Bone Infection in Dogs

Osteomyelitis is an inflammation of the bone or bone marrow resulting from a bacterial or fungal infection. The inflammation can be either acute or chronic and typically spreads from other areas of the body, most often when infection is carried to the bone by the bloodstream. The source of the infection must be documented in order to determine proper treatment and care.

Depending on the location of the infection, symptoms of osteomyelitis may vary. Initial signs of bone infection include:

• Pain
• Swelling
• Fever
• Lethargy
• Depression

If a limb is affected by the inflammation, your dog may exhibit lameness or an inability to move the limb. As the infection spreads, additional symptoms may include:

• Muscle wasting
• Pus-filled discharge

Osteomyelitis is caused by an infection, either bacterial or fungal, that permeates the bone or has traveled to the bone from another part of the body. A bacterial infection can be caused by any pathogenic bacteria and is most commonly a result of surgery or contamination from a wound, such as a bite wound or a bone fracture. Care is needed both during and following any surgery to prevent contamination. Fungal infections vary based on geographical distribution and are usually carried to the bone from another site.

Specific Causes

• Area trauma
• Fractures
• Post-surgery
• Prosthetic joint implantation
• Open wounds
• Wildlife wounds
• Bite wounds
• Claw wounds
• Systemic infections reaching bones

If your veterinarian suspects that your dog has a bone infection, you will be asked to provide a complete history during an initial examination. This, combined with blood work and a urinalysis, allows the veterinarian to develop a more complete profile of your dog’s overall health. Evidence of infection may be revealed through blood cultures, deep fine-needle aspiration, a bone biopsy, or cytology, any of which may be recommended depending on your dog’s condition.

Lab work and further diagnostic tests, such as an x-ray, may be needed to reveal the location of the inflammation and make treatment more reliable. An ultrasound can provide a clearer image of the bones, allowing your veterinarian to determine the extent of the inflammation and the sites that need to be addressed. A culture of pus or other fluid around the infection site may be taken in order to identify the organism causing the infection, the result of which will help determine best treatment options.

Osteomyelitis may require multiple steps to treat, depending on the extent of the infection. There are two main options for treatment, though both require that the wound is cleaned and that pus is drained from the infected area. If the infection occurred as the result of a bone fracture, the bone will need to be stabilized, and dead fragments of bone may need to be surgically removed.

Medical Treatment

A vigorous course of antibiotics can address the source of the infection. Oral or injected antibiotics are typically required for the long term to ensure that the infection is entirely cleared out. Once the results of the culture have been returned, your veterinarian will be able to identify the antibiotics needed to treat the infection and to prevent it from growing. Antifungal medications can be prescribed for a fungal infection.

Surgical Treatment

Depending on the extent of the infection, surgery may be required to drain the affected area, debride the wound, and remove large portions of dead tissue surrounding the fracture. If the fracture is severe enough, your veterinarian may recommend the use of plates, pins, or screws to stabilize the bone. Unfortunately, due to the risk of the infection spreading to other parts of the body, amputation may be necessary in order to save your dog’s life.

The recovery process for osteomyelitis can be a long one. If the original injury was severe, your dog may not be able to put any weight on the affected limb. The bone will need to be stabilized while it heals, which means that any activity must be restricted and that general movement will be limited. You should create a quiet, secure space for your dog to rest in while the fracture heals and limit the number of distractions that may cause anxiety or discomfort during this time.

Antibiotics will likely be administered throughout the healing process. You will need to bring your dog to your veterinarian for follow up examinations at set intervals to check your dog’s response to treatment and to monitor the healing process. X-rays and blood work may be repeated to ensure that the bone is stabilized and that the infection is resolving.

A bone infection can usually be treated medically or surgically. Medically speaking, the wound would need to be cleaned and drained of pus. The veterinarian will usually prescribe injectable antibiotics which can cost between $15 and $38. If the cause of the bone infection is fungal then an antifungal medication would be prescribed. Ketoconazole 200mg usually costs $100 per 100 ct. If the bone infection is surrounding a fracture then it will need to be treated surgically. Once again, the wound would need to be cleaned and drained of pus. The veterinarian may need to remove large portions of the dead tissue in order to get to the fracture. This can cost between $1,500 and $2,250. Plates, pins or screws may be needed to stabilize the bone which can add an additional $500 to the bill. However, more often than not the infection is at risk of spreading throughout the body and causing death. In these cases the veterinarian will suggest amputation in order to save your dog’s life. Amputation usually costs between $400 and $900.