The term "Dagua thrush" does not correspond to a widely recognized or established species in major ornithological references, including authoritative sources such as the International Union for Conservation of Nature (IUCN) Red List, Birds of the World (Cornell Lab of Ornithology), or the Handbook of the Birds of the World. No scientifically accepted bird species is currently known by the common name "Dagua thrush."
Possible interpretations of the term may involve regional or vernacular naming. "Dagua" could refer to a geographical location—such as the Río Dagua in western Colombia—suggesting the name might colloquially describe a thrush species found in that region, such as the Black-billed Nightingale-Thrush (Catharus gracilirostris) or another Catharus species native to the Andes. However, no documentation supports "Dagua thrush" as an official or widely used common name.
Due to the absence of reliable encyclopedic or scientific sources referencing this term, its usage, if any, appears to be informal, localized, or unpublished. Therefore, "Dagua thrush" cannot be confirmed as a valid ornithological designation.