CLINICAL EVALUATION OF TYLOSIN AS A TREATMENT OF VIBRIONIC DYSENTERY IN SWINE.

A 5 year history of swine dysentery and treatment has been described.In 1964, a severe outbreak diagnosed as Vibrionic dysentery in 166 litters farrowed from January - March caused a death loss of 30.3 per cent of the total number weaned. This outbreak was not checked with an organic arsenic, sodium arsanilate, which had previously been relatively effective.A subsequent farrow of 133 litters (June - August, 1964) was infected and again sodium arsanilate was ineffective. Microscopic examination of smears of representative fecal samples revealed the presence of a heavy concentration of vibrio-like organisms. Two test-barns, housing 140 and 172 pigs respectively, were treated with tylosin-tartrate, using one side of each barn as a control, while the other side was being treated. Subsequently, the control sides were treated. Both levels of tylosin used, 1 gm and 2 gm per U.S. gallon of water, resulted in the disappearance of fluid feces within 48 hours of treatment. Soft, granular feces were still present 6-9 days after the start of treatment at the 1 gm level, while in case of the 2 gm level of tylosin, all feces were normal on the third day after medication started. Microscopic examination of feces collected on the third day of treatment still revealed the presence of some vibrio-like organisms. However, these organisms could not be detected in examination of feces collected between 10 to 25 days after treatment. In this test there was no recurrence of dysentery.