Samples were obtained on four occasions from three closed pig farms for the purposes of polymerase chain reaction (PCR) tests to detect the Porcine reproductive and respiratory syndrome virus (PRRSV) and Porcine circovirus 2 (PCV-2). No clinical signs of the disease were observed on those farms. Sera for PRRSV detection and whole blood, nasal swabs, and feces for PCV-2 detection were collected from 313 pigs in 5 age groups: nursery pigs; pigs aged from 1 to 2 months, from 3 to 4 months, and from 5 to 6 months; and sows. Breakdown detection by month is as follows: in August, PRRSV in 1 and PCV-2 in 24 of 72 head; in November, PRRSV in 20 and PCV-2 in 60 of 120 head; in March, PRRSV in 0 and PCV-2 in 9 of 67 head; in June, PRRSV in 3 and PCV-2 in 27 of 72 head. Total percentages: PRRSV 24 head (7.7%) and PCV-2 120 head (38.3%). Frequency of PRRSV and PCV-2-positive pigs increased after the nursery stage. PRRSV frequency peaked among pigs aged from 1 to 2 months. PCV-2 frequency peaked among pigs aged from 3 to 4 months. After those stages, frequencies of pigs positive for PRRS and PCV-2 decreased to reach low levels in grown sows. These results suggest that the frequency of pigs positive to PRRSV and PCV-2 varies seasonally and that, on the farms studied, these infections develop rapidly after weaning.
When introduced to a large-scale beef-cattle farm where outbreaks of respiratory disease had frequently occurred, clinically healthy 10-month-01d Japanese Black cattle and 7-month-old FI cattle received subcutaneous injections of either a mixed vaccine plus enrofloxacin (ERFX group, n=401) or a mixed vaccine plus tilmicosin (TMS group, n=501); and the effects of the inoculations in preventing the onset of respiratory disease were studied. Results were compared with those from cattle receiving the vaccine only (control group, n=236). Incidence of respiratory disease in the ERFX and TMS groups were significantly (P<0.01) lower than in the control group. Three days after injection, bacteriologic tests showed that Pasteurella multocida iso-lation rates were remarkably higher in the control group than in the ERFX and TMS groups. P. multocida and Mycoplasma spp. were isolated from nasal swabs taken when the cattle were introduced to the farm. Both proved highly sensitive to ERFX, although most strains of Mycoplasma spp. resisted TMS.
The diagnostic value of magnetic resonance imaging (MRI) was assessed in the case of a thoroughbred racehorse with a partial rupture of the superficial digital flexor tendon. Ultrasonography delineated the ruptured tendon, but MRI more clearly revealed not only the lesions of the ruptured and loosened tendon, but also hemorrhages and edema of the tendon and connective tissues. Although it requires either anesthesia or immobilization of the patient, MRI was shown to be a very useful diagnostic method for equine tendon disorders.
In March 2000, the owners of a farm breeding 9 Japanese Black Cattle cut branches from trees near the cow barn to use as bedding for the animals. About 12 hours after lying on the bedding, 5 of the cattle exhibited neurological symptoms. Three of them died within about 60 hours. Autopsy revealed large numbers of Illicium religiosum leaves in the contents of their first stomachs. Furthermore 0.5mg/g of anisatin was detected in the leaves. Administration of Illicium religiosum leaf extract to mice resulted in such neurological symptoms as pilo-erection, something like vomiting, straddling posture, and gait abnormalities. On the basis of these findings, the cattle were diagnosed as having contracted Illicium religiosum poisoning.
Histopathological examinations were conducted on 143 biopsy specimens of canine cutaneous histocytoma (CCH). CCH occurred in 11.8%(66.4% in animals under 3 years of age) of 1, 210 specimens of canine skin tumors obtained between April 1999 and July 2001. Measuring about 1cm in diameter, the CCH were located mostly in the face (31.3%), the limbs (28.5%), and the ears (22.2%) and occurred frequently in the Dachshund (16.8%) and Shih Tzu (10.5%) breeds. Tumor cells proliferated within the dermis and subcutis, and the tumor mass pushed the epidermis up. Tumor cells had round or irregularly shaped nucleus and abundant cytoplasm. Immunohistochemically, they were positive for vimentin, MHC class II, and S-100 protein. Numbers of T-lymphocytes occurred in necrotic regions. Tumor recession in CCH suggested the operation of an immunological mechanism.
Detection ability, sensitivity, and specificity of a new test kit (New Kit) for detecting circulating adult heartworm antigens by means of the immunochromatography method were compared with those of an enzyme immunoassay test kit (Control A) and another immunochromatography test kit (Control B). The detection ability of the New Kit was the highest of the 3. In microfilaremic dogs (n=40), sensitivity of the New Kit was 100% in comparison with 97.5% for both Control A and Control B. In microfilaria-negative dogs (n=12), sensitivity of all 3 kits was 58.3%. Dogs without heartworm infection (n=33) were negative with all 3, indicating a specificity of 100% for all. Detection ability of the New Kit was highest of the 3 kits, and sensitivity and specificity of the New Kit were on a par with those of Controls A and B.
By clinical findings and computed tomography (CT), a 4-month-old female Welsh corgi with facial swelling was diagnosed as having craniomandibular osteopathy. Steroid therapy effectively managed the case. Whereas terriers, including the West Highland White Terrier, are said to be of higher incidence of this condition, the development of its symptoms in corgis is very rare.