# 520.1242a Levamisole powder.
(a) *Specifications.* Each package of powder contains 9.075, 11.7, 18.15, 46.8, 362.7, or 544.5 grams (g) levamisole hydrochloride.
(b) *Sponsors.* See sponsors in § 510.600(c) for use as follows:
(1) No. 000061 for use of 46.8- and 544.5-g packages as in paragraph (e)(1)(i), (e)(1)(ii)(B), and (e)(1)(iii) of this section; for 11.7-, 46.8-, and 544.5-g packages as in paragraph (e)(2)(i), (e)(2)(ii)(B), and (e)(2)(iii) of this section; and for an 18.15-g package as in paragraph (e)(3) of this section.
(2) No. 054771 for use of a 46.8-g package as in paragraph (e)(1)(i), (e)(1)(ii)(A), and (e)(1)(iii) of this section; for 11.7- and 46.8-g packages as in paragraph (e)(2)(i), (e)(2)(ii)(A), and (e)(2)(iii) of this section; and for 9.075- and 18.15-g packages as in paragraph (e)(3) of this section.
(3) No. 016592 for use of 46.8- and 544.5-g packages as in paragraphs (e)(1)(i), (e)(1)(ii)(B), and (e)(1)(iii) and (e)(2)(i), (e)(2)(ii)(B), and (e)(2)(iii) of this section.
(4) No. 061133 for use of 46.8-, 362.7-, and 544.5-g packages as in paragraphs (e)(1)(i), (e)(1)(ii)(B), (e)(1)(iii), (e)(2)(i), (e)(2)(ii)(B), and (e)(2)(iii) of this section; and for use of an 18.15-g package as in paragraph (e)(3) of this section.
(c) *Related tolerances.* See § 556.350 of this chapter.
(d) *Special considerations.* See § 500.25 of this chapter.
(e) *Conditions of use.* It is used as an anthelmintic as follows:
(1) *Cattle*—(i) *Amount.* 8 milligrams per kilogram (mg/kg) body weight as a drench.
(ii) *Indications for use.* (A) Effective against the following nematode infections: Stomach worms (*Haemonchus, Trichostrongylus, Ostertagia*); intestinal worms (*Trichostrongylus, Cooperia, Nematodirus, Bunostomum, Oesophagostomum*); and lungworms (*Dictyocaulus*).
(B) Effective against the following adult nematode infections: Stomach worms (*Haemonchus placei, Ostertagia ostertagi, Trichostrongylus axei*); intestinal worms (*T. longispicularis, Cooperia oncophora, C. punctata, Nematodirus spathiger, Bunostomum phlebotomum, Oesophagostomum radiatum*); and lungworms (*Dictyocaulus viviparus*).
(iii) *Limitations.* Do not slaughter for food within 48 hours of treatment. Not for use in dairy animals of breeding age. Conditions of constant helminth exposure may require retreatment 2 to 4 weeks after the first treatment. Consult your veterinarian before using in severely debilitated animals.
(2) *Sheep*—(i) *Amount.* 8 mg/kg body weight as a drench.
(ii) *Indications for use.* (A) Effective against the following nematode infections: Stomach worms (*Haemonchus, Trichostrongylus, Ostertagia*); intestinal worms (*Trichostrongylus, Cooperia, Nematodirus, Bunostomum, Oesophagostomum, Chabertia*); and lungworms (*Dictyocaulus*).
(B) Effective against the following adult nematode infections: Stomach worms (*Haemonchus contortus, Trichostrongylus axei, Teladorsagia circumcincta*); intestinal worms (*Trichostrongylus colubriformis, Cooperia curticei, Nematodirus spathiger, Bunostomum trigonocephalum, Oesophagostomum columbianum, Chabertia ovina*), and lungworms (*Dictyocaulus filaria*).
(iii) *Limitations.* Do not slaughter for food within 72 hours of treatment. Conditions of constant helminth exposure may require retreatment 2 to 4 weeks after the first treatment. Consult veterinarian before using in severely debilitated animals.
(3) *Swine*—(i) *Amount.* 8 mg/kg body weight in drinking water.
(ii) *Indications for use.* Effective against the following nematode infections: Large roundworms (*Ascaris suum*), nodular worms (*Oesophagostomum* spp.), intestinal thread worms (*Strongyloides ransomi*) and lungworms (*Metastrongylus spp.* ).
(iii) *Limitations.* Do not administer within 72 hours of slaughter for food. Pigs maintained under conditions of constant exposure to worms may require retreatment within 4 to 5 weeks after the first treatment. Consult your veterinarian before administering to sick swine.
[69 FR 9753, Mar. 2, 2004, as amended at 69 FR 33839, June 17, 2004; 70 FR 2353, Jan. 13, 2005; 77 FR 28253, May 14, 2012; 78 FR 28822, May 20, 2014; 84 FR 8972, Mar. 13, 2019; 87 FR 58961, Sept. 29, 2022]