Giardiasis in dogs and cats: update on epidemiology and public health significance

Trends Parasitol. 2010 Apr;26(4):180-9. doi: 10.1016/ Epub 2010 Mar 2.


Molecular data have defined seven genetic Assemblages of Giardia duodenalis, named A-G. Humans are infected with Assemblages A and B, dogs primarily with C and D, and cats with F. Assemblage A has been subclassified into subtypes A-I to A-IV: A-I has been reported in humans and animals, A-II in humans, and A-III and IV exclusively in animals. Assemblage B has broad host specificity infecting humans and animals. Recently, small numbers of dogs and cats have been reported to also carry Assemblages A-I or B. Because these genotypes are found primarily in humans, and no comprehensive studies to address zoonotic transmission of G. duodenalis are yet available, the potential role of dogs and cats cannot be conclusively excluded.

Publication types

  • Review

MeSH terms

  • Animals
  • Cat Diseases / epidemiology
  • Cat Diseases / parasitology
  • Cat Diseases / transmission*
  • Cats
  • DNA, Protozoan / genetics
  • Dog Diseases / epidemiology
  • Dog Diseases / parasitology
  • Dog Diseases / transmission*
  • Dogs
  • Genotype
  • Giardia / classification
  • Giardia / genetics
  • Giardia / pathogenicity
  • Giardiasis* / epidemiology
  • Giardiasis* / parasitology
  • Giardiasis* / transmission
  • Giardiasis* / veterinary
  • Humans
  • Molecular Epidemiology
  • Public Health*
  • United States / epidemiology
  • Zoonoses* / epidemiology
  • Zoonoses* / parasitology
  • Zoonoses* / transmission


  • DNA, Protozoan