I am frequently asked about feeding green leafy vegetables to dogs – especially dogs with hypothyroidism. The concern is generally related to the goitrogenic properties in these foods. Goitrogen refers to a substance that may cause the thyroid gland to enlarge (like goiter) and may impede its ability to function properly. Cruciferous vegetables meet the criteria for being labeled goitrogenic as they contain chemical compounds that produce this effect. For years, it was a commonly held belief that people and dogs who have, or are suspected of having, thyroid conditions should avoid kale, cauliflower, and broccoli. Erring on the side of caution is prudent but, in this instance, the antioxidant and Vitamin K benefits definitely outweigh the risks. The goitrogenic properties in these green leafy vegetables are minute and should not cause concern if fed in moderation.