Microangiography and correlated histology: a research technique for examining renal microcirculation

A technique for radiographic delineation of the microvasculature of the canine kidney is described. The renal vasculature was perfused (at a physiologic pressure) with a finely divided barium sulfate. Microangiograms of sagittal renal slices were produced, using a special radiography machine that allows low kilovolt peak, low milliamperage, and exposure times up to 5 minutes. A special high resolution film (800 lines/mm) was used. With this technique, it was possible to delineate interlobar, arcuate, and interlobular arteries, afferent arterioles, glomerular capillaries, and peritubular vessels. The kidney slices prepared for microangiography were undamaged and available for histochemical processing. Thus, the microvascularity was correlated with the histologic appearance of the renal tissues.     

Evaluation of an Artificial Insemination Programme in a Seasonal Breeding Dairy System through Milk Progesterone

In order to evaluate an artificial insemination programme and reproductive efficiency of dairy herds in Uruguay, a survey was conducted with five dairy farms, utilizing a total of 768 lactating Holstein cows. Precision of oestrous detection was assessed by one milk progesterone sample taken on day of breeding and was 11.1%. Two additional samples taken at day 10 and 23 were used to confirm ovulation and early pregnancy. Accuracy of pregnancy estimation by milk progesterone was 70.4%. Reproductive efficiency was determined by the analysis of records. Average intervals from calving to first service were 101 days and to conception 132 days and these were affected by parity, body weight and body condition at calving, but not at breeding, or by milk production. Oestrous detection rates and pregnancy rates were 37.5 and 15.6%, respectively. It was concluded that losses in reproductive efficiency in dairy farms of Uruguay in a seasonal artificial insemination programme were mainly due to unobserved heats, rather than incorrect oestrous detection.     

Mining free-text medical records for companion animal enteric syndrome surveillance

Large amounts of animal health care data are present in veterinary electronic medical records (EMR) and they present an opportunity for companion animal disease surveillance. Veterinary patient records are largely in free-text without clinical coding or fixed vocabulary. Text-mining, a computer and information technology application, is needed to identify cases of interest and to add structure to the otherwise unstructured data. In this study EMR's were extracted from veterinary management programs of 12 participating veterinary practices and stored in a data warehouse. Using commercially available text-mining software (WordStat™), we developed a categorization dictionary that could be used to automatically classify and extract enteric syndrome cases from the warehoused electronic medical records. The diagnostic accuracy of the text-miner for retrieving cases of enteric syndrome was measured against human reviewers who independently categorized a random sample of 2500 cases as enteric syndrome positive or negative. Compared to the reviewers, the text-miner retrieved cases with enteric signs with a sensitivity of 87.6% (95%CI, 80.4–92.9%) and a specificity of 99.3% (95%CI, 98.9–99.6%). Automatic and accurate detection of enteric syndrome cases provides an opportunity for community surveillance of enteric pathogens in companion animals.     

Normal blood supply of the canine patella

The normal blood supply of the canine patella was evaluated, using microangiography and correlated histology. Arterioles entered the cortex of the patella at multiple sites along the medial, lateral, and dorsal aspects. The body of the patella was vascularized uniformly, with many arterioles that branched and anastomosed extensively throughout the patella. The patella was not dependent on a single nutrient artery for its afferent supply, but had an extensive interior vascular network. These factors should ensure rapid revascularization and healing of patellar fractures, provided appropriate fracture fixation is achieved.     

Renal microcirculatory and correlated histologic changes associated with dirofilariasis in dogs

Nine 7-month-old Beagle dogs were inoculated with 200 third-stage larvae of Dirofilaria immitis. The development of cardiac disease secondary to heartworm infection was confirmed by thoracic radiography, echocardiography, and angiography with blood pressure measurements. The only indication of renal disease was mild-to-moderate proteinuria. The dogs were euthanatized approximately 18 months after inoculation. The mean microfilarial count in blood at the time of euthanasia was 88,700/ml, with a mean of 89 adult heartworms in the vena cavae, heart, and pulmonary arteries. The kidneys were perfused for microangiographic and correlative histologic examination of the intrarenal microvasculature and associated renal morphologic features. Angiograms of whole kidneys from 6 dogs revealed attenuation or truncation of the major renal vessels. Microangiograms of all kidney slices revealed attenuation in the microangiographic appearance of the glomerular capillaries. Histologic examination of all kidney slices revealed mild-to-intense, diffuse, chronic interstitial nephritis and generalized membranoproliferative glomerulonephritis. Microfilariae were observed within the glomerular capillaries and the medullary vessels. The microangiographic changes correlated with and were explained in part by the histologic changes in the renal parenchyma.     

