Oxytetracycline for Cow: Uses, Dosing & Side Effects

This information is for educational purposes only. Never give your pet any medication without your veterinarian's guidance. Dosing, frequency, and safety depend on your pet's specific health profile.

Oxytetracycline is a prescription tetracycline antibiotic used in cattle to treat certain bacterial infections. In the U.S., it is commonly sold as injectable products such as Liquamycin LA-200, OXY-TET 200, and Bio-Mycin 200. Long-acting formulations are designed to keep drug levels up for longer after a single dose, which can be helpful when repeated handling is difficult.

This medication is used in beef cattle, calves, and some nonlactating dairy cattle, but the exact labeled use depends on the product and the class of animal. Because cattle are food-producing animals, your vet also has to consider meat withdrawal times, milk discard times, route of administration, and whether the use is on-label or extra-label.

Oxytetracycline works by slowing bacterial growth rather than directly killing bacteria. That means it is most useful when the infection is likely to be caused by oxytetracycline-susceptible organisms and when the full treatment plan also addresses hydration, pain, inflammation, wound care, or herd management if needed.

In cattle, oxytetracycline is commonly used for infectious bovine keratoconjunctivitis (pinkeye), shipping fever or bacterial pneumonia, foot rot, and anaplasmosis. Depending on the labeled product, it may also be used for leptospirosis, bacterial enteritis (scours), wooden tongue, wound infections, acute metritis, diphtheria, and anthrax when the bacteria involved are expected to respond.

Your vet may choose oxytetracycline when a broad-spectrum antibiotic is appropriate, when a long-acting injection would improve treatment compliance, or when cattle on pasture are hard to catch for daily dosing. In other cases, your vet may recommend a different antibiotic based on the likely bacteria, severity of illness, pregnancy status, kidney or liver concerns, or residue restrictions.

It is important to remember that not every cloudy eye, limp, fever, or cough is a bacterial infection. Oxytetracycline will not treat viral disease, parasites, trauma, or every cause of diarrhea. If a cow is depressed, off feed, dehydrated, breathing hard, or rapidly worsening, see your vet immediately so the diagnosis and treatment plan can be tailored to the animal and the herd.

Oxytetracycline dosing in cattle depends on the product concentration, route, disease being treated, age/class of cattle, and whether the use is on-label or extra-label under veterinary supervision. Common labeled injectable dosing for 200 mg/mL products includes either 9 mg/lb (20 mg/kg) once for certain situations such as pinkeye, anaplasmosis, or pneumonia when retreatment is impractical, or 3 to 5 mg/lb (about 6.6 to 11 mg/kg) once daily for up to 4 consecutive days. Severe foot rot and advanced cases are often dosed at the higher end of that daily range.

Route matters. Some labels allow subcutaneous, intramuscular, or intravenous use, but not every route is preferred in every setting. Beef Quality Assurance guidance has discouraged routine intramuscular use when other labeled routes are available because of tissue damage concerns. For IV use, oxytetracycline should be given slowly, since rapid IV administration can cause collapse. Many labels also limit the amount given per injection site, often no more than 10 mL per site in adult cattle.

Because this is a food-animal drug, your vet also needs to set and document the correct withdrawal interval. For many U.S. oxytetracycline 200 mg/mL labels, cattle treated according to label directions have a 28-day slaughter withdrawal, and milk from treated animals must be discarded during treatment and for 96 hours after the last treatment when the label allows use in lactating animals. Withdrawal times can change with route, product, and extra-label use, so never guess. Ask your vet for the exact written instructions for dose, route, frequency, injection-site limits, and withdrawal time for that specific cow.

Many cattle tolerate oxytetracycline reasonably well, but side effects can happen. The most common practical issues are injection-site pain, swelling, and tissue irritation. Some products can also cause muscle discoloration that may need trimming at processing. Shortly after injection, some animals may have temporary dark urine from hemoglobinuria.

More serious reactions are less common but matter. Allergic reactions or anaphylaxis, collapse after rapid IV administration, and overgrowth of nonsusceptible organisms can occur. Tetracyclines can also stress the kidneys and liver, especially in dehydrated, septicemic, endotoxemic, or otherwise unstable cattle. Merck notes that fatal renal failure has been reported in septicemic and endotoxemic cattle given high doses of oxytetracycline.

Use extra caution in young, growing animals, because tetracyclines can bind calcium and become incorporated into developing bones and teeth. They should also be used carefully in pregnant animals and in cattle with known kidney or liver disease. Call your vet promptly if you notice weakness, worsening depression, facial swelling, trouble breathing, severe diarrhea, jaundice, dark urine that persists, or no improvement within 24 to 48 hours.

Oxytetracycline can interact with other medications, so your vet should know about every prescription, over-the-counter product, mineral supplement, and feed additive your cattle are receiving. One classic concern is combining a bacteriostatic drug like oxytetracycline with penicillin, because tetracyclines may interfere with the bactericidal action of penicillin in some situations.

VCA also lists caution with aminoglycosides, beta-lactam antibiotics, digoxin, furosemide, warfarin, retinoid acids, atovaquone, and oral antacids or aluminum-containing products. In cattle practice, mineral interactions matter too. Tetracyclines can chelate calcium and other divalent cations, which is one reason they are known for effects on developing teeth and bone and why formulation and route are important.

Another practical interaction is with the animal's overall condition. Dehydration, endotoxemia, kidney compromise, and concurrent drugs that can affect the kidneys may increase risk. If your cow is receiving multiple treatments for pneumonia, metritis, foot rot, or pinkeye, ask your vet to review the full plan for compatibility, withdrawal timing, and whether each drug is still necessary.