Feline Mammary Hyperplasia: Symptoms, Diagnosis & Treatment Guide [2025]
Feline mammary hyperplasia is often linked to progesterone, presenting as rapid mammary gland enlargement. It may resolve on its own after spaying or stopping medication, though some cases require surgery.
When to See a Vet
Seek Emergency Care Immediately
- •Mammary skin ulceration with heavy bleeding
- •Rapidly enlarging mass that has ruptured and is discharging pus
- •Persistent high fever with severe lethargy
Schedule a Clinic Visit Soon (within 24–72 hours)
- •Noticeable lump or hard mass in the mammary gland
- •Bloody or purulent nipple discharge
- •Cat noticeably avoids being touched around the mammary area
01What symptoms indicate something is wrong?
Mammary hyperplasia typically presents as lumps, tenderness, and discharge, and may affect appetite and activity.
- Palpable lumps or noticeable swelling in the mammary glands
- Visible pain or discomfort when the mammary area is touched
- Bloody or purulent (pus-like) discharge from the nipples
- Cat actively avoids touch and resists handling around the mammary area
- Reduced appetite or noticeably decreased activity levels
Seek emergency care immediately if you notice the following symptoms:
- ⚠️ Mammary skin breaks open with heavy bleeding
- ⚠️ Lump rapidly enlarges and ruptures, draining pus
- ⚠️ Persistent high fever with extreme lethargy
Pet Health Map App
Turn every worry into your pet’s health record
Download the app to save AI Care reports, build your pet’s medical profile, and keep tracking symptoms and care notes.
Android version coming soon. The web version is available now.
02What to do when you notice something unusual? Home monitoring tips and when to go to the emergency vet
Keeping a home record and providing photos or videos helps the vet assess the situation more quickly and arrange appropriate tests.
- Note when symptoms first appeared and how they have changed over time
- Take clear photos of the mammary area and video of any unusual behaviour for the vet
- Monitor and record any changes in appetite and water intake
- Keep an eye on toilet habits and any short-term weight changes
- If discharge or wounds are present, note the colour and amount
- If symptoms are obvious or worsening, book a vet appointment as soon as possible
03How will the vet diagnose this? Common diagnostic tests
At the clinic, the vet will begin with a physical examination and, if needed, add laboratory and imaging tests to confirm the cause.
Physical examination
palpation of the mammary glands, assessment of size and areas of tenderness
Cytology or tissue biopsy to determine whether the mass is benign, malignant, or infected
Imaging
X-ray or ultrasound arranged as needed to evaluate for spread
Blood and biochemistry panels to assess overall health and signs of infection
Urinalysis or additional tests to rule out concurrent conditions or anaesthetic risk
04What treatment and aftercare is needed? Medication, diet, and home care guide
Treatment is determined by diagnostic findings and may involve medication or surgery; regular monitoring of the wound and lump is essential.
- Medication or antibiotics must be given as directed; attend all scheduled follow-up appointments
- If infection or tissue necrosis is present, surgical management may be evaluated
- Restrict activity and keep the wound clean during the recovery or treatment period
- Return for regular check-ups to monitor lump size and wound healing
- Maintaining a balanced diet and healthy weight supports recovery and long-term prognosis
05How to prepare for the vet visit? Key information to help the vet diagnose quickly
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.