Section 520.90a - Ampicillin tablets(a)Specifications. Each tablet contains ampicillin trihydrate equivalent to 50 or 100 milligrams of ampicillin.(b)Sponsor. See No. 054771 in § 510.600(c) of this chapter.(c)Conditions of use in dogs -(1)Amount. 5 milligrams per pound of body weight, at 8-hour intervals, 1 to 2 hours prior to feeding, to be continued 36 to 48 hours after all symptoms have subsided. If no improvement is seen within 5 days, stop treatment, reevaluate diagnosis, and change therapy.(2)Indications for use. Oral treatment of infections caused by susceptible organisms as follows: Upper respiratory infections, tonsillitis, and bronchitis due to Streptococcus spp., Staphylococcus spp., Escherichia coli, Proteus mirabilis, and Pasteurella spp., urinary tract infections (cystitis) due to Streptococcus spp., Staphylococcus spp., E., coli, P. mirabilis, and Enterococcus spp.; gastrointestinal infections due to Staphylococcus spp., Streptococcus spp., Enterococcus spp., and E. coli. ; infections associated with abscesses, lacerations, and wounds caused by Staphylococcus spp., and Streptococcus spp.(3)Limitations. Federal law restricts this drug to use by or on the order of a licensed veterinarian.57 FR 37321, Aug. 18, 1992, as amended at 60 FR 55659, Nov. 2, 1995; 79 FR 28818 , May 20, 2014. Redesignated at 85 FR 18118 , Apr. 1, 2020