Evaluation of risk factors for development of catheter-associated jugular thrombophlebitis in horses: 50 cases (1993-1998)

OBJECTIVE: To evaluate risk factors associated with development of catheter-associated jugular thrombophlebitis in hospitalized horses. DESIGN: Retrospective case-control study. ANIMALS: 50 horses with thrombophlebitis and 100 control horses. PROCEDURE: Medical records from 1993 through 1998 were searched for horses with thrombophlebitis. Horses that were hospitalized for at least 5 days, had an i.v. catheter placed in a jugular vein (other than for solely anesthetic purposes), and had no evidence of thrombophlebitis during admission or hospitalization were chosen as controls. Signalment, history, clinicopathologic findings, primary illness, and treatment were obtained from the medical records. Data were analyzed by use of logistic regression to perform univariate and multivariate analyses. RESULTS: For a horse with endotoxemia, the odds of developing thrombophlebitis were 18 times those for a similar horse without endotoxemia. For a horse with salmonellosis, the odds of developing thrombophlebitis were 68 times those for a similar horse without salmonellosis. For a horse with hypoproteinemia, the odds of developing thrombophlebitis were almost 5 times those for a similar horse without hypoproteinemia. For a horse in the medicine section, the odds of developing thrombophlebitis were 16 times those for a similar horse in the surgery section. For a horse with large intestinal dise, the odds of developing thrombophlebitis were 4 times those for a similar horse without large intestinal disease. For a horse receiving antidiarrheal or antiulcerative medications, the odds of developing thrombophlebitis were 31 times those for a similar horse not receiving these medications. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that patient factors, including large intestinal disease, hypoproteinemia, salmonellosis, and endotoxemia, were associated with development of catheter-associated thrombophlebitis in horses.     

Evaluation of peripheral lymphoreticular biopsy techniques and their clinical side effects in sheep

Tissue samples were collected postmortem from 126 sheep at five lymphoreticular sites by different techniques. The three most successful combinations of sites and techniques were: the third eyelids, using a forceps and scissors, which provided a mean (se) of 5.32 (0.70) lymphoid follicles per 5 microm tissue section, a mandibular lymph node, using a Biopty gun, which gave 1.19 (0.26) lymphoid follicles per 5 microm tissue section, and tonsil, using a biopsy forceps, which gave 1.14 (0.27) lymphoid follicles per 5 microm tissue section. These three techniques were repeated once a month for five months on five sheep under general anaesthesia, and their clinical effects were compared with five control sheep which were restrained and anaesthetised in the same way but from which no biopsies were taken. Most lymphoid follicles (3.47 [0.58] per 5 pm tissue section) were obtained by using the third eyelid biopsy technique. There were no clinical side effects associated with the biopsy procedure. There were increases in the plasma concentration of cortisol in all the animals, suggesting that the restraint and anaesthesia were more stressful than the biopsy procedure.     

Comparison of the analgesic effects of meloxicam and carprofen administered preoperatively to dogs undergoing orthopaedic surgery

Thirty-two dogs undergoing operations to repair a torn cranial cruciate ligament or a fractured long bone were randomly allocated to one of two treatment groups in a study on postoperative pain. Sixteen of the dogs were given 4 mg/kg carprofen and the other 16 were given 0.2 mg/kg meloxicam subcutaneously before the operation. The signs of pain shown by the animals were assessed for 24 hours on a visual analogue scale, a discontinuous scoring system, and a score based on five behavioural and physiological variables. The dogs' heart and respiratory rates and their mean arterial blood pressures were also measured non-invasively at each assessment. Blood samples were taken before the surgery and 24 hours after it, and the concentrations of urea and creatinine were measured in plasma. Both drugs were effective in relieving the signs of pain for up to 24 hours in all the dogs. There were no significant changes in the concentrations of urea and creatinine, and no adverse effects were reported during the postoperative period.     

Estimation of direct and maternal heritability and genetic correlation for backfat and growth rate in swine using data from centrally tested Yorkshire boars.

