By Mindy Cohan, VMD
Maintaining good bone health is essential for a pet’s well-being since they provide crucial support for the entire body. There are a wide variety of bone diseases that can affect pets, yet many present with similar symptoms, such as limping and pain. It is important for pet owners to recognize the signs of bone disease and to seek treatment early to maintain their dog or cat’s optimal health.
Arthritis refers to inflammation of a joint within the body. While it is often associated with pets in their senior years, young animals can develop arthritis secondary to a traumatic injury or congenital poor joint conformation. Pain and inflammation develop in a joint when cartilage—connective tissue which serves as a shock absorber between bones—becomes damaged or compromised.
As arthritis develops, you may notice your dog or cat rising more slowly or having difficulty jumping and climbing stairs. Many pets with arthritis develop a transient or permanent limp or other gait changes. Fortunately, there are many therapeutic options for treating arthritis and alleviating the associated discomfort.
Pets with arthritis fare much better when maintained at a healthy weight. So, encourage regular, moderate exercise for your pet to help burn calories and minimize stiffness without creating an additional strain on the joints. Swimming, for example, is a great option for water-loving dogs.
In addition to activities that improve a pet’s mobility, several medical options are available. Your veterinarian can make recommendations on joint supplements, pain-relieving medications, laser therapy and acupuncture. Some causes of arthritis, such as hip or elbow dysplasia, often require surgical intervention.
A bone infection (osteomyelitis) can result from a traumatic injury, such as a fracture, bite wound or laceration, in which the local skin barrier has been compromised. Systemic infections can also reach bone through the bloodstream. In contrast to pets with arthritis, dogs and cats with bone infections often exhibit additional symptoms like fever, lethargy and decreased appetite. The affected site is usually painful, red, swollen and warm to the touch.
A veterinarian will need to perform a physical exam on your pet, complimented by blood and urine tests, bacterial or fungal cultures and radiographs. Depending on the nature and severity of the infection, your pet will need antibiotics and possibly require hospitalization for supportive care or surgery.
Panosteitis, osteochondrosis, and hypertrophic osteodystrophy are the three most common metabolic bone disorders seen in dogs. While the exact cause of these diseases has yet to be determined, nutrition is suspected to play a role in osteochondrosis and hypertrophic osteodystrophy. All three of these bone problems most commonly affect large and giant breed dogs, and typically when they are under the age of one. A diagnosis is based upon physical exam findings and radiographic changes.
Lameness is the primary problem noticed by owners of dogs suffering from metabolic bone disorders. Panosteitis and hypertrophic osteodystrophy can also cause fever, lethargy and a diminished appetite.
Pain management is vital for treatment. Dogs with panosteitis and hypertrophic osteodystrophy with systemic symptoms sometimes require additional supportive care such as intravenous fluid therapy. Although dogs with osteochondrosis can be managed with anti-inflammatories and other pain medications, the optimal treatment is surgery.
Trauma is the primary cause for fractured bones seen in dogs and cats. Car accidents, falls from a great height, or fights with other animals can lead to breaks in bones. Fractures are categorized as either open or closed. Open, or compounded fractures, involve the protrusion of bone through the skin and should be addressed by a veterinarian immediately to prevent infection.
Pets with fractures are suffering from acute, severe pain and sometimes lash out or bite if touched. Therefore, it is important to exercise caution when handing an injured pet. For large dogs, a makeshift muzzle (long sock, necktie, leash) can be used to protect yourself from bite wounds. Cats and small dogs can be wrapped in thick blankets to provide them with warmth and comfort. It can serve as a buffer between their teeth and your skin, too. Handle injured pets with care and do your best to immobilize the fractured bone.
Depending on the severity and location of the fracture, splinting and strict rest might be adequate for bone healing. For open fractures and closed fractures in which the bone is broken in multiple places or the fracture line runs the length of the bone, surgical correction is warranted. Open fractures also require pet antibiotics to prevent infection. The veterinary team will provide detailed instructions regarding home care and follow-up exams after bone surgery.
Bone tumors in dogs and cats can arise in any bone of the body including the long bones within limbs, toes, spinal vertebrae, ribs and the skull. Tumors can begin either directly in the affected bone, or cancer cells can spread by a process known as metastasis, from other sites. Both primary and metastatic bone tumors occur infrequently in cats.
The site of the bone tumor will dictate the associated symptoms. Tumors in the limbs typically manifest with lameness. Often long bone tumors fail to be diagnosed early as they present similarly to arthritis and acute injuries. If rest and pain medications fail to resolve the bone pain, X-rays often reveal bone cancer.
Because there is an overlap of symptoms, it is often difficult to distinguish whether swelling and pain within a dog or cat’s toe is due to a tumor or infection. The radiographic changes to the bones within a pet’s digit do not always differentiate tumor versus infection. If no improvement is achieved through antibiotics and pain medications, toe amputation is often necessary to obtain a biopsy and definitive diagnosis.
For all types of bone cancer, various tests are necessary to determine if the lesion is malignant and what type of tumor is involved. Your pet’s veterinarian will perform a physical exam, submit blood tests and take X-rays of the affected bone. Additional tests such as chest radiographs, CT scans and bone scans are used to evaluate evidence of metastasis and stage the pet’s disease prior to establishing a treatment plan. A bone biopsy will be submitted to a pathologist to procure a definitive diagnosis.
Treatment options for bone tumors are based upon the type of tumor, staging at the time of diagnosis, the pet’s age and concurrent illnesses and the financial ability of the owner. Some people with geriatric pets that suffer from additional medical issues might opt for palliative care. The goal of palliative care is to improve quality of life while providing pain management and comfort care, rather than prolonging the patient’s life.
Dogs with osteosarcoma, the most common type of bone tumor, will require amputation of the affected limb or limb sparing surgery. Although dogs of every size can develop osteosarcoma, the disease is most prevalent in large and giant breeds. Because of the highly metastatic nature of osteosarcoma, surgery is often followed by chemotherapy. Both dogs and cats do remarkably well following limb amputation and this option should not be overlooked for merely aesthetic reasons.
Despite the overwhelming number of bone disorders, most can be successfully managed with early diagnosis and appropriate care. Your pet’s primary veterinarian as well as orthopedic specialists and oncologists can serve as helpful resources to address your dog or cat’s needs.