Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), and sequencing analysis were used to study the ryanodine receptor gene (ryr1) of the blue fox (Alopex lagopus), wolf (Canis lupus), and domestic dog (Canis familiaris). PCR-amplified ryr1-gene-specific fragments were cloned in a pGem5 Zf(-) plasmid. Double-stranded templates were sequenced by the Sanger dideoxy chain termination method, using Cy-5' labelled primers. We detected G→C transversion (position 1836) in the wolf ryr1 gene, and T→C transition (position 1857) in the blue fox (these mutations do not alter the respective amino acid sequences) and a C→T transition (position 1846) in the ryr1 of the blue fox that changes the amino acid from serine to proline. We did not detect the 1843C→T mutation in the Canidae ryr1 gene.