Our last two programs have dealt with Rhodococcus pneumonia, a very severe form of pneumonia that occurs in young foals around August in hot, dry, and dusty conditions.   Although the disease can be treated, treatment is required long term and can be expensive.  Also, by the time the diagnosis is made, many foals have too much lung damage to survive.  Successful treatment depends on early recognition of the disease.  On farms with a history of this disease, twice weekly veterinary exams with monitoring of blood counts and fibrinogen concentrations have been used to detect Rhodococcus in the early stages.  Prevention of the disease on farms that have had cases in the past is important as the death rate is reported to be 20% to 25% even in cases that are treated. 

Prevention of Rhodococcus centers around decreasing the number of organisms inhaled.  It is important to keep foals out of the heat during the hottest part of the day, and keep the concentration of foals kept together as low as possible.  Also, foals should be kept in areas with grass, areas with the least dust possible, and areas with good ventilation.  Foals kept on sandy soils have an increased incidence of the disease.  Manure should be regularly removed from the pastures and pastures rotated often. 

Another important method of preventing Rhodococcus pneumonia is with the use of hyperimmune plasma.  On farms with a history of this disease, plasma obtained from horses hyperimmunized against virulent strains of Rhodococcus equi is given intravenously to foals the first week of life and again at 25 days of age.  Although this method does not provide 100% protection and is expensive, it has been shown to decrease the incidence and severity of the disease.