title: Efficacy of nitazoxanide to treat natural Giardia infections in dogs.
abstract: Giardia parasites cause gastrointestinal disease in humans, dogs, and many other animals worldwide. The treatment of dogs for giardiasis requires further investigation to ascertain levels of drug efficacy and the possibility of adverse side effects. Nitazoxanide (NTZ) has shown good clinical anti-Giardia activity in humans, yet it has not been evaluated for the treatment of giardiasis in dogs.
  
  
  
  Thirty-five dogs, naturally infected with Giardia were divided into five groups (n = 7): dogs in group NTZ1, NTZ2, and NTZ3 were treated with a single oral dose of 37.5 mg/kg, 75 mg/kg, and 150 mg/kg, respectively, of NTZ on days 0 and 14. The fourth group was treated with a commercially available regimen that includes a combination of pyrantel, praziquantel, and febantel (FEB) administered orally for three consecutive days. Additionally, an untreated control group was established. Giardia cysts from the stool of each dog were quantified on days -3, 0, 5, 7, 9, 11, 14, 18, 25, and 28. Biochemical parameters were evaluated in all dogs, before the first treatment and after concluding the experiment.
  
  
  
  Shedding of Giardia cysts was reduced in all treated groups when compared to untreated controls (P < 0.01). However, NTZ2, NTZ3, and FEB had a lower risk during the study. Furthermore, NTZ was also effective against another protozoan, Cryptosporidium spp. at doses of 75 mg/kg and 150 mg/kg, in contrast to the combination of febantel + pyrantel + praziquantel. Biochemical parameters of treated animals, namely, aspartate transaminase and alanine transaminase enzymes, remained within physiological ranges.
  
  
  
  Based on these results, the implementation of NTZ as a treatment for giardiasis in dogs is proposed. The administration of a single dose is an important advantage of NTZ because it reduces workload, particularly in animals placed in shelters and kennels, where handling of large numbers of animals is required, and personnel is frequently scarce.
authors.affiliation: Departamento de Parasitología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Av. Universidad 3000, Delegación Coyoacán, Ciudad de México, C.P., 04510, Mexico.
authors.forename: Mario
authors.initials: M
authors.lastname: Moron-Soto
authors.affiliation: Departamento de Fisiología y Farmacología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Av. Universidad 3000, Delegación Coyoacán, Ciudad de México, C.P., 04510, Mexico.
authors.forename: Lilia
authors.initials: L
authors.lastname: Gutierrez
authors.affiliation: Departamento de Fisiología y Farmacología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Av. Universidad 3000, Delegación Coyoacán, Ciudad de México, C.P., 04510, Mexico.
authors.forename: Héctor
authors.initials: H
authors.lastname: Sumano
authors.affiliation: Departamento de Genética y Bioestadística, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Av. Universidad 3000, Delegación Coyoacán, Ciudad de México, C.P., 04510, Mexico.
authors.forename: Graciela
authors.initials: G
authors.lastname: Tapia
authors.affiliation: Departamento de Parasitología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Av. Universidad 3000, Delegación Coyoacán, Ciudad de México, C.P., 04510, Mexico. yazmin@unam.mx.
authors.forename: Yazmin
authors.initials: Y
authors.lastname: Alcala-Canto
mesh_terms: D000284:Administration, Oral; D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D000981:Antiprotozoal Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001219:Aspartate Aminotransferases / Q000097:blood; D003457:Cryptosporidiosis / Q000188:drug therapy; D003458:Cryptosporidium / Q000187:drug effects; D004283:Dog Diseases / Q000188:drug therapy* / Q000469:parasitology; D004285:Dogs; D005243:Feces / Q000469:parasitology; D005872:Giardia / Q000187:drug effects / Q000302:isolation & purification / Q000502:physiology; D005873:Giardiasis / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary*; D006146:Guanidines / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D009574:Nitro Compounds; D011223:Praziquantel / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D011716:Pyrantel Pamoate / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D013844:Thiazoles / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use*
chemical_list: D000981:Antiprotozoal Agents; D006146:Guanidines; D009574:Nitro Compounds; D013844:Thiazoles; D011223:Praziquantel; D011716:Pyrantel Pamoate; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; C017309:febantel; C041747:nitazoxanide
keywords: Dogs; Efficacy; Giardia; Nitazoxanide; Parasite