Pneumonia and pleurisy are uncommon in adult horses in
the UK and Eire, but sometimes develop in animals stressed
by long-distance travel. Mixed bacterial infections including
anaerobes are usually present in these conditions and
aggressive antibacterial therapy based on bacterial culture
and sensitivity results is required for treatment; metronidazole
is helpful in cases where anaerobic infections are
present. Rifampicin is frequently used in combination with
erythromycin for the treatment of some pneumonic conditions
in foals, particularly those caused by Rhodococcus
equi infection.