Valley Fever Clinical Signs in Dogs: What to Watch For

The clinical signs of valley fever in a dog usually start in the lungs: a dry, harsh cough that will not settle, a fever, flat energy, a dog who turns away from dinner, and slow weight loss. When the fungal infection spreads beyond the lungs, the picture widens into lameness, hot swollen limbs, draining skin sores, a red or cloudy eye, and in some dogs back pain, behaviour changes or seizures. Any dog with a cough and a fever together, a limp with no injury behind it, or an eye that suddenly looks wrong should be examined by a veterinarian promptly. Collapse, laboured breathing, uncontrolled bleeding or a seizure means an emergency clinic now, not in the morning.

This page covers three conditions owners often search for in the same breath: valley fever, which is a fungal infection; tick fever, including Rocky Mountain spotted fever; and hay fever, which is not a fever at all. They are easy to confuse by name and almost impossible to confuse once you know what each one actually looks like on a dog.

How dogs pick up the fungus, and why signs take their time

Valley fever is the common name for coccidioidomycosis, an infection caused by a soil fungus in the genus Coccidioides. The fungus grows below the surface of dry, dusty ground and produces microscopic spores that break free when soil is disturbed. Digging, wind, construction, dirt roads, a dog nosing through a dry creek bed: all of it puts spores into the air. Dogs inhale them. Nose-down, dirt-loving dogs are simply more exposed than dogs who mostly walk on pavement.

Once inhaled, the spores settle in lung tissue and change form, and the dog's immune system goes to work. Many dogs contain the infection quietly and never look unwell. In others the organism establishes itself in the lungs, and that is where the cough comes from. Signs can appear weeks after exposure, and in some dogs considerably later, which is why owners rarely connect a sick dog in one season with a dusty hike in another.

One reassurance worth stating plainly: valley fever is not passed from dog to dog, or from dog to person, through ordinary contact. Dogs and people both acquire it from the environment, not from each other.

The signs of valley fever, from the first cough to the limp

The lung form comes first in most dogs. What owners typically notice:

• A dry, harsh, persistent cough that sounds different from a throat-clearing or a kennel cough honk
• Fever, often coming and going, with a dog who feels warm and seeks out cool floors
• Lethargy and reluctance to exercise, including backing out of walks the dog normally loves
• Loss of appetite and gradual weight loss
• Faster or more laboured breathing in dogs with more extensive lung involvement

When the fungus spreads beyond the lungs, the clinical picture changes and owners often arrive at the clinic for a completely different complaint. Disseminated signs include:

• Lameness, often severe, that may shift between legs or settle in one limb
• A firm, hot, painful swelling over a bone, most often in a leg
• Skin lumps that open and drain, sometimes over the site of affected bone
• Eye changes: redness, cloudiness, squinting, watering, or sudden loss of vision
• Enlarged lymph nodes
• Neck or back pain, wobbliness, behaviour changes or seizures when the nervous system is involved

A cough that has lasted more than a week, a limp with no injury behind it, or a fever in a dog who has simply gone quiet are all reasons to book a veterinary appointment rather than give it another week.

A limp caused by a fungal bone infection looks very like a sprain for the first few days, and this is exactly where owners lose time. If a limp does not improve with rest, if it worsens, or if it arrives alongside a cough, a fever or weight loss, that is a different problem from a weekend strain and it needs imaging and bloodwork, not patience.

Rocky Mountain spotted fever and the other tick fevers

Tick fever is an umbrella term owners use for several tick-transmitted infections. Rocky Mountain spotted fever is caused by a bacterium delivered through the bite of an infected tick, and it moves fast. Unlike valley fever, which can simmer for months, tick fever usually declares itself within days of the bite.

Rocky Mountain spotted fever clinical signs in a dog commonly include:

• A sudden high fever with marked lethargy and loss of appetite
• Joint pain, stiffness, lameness or an unwillingness to stand
• Swelling of the face, legs or scrotum
• Pinpoint red spots or bruises on the gums, belly or inside the ear flaps
• Nosebleeds or blood in the urine or stool
• Red eyes, eye pain or bleeding visible inside the eye
• Vomiting, diarrhoea or abdominal pain
• Wobbliness, altered mental state or seizures in severely affected dogs

Other tick-borne illnesses, including the ones often labelled tick fever or canine ehrlichiosis, can look similar at the start: fever, lethargy, poor appetite, joint pain, sometimes bleeding tendencies and low platelet counts. Telling them apart is a laboratory job.

This is the most time-critical condition on this page. A dog with an abrupt fever, bruising on the gums, bleeding, or a dog who cannot get up needs veterinary attention the same day, and overnight or at a weekend that means the emergency clinic. The practical prevention story is unglamorous and effective: use year-round tick prevention recommended by your own veterinarian, check your dog over after time in long grass or brush, and remove attached ticks promptly. The same ticks bite people, so if your household has tick exposure and someone becomes unwell, that is a conversation for your own physician.

