RESUMEN
Two Saanen does on the same farm developed signs of polyarthritis. Streptococcus dysgalactiae was isolated on microbial culture of samples from multiple joints of both goats. Antibiotic susceptibility testing of the S dysgalactiae revealed resistance to tetracycline, a commonly used antibiotic to treat arthritis in goats. The isolate was susceptible to penicillin. Polyarthritis was clinically diagnosed in 25 Saanen goats on this farm over a 2-year period. Streptococcus dysgalactiae has been reported as a cause of polyarthritis in calves and lambs and should be considered as a cause of polyarthritis in adult goats. Joint fluid samples for Mycoplasma, aerobic bacterial, and Chlamydia culture and serum samples for caprine arthritis-encephalitis virus serologic testing should be obtained from live goats during clinical evaluation of herd outbreaks of polyarthritis.