What is the source of blastomycosis infection?

Blastomycosis is associated with exposure to fungal spores in the environment, most commonly through inhalation or skin contact. Living conditions and immune status influence the risk — ask your vet for a personalised assessment.

What tests do vets typically use to diagnose blastomycosis?

Diagnosis typically combines blood tests, cytology or tissue biopsy, chest imaging (X-ray or CT), and fungal culture when needed to locate the lesion and confirm the pathogen.

How long does follow-up monitoring last during treatment?

The duration of treatment and monitoring depends on the severity of the condition. It may require weeks to months of antifungal therapy with periodic imaging and bloodwork — follow your vet's recommended schedule.

What home care can help my pet recover?

Provide a quiet resting space, consistent nutrition, and adequate hydration. Monitor weight and breathing regularly, and contact your vet if the condition deteriorates.

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

Blastomycosis in Dogs & Cats: Weight Loss, Respiratory Symptoms, Diagnosis & Treatment [2025]

Blastomycosis is a serious fungal infection common in moist environments that requires long-term antifungal treatment

Take 1 minute to check the symptoms first

Last updated: 2026/01/05

Pethealthmap Editorial Team

Sources: ACVIM, WSAVA, National Taiwan University Veterinary Hospital

When to See a Vet

Seek immediate emergency care

•Persistent rapid breathing with visible signs of respiratory distress
•Repeated seizures or sudden collapse and loss of responsiveness
•Gums or lips turning purple or white with abnormal coloration

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

•Persistent weight loss without an obvious cause
•Persistent fever or abnormal body temperature with otherwise stable behavior
•Recurrent coughing or a noticeable increase in coughing frequency

01What symptoms signal a problem?

Blastomycosis can affect the respiratory, systemic, and nervous systems; common signs include weight loss, fever, and respiratory symptoms.

Persistent, unexplained weight loss
Recurrent or persistent fever — record temperature changes
Recurrent or worsening cough, or dry hacking cough
Increased breathing rate, laboured breathing, or respiratory distress
Seizures, abnormal gait, or other neurological signs
Localised or generalised swelling, or palpable lumps
If any of the above occur, arrange a clinic assessment as soon as possible

Seek emergency care immediately if you notice the following symptoms:

⚠️ Difficulty breathing or severe respiratory distress requires immediate veterinary care
⚠️ Repeated seizures, collapse, or loss of consciousness — go to an emergency clinic immediately
⚠️ Purple or white gums indicate an emergency — seek urgent care

02How can you monitor at home? Key observations and when to go to emergency

Recording observations at home helps your vet quickly understand the disease progression and plan diagnostic steps.

Weigh your pet at the same time each day and record the result
Take temperature at regular intervals and note the time and reading
Log cough frequency, duration, and any triggers
Monitor breathing rate and note any effort or pausing
Assess changes in alertness, energy level, and responsiveness
Track appetite and water intake changes and bring the notes to your appointment
Share your notes or video clips with the vet as a clinical reference

03How will the vet diagnose this? Common diagnostic tests

After a physical examination, the vet will combine blood work, imaging, and cytology to identify the source of infection and affected organs.

Full physical examination

assessment of respiratory, cardiac, and systemic status

Complete blood count (CBC)

checking for infection or inflammatory response

Biochemistry panel

evaluation of liver, kidney, and other organ function

Cytology or histopathology

sampling to characterise the lesion

Chest X-ray or CT scan

assessment of pulmonary or thoracic lesions

Fungal culture or special staining when needed to confirm the pathogen

Referral to a clinic with infectious disease or internal medicine expertise is recommended

04What treatment and care are needed after diagnosis? Medication, diet, and home care guide

Treatment focuses on controlling the infection and supporting respiratory function and nutrition, with regular follow-up to assess response and side effects.

Your vet will prescribe appropriate antifungal or supportive treatment based on assessment
Oxygen supplementation may be provided if needed to support breathing
Dietary adjustment and nutritional support to assist weight recovery
Schedule regular recheck appointments with repeat imaging or bloodwork to monitor progress
Home care focuses on rest, a calm environment, and minimising additional stress
Return to the clinic or seek referral promptly if the condition worsens or new symptoms appear

05What should you prepare before your vet visit? Key information to help the vet identify the cause quickly

Note when symptoms started and how they have changed day by day

Bring weight and appetite records from the past few days

Take photos of any stool, urine, or skin lesion changes for reference

List all current and recent medications and supplements

Bring any previous test reports or imaging if available

Record a video or audio clip if your pet is coughing or breathing abnormally

Call ahead to book an appointment or arrange a specialist consultation slot

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.