Valley Fever is considered a noncontagious disease. Even if multiple animals or humans are affected in a household, each infection was acquired by inhaling spores from the soil. Coughing cannot spread it between animals or people.
In reviewing the records of the Arizona Veterinary Diagnostic Laboratory for the last 50 years and the scientific literature, we were unable to find a case of Valley Fever in any domestic, wild, or exotic bird species. From this, we conclude that Valley Fever does not cause disease in birds.
If your dog lives, hunts, or traveled through the regions where they can get Valley Fever, he/she may need a blood test for common clinical signs (coughing, weight loss, lack of appetite, fever or lameness), or for other undiagnosed, unresolving illness that does not go away.
If your dog lives in a region where Valley Fever is typical, your dog could need a Valley Fever test for any illness that manifests the common clinical signs - coughing, fever, weight loss, etc. - or illnesses with vague signs that will not go away. In addition, your dog will need some serum chemistries and white blood cell counts and sometimes x-rays to aid in diagnosing the illness. A positive test in and of itself is often not enough to diagnose Valley Fever.
For dogs that do not live in regions with Valley Fever but have traveled through or spent time in one, a Valley Fever test may be indicated for undiagnosed, unresolving illnesses. If your dog becomes ill outside the typical locations for Valley Fever, it is important to tell your veterinarian of your dog's travel history
A Valley Fever test, Cocci test, or Cocci titer checks the blood to see if your dog is making antibodies against the Valley Fever fungus. If the test is positive, it means your dog has been infected with the fungus.
If the Valley Fever test is positive, the laboratory then performs a titer. The titer measures how much antibody your dog is making against the fungus. A titer is obtained by doubling dilutions of the positive blood (1:4, 1:8, 1:16, 1:32 . . .) until the test becomes negative. The titer that is reported to your veterinarian is the last positive dilution. The laboratories typically stop the titer at 1:256 and report the result as ≥1:256 if the dog's blood is still positive.
In broad terms, a higher titer is equated with more severe disease. However, some very sick animals have low titers, or even negative Valley Fever tests. For these dogs, other diagnostic tests are necessary for diagnosing the illness. X-rays, blood cell counts, biopsies, and microscopic examination of cellular specimens are a few of the tests your veterinarian may need to run.
Asymptomatic dogs (infected but not showing any illness) may also have low titers, such as 1:4 or 1:8, sometimes 1:16. The titer is helpful in diagnosing Valley Fever in sick dogs, but other tests are usually needed to confirm the diagnosis.
Titers usually reduce over time as the animal's disease heals. Dogs that start with low titers (1:4 or less than 1:4) may undergo little change in the titer. Monitoring your dog's symptoms and other tests, such as blood counts and x-rays, will be better determinants of improvement in cases with low titers.
Some dogs will remain Valley Fever positive with a low titer for life. Continued treatment and monitoring of these animals needs to be determined by your veterinarian on a case by case basis.
The form of the organism in the fluid of draining lesions is not considered to be infectious to people or animals. If your animal is receiving antifungal medication, the number of organisms shed in the fluid is also likely to be very low. Nevertheless, draining lesions are best handled in a way to minimize the fluid in your environment. Where possible, wounds can be bandaged. Bandages should be changed daily or every other day and discarded in outside waste containers to minimize risk of having spores grow on the bandage material and become a risk to humans and others in the house. If the lesion is on the side or back of a dog, a T-shirt can be put on the dog and it should be changed and washed daily or every other day. Cleaning impermeable surfaces with dilute (10%) bleach will kill organisms. Hands should be washed after handling the wounds or bandages.
For immunocompromised persons, pregnant and postpartum women, or babies and very young children living in a household with a pet that has a draining lesion, it is recommended to consult your physician regarding this issue and follow their advice.
Treatment choices vary by the individual veterinarian and patient. Reasons for choice of medication include practitioner's experience with the drugs, costs, side effects, efficacy, severity of illness, and convenience to the owner. If one medication is unsuccessful, another will often be tried.
