Section 522.90b - Ampicillin trihydrate powder for injection(a)Specifications. Each milliliter of aqueous suspension constituted from ampicillin trihydrate powder contains 200, 250, or 400 milligrams (mg) ampicillin equivalents.(b)Sponsors. See Nos. 000010 and 042791 in § 510.600(c) of this chapter.(c)Related tolerances. See § 556.40 of this chapter.(d)Conditions of use - (1)Dogs and cats - (i)Amount. 3 mg/pound (lb) of body weight twice daily by subcutaneous or intramuscular injection.(ii)Indications for use. For treatment of strains of organisms susceptible to ampicillin and associated with respiratory tract infections, urinary tract infections, gastrointestinal infections, skin infections, soft tissue infections, and postsurgical infections.(iii)Limitations. Federal law restricts this drug to use by or on the order of a licensed veterinarian.(2)Cattle - (i)Amount. 2 to 5 mg/lb of body weight once daily by intramuscular injection.(ii)Indications for use. For treatment of respiratory tract infections caused by organisms susceptible to ampicillin, bacterial pneumonia (shipping fever, calf pneumonia, and bovine pneumonia) caused by Aerobacter spp., Klebsiella spp., Staphylococcus spp., Streptococcus spp., Pasteurella multocida, and Escherichia coli.(iii)Limitations. Do not treat cattle for more than 7 days. Milk from treated cows must not be used for food during treatment and for 48 hours (4 milkings) after the last treatment. Cattle must not be slaughtered for food during treatment and for 144 hours (6 days) after the last treatment. Federal law restricts this drug to use by or on the order of a licensed veterinarian.57 FR 37331, Aug. 18, 1992; 57 FR 42623, Sept. 15, 1992; 58 FR 18304, Apr. 8, 1993; 63 FR 41420, Aug. 4, 1998; 75 FR 10167 , Mar. 5, 2010; 76 FR 17338 , Mar. 29, 2011; 76 FR 53051 , Aug. 25, 2011; 82 FR 21690 , May 10, 2017; 85 FR 4208 , Jan. 24, 2020 82 FR 21690, 5/10/2017; 85 FR 4208, 1/24/2020