down to the bone: a look at osteomyelitis
Osteomyelitis is the medical term for inflammation of the bone. Most of the time, this inflammation is caused by bacterial infection, though fungal and viral infections can also occur. You may be wondering how bones buried deep in your pet’s body can be susceptible to bacterial infection, and I’m here to tell you!
Bacterial infection occurs most often after a traumatic injury, such as an open fracture (a broken bone that protrudes from the skin) or the resulting orthopedic surgery to repair said fracture. Bone infection can also be the result of severe systemic disease, as bacterial or fungal organisms that invade the blood are carried by your dog or cat’s blood vessels to the bone. This type of osteomyelitis tends to occur in very young animals, but adults can also succumb if systemic infection is severe enough.
Signs of osteomyelitis occur after a traumatic incident or severe illness. Fever, swelling of the affected limb, pain and a reluctance to use the limb are the most obvious signs owners will see if osteomyelitis is present. If an orthopedic surgery was recently performed, the wound may drain or open as the skin that holds the stitches becomes compromised by infection.
The diagnosis of osteomyelitis will be made based on your pet’s medical history (is there a history of trauma, orthopedic surgery, or severe illness?), clinical signs and bony changes on x-rays.
While diagnosing osteomyelitis isn’t necessarily a challenge, treating it can be. That’s because treatment is not always successful, and it’s generally a pretty lengthy and costly commitment.
Treatment typically consists of surgical intervention to clean up the unhealthy bone and the affected tissues surrounding the bone. Metal implants that are loose or are the source of infection will be removed or replaced. Closing up a surgical incision around tissue that may still be harboring infection is just asking for trouble, as it traps infection inside the body. Instead, the wound may be partially closed or closed at a later time. These types of wounds require intense medical management.
When bacterial infection is to blame for osteomyelitis, antibiotics will be prescribed. Ideally, antibiotics will be given IV for the first week, and then orally for at least six to eight weeks as long as the infection is present. If fungal organisms are causing osteomyelitis, anti-fungal medications will be prescribed, though treatment of this type of osteomyelitis is more difficult.
Whatever the cause of osteomyelitis, frequent recheck x-rays will be recommended to ensure that the infection is resolving.
All of these things add up, both in terms of cost and time commitment. If osteomyelitis is your pet’s diagnosis, remember that treatment can be effective—just be prepared for the long haul!