For disease of the brain and spinal cord, fluconazole (Diflucan) is the drug of choice. Fluconazole also penetrates tissues of the eye and should be employed in ocular cases.
Your veterinarian is skilled in the diagnosis and treatment of your pet's illness. Should you feel that your dog is not responding or may have side effects to the medicine, you should first discuss your concerns with your veterinarian. If the results are not satisfactory, you can seek a second opinion.
All Valley Fever medications have the potential to cause side effects in dogs.
The side effects that are common to all of them are:
- Loss of appetite is the most common and may be severe in some dogs.
- Vomiting and/or diarrhea.
- Elevated liver enzymes – monitored with regular testing of your dog’s blood by your veterinarian.
- Birth defects in fetuses. Published side effect of all drugs in this class. Should be used when benefits to mother outweigh risks to babies.
Less common or drug specific side effects include:
- Lightening of the coat color, especially in red or golden dogs. Effects reverse with discontinuation of the medication (with the exception of a few black dogs this author has heard about that have remained grey). (ketoconazole)
- Dry, thin coat and dry skin with dandruff. (fluconazole)
- Excessive drinking and urination, leaking urine in sleep. (fluconazole)
- Ulcerated or abscess-like lesions of the skin. (itraconazole) A reduction in dose may reduce this side effect, or the dog may have to discontinue the medication.
- Infertility in males (common with ketoconazole; possible with fluconazole; unknown with itraconazole). Reversible when drug is withdrawn.
In 2013, most of the manufacturers of generic fluconazole stopped making it. There are only a few manufacturers left, which has driven the price up 5- to 10-fold. While this has created a hardship for dog owners, especially of larger dogs, there is essentially nothing that can be done about the cost of the drug. It is recommended that owners call different pharmacies to check for the best pricing of fluconazole.
Fluconazole can also be compounded, which generally costs less than generic medication, but compounding also increased in price in 2013. Compounded fluconazole generally works fine, but there may be more prescription-to-prescription variability in the drug than when buying generic. If your dog is not doing well on compounded fluconazole, it is worthwhile to try the generic and see if there is a difference. Online purchase may also be an option, but the research we have done shows little advantage to online pricing for fluconazole, at least for dog owners in Arizona.
Most ill dogs could receive a pet multivitamin supplement safely and possibly with benefit to overall well-being. Vitamin C is often prescribed to be administered with ketoconazole. This aids absorption of the drug by helping to acidify the stomach and may also "boost" the dog's immune system. Use of the vitamin C should be checked with your veterinarian as high doses may cause gastrointestinal irritation.
Talk to your veterinarian about your dog's overall nutrition status and the nutritional goals you need to meet while your pet is ill. The more ill your dog, the more important it is to discuss this issue with your vet. Your veterinarian may have special recommendations, such as hand feeding or appetite stimulants, for dogs that are eating poorly or not at all with Valley Fever. In rare cases, placement of a feeding tube should be considered to meet the nutritional needs of patients that will eat nothing or nearly nothing.
Alternative therapies, such as herbs or acupuncture, have not been scientifically tested to treat Valley Fever. The majority of veterinarians to whom I have spoken use these therapies adjunctively with antifungal drugs to help support the dog's overall health and to improve function of the immune system. If you wish to pursue alternative treatments, this author recommends you consult a veterinarian trained in holistic medicine. These professionals are your best source of help.
Valley Fever is well known to relapse in both humans and dogs. In particular, cases of disseminated infection have a 30-50% rate of relapse in humans, no matter how well the initial infection was treated. It is not known how many canine cases of Valley Fever relapse, but relapses are not uncommon and the rate may be similar to people.
In the case of a relapse, a return to medication is usually enough to make symptoms subside, but the dog may require several additional months of treatment. Dogs that experience more than one relapse or get very sick with the relapse should probably have lifetime treatment with medication considered.
Reinfections – a brand new infection from spores in the environment – in humans are documented only rarely. It is not known at this time whether dogs are susceptible to reinfection or whether recurring illness is always due to the original infection.
No. The tissue phase of the fungus coccidioides spp. is a spherule. The infectious phase is when the "spores" are inhaled from the air.