Fine structural observations on two congenitally lymphoedematous dogs

In two congenitally lymphoedematous dogs, a quantitative fine structural study was made of the subcutaneous tissue. It was found that the blood vessels, inital lymphatics and tissue channels all increased considerably, as did the small vesicles and vacuoles in the endothelium of both blood and lymph vessels. Collagen, fibroblasts, macrophages, and fat containing macrophages "fat cells" all increased greatly, while the small and medium lymphocytes increased to a moderate extent. These results are similar to those found in chronic experimental lymphoedema in dogs, in chronic high-protein oedema and in chronic inflammation. The underlying similarity of all these conditions is emphasised.