👁️ Allergic Conjunctivitis in Dogs and Cats – A 2025 Vet’s Guide to Red Eyes, Relief, and Prevention

By Dr Duncan Houston, BVSc

🔍 What Is Conjunctivitis?

Conjunctivitis is the inflammation of the conjunctiva—the pink, mucus-secreting membrane lining the inside of the eyelids and covering the white of the eye. In dogs and cats, it also covers their third eyelid (nictitating membrane). 🐶👁️🐱

🌸 What Causes Allergic Conjunctivitis?

When caused by allergies, this condition is known as allergic conjunctivitis. Common triggers include:

• 🌿 Pollen and environmental allergens
• 🧹 Dust and molds
• 🥫 Food allergies
• 🧬 Atopy (a genetic predisposition to allergies)

This form of conjunctivitis is not contagious, unlike some viral or bacterial causes. It tends to affect younger adults but can occur at any age.

📋 Symptoms of Allergic Conjunctivitis

• 🔴 Red, swollen eyelids or conjunctiva
• 💧 Clear or whitish eye discharge
• 😿 Blinking, squinting, or pawing at the eyes
• 🐾 Hair loss around the eyes or itchiness
• 🤧 Sneezing, nasal discharge, or coughing (in some cases)

Note: Yellow or green eye discharge is more likely to indicate a bacterial infection than allergies. Always consult your vet to be sure. 🩺

🔬 Diagnosing Allergic Conjunctivitis

Your veterinarian may perform the following to confirm diagnosis and rule out other issues:

• 🧪 Fluorescein dye test to check for corneal scratches or ulcers
• 👁️ Physical examination of the eyes
• 🧬 Discussion of environmental or food allergy history

Identifying the cause is critical for creating an effective treatment plan. 🎯

💊 Treatment Options

1. 👁️ Eye Medications

• 💧 Steroid-containing drops or ointments (e.g., dexamethasone, hydrocortisone)
• ❌ Avoid steroids if there's a corneal ulcer—your vet will screen first
• 🧴 Non-steroid eye lubricants and saline flushes for mild cases

2. 💊 Oral Medications

• 🧠 Corticosteroids (for systemic allergies)
• 🌿 Antihistamines—some OTC options may help but check with your vet

3. 💡 Supportive Care

• 💦 Use sterile saline to clean eyes and remove allergens
• 🧼 Keep bedding and environment dust-free

4. 🛡️ Prevent Eye Damage

To prevent scratching:

• 🧴 Use an Elizabethan collar (cone)
• 🐶 Especially important in brachycephalic breeds like pugs or shih-tzus

5. 🧬 Advanced Testing

If your pet’s conjunctivitis is chronic or severe, your vet may recommend:

• 📈 Referral to a veterinary ophthalmologist or dermatologist
• 🧪 Allergen testing (intradermal or blood testing)

🧼 Prevention Tips

• 🌬️ Use air purifiers to reduce indoor allergens
• 🧹 Vacuum frequently to reduce dust and pet dander
• 🍽️ Run food elimination trials if food allergies are suspected
• 🧴 Bathe pets with hypoallergenic shampoos if skin signs are present

Unfortunately, allergic conjunctivitis may never fully go away, but it can be managed long-term with a combination of treatment and environmental control. 🐕🌿🐈

📲 Ask A Vet for Eye Allergy Support

Not sure if it’s allergies or an infection? Need guidance on eye medications or choosing the right drops? Get expert advice from the Ask A Vet App—we’re here 24/7 to help you and your pet feel better. 📱🐾

Visit AskAVet.com or download the app for real-time support. 👁️🐕🐱

✅ Summary: Allergic Conjunctivitis Key Points

• 👁️ Red, watery eyes and clear discharge often signal allergies
• 🩺 Your vet will rule out infection or injury before prescribing treatment
• 💧 Saline flushes and eye drops soothe irritation
• 💊 Corticosteroids and antihistamines help control inflammation
• 🔬 Severe or chronic cases may require allergen testing or specialist referral

💬 Final Words from Dr Duncan Houston

Allergic conjunctivitis can make life uncomfortable for your pet—but it’s usually very manageable with the right treatment and home care. Whether it’s pollen, dust, or food-based allergies, we can help your dog or cat feel better and protect their precious eyes. 🐶👁️🐱

Still have questions? Use the Ask A Vet App or visit AskAVet.com for fast, professional help. 🩺📱