What is Terramycin Ophthalmic Ointment?
Terramycin is a brand name for a prescription combination eye antibiotic ointment. Its primary ingredients are the antibiotics oxytetracycline and polymyxin B. This medication is generally used in cats to treat a variety of bacterial eye problems, including conjunctivitis and corneal ulcers. Oxytetracycline is a broad-spectrum antibiotic belonging to the tetracycline group, which works by disrupting the bacteria's ability to produce essential proteins for survival. Polymyxin B is derived from the bacteria Bacillus polymyxa.
Uses of Terramycin in Cats
Ophthalmic Terramycin is most commonly used to treat pet cats experiencing conjunctivitis, particularly when infections caused by Chlamydia or Mycoplasma species of bacteria are confirmed or suspected. It is also prescribed for other bacterial inflammatory conditions that may arise from different infectious diseases, such as keratitis, pink eye, corneal ulcers, and blepharitis.
It is important to note that Terramycin does not work on viral infections, which are a very common cause of eye issues in cats.
How to Apply Terramycin Eye Ointment
Applying Terramycin eye ointment requires careful administration to ensure effectiveness and your cat's comfort. It is recommended to wash your hands thoroughly before starting.
- Have your cat facing away from you. Gently tilt their head up so you can clearly see the affected eye.
- While keeping gentle leverage under the chin, use your thumb to raise the upper eyelid and your pointer finger to lower the bottom lid, creating a small pocket.
- Gently squeeze a strip of ointment, approximately one gram (which is typically the same amount for all cats regardless of breed or size), from the tube into the space between the lower eyelid and the eye. Do not let the tube touch the eye to prevent contamination.
- After applying the ointment, gently close the lids with your thumb and pointer finger to allow the ointment to spread across the eye surface.
It is often easier to administer the ointment with two people: one to gently secure the cat and the other to apply the medication. Wrapping your cat in a towel with their head exposed can also help with restraint. Some cats may find eye drops easier to tolerate than ointments.
If your cat has been prescribed other eye drop solutions, it is crucial to administer the Terramycin ointment after any eye drops. Applying ointment first would create a barrier, preventing the liquid solution from reaching the eye surface. However, other eye medications can generally be given around the same time as Terramycin.
Dosage and Frequency
A single dose of Terramycin ophthalmic ointment for cats is typically a strip of ointment long enough to cross the surface of the eye, usually about one gram. Terramycin therapy may be administered to a cat anywhere from every 12 hours to every 6 hours, depending on the veterinarian's prescription. Always follow your veterinarian's directions precisely, even if your pet's symptoms appear to improve, unless otherwise advised. Your veterinarian will determine the appropriate treatment length based on your pet's signs and the type of infection.
Potential Side Effects and Precautions
In the majority of cases, serious side effects from oxytetracycline and polymyxin B are rare, as both antibiotics are generally well-tolerated by the tissues of the eye. However, some individual cats may experience an allergy or sensitivity, which can manifest as inflammation, irritation, or stinging in or around the eye after administration.
A rare but severe reaction is anaphylaxis, a life-threatening allergic reaction that can occur in some cats with hypersensitivity to polymyxin B. This reaction can happen within a couple of hours or less of application. Signs to watch for include vomiting, facial swelling, or general unwellness. If you observe any of these symptoms, contact your veterinarian urgently.
Important Precautions:
- Pregnancy and Sensitivity: Pregnant women and those sensitive to tetracycline antibiotics should use caution when handling this medication.
- Young Animals: Medications in the tetracycline class can impact bone development and cause discoloration of the teeth in young, growing animals. Talk to your veterinarian before using Terramycin in young or pregnant animals.
- Human Use: This medication is not used in human medicine.
- Overdose: It is not possible to overdose a cat with an ophthalmic antibiotic ointment like Terramycin.
How To: Apply Ointment To Your Cat's Eye!
Storage and Shelf Life
Terramycin should be stored at room temperature, ideally between 68-77 degrees Fahrenheit (20-25 degrees Celsius). Fluctuations between 59-86 degrees Fahrenheit (15-30 degrees Centigrade) are permissible. Keep the tube away from moisture and direct sunlight.
An unopened tube of Terramycin typically has a shelf life of 1-2 years. After opening, it should be used within the period recommended on the packaging, which is commonly 30 days.
When to See a Veterinarian
Eye infections in cats can be caused by various factors, including bacterial infections, viral infections, injuries, or other underlying conditions. If your cat exhibits any of the following symptoms, it is crucial to make an appointment with your veterinarian as soon as possible to prevent complications:
- Redness of the whites of the eyes
- Clear, yellow, or green discharge from the eye
- Winking or squinting
- Rubbing or pawing at one or both eyes
- Protruding third eyelid covering part of the irritated eye
Upper respiratory infections frequently cause eye irritation, with symptoms like sneezing or nasal discharge. If your cat shows any of these signs, prompt veterinary attention can help prevent the infection from spreading, becoming more severe, or affecting other pets in the household.
Note: While Terramycin is effective for bacterial infections, it is not effective against viral infections like Feline herpesvirus type 1 (FHV-1), a common cause of feline eye disease. If your cat has a viral infection, your veterinarian will recommend alternative treatments.
Terramycin vs. Other Treatments
While Terramycin is a well-regarded antibiotic ointment, other treatment options exist for feline eye infections. These may include other antibiotic ointments like Vetropolycin® (a triple antibiotic ointment containing bacitracin, neomycin, and polymyxin B), or tetracycline ophthalmic ointment, which may be prescribed for specific bacterial conjunctivitis cases.
Oral antibiotics, such as Azithromycin, can be used for certain bacterial infections, including those caused by Chlamydia and Mycoplasma, as well as underlying respiratory tract infections. Topical corticosteroids may be prescribed to reduce inflammation, and supplements like L-lysine are sometimes used to help manage feline herpesvirus infections, although research into their efficacy is ongoing.
Important Distinction: Human Medications
It is critical to understand that many human medications, including over-the-counter treatments like Neosporin, are not recommended or approved for use on cats. Neosporin topical ointment and Neosporin Ophthalmic contain ingredients like neomycin and polymyxin B, which, while effective in humans, have been linked to severe, even life-threatening anaphylactic reactions and death in cats. Cats are biologically different from humans, and even small amounts of toxic substances can cause severe reactions due to their compact size. Always consult your veterinarian for appropriate treatments for your cat's eye infections and never use human medications without professional veterinary guidance.