To investigate the possible vectorial role of aedine mosquitoes in Akabane-virus transmission, periods of virus persistence in the insects' bodies and hematophagical intervals were studied and transmission tests were performed. Most individuals of Aedes arbopictus insufficiently fed on blood can suck blood again while the Akabane virus remains in their bodies. Mosquitoes fed on blood containing the Akabane virus were introduced into a net cage with a susceptible calf. Since no increase in the calf's neutralizing-antibody titers were observed, the vectorial role of the mosquitoes in Akabane-virus transmission was not confirmed.
Isoflurane anesthesia was evaluated for use in cesarean-section delivery of specific-pathogen-free (SPF) pigs. Pregnant gilts were premedicated with atropine sulfate (0.05mg/kg) and azaperone (2mg/kg) and then anesthetized by inhalation of 4% isoflurane delivered in a mixed gas (N2O: O2=1: 2) through a face mask. After anesthetization, local infiltration anesthesia with procaine hydrochloride was performed at the incision site. While nociceptive reactions were being monitored at 4 to 7 minutes after anesthetization, isoflurane concentration was reduced to 0.5% and maintained at this level until completion of delivery. A small amount of isoflurane (31.4±4.1 MAC·min) resulted in high yields of live piglets (95.8±6.9%) with no notable adverse effects on the gilts.
Pathological studies showed moderate to severe interstitial pneumonia in 30 to 60% of 240 disessed swine autopsied in Gifu Prefecture from 1993 to 1998. The viral antigen for porcine reproductive and respiratory syndrome (PRRS) was immunohistochemically detected in 11.1 to 23.1% of animals with interstitial pneumonia. The viral antigen was detected in 21.4 to 30.8% of animals of less than 3 months of age and in 6.3 to 17.6% of animals of more than 4 months of age.
This retrospective survey of canine skin disorders is based on the records of 534 dogs treated at a referral dermatology clinic. The most common groups of skin disorders were infections (29.5%), allergic disorders (19.1%), and endocrinopathy (13.7%; P<0.01). The final diagnoses of pyoderma (16.3%), seborrheic dermatitis (13.5%), and atopic dermatitis (9.1%) were frequently encountered. The most common clinical course was control of the diseases through continued maintenance therapy (52.2%; P<0.01). In addition to this survey, we conducted a nationwide questionnaire survey of canine skin disorders. Reported from 669 small animal clinics showed that skin disorders including otitis externa is one of the most frequently encountered diseases in canine practice. A seasonal high incidence of skin diseases occurred in summer (64.5%; P<0.01). In clinics, the most common groups of skin disorders were infections (32.1%) and allergic disorders (21.5%); and the most common final diagnoses were flea allergic dermatitis (86.7%), pyoderma (85.1%), otitis externa (84.6%), atopic dermatitis (56.5%), seborrheic dermatitis (50.4%), ear mite infection (48.4%), acute moist dermatitis (47.2%), and acral lick dermatitis (41.9%).
The following percentages of house dogs in 6 regions of Japan had sera reacting positively to the leptospira antibody: Hokkaido 25.8%, Shizuoka Prefecture 40.0%, Toyama Prefecture 8.9%, Hyogo Prefecture 10.0%, Okayama Prefecture 15.0%, and Okinawa Prefecture 29.0%. Antibodies to 6 serovars usually found in Japan (L. autumnalis, L. hebdomadis, L. australis, L. icterohaemorrhagiae, L. canicola, and L. pyrogenes) were detected in these districts, whereas antibodies against 2 serovars with high pathogenicity to farm animals elsewhere but unconfirmed in Japan (L. Pomona and L. hardjo) were not detected. All antibody-positive dogs were clinically normal and free of clinical signs or suggestions of leptospirosis. Their serum glucose, BUN, GOT, GPT, alkaline phosphatase, total cholesterol, and total bilirubin were within normal ranges.
A green iguana (Iguana iguana rhinolopa), about 2 years old, died at the Saitama Children's Zoo in May 1996. During the autopsy, 3, 940 nematodes were isolated from the stomach. The parasites were grayish white. Male body length was 2.73±0.36mm; male body depth was 0.45±0.10mm. Female body length was 3.81±0.86mm; female body depth was 0.45±0.10 mm. The nematodes' surfaces were marked with distinct horizontal stripes. Each had a mouth with two lateral lips; an esophagus consisting of an anterior portion and a posterior portion ending in a bulb; and a single, long spicule without a guburnaculum. Oval eggs (120×150×50μm) had micropyles and asymmetrical walls. On the basis of these findings, the nematodes were identified as Ozolaimus megatyphlon.
Rhodococcus equi (R. equi) was isolated from 4.6 and 4.1% of the mandibular lymph nodes of pigs in Kagoshima and Aomori Prefectures. Virulence of the isolates was investigated by means of immu-noblotting with a monoclonal antibody against a 20-kDa virulence-associated antigen. Most isolates were intermediately virulent manifesting a 20-kDa antigen. As a result of analysis by means of plasmid-DNA restriction cleavage patterns, isolates with the 20-kDa antigen from Kagoshima, Aomori and Miyagi Prefectures were divided into 8 types. Three of the 8 types were observed commonly in the isolates of 3 Prefectures. Of Kagoshima isolates, 94.9%, 63.1% of Aomori isolates and 74.7% of Miyagi isolates were typed as these 3 types. Intermediately virulent R. equi was isolated from the environment of a pig-breeding farm in Kagoshima Prefecture and one plasmid type of soil isolates was proved identical with that of isolates from pigs on the farm. This investigation shows that intermediately virulent R. equi was almost equally prevalent in the mandibular lymph nodes of pigs in Kagoshima, Aomori and Miyagi Prefectures. The role of soil might be significant in distribution of intermediately virulent R. equi in pig-breeding farms.
Examinations were made to know the distribution of gross and histopathological lesions in 74 slaughtered swine suspected of atypical mycobacteriosis (in Hamamatsu). Gross lesions first appeared at the mesenteric lymph nodes and extended to the liver, then to the lungs and spleen, and then to the kidneys and somatic lymph nodes. When lesions were present on the lungs and spleen, it was highly probable that histopathologic lesions would be present on the somatic lymph nodes. In some cases, histopathologic lesions occurred on some parenchymatous organs and somatic lymph nodes, even when gross lesions occurred on only one parenchymatous organ. These findings make it clear that, for the sake of correct diagnosis, thorough examinations, including histopathologic tests, must be conducted.