Individual Dermanyssus gallinae were collected from 72 poultry farms in 20 prefectures, and the development of resistance by D. gallinae to commercial acaricides was studied. In this study, commercial acaricides that were used to target the control of D. gallinae (two kinds of carbamate, organophosphate and one kind of pyrethroid) and to target the control of flies (two kinds of pyrethroid, two kinds of a combination pyrethroid and organophosphate) were examined. The development of resistance by D. gallinae was observed for each acaricides, but carbamate acaricide, carbaryl, and a combination acaricide (fenitrothion, permethrin and phthalthrin) showed lower rates of the development of resistance compared to other acaricides. However, the development of resistance by D. gallinae to each of these three kinds of compound used to target its control could be confirmed in 12 poultry farms out of 72. The development of resistance differs by individual poultry farm, and this difference is considered to be related to the farm's history of chemical control methods.
Using nasal swab samples obtained from 202 healthy cattle on ten fattening farms in Yamagata Prefecture, we conducted tests on the susceptibility to drugs of bacteria causing respiratory disease in cattle. We also examined the types and effects of antimicrobial agents used for the treatment of respiratory diseases on each farm. Many bacterial species, including the Pasteurella multocida, Mannheimia haemolytica and Mycoplasma species, were isolated from each farm. On one farm where ampicillin was used as the drug of first choice for a long period, P. multocida showed resistance to ampicillin and the cure rate was low. When the treatment programs used on three farms were changed on the basis of drug susceptibility, the cure rate using the drug of first choice showed a significant increase (P<0.01) on one farm, and an increase on the other two farms. The results of this study showed that selecting antimicrobial drugs on the basis of drug susceptibility improves the efficacy of treatment and also reduces the overuse of antibiotics.
In January 2005, intussusception of proventriculus was diagnosed in four chicks from a layer farm from a batch of 24, 000 chicks of foreign origin. At autopsy, the proventriculus was invaginated into the gizzard and the esophagus was infused with petechial hemorrhages and covered with a cheesy material. Histopathologically, there were almost no abnormal findings in the medial portion of the invaginate lesion. Degeneration and necrosis of mucosal folds and infiltration of inflammatory cells were observed in mucosa of the lateral portion of the invaginate lesion. On the mucosal surface, there was a pseudomembrane with bacterial clumps. We histologically diagnosed this lesion as pseudomembranous proventriculitis. For other organs, slight atrophy was observed in the thymic cortex.
In ferrets (Mustela putorius furo), the incidence of hemangiosarcomas is low. Cutaneous hemangiosarcomas in ferrets have been reported as in other organs, but the clinical and diagnostic details are unclear. The present case developed an ulcerative lesion on the dorsal skin of the metatarsal region of the left hindlimb, and the limb was surgically amputated due to exacerbation of the lesion. A diagnosis of hemangiosarcoma was obtained based on histopathological examinations. The examinations revealed proliferation of endothelial celllike pleomorphic cells, which were immunohistochemically positive for Factor YIII-related antigen. The present case achieved long-term survival without recurrence or distant metastasis after six months, and is currently showing good prognosis. We describe details of clinical progress usefulness of immunohistochemical staining, and possibility of good prognosis in a ferret cutaneons hemangiosarcoma.
An 11-year-old mongrel cat that was referred for depression and anorexia showed severe splenomegaly and pancytopenia. Because hematologic response to the administration of prednisolone was not noticeable, the cat underwent a splenectomy. After the splenectomy, the pancytopenia improved. Based on histopathologic and immtmohistochemical findings. the dissected spleen was diagnosed with B-cell lymphoma. In this case, lymphadenopathy was not observed. On the basis of these findings, we diagnosed primary splenic lymphoma. The Clinical course of the present case suggests a causal relationship between feline primary splenic lymphoma and pancytopenia.
Antibody responses of dogs inoculated with the inactivated rabies vaccine were investigated using the paired sera obtained from 125 dogs in Tokyo, Shizuoka, Gifu, Kyoto, Miyazaki and Kumamoto Prefectures, Japan, in 2005. Ninety of the 100 dogs that had been previously vaccinated within the past year possessed neutralizing antibodies with titers higher than 25 that are considered as being sufficient for protection. The antibody titers of dogs that were above 8 had geometric mean titers (GMT) of 251. Additional vaccination of those dogs resulted in all dogs acquiring neutralizing antibodies higher than 25, and their titers reached a GMT of 750 one month after the booster inoculation. On the other hand, 23 of 25 dogs having no history of rabies vaccination produced neutralizing antibodies with titers having a GMT of 43, ranging from below 8 to 256, one month after vaccination. Notably, no antibodies were detected in sera collected from two of those dogs even after vaccination. The results seem to suggest that the present vaccination regime in which dogs are vaccinated once a year is important in creating and maintaining consistent immunity in vaccinated dogs.
Serotypes and genotypes of 154 Erysipelothrix rhusiopathiae strains from slaughter pigs at Sueyoshi and Kanoya Meat Inspection Centers in southern Kyushu during the period of April 2004 to March 2006 were determined. The strains were classified into four serotypes, 1a (53 strains), 1b (4 strains), 2 (95 strains) and 11 (2strains). Randomly amplified polymorphic DNA (RAPD) analysis categorized the strains into four genotypes, A (47 strains), B (6 strains), C (91 strains) and D (10 strains). Combination of the serotypes and genotypes formed two major types, 1a-A (47 strains; 29.9%) and 2-C (91 strains; 54.5%). The strains belonging to the major type la-A were isolated only from internal iliac lymph nodes and arthritic fluid, while the strains of the another major type 2-C were isolated from urticaria, kidneys, spleens, and knots of endocarditis. Multiple RAPD types were detected from some farms, but each major RAPD type appeared at the individual farms where the incidence of erysipelas was found to be high. The prevalence of acryflavin resistance among the strains was31.0%(47/154).
Three species of Sarcocystis (types 1-3) distinguished morphologically were detected using light and electron microscopies from wild Sika deer (Cervus nippon yesoensis) in eastern Hokkaido, Japan. Type 1 has a thick wall with a tombstone-like villar protrusion. Type 2 has a thick wall with a finger-like villar protrusion. Type 3 has a thin wall with a hair-like villar protrusion.