Lead toxicosis in cats-a review.

Although the incidence of lead toxicosis in small animals continues to decrease, it remains a significant malady. We have reviewed the literature of the past 45 years, which revealed 70 cases involving cats. Sources, signs, diagnosis, pathology and treatment of feline lead toxicosis are reviewed. In 84% of these cases the source of lead was old paint usually from home renovation. The most common signs in cats are anorexia, vomiting, and seizures. The younger individuals seem more likely to show CNS signs. Since signs are often vague, lead toxicosis may be significantly under diagnosed in cats. The gold standard of diagnostic tests is blood lead concentration, although it does not necessarily correlate with total body burden of lead or with metabolic effects including clinical signs. Diagnostic tests including erythropoietic protoporphyrin (EPP), urine aminolevulinic acid, and others are discussed. Gross findings on necropsy are few and include a yellow-brown discoloration of the liver often with a nutmeg-like appearance. Histological examination may reveal pathognomonic inclusion bodies in liver and renal tissues. Characteristic histological changes in the CNS include neuronal necrosis and demyelination. Treatment of lead toxicosis in cats, as in any species, involves removing the exposure, decontaminating the individual and the environment, supportive care and chelation therapy. The most recently available chelator is succimer (meso 2,3-dimercaptosuccinic acid). Succimer given orally is well tolerated and has a wide margin of safety. A high index of suspicion of lead toxicosis is warranted in cats since they often present with vague and non-specific signs. With any consistent history owners need to be asked about home renovation. Early diagnosis and treatment affords a good prognosis.