If you are living in Southwestern parts of the States, for example, in California or in Arizona — you might want to stick around and read all about Valley Fever.
It is a disease that can affect both humans and dogs. Living in the mentioned parts of the United States puts you and your dog in danger of getting infected by this disease, which can be quite difficult to treat, especially if it is not diagnosed on time.
But, what is Valley Fever? And, how serious is it?
These are important questions… ones that need answering not only because you do have a dog that has this disease or you suspect it might have… we need to arm ourselves with information and learn as much as possible so that we can prevent it.
Prevention and learning to recognize the symptoms are the keys to winning the fight against this disease. Arming yourself with knowledge gives you an upper hand.
So, whether you live in the Southwestern parts or not — here is info on Valley Fever in dogs, including the symptoms, treatment, and other useful information about this disease.
What Causes Valley Fever In Dogs?
This is a fungal disease endemic to North and South America. It is caused by a fungus called Coccidioides immitis. The scientific or medical name for the disease is Coccidioidomycosis.
But, there are many other non-scientific names. For example, San Joaquin Valley Fever, California Disease, or Desert Rheumatism. And, of course, the most common name — Valley Fever in dogs.
Fungi are usually small organisms that are classified separately from other kingdoms (plants, animals, etc.). They are able to produce spores as a form of reproduction, and we will later learn that these spores are the main cause of problems.
Of course, these are not the same fungi that cause mold. However, their reproduction cycle and spreading are similar, and it includes spores that cause the consequential fungal infection.
As with any other type of disease, no matter if it affects humans or dogs, it is very important to recognize the first symptoms. Noticing these first signs that your dog has a disease can be life-saving.
So, we know it is a fungus that causes Valley Fever in dogs. Now, let’s learn the signs that tell us our doggo has it. Some symptoms are mild and barely noticeable, but some can be more obvious and alarming.
Let’s find out more about all of them…
Symptoms Of Valley Fever In Dogs
When a dog gets infected with the fungus that causes Valley Fever, there are two ways the disease can further develop. In essence, it all depends on the immune system of your dog.
Luckily, in most cases, a dog is healthy and has a strong immune system, and its immune cells quickly subdue the disease. This is the first, easier form of Valley Fever in dogs.
In another case, the immune system of a dog is not strong enough, and the disease can further develop. This is the more serious, second form of the disease.
Mild-Version Symptoms
When the immune system of the dog functions adequately, the dog stays healthy and most of the diseases pass by without major problems.
This is what happens during the first form of Valley Fever in dogs. A dog’s immune system is not weak, but strong, and it fights off the spores that enter the dog’s body.
What exactly happens is that the dog’s immune system sequestrates the spores as foreign objects and prevents them from further developing and spreading.
This means that the symptoms are usually mild and barely noticeable:
- Less active than usual
- Occasional sneezing
- Sleeping more than usual
These are all signs that the dog’s body is fighting a battle. It needs more energy — so the dog sleeps more and is less active. The dog doesn’t know that it should rest more – it is just instinctively dealing with the feeling of tiredness.
These sudden, sometimes odd changes in behavior should not last long. You might think that the dog got a cold or it ate something bad. But, there shouldn’t be any signs of fever or serious coughing.
This first mild phase goes unnoticed because the dog’s immune system fights and defeats the fungi on its own. In other words… your dog won’t look ill.
Serious-Version Symptoms
What happens if your dog doesn’t have a strong immune system? What if it’s already compromised by some other chronic or acute disease, or if it is an old or very young dog?
Well, then the fungi have a chance to spread throughout the dog’s body and invade various organ systems. The signs will be noticeable and much more serious.
The symptoms are:
- Dry cough
- Fever
- Lack of appetite
- Lethargy
- Depression
- Loss of weight
- Eye inflammation
- Seizures
- Swollen joints
- Lameness
When your dog’s immune system cannot defend itself, the disease can further develop into two forms:
- Primary disease
- Disseminated disease
Primary Disease
The dog inhales the spores, which start to grow and develop into larger structures. These structures (made of Coccidioidomycosis spores) are called spherules. These spherules are filled with endospores waiting to be released into the surrounding tissue.
