Uh-huh! We would actually recommend it! Krill is more potent, containing both astaxanthin (a powerful antioxidant) and Omega-3 fatty acids (EPA/DHA).
It also contains phospholipids, a more efficient delivery method for Omegas than, say, salmon oil because it takes the essential EPA & DHA to where your pet will benefit from them the most.
Krill are also one of the smallest on the food chain, so they contain fewer heavy metals, mercury, and toxins than you would find in salmon or concentrated salmon oil.