Can histoplasmosis be transmitted to people or other pets?

Histoplasmosis is primarily an environmental fungal infection; dogs and cats are infected through environmental exposure. The risk of transmission to humans is relatively low but does exist — consult your vet if you have concerns and practise good personal hygiene.

What tests are commonly performed at the clinic?

Common tests include physical examination, blood work, cytology or culture, serology or antigen testing, and chest or abdominal imaging. The combination of tests depends on the symptoms and the vet's clinical judgement.

How long before I see improvement with treatment?

The time to improvement varies with severity. Mild cases may show progress within a few weeks, while severe or disseminated infections may require months of treatment and regular monitoring. Follow your vet's guidance on scheduling follow-up visits.

What home care preparations can I make?

Record temperature, food intake, and weight daily; save stool samples or video breathing patterns; and bring all current medications and past test results as advised by your vet.

How much do the tests and treatment usually cost?

Costs vary by clinic and region — ask your vet for an estimate before proceeding.

Disease Guide

Histoplasmosis in Dogs & Cats: Respiratory & Digestive Symptoms, Diagnosis & Care [2025]

Histoplasmosis is a systemic fungal disease caused by a soil-dwelling mould, affecting the lungs, intestines, eyes, and more. Treatment requires long-term antifungal medication over several months; most cases carry a good prognosis.

Take 1 minute to check the symptoms first

Last updated: 2026/01/05

Pethealthmap Editorial Team

Sources: Merck, WSAVA, National Taiwan University Veterinary Hospital

When to See a Vet

Seek immediate veterinary care (emergency)

•Persistent open-mouth breathing with rapid breathing that will not settle
•Gums turning purple or pale with dull, weak spirits
•Sudden collapse with no response or clouded consciousness

Schedule a veterinary visit soon (within 24–72 hours)

•Repeated fever but still able to move around and drink
•Continuous diarrhea with blood or mucus in the stool
•Persistent coughing or noticeable wheezing while spirits remain fair

01What Symptoms Indicate a Problem?

Histoplasmosis commonly causes digestive and respiratory symptoms in dogs and cats, and may also present with fever and weight loss. Symptoms vary widely — monitor closely and keep a record of any changes.

Reduced appetite or refusal to eat for more than one day
Persistent diarrhoea, or stools containing blood or mucus
Gradual weight loss — weigh your pet regularly and keep a record
Recurrent fever or abnormal body temperature — measure and log readings
Persistent cough, dry cough, or audible wheezing
Rapid breathing or difficulty breathing requires prompt evaluation
If symptoms persist or worsen, schedule a veterinary appointment

Seek emergency care immediately if you notice the following symptoms:

⚠️ Severe difficulty breathing or open-mouth breathing
⚠️ Purple or pale gums with low energy
⚠️ Sudden collapse or loss of consciousness — seek emergency care immediately

02How to Assess Abnormalities at Home: Key Observations and Emergency Warning Signs

At home, systematically record body temperature, weight, food intake, and bowel movements; save stool samples or videos for your vet's reference.

Take your pet's temperature at the same time each day and record the reading
Log daily food intake and note any refusal to eat or vomiting
Keep or photograph stool samples for testing or for the vet to review
Record a video of any coughing, wheezing, or breathing difficulty
Weigh your pet weekly and track the trend
If symptoms worsen or emergency signs appear, seek veterinary care promptly

03How Will the Vet Diagnose This? Common Diagnostic Tests

At the clinic, your vet will use physical examination along with laboratory and imaging tests to determine whether histoplasmosis is present and which organs are affected.

Physical examination

assessing breathing, mucous membrane colour, and overall condition

Blood tests

evaluating white blood cell count and organ function markers

Cytology

microscopic examination of cells from tissue or body fluid

Culture testing

bacterial or fungal culture to identify the causative organism

Serology or antigen testing

detecting immune response or antigen evidence

X-ray or CT imaging

assessing lung involvement and other affected organs

For complex cases, referral to a specialist or teaching hospital may be recommended

04Treatment and Care After Diagnosis: Medication, Diet, and Home Management

Treatment is tailored to the severity of infection and organs involved; completing the full course and attending regular follow-ups is essential. Home care focuses on monitoring and supportive management.

Complete the full treatment course as directed and attend all scheduled follow-up appointments
Continuously monitor body temperature, weight, and respiratory rate
Hospitalisation and oxygen support may be required when necessary
Adjust diet and record food intake and digestive response
Administer medications as prescribed and report any side effects to your vet
If symptoms recur or do not improve, consider referral to a specialist centre

05What to Prepare Before the Vet Visit: Key Information to Help Your Vet Diagnose Quickly

Note the onset date, duration, and progression of symptoms

Bring a record of daily feeding amounts and food types

Keep a record of bowel movements or bring a stool sample for testing

List all current medications, supplements, and any known allergies

Bring any previous imaging or laboratory reports if available

Call ahead to make an appointment and ask whether any specific samples need to be prepared

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.