The purpose of this study was to estimate components of variance and covariance for backfat and growth rate in swine tested in central test stations in the United States. Data were collected from 26 central boar test stations from 1984 through 1990. The traits analyzed were backfat adjusted to a 104.5-kg basis and ADG adjusted to a 36-kg on-test weight. Records from 7,951 purebred Yorkshire boars were analyzed. Contemporary groups were defined as boars of a breed that were tested and sold as a common group in a test station. Variance components were estimated using a pseudo-expectation method with a multiple-trait, sire-maternal grandsire model. Direct heritabilities for backfat and ADG were estimated to be .56 and .24, respectively. Direct maternal effects were significant for both backfat and ADG; they accounted for 11 and 23% of the variance, respectively. The additive genetic correlation between backfat and ADG was approximately zero. Within this population of centrally tested Yorkshire boars, heritability seems to be high for backfat and moderate for ADG, with a significant maternal effect on each trait.     

A spontaneous thymic carcinosarcoma in a young Sprague Dawley rat

We encountered a case of spontaneous thymic carcinosarcoma in a young Crl:CD (Sprague Dawley) rat. Grossly, a white multinodular mass replaced the thymus in the thoracic cavity. Histologically, multiple nodules were separated by fibrous stroma, and each nodule included isolated regions that were composed of epithelial or non-epithelial tumor cells. The epithelial tumor cells were relatively large and round to polygonal cells with large nuclei and weakly eosinophilic cytoplasm. These cells were cytokeratin-positive and vimentin-negative. These cells infiltrated the lungs. The non-epithelial tumor cells were poorly differentiated, small, round to spindle-shaped cells with small nuclei and basophilic cytoplasm. These cells were vimentin-positive and mostly cytokeratin-negative. Many islands of cartilage were observed near non-epithelial cells. Based on these findings, the tumor was diagnosed as a primary thymic carcinosarcoma consisting of a malignant thymoma composed of epithelial tumor cells and a mesenchymal chondrosarcoma composed of non-epithelial tumor cells.     

Management and environmental factors associated with annual sow culling rate: A path analysis

The relationships between management and environmental factors and annual sow culling rate were investigated in 152 Minnesota swine breeding herds. Data were obtained through a postal survey. A general path model was hypothesized to describe relationships among variables. Multiple least-squares and logistic regressions were used to test the statistical significance of pathways. The associations between the indepen variables and the annual culling rate (ACR) were decomposed into direct, indirect, and common cause associations.

The mean ACR of the 152 farms was 39% ± 2% rm(SE). Using path-analysis techniques, only the type of flooring during gestation, the size of the herd and the lactation length had a direct relationship with ACR. The type of housing during gestation and farrowing were related indirectly to the ACR. Their association was mediated by the type of flooring during gestation and the weaning age. Herds housing their sows in total confinement during gestation were most likely to keep them on partially or totally slatted floors which were associated with a higher ACR. Sows kept in crates during the farrowing period were more likely to have a short lactation length which was associated with a higher ACR.

Most associations between the use of preventive veterinary services and the ACR were due to association with other variables. Herds using veterinary preventive medicine were most likely to have a short lactation length, a large number of females, and sows housed in total confinement during gestation and in crates during the farrowing period. All of the aforementioned variables were associated with a high ACR.

The relationships of other management and environmental factors with the ACR were due to common cause associations. These factors included having the sows individually identified, using a more comprehensive recording system, mainly a hand-mating system, testing regularly for pregnancy and housing sows in total confinement during the breeding period. The strongest associations with the ACR were the type of flooring during gestation and the size of the herd.     

Respiratory airflow patterns in ponies at rest and during exercise.

