Angular Limb Deformities in Cats

Angular limb deformities is the term used to describe deviation in bone shape from what is considered to be normal. Angular limb deformities in cats can be either congenital or developmental. Congenital deformities are present at the time of birth, whereas developmental deformities develop during the feline’s growth period, typically between four to eight months of age. Angular limb deformities are a result of irregularities of the growth plates responsible for bone growth as the feline matures. The growth plates are soft and do not fuse until one year of age, therefore, trauma or nutritional experiences before the feline reaches one year will result in angular limb deformities. 

Angular limb deformity in cats is an abnormal bone growth that has resulted in irregularly shaped or crooked limbs. Angular limb deformities can be present at the time of birth or develop during the cat’s growth period. The forelimbs are the most common area to be affected by angular limb deformities, as they are made up of two long bones, but the rear limbs can also be affected. Cat owners will note a prevalent bowing of the legs, either inward our outward. Some felines with angular limb deformities will not experience complications, whereas others experience clinical signs of limping, pain, and the inability to complete certain tasks. Many develop arthritis with age.

Clinical signs of angular limb deformities in cats are noted by the presence of the bones of the limbs bowing away or toward the feline’s midline. Commonly affecting the ulna and radius, pet owners will observe this irregularity from the front of the feline, as her standing stance will seem abnormal. Some felines may not experience discomfort from the present deformity, whereas others may experience pain and limited mobility. On a radiograph, the presence of a bone deformity will be visible, but pet owners may notice symptoms including: 

• Pain
• Reduced range of motion in joints
• Limping 
• Inability to perform certain activities (jumping, running) 
• Arthritis (later in life) 

Types

Congenital 

Congenital angular limb deformities in cats are present at the time of birth and are often the result of a genetic disorder or fetal malpositioning.

Developmental 

Developmental angular limb deformities in cats occur during the feline’s growth period (4-8 months) as a result of trauma to the growth plates. 

Angular limb deformities in cats have numerous causes, with the most common causes being trauma or a genetic disorder. 

Traumatic causes of angular limb deformities in cats include:

• Falls
• Hit-by-car
• Being dropped 
• Being stepped on 

Congenital causes of angular limb deformities in cats include:

• Hereditary malformation 
• Genetic disorder 

Angular limb deformities in cats affect a feline at an early age and a medical record may not yet be established to review as part of the diagnostic procedure. However, cat owners can aid the veterinarian by providing vital information that is relevant to the feline’s condition. Informing the doctor of past trauma the young cat has sustained or familial disorders with the parents or siblings is crucial information for you to relay to the vet. A physical exam of the affected feline will be conducted, moving the affected limbs to detect range of motion and the presence of pain. 

X-ray (Radiography) 

An x-ray is the primary method a veterinarian will use to investigate a limb deformity. The radiograph enables the doctor to view the location, direction, and magnitude of the bone abnormality. 

CT scan (Computed tomography) 

A CT scan is often completed after an x-ray as this exam provides a cross-sectional image of the affected limb(s). This 3-dimensional image will provide the veterinarian with additional information about the deformity in comparison with the x-ray.

Many felines with mild angular limb deformities can be managed without the need for surgery. A mild angular limb deformities in cats is primarily a cosmetic flaw, not accompanied by pain or mobility issues. The veterinarian may treat these cases with conservative management methods such as weight management, provision of joint supplements and avoidance of intense exercise. A conservative management method is set in place to decrease unnecessary stress to the joints, preventing injury and arthritis later on in the cat’s life. 

Cats with severe angular limb deformities may require surgical correction and are often referred to a specialist. Surgical correction of an angular limb deformity requires the placement of skeletal fixators to straighten the bone and keep them aligned. Surgical correction of angular limb deformities in cats has potential risks that your veterinarian will discuss with you if your cat is suffering severely from angular limb deformities. 

The prognosis for cats that have received conservative management for their angular limb deformities is a relatively positive end result. The main goal in management of an angular limb deformity is to decrease stress to the joints, therefore it is crucial to follow veterinary instructions. Felines that have undergone surgical correction will be reevaluated frequently to ensure the bones have not continued to twist and are healing correctly.