Hay fever in dogs is an allergy, not a rise in temperature

Hay fever is the one on this list that is misnamed. In dogs it refers to seasonal environmental allergy, a reaction to pollens, grasses, moulds and dust. It does not raise body temperature. A dog with hay fever signs and a genuinely elevated temperature has something else going on as well.

Dogs also express allergy differently from people. Where a person sneezes, a dog usually itches.

Dog hay fever signs most often include:

• Persistent scratching, especially around the face, ears, armpits, groin and belly
• Licking and chewing at the paws until the fur stains a rusty colour
• Face rubbing on carpet, furniture or grass
• Recurrent ear irritation, head shaking and a warm, red ear canal
• Red, inflamed skin, hair loss from scratching, and secondary skin or ear infections
• Sneezing, reverse sneezing or a clear runny nose in some dogs

Dog hay fever symptoms around the eyes are one of the clearest seasonal tells: watery discharge, pink or red conjunctiva, puffy eyelids, squinting, and a dog who rubs an eye against the sofa or paws at it. The discharge is usually clear and affects both eyes. That matters, because a single red, cloudy or painful eye, or thick coloured discharge, points away from simple allergy and toward something that needs examining quickly. Eyes are unforgiving, so talk to your veterinarian rather than reaching for a leftover eye product from a previous pet.

Seasonal allergy signs build and ease with the pollen calendar, flare in the same months each year, and respond to management rather than resolving on their own.

Three conditions side by side

	Valley fever	Tick fever (incl. Rocky Mountain spotted fever)	Hay fever
Cause	Soil fungus inhaled as spores	Bacteria delivered by a tick bite	Pollens, grasses, moulds, dust
Body temperature	Often raised, may come and go	Usually raised, sometimes abruptly	Normal
Hallmark sign	Dry persistent cough	Sudden fever with lethargy and joint pain	Itching, paw licking, watery red eyes
Eye picture	Redness, cloudiness, squinting if spread	Redness, bleeding inside the eye	Clear discharge, puffy lids, both eyes
Speed of onset	Weeks to months after exposure	Days after the bite	Seasonal, builds and eases
Typical workup	Blood antibody titre, chest imaging	Blood tests, platelet count, exposure history	Pattern over seasons, allergy workup
Urgency	Prompt appointment	Same day or emergency	Routine appointment

What your veterinarian will do to tell them apart

All three begin with the same two things: a physical examination and an actual temperature reading. Normal canine body temperature sits roughly between 101 and 102.5 degrees Fahrenheit, and anything meaningfully above that is a real fever rather than a dog who has been lying in the sun.

From there the paths separate. Suspected valley fever is usually investigated with chest radiographs and a blood antibody titre, sometimes with sampling of a swollen bone, lymph node or draining lesion. Suspected tick-borne disease is investigated with blood work, including a platelet count, and targeted infectious disease testing, with treatment frequently started before results return because waiting costs the dog ground. Suspected allergy is diagnosed by pattern, by ruling out parasites and infection, and sometimes by referral for allergy testing.

Treatment for the two infections is prescription territory. Your vet may prescribe medication, often for a long course in the case of a fungal infection, with recheck testing to decide when it can safely stop. Finish what is prescribed, keep the recheck appointments, and raise any side effect you notice rather than quietly stopping a course on your own.

Key Takeaways

• Valley fever clinical signs in dogs begin with a dry cough, fever, low energy, poor appetite and weight loss, and may progress to lameness, bone swelling, draining sores or eye changes.
• A limp that does not improve with rest, especially alongside a cough or fever, deserves imaging rather than more waiting.
• Rocky Mountain spotted fever clinical signs come on fast: high fever, joint pain, bruising on the gums, bleeding and sometimes neurological signs. Same-day veterinary care.
• Hay fever does not raise a dog's temperature. It shows up as itching, paw licking, ear irritation and watery, red, puffy eyes in both eyes.
• A single painful, cloudy or discharging eye is not hay fever and needs examining quickly.
• Tick prevention recommended by your own veterinarian, plus tick checks after time outdoors, remains the most effective lever owners control.

For plain-English explanations of other canine health problems and the signs that go with them, pawgen keeps an educational library at conditions.

None of this replaces an examination. Your veterinarian owns the diagnosis and the treatment plan, including imaging, laboratory testing and any medication your dog needs. Everything an owner does at home, from tick checks to nutrition to keeping a symptom diary between appointments, works inside the space that proper veterinary care creates. Bring your observations to the appointment, ask questions until the plan makes sense to you, and talk to your veterinarian before changing anything about how your dog is being managed.