When the spherules grow big enough, they burst, releasing the endospores into the tissue and into the bloodstream. If it stays in the lungs — it is a primary disease.
The primary version of Valley Fever in dogs is the most common version. It is restricted to the lungs, and its symptoms are related to respiratory symptoms — coughing, wheezing, sneezing, etc. If you touch your dog’s head, it might feel hot. This condition is a common sign of a fever.
An interesting fact about this primary disease is that it doesn’t have to be active right away. Every disease has an incubation period — a time from entering the body until the first symptoms. In the primary disease of Valley Fever in dogs, this incubation period can last up to three weeks.
But, sometimes it can last more than three years! That means that the dog has the spores inside its lung tissue, but they are dormant — they are not active. You can say they are having a long nap, waiting for the perfect conditions in order to start developing the spherules.
Once the conditions are perfect for growth, the spores “wake up” and start building spherules filled with new spores (endospores).
Disseminated Disease
When the mentioned spherules burst and enter the surrounding tissue, some of them enter the bloodstream as well. Luckily, blood is filled with immune cells that catch any foreign body that enters the bloodstream. But, some of the spores can escape these immune cells.
When that happens, the bloodstream can take them to another organ system entirely, and they can infect a new organ. For example, they can go to the brain, heart, etc.
This is called a disseminated disease because the process of going from one organ to another organ via the bloodstream is called dissemination. Where the spores end up depends on the blood vessel they entered and the immune cells of the new organ or tissue.
But… essentially, there are no rules. Spores can go anywhere — from the bladder to the brain. However, the spores will most likely end up in the bones and joints. Why?
The reason might be because the bones are connective tissue that is present everywhere, and because they are highly vascularized — they have a lot of blood vessels, which makes them more reachable than other tissues and organs.
Because the spores have spread throughout the body, the symptoms will vary. Fever, lethargy, weight loss, and loss of appetite are still present, but other (more specific) symptoms can occur as well.
If the bones and joints are affected, then the dog will have swollen joints, and it will avoid using the affected leg.
The spores don’t have to disseminate from the lungs into only one other organ or tissue. They can infect more organs at the same time. The spherules keep on growing and bursting in a repetitive cycle. Of course, this happens until we put a stop to it.
How Do You Treat Valley Fever In Dogs?
We saw that there are two versions of this disease. The first one is mild and the symptoms are (most of the time) unnoticeable. This means that this version of Valley Fever in dogs goes away on its own.
However, if it develops into the second version of the disease, treatment will be necessary. Once again, the treatment and the outcome depend on the immune system and the severity of the disease.
Your veterinarian will examine the dog’s symptoms and choose the best treatment depending on the localization of the disease — where the spherules and spores are located.
If they are located only in the lungs, the treatment will include antifungal medication combined with symptomatic treatment — lowering body temperature to stop the fever, helping your dog breathe, stopping the cough, etc.
The most common antifungal drugs are:
- Fluconazole (Diflucan – brand name)
- Ketoconazole (Nizoral – brand name)
- Itraconazole (Sporanox – brand name)
If your dog has a disseminated disease, then the treatment will be antifungal medicine, and it will include treating other organs, too. Again, it depends on the localization.
- Brain — treating seizures (anti-seizure medications)
- Heart — treating heart failure, heart congestion, etc. (surgical)
- Joints — antiinflammatory drugs + pain-killers
- Eyes — reducing eye pressure (surgical)
During this treatment period, you can consult your vet and implement some alternative therapies, such as vitamin and mineral supplements. You can add veggies that are safe for dogs to your dog’s diet (e.g., carrots, brussels sprouts, etc.).
Side Effects
Unfortunately, these antifungal drugs are often toxic, and they can cause serious problems with the liver. This is one of the most serious side effects of Valley Fever treatment.
Other side effects include vomiting and prolonged loss of appetite.
