[Determination of the activity of delta-aminolevulinic acid dehydratase--a method for the diagnosis of lead poisoning in birds].

In avian patients enteral, parenteral and aerogenous lead intoxications are frequently observed. Ingestion of non-metallic lead may not be diagnosed by radiography. Alternatively, estimation of the delta-aminolevulinic acid dehydratase (delta-ALA Dehydratase) activity is a suitable diagnostic test for lead intoxications. The enzyme delta-ALA Dehydratase, which plays a central role in erythropoiesis, is inhibited by lead and is therefore a specific indicator for lead intoxications. The activity of delta-ALA Dehydratase is measured directly in the blood; not the amount of excreted delta-ALA in the urine as in mammals. Blood volumes of 0.45 ml are necessary and thus allow to perform the test in birds as small as 45 g body weight (e.g. Budgerigars). Possible ranges of application as well as a suitable therapy for lead intoxication in birds are presented.