Research conducted over 3 years in stud Millennium, which specializes in breeding of thoroughbred horses (Donetsk region). Every year observed loss of young foals from diseases of the lower respiratory tract, which clinically manifested as purulent bronchopneumonia. Within three years observations we mark the age dependence of morbidity and mortality foals from bronchopneumonia. Peak of foals mortality was in 7 - 10 weeks of age.

 Clinical signs of the disease appeared in foals starting at 4 weeks of age. Disease in foals ranged from mild to severe. The first clinical signs of bronchopneumonia in foals was intermittent fever, which later passed into the permanent fever. Body temperature was higher at night, and in some foals reached 40,6 °C. As a result of our observations, the presence of cough and nasal discharge was not characteristic feature of bronchopneumonia in the early stages of development.

Foals with severe bronchopneumonia shows signs of respiratory failure - tachypnea, expiratory dyspnea, and as a result, the presence of abdominal type of breathing, which is manifested in the form of "inflammatory cove". Coughing in these foals was infrequent, however, periodic, deep and loud. Auscultation of the lungs was observed pathological noise - rattles of various kinds, crackling. In some sick foals was not wiretapped noise in some areas of lung field during auscultation, which indicating a swelling of lung tissue or abscess formation in the relevant area. Foals with severe course of disease often lay and not actively suck the mares which subsequently displayed on the lag in growth and development.

In the dead foals, during autopsy, observed changes in lung tissue in the form of purulent bronchopneumonia and hyperplasia of regional lymph nodes, sometimes with formation abscesses on the surface of the lung. Bacteriological studies of pathological material identified culture microorganisms of Rhodococcus equi and Micrococcus flavus.

During period of study in 2014 observed disorders of gastrointestinal tract in 60% of lactating foals which clinically manifested as diarrhea. Diarrhea in these foals started at 7 - 10 days after birth, some foals first time observed on 30 day of life. Feces were rare, not fetid, from yellow-green to dark brown colored. During diarrhea fever were not observed, except foals with development of bronchopneumonia. In some foals diarrhea periodically arose several times up to two-month old. Typically, intestinal disorders disappear within a few days. Complications or death from the gastrointestinal tract disorders in foals were not observed. We were not determining the cause of recurrent diarrhea in foals, but we believe they have multifactorial character and as the result of adaptive processes foals to changes in microbial flora of intestine, so it maybe intestinal form manifestations of Rhodococcus equi infection. To determine etiology of diarrhea in the foals by laboratory methods was not possible in the farm.

Analyzing the situation in the stud with respect to mass illness and death of foals, based on research conducted there were assumptions about the presence of Rhodococcus equi infection of horses as the main reason outbreaks of respiratory disease in foals. It was proposed in 2014 for experimental purpose use commercial hyperimmune plasma to all foals this year birth. As a result the mortality rate of foals from bronchopneumonia in 2014 was 10%, which is on 9% lower than in 2012 and on 26% lower than in 2013.

Key words: foals, bronchopneumonia, Rhodococcus equi, hyperimmune plasma.