#### § 558.300 Ivermectin.

(a) *Specifications.* Type A medicated article containing 2.72 grams ivermectin per pound (g/lb).

(b) *Sponsor.* See No. 000010 in [§ 510.600(c) of this chapter](/on/2024-09-23/title-21/section-510.600#p-510.600(c)).

(c) *Related tolerances.* See [§ 556.344 of this chapter](/on/2024-09-23/title-21/section-556.344).

(d) *Special considerations.* See [§ 500.25 of this chapter](/on/2024-09-23/title-21/section-500.25).

(e) *Conditions of use in swine.* It is used in feed as follows:

| Ivermectin in grams/ton | Combination in grams/ton | Indications for use | Limitations | Sponsor |
| --- | --- | --- | --- | --- |
| (1) 1.8 | | Weaned, growing-finishing swine: For treatment and control of gastrointestinal roundworms (*Ascaris suum,* adults and fourth-stage larvae; *Ascarops strongylina,* adults; *Hyostrongylus rubidus,* adults and fourth-stage larvae; *Oesophagostomum* spp., adults and fourth-stage larvae); kidneyworms (*Stephanurus dentatus,* adults and fourth-stage larvae); lungworms (*Metastrongylus* spp., adults); threadworms (*Strongyloides ransomi,* adults and somatic larvae); lice (*Haematopinus suis*); and mange mites (*Sarcoptes scabiei* var. *suis*) | Feed as the only feed for 7 consecutive days to provide 0.1 milligrams per kilograms (mg/kg) of body weight per day. Withdraw 5 days before slaughter | 000010 |
| (2) 1.8 | Bacitracin methylenedisalicylate, 10 to 30 | Weaned, growing-finishing swine: For treatment and control of gastrointestinal roundworms (*Ascaris suum,* adults and fourth-stage larvae; *Ascarops strongylina,* adults; *Hyostrongylus rubidus,* adults and fourth-stage larvae; *Oesophagostomum* spp., adults and fourth-stage larvae); kidneyworms (*Stephanurus dentatus,* adults and fourth-stage larvae); lungworms (*Metastrongylus* spp., adults); threadworms (*Strongyloides ransomi,* adults and somatic larvae); lice (*Haematopinus suis*); and mange mites (*Sarcoptes scabiei*var. *suis*); and for increased rate of weight gain and improved feed efficiency | Feed as the only feed for 7 consecutive days to provide 0.1 mg/kg of body weight per day. Withdraw 5 days before slaughter | 000010 |
| (3) 1.8 | Bacitracin methylenedisalicylate, 250 | Weaned, growing-finishing swine: For treatment and control of gastrointestinal roundworms (*Ascaris suum,* adults and fourth-stage larvae; *Ascarops strongylina,* adults; *Hyostrongylus rubidus,* adults and fourth-stage larvae; *Oesophagostomum* spp., adults and fourth-stage larvae); kidneyworms (*Stephanurus dentatus,* adults and fourth-stage larvae); lungworms (*Metastrongylus* spp., adults); threadworms (*Strongyloides ransomi,* adults and somatic larvae); lice (*Haematopinus suis*); and mange mites (*Sarcoptes scabiei* var. *suis*); and for control of swine dysentery associated with *Treponema hyodysenteriae* on premises with a history of swine dysentery, but where symptoms have not yet occurred, or following an approved treatment of disease condition | Feed as the only feed for 7 consecutive days to provide 0.1 mg/kg of body weight per day. Withdraw 5 days before slaughter | 000010 |
| (4) 1.8 to 11.8 | | Adult and breeding swine: For treatment and control of gastrointestinal roundworms (*Ascaris suum,* adults and fourth-stage larvae; *Ascarops strongylina,* adults; *Hyostrongylus rubidus,* adults and fourth-stage larvae; *Oesophagostomum* spp., adults and fourth-stage larvae); kidneyworms (*Stephanurus dentatus,* adults and fourth-stage larvae); lungworms (*Metastrongylus* spp., adults); threadworms (*Strongyloides ransomi,* adults and somatic larvae, and prevention of transmission of infective larvae to piglets, via the colostrum or milk, when fed during gestation); lice (*Haematopinus suis*); and mange mites (*Sarcoptes scabiei* var. *suis*) | Feed as the only feed for 7 consecutive days to provide 0.1 mg/kg of body weight per day. Withdraw 5 days before slaughter | 000010 |
| (5) 1.8 to 11.8 | Bacitracin methylenedisalicylate, 250 | Pregnant sows: For treatment and control of gastrointestinal roundworms (*Ascaris suum,* adults and fourth-stage larvae; *Ascarops strongylina,* adults; *Hyostrongylus rubidus,* adults and fourth-stage larvae; *Oesophagostomum* spp., adults and fourth-stage larvae); kidneyworms (*Stephanurus dentatus,* adults and fourth-stage larvae); lungworms (*Metastrongylus* spp., adults); threadworms (*Strongyloides ransomi,* adults and somatic larvae, and prevention of transmission of infective larvae to piglets, via the colostrum or milk, when fed during gestation); lice (*Haematopinus suis*); and mange mites (*Sarcoptes scabiei* var. *suis*); and for control of clostridial enteritis caused by *Clostridium perfringens* in suckling piglets | Feed as the only feed for 7 consecutive days to provide 0.1 mg/kg of body weight per day. Withdraw 5 days before slaughter. Feed bacitracin methylenedisalicylate Type C medicated feed to sows from 14 days before through 21 days after farrowing on premises with a history of clostridial scours | 000010 |
| (6) 18.2 to 120 | | Adult and breeding swine: For treatment and control of gastrointestinal roundworms (*Ascaris suum,* adults and fourth-stage larvae; *Ascarops strongylina,* adults; *Hyostrongylus rubidus,* adults and fourth-stage larvae; *Oesophagostomum* spp., adults and fourth-stage larvae); kidneyworms (*Stephanurus dentatus,* adults and fourth-stage larvae); lungworms (*Metastrongylus* spp., adults); threadworms (*Strongyloides ransomi,* adults and somatic larvae, and prevention of transmission of infective larvae to piglets, via the colostrum or milk, when fed during gestation); lice (*Haematopinus suis*); and mange mites (*Sarcoptes scabiei* var. *suis*) | Top dress on daily ration for individual treatment for 7 consecutive days to provide 0.1 mg/kg of body weight per day. Withdraw 5 days before slaughter | 000010 |

[[72 FR 37437](https://www.federalregister.gov/citation/72-FR-37437), July 10, 2007, as amended at [81 FR 17609](https://www.federalregister.gov/citation/81-FR-17609), Mar. 30, 2016; [81 FR 95005](https://www.federalregister.gov/citation/81-FR-95005), Dec. 27, 2016; [84 FR 12499](https://www.federalregister.gov/citation/84-FR-12499), Apr. 2, 2019; [84 FR 39185](https://www.federalregister.gov/citation/84-FR-39185), Aug. 9, 2019]