Disease Guide

Granulomatous Sebaceous Adenitis in Dogs & Cats: Symptoms, Diagnosis & Care [2025]

Sebaceous gland inflammation causing hair loss and scaling

Last updated: 2026/01/06
Pethealthmap Editorial Team
Sources: WSAVA, ISFM, National Taiwan University Veterinary Hospital

When to See a Vet

Seek immediate veterinary care (emergency)

  • The skin is producing a large amount of pus and continues to bleed or ooze without stopping
  • Severe lethargy or refusal to eat for more than one day
  • The affected area is rapidly swelling and feels hot to the touch

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

  • Repeated localized itching has caused hair loss, broken skin, or pus formation
  • Small nodules or firm lumps appear and do not go away
  • The skin is oily, has an odor, or continues to shed large amounts of scale

01What symptoms indicate something is wrong?

This condition commonly presents as localised or widespread hair loss, persistent itching, and skin changes; lesions may be accompanied by nodules or discharge.

  • Noticeable hair loss or irregular bald patches on the skin, which may be localised or spreading
  • Repeated or persistent scratching, rubbing, or biting at the same area of skin
  • Greasy or scaly skin with an unusual odour or sticky discharge
  • Localised redness, nodules, or tenderness; severe cases may involve oozing pus
  • If symptoms persist or worsen, seek a dermatology assessment as soon as possible

Seek emergency care immediately if you notice the following symptoms:

  • ⚠️ Seek immediate veterinary attention if there is heavy discharge of pus or persistent bleeding

02How can I assess the situation at home? Key observations and when to go to emergency

Keeping a home observation record and photos can help your vet form an initial assessment of the condition and possible cause — note changes and timestamps.

  • Take front, side, and close-up photos of the affected area with timestamps
  • Record the date symptoms began, the frequency of scratching or hair loss, and whether they are worsening
  • Note whether the pet repeatedly targets the same spot, or whether there are signs of secondary infection
  • Observe for any noticeable changes in energy, appetite, water intake, or toilet habits
  • If pus, blood, or abnormal discharge is present, photograph it and arrange a vet visit promptly

03How does the vet make a diagnosis? Common diagnostic steps

The clinic will carry out a systematic examination and tests to rule out infection, parasites, and other skin conditions — a tissue biopsy may be needed to confirm the diagnosis.

Physical examination

a thorough assessment of the distribution and appearance of skin, coat, and any suspected nodules

Skin scraping and microscopy

to check for fleas, Malassezia yeast, fungi, or other external causes

Superficial or deep tissue biopsy

histopathological evaluation to determine whether granulomatous changes are present

Bacterial culture and sensitivity testing

to identify the causative organism and guide antibiotic selection

Blood tests and advanced imaging (ultrasound or CT)

to assess systemic health and deeper lesions

04How is this treated and managed after diagnosis? Medications, diet, and home care guide

Treatment is tailored to test results and may include anti-infective or anti-inflammatory strategies, with regular follow-up to monitor wound healing and pathology findings.

  • Antibiotics or anti-inflammatory therapy are adjusted based on culture results, sensitivity testing, and pathology reports
  • A tissue biopsy may be arranged if needed to confirm granulomatous pathological changes
  • Dietary adjustments and topical care products can support treatment by improving the skin environment
  • Home care: keep the affected area dry and clean to prevent secondary infection from repeated scratching
  • Attend scheduled follow-up appointments to assess treatment response and adjust the plan as needed
  • A veterinary hospital with dermatology capability is recommended for ongoing monitoring and follow-up

05What should I prepare before the vet visit? Key information to help your vet understand the problem quickly

1
Record the onset date and a timeline of how symptoms have developed and changed
2
List all current and recent medications, topical treatments, or supplements being used
3
Prepare notes on any recent changes to diet, bowel and urinary habits, and general energy and appetite
4
Bring clear photos or short video clips of the affected area for comparison
5
If previous test results or imaging are available (blood tests, cultures, pathology reports), bring those along

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.

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