HISTOPATHOLOGICAL SURVEY OF PROTOZOA, HELMINTHS AND ACARIDS OF IMPORTED AND LOCAL PSITTACINE AND PASSERINE BIRDS IN JAPAN

A total of 534 psittacine and passerine birds consisting of 241 imported and 293 local birds were examined histologically. As a result, the following parasites were found : Giardia (86 cases), Knemido-coptes (26 cases), coccidia (10 cases), Ascaridia (6 cases), Cryptosporidium (5 cases), Sarcocystis (5 cases), tapeworm (4 cases), microfilaria (2 cases), Hexamita (1 case), and Spiroptera (1 case). High incidences of giardiasis and knemido-coptic infestation were detected in the local birds, but rarely in the imported birds. Giardial trophozoites were observed mainly in the duodenum of budgerigars (Melopsittacus undulatus). Knemidocoptic mites burrowed into the epidermis producing proliferative dermatitis in 25 budgerigars and l African Grey Parrot (Psittacus erithacus erithacus). This ectoparasite often infested the skin around the cloaca. Coccidiosis was seen only in the small intestines of the finch (Poephila gouldiae gouldiae), African Grey Parrot, Rainbow lory (Trichoglossus haematodus), Indian Ring-necked parakeet (Psittacula krameri manillensis) and peach-faced lovebird (Agapornis roseicollis). Two parrots (Amazona aestiva aestiva and Psittacus erithacus erithacus) and two budgerigars had intestinal cryptosporidiosis. Conjunctivitis associated with cryptosporidial infection was seen in a lovebird. Sarcocystis cysts containing crescent-shaped bradyzoites were found not only in the thigh and breast but also in the heart and cloacal muscles. Other organisms such as Ascaridia, tapeworm, microfilaria, Hexamita, and Spiroptera were clinically less significant. However, infections such as Giardia and Cryptosporidim might have zoonotic implications

HUMAN FOCAL NODULAR HYPERPLASIA-LIKE LESION IN THE LIVER OF A CAT

A young cat clinically displaying marked ascites had multiple nodular hyperplasia in the liver. One of the nodules sampled at exploratory laparotomy was studied histopathologically. The nodule consisted mainly of hyperplastic hepatocytes with a central stellate scarlike connective tissue. The connective tissue had thick-walled blood vessels and radiating bands of fibrous connective tissue extending peripherally, dividing the nodule into pseudolobules. The lesions resembled focal nodular hyperplasia (FNH) in man. Serial section revealed a single large artery with the splitting of the internal elastic lamina running into the central connective tissue and branching to connect with the main vessels. The arterial branchings formed a spider-like structure. From these findings, it was suggested that the nodule had developed from a hepatic response to pre-existing vascular anomalies as had been reported in human FNH

DISSEMINATED INTRAVASCULAR COAGULATION (DIC) IN RABBIT HAEMORRHAGIC DISEASE

Seven rabbits experimentally infected with rabbit haemorrhagic disease virus were examined haematologically and histologically. Haematologically, activated partial thromboplastin time and prothrombin time were markedly prolonged in the terminal phase of the disease, just prior to death (all the animals died between 27 and 40 hr after inoculation with rabbit haemorrhagic disease virus). There was an increase in the titre of fibrin degradation products and a decrease in antithrombin III activity during the same interval. Acute necrotic hepatitis and disseminated intravascular coagulation (DIC) in many organs, including the lung, kidney, spleen and heart were the characteristic histopathological changes. Thus, the haematological and histological changes suggested that DIC was induced by rabbit haemorrhagic disease virus infection. Severe liver necrosis was considered to be a factor causing DIC by inducing a hypercoagulable condition in the systemic blood circulation

SUSPECTED NUTRITIONAL MYOPATHY IN TWO CAPTIVE BENNETT'S WALLABIES (MACROPUS RUFOGRISEUS)

Between January and April, 1992, two captive Bennett's wallabies (Macropus rufogriseus) from a wildlife park in Iwamizawa City, Hokkaido, Japan, were diagnosed as having nutritional myopathy. One wallaby, four-year-old adult male, had mild fresh lesions, confined to the skeletal muscles, with poor cell reaction. The other wallaby, 8-month-old female joey, had marked and extensive lesions with cellular reactions and regenerative muscle fibers in the locomotor muscles. Involvement of other striated muscles such as those of the tongue, diaphragm and heart was mild with minimal cellular reaction. Age susceptibility may account for the difference in the extent of severity of the lesions between these two animals

CATARRHAL PROVENTRICULITIS ASSOCIATED WITH A FILAMENTOUS ORGANISM IN PET BIRDS

Catarrhal proventriculitis due to infection by an unidentified organism was diagnosed in 79 of 534 pet birds examined histologically. It was more prevalent in domestic birds (70 cases) than in imported ones (9 cases). A high incidence of the disease was encountered in budgerigars (Melopsittacus undulatus) and it was occasionally found in finches (Poephila gouldiae gouldiae), parakeets (Psittacula Krameri manillensis), Amazona parrots (Amazona aestiva aestiva) and cockatiels (Nymphicus hollandicus). The agent was a large filamentous rod, and was stained positively with Gram, GMS and PAS methods. Histologically, it induced a mild to moderate exudative or proliferative inflammation in the proventriculus. All the cases had an erosion in the gizzard. Ultrastructurally, the organism had a eukaryotic nucleus and three cell-wall layers. Concurrent infections were very common, including adenoviruses (37 cases), giardiasis (31 cases), candidiasis (13 cases), papovaviruses (11 cases) and knemidocoptic mites (11 cases)

NUTRITIONAL SECONDARY HYPERPARATHYROIDISM OCCURRING IN A STRAIN OF GERMAN SHEPHERD PUPPIES

Five German shepherd puppies, aged between 66 and 174 days (4 of which had the same parents) had ananastasia with deformation of limbs. Histopathologically, all the puppies showed moderate to marked fibrous osteodystrophy with parathyroid gland activation. These puppies were fed a diet consisting of 80% steamed rice and 20% raw meat. It was implied that though the diet contained the required level of calcium, it contained more than the required level of phosphorus. From the results, the present cases were diagnosed as nutrtional secondary hyperparathyroidism caused by a diet containing too much phosphorus. Based on the clinical aspects concerning the development of this condition a familial factor was suggested

DIRECT ABC IMMUNOHISTOCHEMISTRY TO ENCEPHALITOZOON-CUNICULI

Among the sera from 9 rabbits spontaneously infected with Encephalitozoon cuniculi, a serum which revealed a high titer for E. cuniculi by indirect protein A-gold (IPAG) immunohistochemistry and reacted with the outer layer of the shell of E. cuniculi spores on immunoelectron microscopical examination, was biotinylated. The biotinylated rabbit anti-E. cuniculi IgG reacted immunohistochemically with E. cuniculi, but not with other protozoa tested, namely Neospora caninum, Toxoplasma gondii and sarcocystis. The direct avidin-biotin-peroxidase complex (ABC) immunohistochemistry using biotinylated rabbit anti-E. cuniculi IgG in this study is a useful tool for the diagnosis and study of encephalitozoonosis.Y