Raw fish is often incorporated into sushi, as are many other types of fatty fish. Raw fish is a well-known and highly problematic source of parasites in the intestines. Although food facilities generally have strict regulations and inspections in place to ensure that their ingredients are free of parasites, the worst can still happen.
Even uncooked sushi-grade fish, such as salmon or tuna, can cause serious diseases in your dog. Fish that you buy raw may contain harmful bacteria, tapeworms, roundworms, and other harmful organisms. These common infections found in raw fish include listeria or salmonella, which can damage your dog's immune system. It can even get fatal!