Valley fever is a fungal disease caused by the organism Coccidioides immitis
Cocci is a common organism found in the soil and plant litter of deserts in the southwestern United States. It grows in a microscopic branching form known as mycella. The mycella form the infectious part of the fungus called an arthrospore.
Infection occurs primarily by inhalation of arthrospores. Rarely, cutaneous inoculation occurs. Once in the lungs, the arthrospores germinate and develop the disease Valley Fever. Lymph nodes and other organs of the body can become infected as the disease spreads. Patients with this illness are NOT contagious to others.
The immune system mounts an attack against the infection and often will fight off the disease. In humans, cocci infections are usually no worse than a severe flu attack. In fact, in humans, the disease rarely spreads. Unlike humans, dogs and some cats seem to commonly develop more severe, complicated and more life threatening cocci infections. In 1979 a study of 278 cases found a mortality rate of 38% in infected dogs. In a more recent study, the mortality rate was less than 20%, indicating that we are doing a better job in treating.
In virtually all cases, INFECTED PETS ARE NOT CONTAGIOUS TO HUMANS. Cases with draining wounds may be of concern to humans due to contamination of dressings, furniture or carpets. Your veterinarian can best address these concerns.
Pulmonary or Lung Cocci: Infections in dogs occur most commonly as a lung infection (pneumonia). The lung disease involves an area of pneumonia that weakens the dog. Lymph tissue near the bronchi or windpipe often becomes swollen and infected. When this occurs, pressure on the windpipe can lead to a hacking type cough. Dogs may develop a fever, become lethargic and occasionally have difficulty breathing.
Bone Cocci: The second most common place for cocci to cause disease is in the bones. When the infection spreads beyond the lungs, one or more bones may be affected. Bony lesions can cause swelling at the site of infection and can cause lameness in the affected limb.
Disseminated Cocci Occasionally, cocci infections may cause multiple lung lesions, spread to multiple bone sites, spread to any abdominal organ, the heart and surrounding tissues, eyes, genitalia, skin or the central nervous system (brain and spinal cord). It may spread to one or more sites at a time. Clinical signs often reflect an abnormality in the affected site(s).
Identification of specific cocci antibodies in the blood is required for diagnosis. Serum chemistry and blood counts may be needed to further evaluate the extent of the damage. X-rays of the chest or bony lesions are also important for damage evaluation and for monitoring the progression of treatment.
The goal for treatment is resolution of the cocci lesion(s). Many cases can he resolved in as little as 3 months. A fair number of cases take 6-9 months to achieve resolution. A few cases, unfortunately, require long-term therapy of a year or more. By periodically rechecking the antibody titer and x-rays, the response to treatment can be followed and therapy adjusted as necessary. These steps are very important because they provide the information your doctor needs to decide when it is safe to stop treatment.
Ketoconazole (Nizoral) is the drug of choice for many cases of cocci. Disseminated cocci may require Itraconazole (Sporonex), or Fluconazole (Diflucan). Please see the enclosed information regarding this medication.
For Your Dog
_____1) A blood test and x -rays will be needed to determine your pet’s status.
_____2) Your dog has a positive blood titer of 1: _____ as of (date) ____________.
________ 3) Begin your dog on ______mg, ______ tablet(s) every 12 hours. Please call our office if your dog will not eat or if your dog vomits.
_____4) In 2-3 months, a doctor will re-examine your dog and a blood titer will be done to monitor response to treatment. At this time additional blood tests will also be performed to make sure your dogs’ body is tolerating the drug, as occasional severe liver changes can occur.
____ 5) In 2-3 months, an x-ray may be taken to monitor response to treatment.
____ 6) Maintain contact with our doctors and call if you have questions or if your dog has any problems. The most common side effect with the medication is lack of appetite. Some owners have noticed the hair coat gets lighter. Valley Fever is an expensive and sometimes frustrating disease to treat. We will do everything we can to make the treatment and follow-up tests as easy as possible. Many cases can be cured completely. Some cases do not respond completely and need treatment for a long time.