Because of their vulnerability and popularity as human companions, dogs account for the majority of valley fever cases. In Arizona, in particular, owners spend hundreds to thousands of dollars each year diagnosing, treating, and following up on their dogs with Valley Fever. It is estimated that valley fever costs all dog owners in Arizona at least $60 million a year.
What is Valley Fever?
Valley fever is a disease caused by a fungus known as Coccidiodes immitis. Although the correct name for this disease is coccidioidomycosis, it is more commonly called valley fever, California disease, desert rheumatism, or San Joaquin Valley fever.
Where is valley fever found?
This ground fungus has adapted to survive in desert climates and is common in parts of Arizona, California, Nevada, New Mexico, Texas, Utah, northwestern Mexico, and parts of Central and South America. . It has also been reported in south-central Washington State. Infection rates vary greatly from county to county, and not all contributing factors to infection rates in an area have been identified. Valley fever occurs at certain times of the year.
Which species can be infected with valley fever?
This disease is common in humans and has been isolated in dogs, cattle, horses, deer, moose, mules, llamas, great apes, monkeys, kangaroos, wallabies, tigers, bears, badgers, otters, fish, and marine mammals.
Dogs appear to be very susceptible to valley fever infection, possibly because they sniff the ground and dig into the dirt, inhaling large numbers of spores at one time.
How is valley fever transmitted?
Like many fungi, C. immitis has a complex life cycle. It has two completely different forms depending on whether it is in the environment or has entered a host animal. When found in the environment, it exists as mold. During periods of drought, mold is dormant in the soil and can remain dormant for long periods of time. As soon as the rains come, the fungus grows and produces long threads of a mold containing infectious spores. The tiny spores are easily carried through the air when the soil is disturbed by the wind or by construction, agriculture, or excavation work. When the spores are inhaled, they transform into a yeast-like organism that infects the lungs.
“The disease cannot be transmitted directly from person to person, nor from humans to animals.”
The disease is spread by inhaling the fungal spores. The disease cannot be transmitted directly from human to human, nor from human to animal. In other words, an animal with valley fever is not contagious to other pets or to your family members.
What are the symptoms of valley fever in dogs?
Once inhaled into the lungs, the spores develop into larger structures called blood cells. In a healthy adult dog, the dog’s immune system blocks the organisms present in the blood cells and no further problems occur. In these cases, the signs of the disease are usually very mild, often the dog does not even visibly get sick.
“Once inhaled into the lungs, the spores develop into larger structures called blood cells.”
However, serious illnesses can develop in dogs with weak immune systems due to age or an underlying disease, so both very young puppies and older dogs are more susceptible to valley fever disease. In these patients, the blood cells continue to grow and eventually burst, releasing other infectious organisms that spread to the lungs or other organs of the body, where the cycle repeats itself several times.
READ MORE: Anaplasmosis in Dogs
In dogs, valley fever can take two main forms: primary disease and disseminated disease.
Primary disease is limited to the lungs. Signs of primary valley fever include severe dry cough, fever, loss of appetite, and lethargy or depression. These signs usually appear about three weeks after infection, although the body can sometimes lie dormant for up to three years before the signs appear.
In disseminated disease, the fungus has spread or spread to other parts of the body. Bones and joints are most commonly infected, and lameness is the most common sign. The joints may be swollen and painful. Other signs are nonspecific and may include loss of appetite, lethargy or depression, persistent fever, and weight loss. The eyes can become infected, causing inflammation and sometimes blindness. In rare cases, the fungus also enters the brain and causes seizures there.
READ MORE: potassium bromide for dogs
How is valley fever diagnosed?
If you live in an area where this disease is widespread and your dog is showing signs consistent with valley fever, your veterinarian will recommend diagnostic tests to determine if your dog has this infection. This test will certainly include a titer test to determine if your dog has antibodies to Valley Fever (detecting exposure to the fungus). Depending on your dog’s symptoms and the severity of the disease, your vet may also recommend additional blood tests and diagnostic X-rays of the chest and affected legs. The fungus can also be detected by microscopic examination of infected fluid or tissue samples.
Veterinarians in other parts of North America rarely, if ever, see cases of valley fever. Therefore, if your dog has been to an area where this disease is common, it is important that you inform your veterinarian of this travel experience if your dog develops any signs of valley fever.
How is valley fever treated?
Currently, dogs that develop valley fever require a lengthy course of antifungal medication. The duration of treatment depends on the severity of the infection. In many cases, treatment is required for 6-12 months. If the fungus has invaded the nervous system, the dog may need antifungal medication for life.
“Currently, dogs that develop valley fever require prolonged treatment with antifungal drugs.
There are numerous antifungal drugs that are effective against the disease. The most commonly prescribed drugs are ketoconazole (brand name Nizoral®), itraconazole (brand names Itrafungol® and Sporanox®), and fluconazole (brand name Diflucan®). Although treatment is lengthy, dogs are usually better within 1-2 weeks of starting treatment.
The most common side effects of these drugs include vomiting and loss of appetite. Because they can be toxic to the liver, your vet will recommend regular blood tests to monitor liver function.
Depending on the site of infection, additional supportive measures may be necessary. This may include hospitalization for IV fluid or oxygen therapy; treatment of congestive heart failure may require surgery, and infected and painful eyes may require surgery to relieve pain.
READ MORE: Pannus in Dogs: Symptoms & Treatment
What is the prognosis for recovery?
A small number of dogs, usually those who develop the disseminated disease, die from valley fever. However, most dogs that are treated appropriately will recover from the disease. The vet will repeat the antibody titer test periodically to determine when the antifungal medication can be discontinued.
Are Valley Fever Symptoms the Same in Dogs and Cats?
Although dogs and cats share many similar symptoms, there are some differences between the two:
READ MORE: Should You Spay a Pregnant Cat?
Symptoms of Valley Fever in Cats
As previously mentioned, valley fever is less common in cats than in dogs. When this disease occurs in cats, it is usually in younger, active cats that live outdoors, as the spores are usually found below the surface but become airborne when the cat is digging or when it is very windy.
Common symptoms of valley fever in cats include:
- Non-healing skin lesions that look like abscesses or dermatitis and may ooze pale yellow to reddish fluid
- difficulty breathing
- changes in behavior
Cats with valley fever that are evaluated by our veterinarians at the Veterinary Specialty Center in Tucson are typically much sicker than dogs that have been diagnosed with the disease. This may be because it’s harder to tell when a cat is unwell, so pet owners don’t notice the symptoms until the disease is more advanced.
Treating valley fever in pets takes time. Most pets will be on antifungal medication for at least 6-12 months, but once the disease has spread throughout the body, there is a chance they will need to take antifungal medication for life.
Is valley fever in pets curable?
The prognosis for pets diagnosed with valley fever depends on the severity of the disease and other factors such as your pet’s general health and age.
Prognosis for cats with valley fever
If the disease is caught early, or if your cat has only local skin symptoms, the prognosis is generally good. If valley fever has spread throughout your cat’s body, the prognosis is poor.
While your cat’s condition may improve during treatment, relapses are very common. It is estimated that around 60-90% of cats recover from Valley Fever after treatment.
the source: vcahospitals