Relationship between the indicators of performance and the weight of pneumonic lesions from pigs at slaughter.

Lungs from pigs at slaughter were examined and the extent of the lesions was estimated as the percentage by weight of the lung affected by pneumonia in relation to the weight of the whole lung. Linear regression analyses of mean daily gain in liveweight and days to slaughter on the percentage by weight of pneumonic lung were performed. Within a range between 3.32 and 74.55 per cent for the weight of pneumonic lung, a 10 per cent increase in the weight of pneumonic lung was associated with a decrease in mean daily gain of 31.4 g and a 13.2-day increase to slaughter at 104.2 kg liveweight. When subgroups of pigs were evaluated by farm of origin, significant associations between indicators of performance and pneumonia for pigs from only one of the farms were found.

Is maintenance chemotherapy appropriate for the management of canine malignant lymphoma?

A retrospective study was conducted between two groups of dogs with histopathologically diagnosed multicentric malignant lymphoma to determine if treatment with either short-term or continuous chemotherapy resulted in a significant difference in first-remission length or survival time. One group was treated with single agent, short-term (three cycles) of doxorubicin. Dogs obtaining complete remission while receiving doxorubicin were given no further chemotherapy. The other group received combination agent, long-term chemotherapy consisting of cyclophosphamide, vincristine sulfate, and prednisone (COP). Dogs obtaining complete remission on COP by the end of 6 weeks were given maintenance chemotherapy of cyclophosphamide, prednisone and methotrexate. One hundred and five dogs were treated. Thirty-eight dogs received doxorubicin and 67 received COP. All dogs were evaluated at 6 weeks for response to chemotherapy and followed until death. No significant differences were observed in first-remission length or survival time when comparing dogs treated with either short-term doxorubicin or long-term COP (P greater than 0.05). Sex, weight, age, clinical stage, performance status, histopathologic cell type, and grade were not significant factors for determining the responsiveness to either chemotherapy protocol. However, within either treatment group, significant differences in first-remission length were observed in dogs evaluated histopathologically by the Keil and NCI working formulation and in survival time when evaluated by performance status (P less than 0.05).

Association between growth indicators and volume of lesions in lungs from pigs at slaughter.

Conflicting findings exist among studies on the effect of pneumonia on growth in pigs. We determined the extent of pneumonia in market-weight pigs by use of an objective, volumetric method and linear regression analyses of mean daily gain and days-to-slaughter weight on the percentage of pneumonic lung. In a range of extent of pneumonia between 1.33 and 70.44%, a 10% increase in the volume of pneumonic lung was associated with a decrease in mean daily gain by 41.1 g and a 16.7-day increase in number of days to a slaughter weight of 104.5 kg.

Cerebrospinal fluid changes after iopamidol and metrizamide myelography in clinically normal dogs.

Cerebrospinal fluid samples from 2 groups of clinically normal dogs were compared after iopamidol (n = 9) and metrizamide (n = 8) myelography. Iopamidol (200 mg of I/ml) and metrizamide (170 mg of I/ml) were administered by cerebellomedullary injection at dosage of 0.45 ml/kg of body weight. In dogs of both groups, postmyelographic CSF changes included high specific gravity, Pandy score, protein concentration, and WBC count. The high specific gravity and Pandy score were false-positive effects attributed to nonionic contrast media. Although postmyelographic protein concentration and total WBC count were greater in CSF samples from dogs given metrizamide than in those given iopamidol, differences were not statistically significant. The differential WBC counts were consistent with mild, acute leptomeningitis; these findings were supported by results of histologic examination. Iopamidol and metrizamide should be considered low-grade leptomeningeal irritants in dogs.

Pet populations in the catchment area of the Purdue Comparative Oncology Program.

Using a 1-stage random-digit dial telephone survey, we estimated the number of pet dogs and cats and cancer case ascertainment in the principal catchment area of an animal tumor registry in Indiana, the Purdue Comparative Oncology Program (PCOP). These findings will assist in the estimation of pet cancer incidence rates for the PCOP. The estimated canine and feline populations for Marion County were 144,039 (95% confidence interval, 121,555 to 166,523) and 94,998 (74,384 to 115,648), respectively. For Tippecanoe County (excluding university housing residences), the estimated canine population was 18,000 (14,445 to 21,555), whereas the estimated feline population was 17,165 (12,569 to 21,761). The estimated cancer case ascertainment was 88.3% (dogs, 92.5%; cats, 83.0%) with no statistically significant difference in the estimated ascertainment by county of residence or by species of pet. The amount that owners report themselves willing to pay for treatment of cancer in dogs or cats, however, differed in counties polled. This method's appropriateness for estimating pet populations in general and the validity of the data gathered were supported by response rate of 88.0% and by concurrence with census data for household characteristics previously documented to be associated with pet dog and cat ownership.

