• Posted April 17, 2025

Improved Canine Eyedrops Deliver Antibiotics More Effectively

THURSDAY, April 17, 2025 (HealthDay News) — Newfangled eyedrops for dogs might be better at helping them fight off infections, a new study says.

Eyedrops containing hyaluronic acid helped antibiotics better coat the eyes of healthy dogs, compared to traditional eyedrop formulations, researchers recently reported in the journal Veterinary Ophthalmology.

As a result, higher concentrations of the antibiotics remained longer in the canine’s eyes, which could potentially improve the eyedrops’ effectiveness against infection, researchers said.

The drops still need to be tested in dogs with eye infections. If they work, then they should also help humans with eye problems, researchers said.

“The findings of this study offer clear benefits for our veterinary patients, but they also carry translational relevance for human medicine,” said senior researcher Dr. Lionel Sebbag, an ophthalmologist at Hebrew University of Jerusalem’s Koret School of Veterinary Medicine in Israel.

“Dogs are affected by many of the same ocular diseases as humans, and their ocular anatomy and physiology are much more comparable to human eyes than those of the more commonly used pre-clinical research species, such as rabbits or rodents,” Sebbag said in a news release. “This makes dogs an especially valuable model in ophthalmic research.”

Hyaluronic acid is a gooey, slippery substance that the human body produces naturally, according to the Cleveland Clinic. 

It helps lubricate joints, keeps skin stretchy and flexible, and maintains hydration in the body. It's also a popular ingredient in skin care products thanks to its ability to attract and retain moisture, helping the skin appear plumper and more hydrated.

For this study, researchers crafted hyaluronic acid eyedrops containing two different antibiotics, cefazolin and chloramphenicol.

The drops were then tested in the eyes of 10 dogs to see how well they worked, compared to traditional eyedrops containing polyvinyl alcohol solution.

Overall, antibiotic exposure was 2.4 times greater for cefazolin and 4.2 times greater for chloramphenicol with the hyaluronic acid drops compared to the traditional eyedrops, researchers found.

Vets might be able to treat eye infections using lower or fewer doses of eyedrop antibiotics containing hyaluronic acid, since higher concentrations of the antibiotic coat the eye for longer, researchers said.

This approach also could reduce the risk of antibiotic resistance, they added.

Hyaluronic acid also has positives of its own, beyond its usefulness as a drug delivery vehicle, researchers added.

It’s known to possess antibacterial properties and can help wounds heal faster, which might help people with an eye injury like a corneal scratch, researchers said.

The substance also can improve the quality of a person’s tears, which is why it’s often used to treat dry eyes, the Cleveland Clinic says.

The next step will be to test the drops in dogs with eye infections, researchers said.

More information

The Cleveland Clinic has more about hyaluronic acid.

SOURCE: Hebrew University of Jerusalem, news release, April 2, 2025