Hip dysplasia is a disease that consists of a bad union between the articular surfaces of the hip joint: the acetabulum and the head of the femur. When this happens, cats begin with weakness and dislocation of the joint until a series of morphological and degenerative changes occur in the area that require treatment so that the cat can have a better quality of life.
Seems more common in purebred females such as Persians, Maine Coons, or British Shorthairs. Despite the fact that this disease begins to develop when they are small, it is with age when it becomes more manifest and is usually diagnosed due to the speci alty that cats have to hide their ailments. Keep reading this article on our site to learn all about hip dysplasia in cats, its symptoms and treatment.
What is hip dysplasia?
Hip dysplasia is a maladaptation or an incongruence between the articular part of the hip (acetabulum)with the articular part of the femur (head). This results in joint laxity , so that the head of the femur can shift or move, progressively inflaming and weakening the joint area with cartilage erosion, microfractures and subluxation. All this leads to instability in the hip joint that will give rise to a series of degenerative alterations such as osteoarthritis with discomfort, pain or lameness, degenerative osteoarthritis and atrophy of the muscles of the hind limbs.
The development of this trauma condition is due to the interaction between genetic and environmental factors Although the parents of a cat with dysplasia have not manifested, the offspring has inherited his genes. Sometimes it can be accompanied by a dislocated patella.
Cat breeds most predisposed to hip dysplasia
There is a racial predisposition to hip dysplasia, so the most prone breeds are:
- Persian
- Maine coon
- British Shorthair
- Himalayan
- Siamese
- Abyssinian
- Devon rex
Also, it seems more frequent in females than in males.
Symptoms of Hip Dysplasia in Cats
The symptoms of feline hip dysplasia will depend on the degree of incongruity of the joint. They can start between 4 and 12 months of age with weakness in the joints until degenerative signs, when the cat is reaching age with the problem. In this way, we can find the following range of clinicalsigns:
- Inactivity increased.
- Difficulty jumping, running or climbing.
- Exercise intolerance.
- Hind legs closer together than normal.
- Decreased mobility of the hind limbs and the hip, so that it is common to see the cat drag its hind legs.
- Muscular atrophy of the thigh.
- Increase of the muscles of the forelimbs (to compensate for the atrophy of the hind limbs).
- Difficulty getting up.
- Hip snapping when walking or standing up.
- Hip pain.
- Intermittent or persistent lameness of the hind legs.
An important thing to note is that Overweight and obesity further promote the progression and worsening of clinical signs of hip dysplasia in cats.
Unlike what happens in dogs, cats, being experts in hiding their ailments, show very few symptoms, which suggests that this disease may be very underdiagnosed in this species. These felines with few symptoms may not want to climb to high places, stairs, be less active or sleep more, which may go unnoticed by the caregiver or, if they are old, relate it to aging.
This few symptoms may be due to the following particularities of cats, in relation to dogs:
- More sedentary lifestyle inside the house, moving as little as possible.
- Greater size and location of the lumbar spinous and transverse processes, as well as differences in the femurs and pelvic tuberosities can modify the degree of support of the muscle masses that are inserted in the area.
- Lighter skeleton with stronger muscle mass that would explain why the joint remained strong for longer, delaying or avoiding arthritis and the consequent pain.
Diagnosis of hip dysplasia in cats
The diagnosis of hip dysplasia in cats should be made by first ruling out other orthopedic disorders with similar clinical signs. The necessary tests to complete the diagnosis of this disease are:
- Urinalysis and blood tests (CBC and biochemistry).
- Palpation of both hip joints.
- Radiographs of the hip in various projections to assess whether there are characteristic changes of the pathology through a series of measurements, such as the Norberg angle to assess dislocation/subluxation, increased acetabular width and decreased depth, or flattening and deformity of the femoral head.
It should be noted that hip dysplasia in Persian cats is especially common, and it is important to take X-rays from one year of age in this breed.
Treatment of hip dysplasia in cats
Once feline hip dysplasia is detected, treatment must begin, otherwise the disease will progress and the cat will feel worse and worse, with more obvious signs.
Symptomatic treatment
Initially, treatment should be symptomatic to improve the cat's quality of life, slow down the progression of degenerative changes and reduce inflammation and pain. The following drugs are used:
- Corticoids: such as dexamethasone in a single dose at the beginning, continuing with prednisolone due to its anti-inflammatory effect, of choice in acute cases of inflammation of the joint capsule. They should not be used long-term, as it can reduce the formation of collagen and proteoglycans, damaging cartilage.
- Non-steroidal anti-inflammatory drugs: those that act against cyclooxygenase 1 and 2 (COX-1 and COX-2) are chosen to inhibit the synthesis of prostaglandins that mediate pain and inflammation.
- Glycosaminoglycans (GAGs): Being part of joint cartilage, they are used as precursors of glucuronic acid, glucosamine and glutamine, among others. They serve to regenerate joint cartilage and reduce symptoms thanks to their analgesic and anti-inflammatory properties.
Surgery
In cats with severe hip dysplasia or those that do not respond to conservative treatment, surgical intervention should be considered, performing:
- Excision of the head of the femur: to form a fibrous pseudojoint that can reduce pain.
- Triple hip osteotomy (OTC): performing osteotomy of the pubis, ilium and ischium to free the acetabulum and reorient it to improve congruence between it and the head of the femur. This can correct the subluxation and increase the stability of the joint.
- Artificial prosthetics When the osteoarthritis or the disease is very advanced, the acetabulum and the femoral head and neck are removed to replace them with implants. Its great disadvantage is its high cost.
Physiotherapy can also be very helpful in cats with hip dysplasia.
