[Treatment with oxytetracycline hydrochloride in the prevention of atrophic rhinitis in baby pigs].

Atrophic rhinitis (AR) caused serious losses in a breeding herd including approximately 120 sows. The extent to which piglets were affected by AR was assessed by determining the degree of shortening of the upper jaw. Animals showing a crooked nose or grade two or more of shortening of the upper jaw were considered to be clinically positive. Grades three and four of the upper jaw were observed in those animals which were severely affected by Atrophic rhinitis. Treatment of all piglets up to about eight weeks of age by the antibiotic oxytetracycline hydrochloride directed against the bacteria Bordetella bronchisepica and Pasteurella multocida was successful in reducing the proportion of clinically affected piglets from 30 per cent to 0 per cent within eight weeks. There was found to be a positive relationship between the proportion of piglets infected with the two above bacteria at an age of about five weeks and the incidence of shortening of the upper jaw at an age of about eight weeks. The proportion of piglets with shortening of the upper jaw rose following a marked increase in the number of piglets in farrowing and flat-deck houses and as a result of the supply of inadequately medicated feed.