Halquinols (halquinol) is an antimicrobial for treatment of skin infections available as topical skin pharmaceutical. Tarquinor skin cream, a dermatological preparation of halquinol 0.2% and 1% coal tar has been approved for use in New Zealand in 1962 and is in use in Australia at present. Halquinols has a broad antimicrobial activity in vitro against a wide variety of bacteria, fungi and protozoa including Candida albicans, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus pyogenes. It has a significant antimycoplasmal (MICs of 3 to 4 ug/ml) and anticryptosporidial activity at 1 or 20 uM against Cryptosporidium parvum. As some antimicrobials halquinol has been used as a growth promotor in poultry. Study of fresh water fish Catla catla treated with halquinol suggested enhanced anabolic metabolism resulting in weight gain. However, the mechanisms by which the drug improves performance are not fully understood. Halquinol was the only antimicrobial drug tested in chicken that did not affect microbial membership compared to the control group.