A dog eye stye is a painful red bump on the edge of the eyelid. Vets call it a hordeolum. Like a pimple, it forms when a small gland in the eyelid gets infected, and it tends to come up fast, swell, and hurt when the lid is touched.
That's the textbook stye. Plenty of eyelid lumps look like one and aren't. A firm, painless bump that has been slowly growing on an older dog is more often a blocked gland (a chalazion) or a small eyelid gland tumor, and most of those are benign. You can't tell them apart from a photo, so the plan is the same either way: don't squeeze it, don't put drops in it, and have your vet look at it.
What Is a Stye in a Dog?
Your dog's eyelids are lined with tiny glands. Small oil and sweat glands (the glands of Zeis and Moll) sit at the base of the eyelashes, and a row of larger oil glands, the meibomian glands, runs along the edge of each lid and helps keep the tear film healthy.
A stye is an infection and inflammation of one of these glands. Veterinary ophthalmologists split them in two:
- External hordeolum: an infected gland of Zeis or Moll at the base of the lashes.
- Internal hordeolum: an infected meibomian gland, deeper in the lid.
The hallmark sign is pain when the eyelid is handled, according to conference notes by veterinary ophthalmologist Dr. David Ramsey, DACVO. Bacteria are the usual cause: the Merck Veterinary Manual notes that staphylococci are often involved in eyelid gland infections, sometimes alongside streptococci. A stye can also be one part of a wider inflammation of the eyelid called blepharitis.
What Does a Stye on a Dog Look Like?
A stye usually shows up as a red or pink swollen bump right on the edge of the upper or lower eyelid, with some puffiness around it. It may form a pale or yellow head, and it can burst and leak pus.
Your dog may also:
- Rub or paw at the eye
- Squint or blink more than usual
- Have a watery eye or more discharge than normal
- Pull away when you touch the face near the eye
A lump like the one in the photo above could be a stye, a chalazion or a small gland growth. From the outside they can look almost the same.
When the whole eyelid is red and swollen rather than one spot, the problem is more likely blepharitis itself. Skin disease, mites, fungal infection, irritants and autoimmune disease can all cause it, and it needs its own work-up.
Stye, Chalazion or Eyelid Tumor?
These three cause most of the "bump on my dog's eyelid" worries. Here's how they usually differ:
What to compare | Stye (hordeolum) | Chalazion | Meibomian gland tumor |
|---|---|---|---|
What it is | An infected eyelid gland | A blocked meibomian gland; the trapped oil leaks into the lid and causes a firm inflammatory lump | A growth of the meibomian gland, usually an adenoma or epithelioma |
How it feels to your dog | Painful, especially when touched | Usually painless | Often painless, but it can rub the eye |
How it looks | Red, swollen, comes up quickly | Firm, yellow-gray lump, best seen on the inner surface of the lid | Pink, tan, gray or dark growth on the lid edge, often with a bumpy, cobblestone-like surface |
Typical dog | Any age | Often older dogs, because it often sits behind a small gland tumor | Mostly middle-aged and older dogs |
What the vet may do | Drain it, prescribe medication | Scrape it out through the inside of the lid | Remove it and send it to a lab |
The tumor column is the one owners don't expect. According to the Merck Veterinary Manual, eyelid tumors are the most common eye tumors in dogs, and most of them come from the meibomian glands. The American College of Veterinary Ophthalmologists (ACVO) says eyelid growths are common, typically develop in older dogs, and mostly behave in a benign way, though they usually keep growing and can irritate the eye.
How often are they cancer? A 2022 review in Today's Veterinary Practice by Dr. Braidee Foote, a board-certified veterinary ophthalmologist, puts canine eyelid tumors at least 3 to 8 times more likely to be benign than malignant. In a 2019 study of 119 eyelid masses removed from 118 dogs at a university veterinary hospital and a referral eye center in Taiwan, about two thirds were benign tumors and fewer than 1 in 10 were malignant. Reassuring, but those lumps had already been removed and tested. Only a lab report tells you which group your dog's lump belongs to.
Chalazia and tumors are also linked. A blocked gland is often blocked because a small meibomian tumor is sitting in its path, so a "chalazion" can be the first sign of one.
Other Problems That Can Look Like a Stye
Your vet will also consider these look-alikes:
- Cherry eye: a red, round swelling in the inner corner of the eye. It's the tear gland of the third eyelid popping out of place, not an infection, and breeds such as English Bulldogs, Beagles and Cocker Spaniels are prone to it. Vets usually put the gland back rather than remove it, because removing it raises the risk of dry eye later.
- Papilloma: a wart-like growth, often in young dogs, that may go away on its own.
- Histiocytoma: a small, raised, pink, hairless lump that grows quickly, mostly in young dogs, and often regresses within weeks.
- Melanoma: a dark, pigmented growth on the lid or lid edge. Eyelid melanomas in dogs are usually superficial and benign, but only a biopsy confirms it.
- Mast cell tumor: a skin tumor that can show up on the eyelid. It needs a sample or biopsy to identify.
- Conjunctivitis: red, goopy eyes from inflammation of the pink tissue lining the lids, rather than a single bump.
Why You Shouldn't Treat a Dog Stye at Home First
It's tempting to grab a warm washcloth or a leftover tube of eye ointment. It's a bad first move.
