The deal calls for Mars to pay $93 for each of VCA’s shares and to assume VCA’s $1.4 billion in debt. VCA’s stock — whose ticker symbol is WOOF — soared $20.02, or 28%, to close at $90.79 a share in trading Monday. “VCA is a leader across pet healthcare and the opportunity we see together — for pets, pet owners, veterinarians and other pet care providers — is tremendous,” Mars Chief Executive Grant Reid said in a statement. The deal was approved by both companies’ directors, but remains subject to approval by VCA’s stockholders. It is expected to be...