In the face of an outbreak of enzootic pneumonia in a closed herd or when a chronic problem is recognised, it is important to attempt to identify the causative agents and management and environmental factors in order to target preventive measures in the future.

For the acute form of enzootic pneumonia, nursing and isolation of affected calves is important in all treatment regimes. Vitamins can be administered as a supportive therapy, and a multitude of treatments from antihistamines to expectorants have been found effective in alleviating the condition. Antimicrobials and both steroid and non-steroid anti-inflammatory drugs are usually the main line of treatment. Antibiotics are often used in in-contact animals as well as in the affected ones. Vaccines can occasionally be used for the in-contact animals, and have been shown to provide protection when the causative agent is identified fast enough (Gourlay et al., 1989; Laven and Andrews, 1991).

Whilst it is unacceptable, under the organic standards, to use antibiotics and/or steroid drugs in a prophylactic manner, it is important to use all effective means to alleviate the condition during an outbreak. The use of antibiotics in symptomless, in-contact animals is also justifiable in the face of an outbreak in order to avoid further spread of the disease if isolation and close monitoring are impossible. The need for antibiotic cover for in-contact animals can, however, be minimised if an isolation facility exists and the affected animals are immediately removed from rest of the herd.

Many of the antibiotics used in the treatment of enzootic pneumonia, particularly to give protection to in-contact animals, are long acting formulations with very long statutory withdrawal periods of up to 60 days. A recently launched new product, containing fluoroquinolone enrofloxacin, has been marketed to veterinarians as suitable for treatment of enzootic pneumonia on organic farms due to its shorter statutory withdrawal period (14 days). Whilst withdrawal periods are seldom a major consideration for drug choice in young animals, the use of fluoroquinolones should be avoided on organic farms if alternative antibiotics exist. Fluoroquinolones are a group of antibiotics whose use in production animals has caused most concern in regard to the transfer of antimicrobial resistance to humans from animals (Wray et al., 1993; Endzt et al., 1991; Aarestrup et al, 1998).

 The chronic form of enzootic pneumonia is normally not treated unless the calf has a severe cough. Antibiotics, when chosen carefully, are effective. It should, however, be noted that chronic enzootic pneumonia in calves is a herd problem. When the condition becomes severe enough to require treatment, it is necessary to attempt to identify the causes of the condition. Improvement of the management and environment or eradication of the causative agent/agents with the help of a comprehensive disease control plan is required.