Controlled study of the efficacy of clavulanic acid-potentiated amoxycillin in the treatment of Chlamydia psittaci in cats.

Twenty-four specific pathogen-free cats were inoculated with 3 x 10(3) infectious units of a field isolate of Chlamydia psittaci on to the corneal surface. Seven days later they were assigned randomly to three groups of eight and treated orally for 19 days with either clavulanic acid-potentiated amoxycillin, doxycycline or a placebo. Both treated groups responded rapidly, with a marked reduction in isolation rates and clinical scores which were significantly lower than in the placebo group within two and four days, respectively. After two days the group treated with potentiated amoxycillin had a significantly lower isolation score than the group treated with doxycycline. Forty days after they were infected the clinical signs recurred in five of the eight cats treated with potentiated amoxycillin, but a four-week course of potentiated amoxycillin resulted in a complete clinical recovery with no evidence of a recurrence for six months.