Canine Genetic Mutations to the Multi Drug Resistance Gene (MDR1)

Certain chemical dyes injected into the peripheral circulation infiltrated most organs with one an exception, the brain.  This led to the well know concept of a blood-brain barrier. Janet Ryland of Animal Genetics describes a deletion in multi drug resistance gene, most important drug efflux system of the barrier, to be responsible for dogs’ sensitivity to a wide range of medications including anti-parasites, cancer drugs, sedatives, anti-diarrhoea, pain medications and heart drugs.