title: Fenbendazole treatment and litter size in rats.
abstract: Fenbendazole is commonly used in laboratory animal medicine as an anthelmintic for elimination of pinworms. It is generally regarded as a safe drug with minimal side effects. In our facility, 2 breeding colonies of rats were treated with fenbendazole to eliminate pinworms. Analysis of the breeding records revealed that feeding Sprague-Dawley rats a diet containing fenbendazole on a continuous basis for 7 consecutive weeks was associated with a significant reduction in litter size. Although the mechanism underlying this effect is unknown, the finding prompts caution when using fenbendazole to treat valuable breeding colonies or strains that are poor breeders.
authors.affiliation: Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois, USA. njohnston@siumed.edu
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Johnston
authors.forename: Jeremiah R
authors.initials: JR
authors.lastname: Bieszczak
authors.forename: Steven
authors.initials: S
authors.lastname: Verhulst
authors.forename: Kimberly E
authors.initials: KE
authors.lastname: Disney
authors.forename: Kyle E
authors.initials: KE
authors.lastname: Montgomery
authors.forename: Linda A
authors.initials: LA
authors.lastname: Toth
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D001947:Breeding; D004757:Enterobius / Q000187:drug effects; D005260:Female; D005273:Fenbendazole / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D008098:Litter Size / Q000187:drug effects*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley / Q000469:parasitology / Q000502:physiology; D012189:Retrospective Studies
chemical_list: D000871:Anthelmintics; D005273:Fenbendazole