It is illegal for a producer or veterinarian to administer nitrofurazone topically or via any other means since 2002.
Consult your vet!!
PS. it didn't help much for pinkeye anyway.
February 7, 2002
FDA PROHIBITS NITROFURAN DRUG USE IN FOOD-PRODUCING ANIMALS
FDA is issuing an order prohibiting the extralabel use of topical nitrofuran animal and human drugs in food-producing animals. This order is based on evidence that extralabel use of topical nitrofuran drugs in food-producing animals may result in the presence of residues that are carcinogenic and have not been shown to be safe. The Agency finds that such extralabel use presents a risk to the public health for the purposes of the Animal Medicinal Drug Use Clarification Act (AMDUCA) of 1994.
AMDUCA amended the Federal Food, Drug, and Cosmetic Act to allow licensed veterinarians to prescribe extra-label uses of approved animal drugs and human drugs in animals. Section 2(a)(4)(D) of the AMDUCA provides that the Agency may prohibit an extra-label drug use in animals if, after affording an opportunity for public comment, the Agency finds that such use presents a risk to the public health.
In the past, FDA permitted two approved topical nitrofurans to be used in cattle. These products were:
Furazolidone aerosol powder (trade names such as Topazone and Furox aerosol.)
Nitrofurazone topical powder for pinkeye and wounds (trade names such as NFZ Puffer and P.E. 7.)
A carbon-14 (C-14) radio-label residue depletion study conducted by the FDA showed that detectable levels of nitrofuran derivatives are present in edible tissues (milk, meat, kidney, liver) of cattle treated by the ocular (eye) route. The study indicates that use of these nitrofuran products may pose a risk to public health because residues of known carcinogens are present in edible tissues.