Malformed frog (image) University of Washington Share Print E-Mail Caption A deformed Pacific tree frog (Pseudacris regilla). The parasite Ribeiroia ondatrae infects amphibians like this frog and can cause limb malformations. Credit Pieter Johnson/University of Colorado Boulder Usage Restrictions credit required Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.