Necrotizing Fasciitis in Dogs

Necrotizing fasciitis is a rare, grave, incapacitating disease that can result in systemic illness in your dog. It is difficult to diagnose as initial symptoms are similar to those of other less serious conditions. Due to its rapid progression and difficulty to diagnose, it can lead to death in infected dogs. Necrotizing fasciitis may also be referred to as “flesh eating bacteria” and it can destroy skin, fat, and muscles.

Necrotizing fasciitis is a rare, bacterial soft tissue infection that appears suddenly and progresses rapidly, leading to systemic illness and often death.

Dogs that are suffering from necrotizing fasciitis will experience intense pain. The areas that are most likely to be impacted are hock joints, flanks and the skin of the abdomen. Other symptoms include:

• Painful, deep lesions of the skin along your dog’s limbs or trunk
• Infection may start with a small skin lesion and progress to a large area of necrosis and ulceration within a few hours
• Pain initially seems out of proportion with what can be seen on the skin
• Fever 
• Within 24-48 hours skin often sheds
• Localized swelling
• Erythema
• Signs of shock
• Disseminated intravascular coagulation
• Significant pain that seems out of proportion to what is seen upon physical examination

Types 

While necrotizing fasciitis is rare, it is serious. It can occur in humans as well as dogs. It is more likely to occur in young dogs or elderly dogs; healthy adult dogs are not as prone to infections.

Necrotizing fasciitis can be caused by an infection with Streptococcus canis, B-hemolytic streptococcus, Staphylococcus pseudintermedius and E. Coli may also cause necrotizing fasciitis. The lungs and throat are the most likely places where your dog will contract the bacteria. Transmission may occur through sharing a water bowl, a run, or bedding with an infected dog. Your dog could also acquire the bacteria by licking the face of a person who is carrying the bacteria or from being in crowded conditions with other dogs (like in dog shows). Stress (from traveling long distances, for example) may also lead to a decreased resistance to the disease.

It is important that your dog is diagnosed quickly in order to immediately undergo treatment. Unfortunately, it is difficult to diagnose necrotizing fasciitis as the early signs of the condition are no different than the signs of other, less serious problems (for example, cellulitis). A veterinarian will confirm the diagnosis of necrotizing fasciitis through bacterial culture and histopathological examination, however to be most successful, treatment must begin prior to the results of these evaluations. It is recommended that treatment begin once the clinical diagnosis points to necrotizing fasciitis, as this will lead to the best chance of recovery for your dog.

It has been noted that in cases of necrotizing fasciitis, the severe pain that the patient is experiencing is out of proportion to what is seen during the physical exam. This is due to the extensive tissue damage under the skin that is caused by bacterial toxins and enzymes that damage tissue. All of this is occurring underneath the surface, with little change initially seen on the animal’s skin. Many of the dogs that have been diagnosed with necrotizing fasciitis have also exhibited serious systemic disease (including hypotension and sepsis).

Quick and aggressive treatment is imperative for a dog suffering from necrotizing fasciitis. Initially, intravenous antibiotics (either clindamycin or amoxicillin-clavulanate) will be administered. Once the veterinarian has sensitivity testing results, the antibiotic may be changed. Other treatment may include:

• Intravascular fluid therapy
• Plasma transfusions
• Nutritional support
• Surgically removing dead and infected tissue and draining wounds
• Amputation

It is noted that fluoroquinolone antibiotics should not be used. These may increase the toxicity of the streptococcus strains and should be avoided. Tests have shown that Streptococcus canis is usually sensitive to penicillin G and ampicillin. Homeopathic options such as Carbo Veg.IM and Arnica have been suggested by some but many vets refute their role in treatment.

It is likely your dog will require multiple follow-up appointments for additional long-term treatment. Recovery from and management of necrotizing fasciitis is intense and should be expected to be long. Initially, you will want to clean your dog’s wounds and frequently change his bandages. Antibiotics will need to be given for some time. Damaged areas will likely need to be repaired and reconstructed, and skin grafts may be necessary. These procedures will require surgery and an anesthetic. It is important to follow the instructions of your veterinarian to best help your dog recover.