Use of farrowing rate as a measure of fertility of boars.

The first 100 single-boar services of 140 boars were analyzed to determine whether the farrowing rate resulting from initial services predicted the farrowing rate of subsequent services. The data were analyzed for the influence of parity, number of matings per estrus, season of service, and interaction of these variables on farrowing rate. Sow parity influenced farrowing rate. Sows with parity greater than 8 and gilts had the lowest farrowing rates (P less than 0.01). Sows with parity 2 through 5 had the highest farrowing rates (P less than 0.01). One and 2 matings/estrus resulted in reduced farrowing rates (P less than 0.01), compared with farrowing rates of greater than 2 matings/estrus. Farrowing rate for services during the summer was lower than that for other seasons of the year (P less than 0.01). Evidence of interaction among these variables was not found. Therefore, the results of each service recorded was adjusted to the mean farrowing rate of sows with parity 2 through 5, sows mated greater than or equal to 3 times/service, and sows serviced in the spring. After these adjustments, the farrowing rates for the first 10, 20, 30, 40, and 50 services were analyzed to determine associations with farrowing rates for subsequent services through 100 farrowings. These data also were analyzed to determine whether the associations were strengthened by removal of the first 10 services from the data. The best farrowing rate association indicated that for each 1% increase in farrowing rate subsequent to the first 50 services, the farrowing rate for the second 50 services increased 0.33% (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Epizootic of pseudorabies among ten swine herds.

An epizootic of pseudorabies in 10 swine herds located near Greensburg in Decatur County, Indiana was investigated. Records of Decatur County swine herds previously quarantined because of pseudorabies were obtained. For the 1988 epizootic, clinical findings were considered, location of each of the 10 swine herds in relation to the other herds was determined, and potential fomites were considered. Meteorologic data prior to, during, and after the epizootic were obtained, correlated, and analyzed. A source-receptor model, based on wind direction and speed data, was used to determine whether weather conditions in the Greensburg area enhanced the potential for aerosol spread of pseudorabies virus between herds. On the basis of lack of other modes of spread of pseudorabies and on meteorologic and source-receptor data, aerosol transmission of pseudorabies virus between the 10 herds was probable.

Pathologic response of the lung to irritant gases.

The pathologic response of the lung to irritant gases ranges from the acute exudative phase through the subacute proliferative phase to the chronic fibrosing phase. These responses are based on damage to the Type I cells, and possibly endothelial cells, and the subsequent proliferative and repair processes in the surviving animals. Responses to high dose exposures appear at the microscopic level as exudation of protein rich fluids into alveoli (alveolar edema) and subsequent death due to anoxia. Physiologically, this could be described as a mismatch of ventilation with perfusion, resulting in impaired gas exchange. Animals surviving this acute exudative phase resolve the alveolar edema to fibrin, and Type II cells become hypertrophic and hyperplastic in the process of replacing the damaged Type I cells. The acute and subacute responses also elicit inflammatory changes in the interstitium of the lung that may progress to fibrosis in the chronic stage of a survivable exposure. Diagnostic cases in livestock involving irritant gases reflect similar toxic injuries to the lung.

A prospective clinical trial comparing metrizamide and iohexol for equine myelography.

A prospective clinical trial comparing adverse postmyelographic effects and myelographic quality of metrizamide and iohexol was conducted. Using a predetermined, randomized assignment, 24 horses exhibiting neurologic signs were administered either metrizamide (180 mgl/ml) or iohexol (180 mgl/ml) via cerebellomedullary puncture. Each horse was evaluated postmyelographically for adverse effects. Myelographic quality was assessed by a numerical scoring method. Adverse effects were observed more frequently with metrizamide (21) compared with iohexol (6) myelography (p < 0.05). Seizures, intensification of preexisting neurologic signs and prolonged anesthetic recovery were the most common complications after myelography. There was no difference in myelographic quality (p > 0.05). We conclude that iohexol is safer than metrizamide for equine myelography and that quality myelograms can be obtained with either contrast medium.