It should not be used in patients with liver disease. It is uncommon for pyoderma to be complicated by Gram negative bacteria. These are broad spectrum, bactericidal, derivatives of nalidixic acid. They work by inhibiting DNA gyrase and therefore DNA replication. They are very effective against Pseudomonas .
Resistance occurs with chronic use.
In order to be effective against Staphylococcus intermedius high doses are recommended. The most commonly used quinolones in veterinary medicine is enrofloxacin. It penetrates very well deep tissues and it should be reserved for deep pyodermas. These doses are much higher than the ones recommended by manufacturer but they are the only effective in difficult cases of ear infections. It should not be used in young dogs since articular cartilage may be damaged.