on young kittens at risk of developing hip dysplasia. It involves the intentional fusion of the pubic symphysis, which can help improve hip joint congruency as the kitten grows. 

What's The Average Cat Hip Dysplasia Surgery Cost?

There are a few common types of hip dysplasia surgery, each with different costs:

• Femoral head replacement (replacing the "ball" of the joint) can cost anywhere from $1,000 to $3,000
• Total hip replacement (replacing one hip) typically costs around $4,000
• Bilateral hip replacement (replacing or operating on both hips) costs upwards of $7,000

Conclusion

Hip dysplasia in cats, a degenerative disease affecting the hip joint, presents significant challenges in feline health care. This condition, often characterized by a misalignment known as subluxation, can lead to pain, reduced mobility, and arthritis over time. It is particularly prevalent in purebred cats, with the following breeds being notably at risk: Maine Coons, Persians, and Himalayans.

While severe cases of hip dysplasia may require surgical intervention to restore joint function and alleviate pain, mild cases can often be managed with conservative treatments such as weight management, nutritional supplements, and pain relief medications.

Preventive measures, including responsible breeding practices and proper nutrition, are essential to reduce the incidence of this disease in feline populations. Continued research into the genetic and biomechanical aspects of the condition will further enhance our ability to diagnose, treat, and prevent hip dysplasia in felines, ultimately improving their overall health and well-being.

References

1. Černá, P., Timmermans, J., Komenda, D., Nývltová, I., & Proks, P. (2021). The Prevalence of Feline Hip Dysplasia, Patellar Luxation and Lumbosacral Transitional Vertebrae in Pedigree Cats in The Czech Republic. Animals : an open access journal from MDPI, 11(9), 2482. https://doi.org/10.3390/ani11092482

2. Cornell Feline Health Center. (n.d.). Hip dysplasia. Cornell University College of Veterinary Medicine. Retrieved May 27, 2024, from https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/hip-dysplasia#:~:text=A%20specific%20cause%20of%20feline,breeds%2C%20such%20as%20Maine%20Coons

3. Loder, R. T., Todhunter, R. J., & Lattimer, J. C. (2016). Hip dysplasia: A comprehensive analysis. Journal of Feline Medicine and Surgery, 18(4), 312-327. https://doi.org/10.1177/1098612x16631227