In our last home, we had a beautiful pond and waterfall in the corner of our living room, complete with some fairly large goldfish. Surprisingly, our three golden retrievers showed no interest in the pond. Once in awhile though, one of the fish would jump out of the water; luckily, someone was usually there to scoop up the escapee and return him to safety. On two occasions, however, we weren’t around and the fish met a different fate. Fishy dog breath and orange scales imbedded in the carpet told us the tale. One or more of our goldens had helped themselves to some fresh Sushi!

Meanwhile, Tyrone, a Persian-Tabby cross, who was the absolute and undisputed king of our household, insisted on having the very best gefilte fish, beautiful patties made from ground de-boned white fish.

Most dogs and cats love fish and shellfish, and because it offers high quality protein and Omega-3 fatty acids, it can be an excellent addition to your animal’s diet. The problem is, due to widespread environmental pollution, nearly all species of fish contain traces of toxins that can have an adverse affect on your animal’s health if you feed indiscriminately. Mercury, for example, is found in varying amounts in a wide range of fish, which means you need to do some detective work to determine what’s safe for your best friend (and yourself!), and what’s not.

Where does mercury come from and what does it do?
Mercury is released into the air through pulp and paper processing, mining, and the burning of garbage and fossil fuels. It accumulates in streams and oceans, where it is turned into methylmercury. As they feed, fish absorb methylmercury, which binds to the proteins in their tissue. The larger the fish and the longer they have lived, the higher the levels of methylmercury they contain. In toxic amounts, mercury prevents the body’s cells from transporting glucose. This can result in convulsions, anorexia, tremors, swollen gums, and behavior problems in both humans and animals. At high enough levels, methylmercury can cause brain and kidney damage.

How do I choose the best fish?
Should you avoid feeding fish to your dog or cat? The answer is “no.” The key is to become an educated consumer and only buy fish with the lowest possible levels of mercury. A variety of programs and tools exist that can help you make healthy choices.

• Both the Environmental Protection Agency (EPA) and Food and Drug Administration (FDA) provide up-to-date information about the levels of mercury found in fish (see sidebar).

• Another resource is the “Got Mercury” calculator at www.gotmercury.org. Just enter your dog or cat’s weight, and the type and amount of seafood to be eaten, and the mercury exposure will be calculated for you, based on EPA and FDA data.

• For those who live on the west coast, the Pacific Seafood Group (www.pacseafood.com) has recently launched its new Safe Harbor brand of fresh fish, guaranteed to contain low levels of mercury. Using a new scanning system developed by San Francisco’s Micro Analytical Systems (MAS), mercury levels in fish can be attained in about 40 seconds. More than 1,000 pounds of seafood are tested every day.

Audi Donamor has been successfully creating special needs diets for dogs and cats for ten years.