Dogs can warn humans of this quickly spreading disease, study reveals

Dogs are more than just loyal companions. A new study from UC Davis suggests they could also play a surprising role in public health by helping detect the early spread of Valley fever.

It is a serious and sometimes overlooked fungal disease affecting parts of the western United States. Researchers discovered that dogs are often exposed to the fungal spores before humans. This is because they frequently come into close contact with soil and have a natural tendency to dig or sniff the ground. By tracking infections in dogs, scientists believe it may be possible to identify hotspots of Valley fever before human cases start rising.

This could offer a valuable early warning system and help doctors and health officials respond more quickly to potential outbreaks.

What is Valley fever by which dog can alert humans

Valley fever, also known as coccidioidomycosis, is caused by inhaling spores of the fungus Coccidioides immitis or Coccidioides posadasii. These spores live in dry, dusty soil and can become airborne when the ground is disturbed by wind, farming, or construction. Once inhaled, the spores can cause flu-like symptoms such as fever, cough, fatigue, and muscle aches.

In more serious cases, especially in people with weakened immune systems, the infection can spread to the brain, bones, skin, or other parts of the body.

What dogs are revealing

Dr. Jane Sykes, the lead researcher, and her team analysed thousands of dog blood tests from across the country. They noticed that canine infections often matched areas where Valley fever is already known to exist. But surprisingly, they also found small clusters of infections in places where the disease hadn’t been previously reported.

This suggests that dogs may help identify new risk zones before human cases are recognized.“Dogs are sentinels for human infections,” Sykes said. Since dogs are closer to the ground, often digging and sniffing in the soil, they’re more likely to be exposed to the fungal spores before people are.

Why dogs are at higher risk

Any dog that spends time outdoors in dry, dusty environments can be at risk. Certain breeds may be more vulnerable to respiratory infections, but the biggest factor is exposure to disturbed soil.

Dogs playing in backyards, walking near construction sites, or running through open fields can easily breathe in the spores.Weather plays a big role too. Long periods of drought dry out the soil, and strong winds can send spores flying. On the other hand, heavy rainfall encourages fungal growth. These changing weather conditions can lead to spikes in Valley fever cases, both in pets and people.

Climate change may be expanding the threat

Climate shifts are affecting where the fungus can grow.

In recent years, over 130 locations in the United States have seen sudden increases in rainfall. This could mean the fungus is spreading to new areas. As soil conditions change, Valley fever might show up in places where it hasn’t been seen before, and dog infections could be the first sign.

How to protect pets and people

While it’s nearly impossible to avoid all exposure, there are steps pet owners can take. Try to stay away from dusty areas, especially on windy days.

Avoid letting dogs dig in dry soil, and keep an eye out for symptoms like coughing, limping, or lethargy. Vets in high-risk regions are trained to spot signs early, and antifungal treatments are available for dogs that test positive.For people, especially those with health conditions, it’s important to be aware of local risks. If you live in or travel to areas known for Valley fever, talk to your doctor if you develop unusual respiratory symptoms.

What this means going forward

This study highlights the value of watching dog health as a way to spot public health risks. In some regions, canine cases may be noticed long before human ones, giving communities a chance to act early. Researchers hope more states will collect and share data to improve early detection.As Dr. Sykes put it, some regions may be underestimating the disease simply because doctors don’t expect to see it there. By paying closer attention to what’s happening with animals, we may be able to avoid larger outbreaks in humans.Dogs might not just be our best friends—they could also help protect us from a growing health threat.