VCA Antech Inc. said Wednesday that it has agreed to buy privately held Healthy Pet Corp. for $153 million in cash.

Fairfield, Conn.-based Healthy Pet, which has most of its clinics in the Northeastern U.S., adds 44 facilities to Los Angeles-based VCA’s network of more than 430 hospitals in 40 states.

VCA shares were up 55 cents, or 1.3 percent, to $40.85 in afternoon trading Wednesday on the Nasdaq.