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Terramycin® ophthalmic ointment is a veterinary antibiotic medication that is designed to treat eye infections in cats, dogs, and certain livestock like goats and sheep. It is manufactured and distributed around the world by Pfizer Animal Health, and is usually available only by prescription. In most cases the drug requires direct application to the eyeball and affected eye tissues; veterinarians themselves often perform the application, at least initially, and usually teach owners how to continue the regimen at home. Owners should also be on the lookout for some of the most common side effects, which can include blurred vision and disorientation. The active ingredients in the ointment are similar to those in creams that are intended to treat related infections in humans, but the proportions and formulations are usually really different. As such, humans shouldn’t use the medication, and neither should animals use similar creams that have been made for people.
Eye infections often impact animals more than they do people, in part because the anatomy of most small creatures means that their eyes are more likely to come into contact with bacteria on the ground or in the environment. Once bacterial strains root themselves in the moist eye area, they don’t often die off on their own; in fact, they can often spread and grow, causing potentially permanent vision problems and posing a much more serious health risk to the body generally. As a consequence, prompt medical treatment is usually a must.
Terramycin® ophthalmic ointment is one of the options available in many places. It is a bright yellow ointment uses a petroleum base, and in most cases it needs to be applied directly to the eye in order to be effective. Terramycin® contains the antibiotics oxytetracycline and polymyxin B sulfate, and it’s usually considered a “versatile broad-spectrum antibiotic” — meaning basically that it can target and kill a range of related bacterial strains. It is commonly used to treat infections resulting from both Gram-positive and Gram-negative bacteria, along with rickettsiae, spirochetes and other discrete causes.
One of the primary ingredients in this antibiotic eye medication is polymyxin B sulfate, which is derived from bacillus polymyxa. This compound is rapidly effective against Gram-negative bacteria. Oxytetracycline, the other main ingredient, blocks the ability of bacteria to produce the proteins necessary for bacterial growth. Polymyxin B is also effective in treating infections associated with pseudomonas aeruginosa. Some research also indicates that polymyxin B sulfate is effective as an anti-fungal ingredient.
This preparation is often most commonly used to treat conjunctivitis, also known as “pink eye.” Pink eye is highly contagious, and animals that live in close proximity to each other often share it. Regular application of this or a related antibiotic ointment will usually clear it up in a few days. The cream is also commonly recommended for animals suffering from inflamed eyelids and corneal infections and irritations.
Terramycin® can be used to treat eye infections caused by secondary bacterial complications of canine distemper in dogs, and may occasionally be used in cats to treat chlamydia. This latter problem is often more commonly thought of as a respiratory disorder, but in extreme cases it can spread up to the eyes, too.
The tube the ointment comes in is usually sterile, and it should have an angled tip on the end of the applicator. In general this tip should not be touched directly by either the animal’s eye or a person’s finger in order to prevent the risk of contamination. Most vets and others wear sterile gloves when working with this medication to keep the workspace clean. It should typically be applied in a thin layer on the inside of the animal's lower eyelid, usually from two to four times daily. The prescribing veterinarian will usually provide a schedule of drug administration based on the animal’s specific needs.
Risks and Common Precautions
Like most medications, this one does carry a few risks. Animals allergic to polymyxin B, oxytetracycline, tetracycline, or doxycycline shouldn’t usually be treated with Terramycin®, for instance. The ointment can also cause temporary blurred vision, and animals being treated should be monitored for signs of visual disturbance and disorientation.
Prolonged use can sometimes lead to a drug-resistance problem that can result in a more serious fungal or bacterial infection. It’s also important that other eye medications not be used simultaneously unless specifically recommended by a veterinarian. Anyone who ahs concerns about this medication or wonders if it’s right for their pet should talk to an animal health expert to evaluate the specific risks and benefits for their situation.