A stye, medically known as a hordeolum, is a painful condition resulting from a bacterial infection of a small oil gland located within your dog’s eyelid. These meibomian glands produce oil to lubricate the eye, but they can become blocked. When bacteria, often Staphylococcus aureus, infects this blockage or an eyelash follicle, it leads to characteristic inflamed, localized swelling.
Key Visual Signs of a Canine Stye
A canine stye presents as a small, localized, red, and tender lump directly on the edge of the eyelid, either on the upper or lower lid. This bump is distinct and often resembles a pimple or small boil where the eyelashes emerge. The lump is typically small, often no larger than a pea, but the surrounding tissue may swell considerably, making the entire eyelid look puffy and inflamed.
As the infection develops, the center of the lump may come to a head, appearing as a small, pale, or yellowish spot due to the accumulation of pus. This localized infection causes significant discomfort, leading to behavioral signs like excessive pawing or rubbing at the affected eye. The pain and irritation often lead to blepharospasm (involuntary squinting or rapidly blinking) and increased tear production.
The affected eye may also display other signs of irritation, such as generalized redness of the tissue surrounding the eyeball. Due to the inflammation, the dog may become sensitive to bright light, and their third eyelid may appear more prominent as a result of the discomfort.
Stye or Something Else?
Identifying a stye requires differentiating it from other canine eye conditions that cause similar lumps or redness. A stye is characterized by acute onset, pain, and bacterial infection. This distinguishes it from a chalazion, which is a sterile, non-infectious blockage of the meibomian gland. A chalazion typically develops farther back on the eyelid, is firmer, and is generally painless unless it irritates the eye surface.
Conjunctivitis (pink eye) involves inflammation of the eye’s lining, causing widespread redness and discharge but lacking the singular, localized lump of a stye. Eyelid tumors, more common in older dogs, can also appear as a lump, but they are often persistent, irregular in shape, and do not present with the acute pain and sudden onset of a bacterial infection.
Because the treatment for each condition varies significantly, a definitive diagnosis from a veterinarian is important. A stye’s pain and pus formation indicate an active infection, whereas a painless chalazion is simply a chronic blockage. Differentiating between these requires a thorough examination, sometimes involving a microscopic evaluation of the cells, to rule out more serious underlying issues.
What to Do If You Spot a Stye
If you observe a stye, focus on providing comfort and preventing self-trauma. Do not squeeze or try to pop the stye, as this can force the infection deeper or cause corneal damage. Gently apply a warm compress to the affected area for five to ten minutes several times a day.
The heat from the compress encourages the gland to open and drain naturally, relieving pressure and speeding resolution. Use a clean cloth soaked in warm (not hot) water, holding it against the closed eyelid as long as your dog tolerates it. Monitor the condition closely, keeping the area clean, and use an Elizabethan collar if the dog attempts to rub or scratch the eye.
Seek veterinary attention promptly if the stye does not improve within 48 to 72 hours of home care or if it appears to be worsening. A visit is also warranted if your dog shows signs of significant illness, such as fever, severe pain, or if swelling affects their ability to see. The veterinarian can determine if prescription treatments, such as topical antibiotics or anti-inflammatory medication, are required to fully resolve the infection.