Section 520.2123b - Spectinomycin powder(a)Specifications. Each gram (g) of powder contains spectinomycin dihydrochloride pentahydrate equivalent to 0.5 g spectinomycin.(b)Sponsor. See No. 061133 in § 510.600(c) of this chapter.(c)Related tolerances. See § 556.600 of this chapter.(d)Conditions of use in chickens. It is administered in the drinking water of growing chickens as follows: (1)Indications for use and amounts.(i) As an aid in controlling infectious synovitis due to Mycoplasma synoviae in broiler chickens, administer 1 g per gallon of water as the only source of drinking water for the first 3 to 5 days of life.(ii) As an aid in the prevention or control of losses due to CRD associated with M. gallisepticum (PPLO) in growing chickens, administer 2 g per gallon of water as the only source of drinking water for the first 3 days of life and for 1 day following each vaccination.(2)Limitations. Do not administer to laying chickens. Do not administer within 5 days of slaughter. Federal law restricts this drug to use by or on the order of a licensed veterinarian. 73 FR 6607 , Feb. 5, 2008, as amended at 81 FR 94990 , Dec. 27, 2016; 84 FR 8973 , Mar. 13, 2019 As amended at 81 FR 94990, 12/27/2016; 84 FR 8973, 3/13/2019