🩸 Vet Guide 2025: Hemangiomas in Dogs and Cats – Causes, Diagnosis & Treatment 🐾

By Dr Duncan Houston, BVSc

Hemangiomas are benign tumors that arise from blood vessel cells in the skin or subcutaneous tissue. While these growths are non-cancerous, their malignant cousin—hemangiosarcoma—can pose a life-threatening risk. Understanding how to recognize hemangiomas, identify risk factors, and explore treatment options can help ensure your pet stays safe and healthy. In this 2025 guide, we’ll cover everything you need to know. 🐶🐱

🔬 What Is a Hemangioma?

Hemangiomas are benign tumors that originate in the blood vessels or skin. They are structurally similar to hemangiosarcomas—an aggressive, malignant cancer—but lack the ability to invade or metastasize. Still, it’s important to diagnose and differentiate the two through proper testing. 🧠

Key Facts:

• 🧬 Caused by mutations in blood vessel cells
• ☀️ UV light and sun exposure may trigger skin-based forms
• 🧪 Requires biopsy or lab analysis to confirm diagnosis

📌 Who Gets Hemangiomas?

🐕 Dogs:

• Breeds: Pitbull Terrier, Basset Hound, Beagle, Boxer, Dalmatian, English Bulldog, English Pointer, Greyhound, Italian Greyhound, Staffordshire Terrier, Whippet
• Risk Factors: Light skin, sparse hair, and love of sunbathing
• Age: Middle-aged to older
• Sex: Males and females equally affected

🐈 Cats:

• Breed: No breed predisposition
• Common Sites: Light-colored ear flaps (pinnae), head
• Age: Middle-aged to older
• Sex: Males and females equally affected

🧬 Types of Hemangiomas

1️⃣ Subcutaneous (Under the Skin)

• 📍 Often appears as a single mass
• 🩹 May bruise, ulcerate, or bleed easily
• 😖 Can be painful when touched
• 🩸 About 1/3 of dogs show related illness: lethargy, appetite loss, lameness, coughing, neurologic symptoms

2️⃣ Cutaneous (Skin-Associated)

• 🔴 Typically small red to purple bumps
• 🌞 Found in areas exposed to sunlight (chest, belly in dogs; ears/head in cats)
• 🧊 Usually non-painful and slow-growing

🔍 Diagnosing Hemangiomas

A visual exam may raise suspicion, but diagnosis must be confirmed through testing. Here's what to expect: 🧪

• 📊 Blood tests: May reveal anemia if internal bleeding is present
• 🔬 Fine needle aspirate: May only yield blood; often non-diagnostic
• ✂️ Biopsy or surgical removal: Required for definitive diagnosis
• 🖥️ Ultrasound or imaging: Recommended if internal mass or hemangiosarcoma is suspected

Remember: Only tissue analysis can distinguish benign hemangiomas from malignant hemangiosarcomas. 🧠

🩺 Treatment Options

1️⃣ Surgical Removal: The primary and most effective treatment. Most pets recover fully with no further intervention required.

2️⃣ Monitoring: Small, slow-growing skin lesions may be monitored, but growth or ulceration warrants removal.

3️⃣ Prevent Recurrence:

• ☀️ Limit sun exposure
• 🧴 Use pet-safe sunscreens on vulnerable skin
• 🧑‍⚕️ Follow-up with your vet if new lesions develop

⚠️ Pets with solar-induced hemangiomas may develop others

It’s not uncommon for pets with one hemangioma to develop more in sun-damaged areas over time. Additional surgeries may be needed if new lesions arise. 🔄

📲 Ask A Vet for Expert Guidance

If your pet has a suspicious skin lump or you've received a diagnosis of hemangioma, AskAVet.com can provide instant help. 🐾

With the Ask A Vet App, you can:

• 📸 Share photos of lumps or biopsy reports
• 💬 Ask about next steps, monitoring, or surgical referrals
• 📅 Get alerts for follow-up and recheck visits

Get peace of mind—fast. 📱

📝 Final Thoughts

Hemangiomas in dogs and cats are typically benign and treatable. Still, they can look and behave like more dangerous cancers—so don’t delay diagnostics. Early surgical removal offers the best outcome, and prevention strategies like sun protection can reduce recurrence. ☀️🛡️

Have questions? The team at AskAVet.com is available 24/7 to guide you. Your pet’s health is our priority. 🐶🐱