Experimental Assessment of the Efficacy of Five Veterinary Broad-Spectrum Anthelmintics to Control the Intestinal Capillariasis in Zebrafish (Danio rerio)

Abstract

Zebrafish in research facilities are frequently infected with capillarids. Since the health status (as a nonprotocol source of variation) of zebrafish can affect the validity of experiments, it is important to develop therapies for common zebrafish diseases. Regarding the likelihood of (1) the development of drug resistance and (2) the loss of the efficacy of a drug for laboratory zebrafish, the availability of alternatives for treatment is of direct importance. The efficacy of five dewormers from the same or different therapeutic groups was assessed in the current study. The exposure to each drug was repeated in triplicate (i.e., 3×100 fish in each treatment). The (1) elimination of parasite eggs, larvae, or adults from fresh fecal droppings (as the first main criterion) and (2) dissection of one-third of treated fish (i.e., 100 fish per drug) and examination of their gut contents (as the second major criterion) were considered to verify the efficacy of the drugs to eradicate the infection. Mebendazole (meb), praziquantel (pra; after the first round of treatment, i.e., six-fold administration, twice a day, for 3 days), fenbendazole (fen; after the second round of treatment), and ivermectin (ive; just after two administrations: twice during a day, i.e., a successful treatment with the smallest therapeutic effort) eradicated the infection, while albendazol (alb) was ineffective, although alb in a combined therapy with fen was successful. No age-, sex-, or disease severity-dependent responses to drugs were observed. The meb, pra, and ive were eliminating parasite eggs effectively in contrast with fen (that just was effective on adults). The drugs produced no observable side effects in zebrafish.

Zebrafish as a Model to Screen the Potential of Fatty Acids in Reproduction

“…42,43,44 The fresh fecal droppings of the fish were macro-and microscopically examined for any sign of the presence of intestinal parasites. 45,46 Sick fish were discarded or subjected to proper treatments. 46 The quarantine period of 3-4 weeks also allowed zebrafish to adapt to laboratory conditions.…”

Recommendations for Health Monitoring and Reporting for Zebrafish Research Facilities

“…Three recent publications described effective treatments for zebrafish infected with this parasite. [44][45][46][47] These include use of fenbendazole, ivermectin, emamectin benzoate, mebendazole and praziquantel.…”

Further evaluation of the efficacy of emamectin benzoate for treating Pseudocapillaria tomentosa (Dujardin 1843) in zebrafish Danio rerio (Hamilton 1822)

“…Once the infection occurs, gastrointestinal helminths, including those that infect fish, can be controlled with antihelminthics added to feed. Several of these have been used with considerable success with P. tomentosa in zebrafish (Collymore et al, ; Maley, Laird, Rinkwitz, & Becker, ; Pack, Belak, Boggs, Fishman, & Driever, ; Samaee, ).…”