Psittacosis was diagnosed in 13 (24%) of 55 pet bird submissions in the first 3 months of 1983, compared with 18 (17%) of 103 in 1982, 4 (4.6%) of 87 in 1981, and 3 (8%) of 36 in 1980. The numbers and types of birds in which psittacosis was diagnosed were 2 of 47 budgerigars, 8 of 45 cockatiels , 3 of 11 small parrots ( lovebirds , conures ), 20 of 116 medium-sized parrots (African Grays, Amazons ), 2 of 21 macaws , and 3 of 21 cockatoos . Thirty-nine percent of psittacosis-positive birds were received from pet bird owners, compared with 21% from pet shops, 18% from pet bird breeders and fanciers, and 13% from pet bird jobbers and retailers . Most frequently observed clinical signs were anorexia, weight loss, and diarrhea or yellowish droppings. Major gross lesions were splenohepatomegaly (77%), followed by enteritis (53%), sinusitis (47%), airsacculitis (37%), pneumonitis (23%), and pericarditis (10%). Regarding the 38 cases of confirmed psittacosis in pet birds since 1980, transmission of the disease to human beings was confirmed in 2 cases and suspected in 4 cases.