Application of a sodium phosphate containing enema caused life-threatening metabolic disorders in a Dachshund and two cats. Clinical signs were characterised by dehydration and various neurological deficits including seizures. Most striking laboratory abnormalities were hypernatremia, hypocalcemia, hyperphosphatemia, and polycythemia. Despite intensive treatment the dog died, whereas the cats recovered completely. In face of possible severe and potentially fatal metabolic abnormalities sodium phosphate enemas, such as Practo-Clyss, should be used with caution or not at all in cats and small dogs.