What should you know about intramammary antibiotics for cows?

The medicine is placed into an affected quarter so it can act locally in the udder. A veterinarian or trained animal-health professional decides whether infection is likely, which product is suitable and whether treatment should follow milking or another farm protocol. Signs of mastitis can include abnormal milk, a swollen or painful quarter, warmth or changes in the cow's general condition. Antibiotics do not treat every cause of udder change, and use without assessment can delay the right care or encourage resistance. Human infections such as [Brucellosis](/conditions/brucellosis/) are a separate concern and need medical assessment.

Follow the product label and veterinary instructions for cleaning the teat, administering the dose, storing the medicine and completing treatment. Use clean equipment and record the cow, quarter, product and treatment times. Milk from a treated cow must be kept out of the food supply for the full withdrawal period specified by the veterinarian or label. Do not use leftover medicine in another animal or combine products without advice. Wear suitable protective equipment and wash hands after handling.

Contact a veterinarian urgently if the cow is very unwell, stops eating, becomes weak, has a high temperature, shows marked udder swelling or produces severely altered milk. Rapid deterioration can require more than local treatment. Seek medical advice if a person handling the medicine develops a rash, breathing difficulty, eye exposure or an accidental injection. Do not put treated milk into household food.

Ask which quarter is affected, whether a milk sample is needed, how to administer and store the product, when milk can re-enter the food supply, and what signs mean the cow needs reassessment.