Health performance of feeder calves sold at conventional auctions versus special auctions of vaccinated or conditioned calves in Ontario

OBJECTIVE: To compare health performance during the first 28 days in the feedlot for vaccinated or conditioned feeder calves sold through special auctions in Ontario with health performance for calves sold through conventional auctions in the province. DESIGN: Cohort study. ANIMALS: 12,313 calves sold through conventional and special auctions at the Keady Livestock Market during the fall of 1999 and 2000. PROCEDURE: Buyers of calf groups were approached at the auction market or contacted by telephone and asked to record the number of calves requiring treatment for bovine respiratory tract disease (BRD) during the first 28 days after purchase. RESULTS: 211 calf groups (> or = 20 calves/group) were followed up for 28 days after purchase. Multivariate logistic analysis indicated that vaccinated calves purchased through special auctions were 0.68 (95% confidence interval, 0.50 to 0.93) times as likely to receive treatment for BRD as were calves purchased at conventional auctions and that conditioned calves were 0.22 (95% confidence interval, 0.12 to 0.38) times as likely to receive treatment. Groups that received antimicrobials by injection on arrival at the feedlot were 0.64 (95% confidence interval, 0.43 to 0.96) times as likely to be treated as were groups that did not. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that vaccinated and conditioned calves were less likely to receive treatment for BRD during the first 28 days in the feedlot; however, there was no difference in mortality rate.     

The effects of changing demographics on the distribution of marine anemia in farmed salmon in British Columbia.

The changing geographic distribution of marine anemia (plasmacytoid leukemia) was compared with the evolving demographics of the chinook farming industry in British Columbia to explore the hypothesis that the disease had spread throughout the province between 1987 and 1992. Through retrospective and prospective methods, it was shown that the apparent spread of the disease was likely an artifact, resulting from changes in the distribution of fish farms throughout the province and corresponding changes in the intensity of regional disease surveillance. When viewed over a 5-year period, there were no statistically significant differences in the prevalence of the disease amongst fish sampled from each of the major salmon farming regions of British Columbia. By increasing the intensity of surveillance for the disease in apparently negative regions or chinook farms, one could routinely find cases of the disease. The results suggest that marine anemia is an endemic problem for farmed chinook salmon in British Columbia and is not a spreading epidemic.     

Relationship Among Follicular Growth, Oestrus, Time of Ovulation, Endogenous Estradiol 17β and Luteinizing Hormone in Bos Indicus Cows After a Synchronization Program

To determine the pattern of follicular growth during oestrus and the relationship with estradiol and luteinizing hormone in ovulating and non-ovulating cows, three groups of (n = 10), thirty cyclic, Bos indicus cows were synchronized with CIDR, consecutively at 9-day intervals. Twenty-four hours after implant withdrawal, all cows synchronized in the same group with other cows displaying estrous behaviour after implant withdrawal were subjected to an intensive period of ultrasonographic observations (every 6 h for 120 h). Blood samples were taken to evaluate LH surge and 17-beta estradiol. No differences were observed in follicular growth, ovulatory diameter and growth average in the three groups of synchronized cows. Cows ovulating (CO) had a better growth average in comparison with the group of cows not ovulating (CNO) (1.4 +/- 0.7 mm vs 0.7 +/- 0.5 mm, p < 0.06). The average time from estradiol release to LH surge was 39.3 +/- 24.6 h. Differences were also observed between CO and CNO with respect to both the first concentration (27.7 +/- 5.2 vs 58.6 +/- 31.9, p < 0.004) and last concentration (79.3 +/- 23.3 vs 99.2 +/- 27.3, p < 0.05) of estradiol above 5 pg/ml. The average time from overt signs of oestrus to LH release was 8.4 +/- 7.7 h. In the CNO, the increase in LH concentration was never above two SD from the basal average. In conclusion, there is a wide variability in follicular growth and ovulatory diameter between CO and CNO, which can affect the intervals of LH release, estradiol peak and ovulation. Yet, LH surge might be a good marker for timing ovulation in Zebu cows.