Table 2.

Definitions of levels of evidence used by the COAST Development Group for the treatment recommendations based on the available literature.

Levels of evidence
High	Randomized controlled trials in dogs
	Prospective, non-randomized controlled trials in dogs (adequate sample size/ no major methodological flaws)
Medium	Experimental laboratory trials in dogs
	Retrospective clinical studies with intervention and control groups in dogs
Low	Case series or case reports in dogs without control groups
	Studies in other species
	Expert opinion

Adapted from (25).