You may not be treating a stye. A compress won't shrink a tumor, and an ointment won't fix a cherry eye. Eyelid growths are easiest to remove while they're small, so every week spent guessing works against your dog.
Squeezing or popping it can hurt your dog or make the stye worse. The eyelid is thin and sits right on top of the eye.
Leftover drops and human medicine are a gamble. Use only what your vet prescribes for this problem; Merck advises against putting products that aren't made for the eye on inflamed eyelids.
Eye pain is easy to miss. Squinting and a watery eye can mean the cornea, the clear front of the eye, is scratched or ulcerated. That needs a vet, not a compress.
Warm compresses do have a place in treating styes, but as the Merck Veterinary Manual's guide for dog owners puts it, your veterinarian recommends the treatment program. If compresses are in it, your vet will show you how.
How Your Vet Diagnoses an Eyelid Lump
Expect questions first: when you noticed the lump, whether it came up overnight or grew slowly, and whether your dog rubs it. Then comes a close look at both eyes. Your vet may:
- Check whether the lump is painful and whether it's on the skin, the lid edge or the inner surface of the lid
- Look for eyelashes or a growth rubbing on the eye
- Put a dye on the eye to check for a corneal ulcer
- Run tests to rule out problems that make an eye red and sore, such as glaucoma and dry eye
- Take a small sample with a needle, or a biopsy, if the lump doesn't look like a typical stye
Your vet can often recognize a typical stye or chalazion on the exam. Growths are different. Only a pathologist examining the tissue under a microscope (histopathology) can give a definitive diagnosis, which is why Dr. Foote's review advises sending every removed eyelid tumor to the lab.
Treatment Options Your Vet May Recommend
Treatment depends on what the lump turns out to be. Your veterinarian chooses the medication, the dose and how long to use it.
For a stye or an inflamed eyelid, options include:
- Opening and draining the stye, often with sedation so your dog stays still and comfortable
- Antibiotic eye ointment or drops made for use in the eye
- Anti-inflammatory and pain medication, sometimes by mouth when the whole lid is inflamed
- Warm compresses, if your vet includes them in the plan
For a chalazion, the usual fix is a small procedure: the vet opens the gland from the inside of the eyelid and scrapes out the trapped material, without cutting the skin.
For an eyelid tumor, removal is often recommended because these growths tend to keep getting bigger and irritate the eye. Depending on size and position, your vet or a veterinary ophthalmologist may remove the growth at its base and freeze the remaining gland tissue (cryotherapy), or remove a small wedge of the lid edge and stitch it closed. Small growths can sometimes be handled with sedation and local anesthetic; larger ones often need general anesthesia. A pathologist then confirms what it was and whether more treatment is needed.
If the surgery needed stitches, your dog will usually go home in an Elizabethan collar (the cone) so they can't rub the stitches or the eye. Keep the follow-up appointments, since that's where your vet confirms the eyelid has healed and nothing is growing back.
When to Call Your Vet About a Lump on Your Dog's Eyelid
Any new lump on the eyelid deserves a vet visit. How fast depends on what else you see:
Mention at your next visit:
- A lump your vet has already checked and diagnosed, with no change in size, color or comfort
See your vet soon:
- Any new bump on the eyelid, even a small, painless one
- A red, swollen bump that looks like a stye
- A lump that is growing, bleeding or turning darker
- Your dog keeps rubbing or pawing at it
Call now:
- Squinting, holding the eye shut, or obvious eye pain
- The eye itself looks cloudy or very red
- Yellow or green discharge
- The whole eyelid or the area around the eye swells quickly
- Your dog seems unwell, or you're not sure
A sore, squinting eye can mean the cornea is involved, and Merck advises dealing with corneal problems promptly. When in doubt, call.
Can You Prevent Styes in Dogs?
Not reliably. Infections, gland blockages and eyelid tumors aren't things you can wash away. What you can do is catch them early: look at your dog's eyelids when you groom them, note the date and rough size of any new lump so your vet can tell whether it's growing, and get it checked while it's small. If your dog has ongoing skin problems, keep up with that treatment plan, since inflamed skin can involve the eyelids too.
The Bottom Line
A sore red bump that appeared overnight and a painless lump that has crept up over months are different problems with different treatments. Most eyelid lumps in dogs turn out to be benign, but only your vet, and sometimes a lab, can say which one your dog has. Book that check while the lump is small, and call the same day if the eye itself looks sore.
Sources
- Merck Veterinary Manual: Eyelids in Animals
- Merck Veterinary Manual: Ocular Neoplasia in Dogs
- Merck Veterinary Manual (dog owners): Disorders of the Eyelids in Dogs
- Merck Veterinary Manual (dog owners): Cancers and Tumors of the Eye in Dogs
- Merck Veterinary Manual (dog owners): Disorders of the Cornea in Dogs
- American College of Veterinary Ophthalmologists: Canine Eyelid Masses
- Today's Veterinary Practice: Diagnosis and Treatment of Eyelid Tumors (Foote, 2022)
- VIN: Conditions of the Eyelids and Ocular Adnexa in Dogs and Cats (Ramsey, Michigan State University, 2001)
- Vet Record Open: The investigation of histopathology and locations of excised eyelid masses in dogs (Wang et al., 2019)
- Vetster: Will my dog's stye go away on its own?
This article is for general information and is not a substitute for advice from your veterinarian.