A dog needs energy to fight the disease. This energy comes from the food a dog eats, and if a dog can’t or won’t eat, then the entire body and the treatment prognosis is in trouble. That’s why the veterinarian can prescribe intravenous fluids for some period of time.
This way, a dog will receive the necessary nutrients directly into the bloodstream. Also, a vet can order blood tests to keep an eye on the liver. The most common sign that a liver is not functioning correctly is a high level of ALT (Alanine transaminase) in the blood.
The Prognosis
Treatment of Valley Fever in dogs is a long process. It often takes a lot of time — up to a year. But, the good thing is that dogs usually feel better after a couple of weeks, but it will take time, money, and patience.
Another good thing is that a large majority of dogs get cured. So, the process of treatment is long, but it is worthwhile. Your doggo has a good chance of beating those gnarly fungi and getting back to its old self.
A dog that has a disseminative disease can develop the chronic form of Valley Fever. This happens when the spores enter the brain or spinal cord and affect the nervous system after dissemination from the lungs. This means that the dog will have to take antifungal medication for the rest of its life.
Often, the dog will need to take anti-seizure medication as well because the disease can cause grand mal or petite mal seizures.
And, unfortunately… a small number of dogs infected with this fungus will die. The reason is complex, and it often includes more factors. Sometimes, seizures can be a reason to euthanize your dog.
Dogs that succumb to this disease are usually either senior dogs or very young puppies. In both cases, their immune system is compromised and not strong enough to fight the fungi.
It also depends on the parts of the body the spores are disseminated into. The prognosis is not the same for treating Valley Fever, which affects the brain, and the one that affects joints.
Where Is Valley Fever Found?
Valley Fever in dogs can be found in North and South America.
Cases of Valley Fever in North America have been reported in:
- California
- Nevada
- Arizona
- Texas
- Utah
- New Mexico
- Northern parts of Mexico
- South of Washington State (rare cases)
In South and Central America:
- Guatemala
- Honduras
- Venezuela
- Brazil
- Bolivia
- Paraguay
- Argentina
When it comes to the States, the highest incidence is in California and in southern Arizona. As you can see, Coccidioidomycosis is common in arid desert climates and desert regions that have a high percentage of salt. This is the best environment for these fungi to grow.
The highest chance of your dog getting infected with Valley Fever is during the late summer or in the fall. You and your dog can get infected during the whole year, but starting from the end of August to late October — take extra precautions.
How Do Dogs Get Valley Fever?
Every dog is born with a so-called innate immune system. This means it has certain cells called immunoglobulins that fight diseases. The other system is the acquired immune system, and it is the type that “happens on the go”.
This means that the dog’s body makes new immune cells to fight new diseases that a dog comes in contact with.
A dog can get infected by various bacteria, viruses, or fungi. But, this doesn’t mean that every infection turns into a disease. This is also the case with Valley Fever in dogs. Dogs can get infected, but they can also “get rid of” the spores easily.
However, dogs are prone to Valley Fever. Why?
The reason why Valley Fever in dogs is so common for this animal species and not some others is the way dogs explore. They use their nose to sniff around and learn about the world.
And, the way the spores enter the dog’s body is through the upper respiratory system — the nose and mouth.
So, what happens? The dog will go and sniff and dig the ground. This is especially common in Terrier dogs because they were bred to dig and go underground to chase all kinds of small animals.
But, of course, any breed of dog can get infected.
When the dog comes across the fungi, they release their fungal spores, which enter the dog’s body. They travel through the respiratory tract, from the nose and mouth through the trachea, and end up in the lung tissue.
From there, as we already mentioned, they can either develop into a primary or a disseminated disease, or they can go unnoticed if the dog’s immune system is strong.
If you suspect your dog might have Valley Fever, the next step is to take it to the vet.
Diagnostic Tests
Veterinarians can do a Cocci titer test that tells whether your dog’s immune system is fighting the disease appropriately. In other words, it can tell the vet if the dog’s body is producing antibodies that fight the fungi and their spores.
