The best replacement for giardia is coccidia.

The best alternatives to giardia are rated as following:
★★★★★  coccidia
★★★★  cryptosporidium
★★★  amebiasis
★  tritrichomonas
★  parvo
★  e coli
★  travelers diarrhea
★  salmonella
  cholera
  shigella

Your alternative for giardia is not listed? Suggest!
Speaking about giardia, one probably shouldn't forget about panacur.

Other search terms related to giardia and their ratings are:
★★★★★ panacur
★ fenbendazole
★ grapefruit seed extract
grapefruit seed extract in dogs
You have in mind a companion for giardia and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of giardia in all years. Click on graph for more.
giardia
coccidia
cryptosporidium