MDR1 Multi Drug Resistance – Cat

Multidrug Resistance 1 (MDR1), sometimes known as Ivermectin Sensitivity, is a disorder that affects the blood-brain barrier. As a result, affected animals can be in effect poisoned when given certain drugs as part of standard veterinary procedures. In cats, a variant of the disease is caused by a recessive mutation to the gene ABCB1.

It is estimated that this mutation occurs in approximately 4% of domestic cats.