Other diagnostic methods, like X-rays, are needed if the disease has rapidly escalated and caused serious problems in your dog’s body, such as the presence of bone lesions. The X-ray is needed to confirm that the lesion is caused by the fever and not some other type of disease.
Can A Dog Get Infected With Valley Fever More Than Once?
There are two terms we have to separate:
- Relapse
- Reinfection
Relapse is when the symptoms and signs of illness return after the initial improvement. In other words, when a vet starts with the treatment, the dog responds well. The medications are doing their job well and we can see improvement.
The dog feels much better, gains strength, gets its appetite back, there is no fever, etc. So, it seems that everything is going well, and that the dog’s body is fighting the Valley Fever successfully.
But, after a few weeks or a month or a couple of months, the symptoms return and the dog starts to feel bad again — its condition gets worse.
Reinfection is when a dog gets completely cured, but then after a while, it gets infected again with other spores… not the ones that were in its body.
The pattern seems the same — the dog gets better, and there are no signs of disease present in the dog’s body, but after a while, the symptoms come back.
So, the answer is yes. A dog can get Valley Fever more than once.
The problem is that we don’t know for certain if it’s a relapse or a true reinfection. It could be that the medicines subdue the infection — for a while! And, when the immune system gets weaker in the future, the spores “attack” again.
This relapse can be as long as a year; hence, the problem of deciding whether it is a brand new infection or an old infection that was lying dormant somewhere in the tissue.
Are There Any Preventive Measures?
If you are located in some of the mentioned countries, then there are precautionary measures you can take. However, there are no vaccines or preventive medications to completely prevent the Cocci spores from entering your or your dog’s body.
But, there are things we can do:
- Avoid visiting areas with lots of dust
- Try to stop your dog from digging in these areas
- Try to stop your dog from sniffing holes in these areas
- Do not go outside with your dog during storms
- Close your windows during storms
- If your dog has injuries, clean them thoroughly (use soap and water)
- If your dog has a weak immune system (due to disease, old age, young age), then keep it more inside than outside
As you can see, the only preventive measure (for now!) is to avoid dusty areas and stop your dog from digging and sniffing. Basically, these measures are supposed to prevent exposure to spores.
It can be very hard to stop your dog from sniffing the ground. But, if you know there is no way you can stop your doggo from sniffing around, then the best option is to not go on hikes into desert areas or dusty areas.
Stay in the city or close to your home.
You can also hire a professional dog trainer to train your dog not to sniff or dig if not allowed. This is the case if you cannot teach your dog not to do these things on your own.
Will There Be A Vaccine?
Scientists have been working on a vaccine for a long time. They are focused on making a vaccine not only for dogs, but for humans as well.
The vaccine has not been made — yet. However, scientists all across the States, especially from the Valley Fever Center For Excellence, are working hard to make one.
There have been reports that we may have a vaccine in one year or less. Let’s keep our fingers crossed that they’ll make one equally successful for dogs and people.
The Conclusion
Valley Fever in dogs is a fungal disease that is not life-threatening… in most cases.
The infection, incubation, progress, and outcome of this disease depend on several factors – one of which is whether your dog’s immune system is weak or strong. It also depends on the number of spores inhaled, the area where you live, and the age of your dog.
Most dogs fight off this disease without even having obvious signs of illness. Some dogs are just a bit slower or eat less than usual for a few days. Unfortunately, there are those dogs that get hit hard, and they show all the symptoms of Valley Fever.
However, even when they get a fully-expressed disease, most dogs respond well to treatment, and they fully recover after 6 to 12 months.
But, there is a small percentage of dogs that cannot fight this disease no matter how hard we try to help them with medication, IV fluids, or any other therapy that might help them. This small number of dogs eventually has to be euthanized to stop them from suffering.
To sum it up… this can be a serious disease for your dog, but in most cases, a healthy dog won’t have too many problems fighting it.
So, polish your knowledge on preventive measures, and keep an eye on your doggo if you live in the Southwestern part of the States, or North America in general.