Prepn: L. D. Spicer, J. J. Hand, ZA 7105803 (1972 to Am. Cyanamid), C.A. 78, 72151h (1973). Prepn and resolution of isomers: eidem, FR 2199979; eidem, US 3899583 (1974, 1975 both to Am. Cyanamid). Efficacy and safety in dogs: B. T. Alford et al., Vet. Med. Small Anim. Clin. 74, 487 (1979). Evaluation in horses and ponies: R. B. Grieve et al., Am. J. Vet. Res. 40, 139 (1979).