What is the nature of corroborative evidence required to support witness testimony?

Appellant would have us hold the nature of the corroborative evidence necessary here is identical to that required to support accomplice testimony. We find such an analogy inappropriate. Dog-tracking evidence is not "inherently suspect because of a self-interested source." (People v. Malgren, supra, 139 Cal.App.3d at p. 241, 188 Cal.Rptr. 569.) The rationale for independent corroboration of accomplice testimony is predicated upon the need to ensure the trustworthiness of the information, not upon whether the evidence is substantial in and of itself.