The exercise-induced changes in the equine breathing pattern were studied by analyzing tidal breathing flow-volume loops recorded in ten ponies both at rest and during a standardized exercise. Airflow, tidal volume, esophageal pressure and mask pressure were simultaneously recorded before, during and after a treadmill exercise. From the collected data, respiratory frequency and total pulmonary resistance were calculated, tidal breathing flow-volume loops were retraced using a computerized method and loop indices were measured for each period of the experimental protocol. For each pony, results of three consecutive daily measurements were averaged. The exercise loop indices were compared with the corresponding resting values using a one-way analysis of variance. The significantly changed indices were correlated with respiratory frequency and total pulmonary resistance. Several types of respiratory patterns were observed at rest as well as during exercise, although each pony was relatively constant in its own pattern of breathing. Most resting inspiratory and expiratory airflow curves were found to be biphasic. When ponies started running, the airflow developed an increasingly rectangular pattern. During strenuous exercise, both inspiratory and expiratory airflow curves showed a substantial increase of the volume acceleration and tended to a plateau. The loop indices relating the expiratory to the inspiratory airflow were significantly increased compared with their rest values. Correlations of these indices with respiratory frequency and total pulmonary resistance were weak.(ABSTRACT TRUNCATED AT 250 WORDS)     

不同植被类型大油芒种群构件特征的比较研究

在松嫩草地和内蒙古图牧古国家级自然保护区内,对草甸和草甸草原上大油芒种群构件的特征进行了比较研究.结果表明,两种植被类型中,大油芒种群分蘖株的数量和生物量分别山3个和2个龄级组成,且均以1a所占比重最大,呈增长型龄级结构;根茎分别以2a和1a所占比重最大,呈稳定型和增长型;大油芒种群的单株生物量均以1a最高,且均随着龄级的增加依次减少.整体水平上,草甸草原上大油芒平均单株重显著高于草甸.草甸草原上各龄级根茎单位长度生物量均极显著高于草甸.两种植被类型中,根茎顶端芽所占比例分别为22.5％和44.1％;分蘖节芽均以1a所占比重最大,且随着龄级的增加而减少.大油芒种群在生长季末期储备了充足的芽用于翌年地上部分的更新.草甸草原上的大油芒种群具有更强的种群更新能力.     

Pathologic features of polybrominated biphenyl toxicosis in the rat and guinea pig.

Young male rats were fed a diet containing 0, 1, 10, 100, or 500 ppm of a commercial mixture of polybrominated biphenyls (PBB) that had been accidentally incorporated into a mineral mixture and fed to Michigan livestock and poultry. After 30 days, 9 of the 12 rats in each group were killed and tissues were examined. Liver weight to body weight ratios were significantly increased at all feeding levels; at 500 ppm, liver weight had more than doubled. Kidney weight was not affected. Microscopic lesions were mostly confined to the liver and consisted of extensive swelling and vacuolation of hepatocytes in rats fed diets containing 100 and 500 ppm of PBB. Slight swelling and vacuolation were seen in rats fed the diet containing 10 ppm, and lesions were not found at 0 or 1 ppm. There was a significant increase in hepatic mitochondrial size at 1 ppm, and smooth endoplasmic reticulum was markedly increased at 100 and 500 ppm. Myelin bodies were present at 100 and 500 ppm, and vacuoles were numerous. Rats killed at 60 days had similar lesions. The activity of hepatic microsomal enzymes increased at all levels of feeding of PBB. Rat pups nursing dams fed a diet containing 10 ppm of PBB had microscopic and ultrastructural hepatic lesions. When guinea pigs were fed PBB at the same amounts as were rats, the results were strikingly different. Guinea pigs fed a diet containing 500 ppm of PBB died within 15 days; at 100 ppm, only 2 of 6 survived for 30 days. Effects on liver weight were inconsistent, but 2 of 6 fed a diet containing 10 ppm had enlarged livers.     

Outbreak of disseminated zygomycosis and concomitant pulmonary aspergillosis in breeder layer cockerels

Disseminated zygomycosis and concomitant pulmonary aspergillosis were diagnosed in breeder layer cockerels. Five- to 9-week-old breeder layer cockerels with a history of an increased mortality rate were presented to a diagnostic laboratory for examination. On necropsy, large, multifocal, firm, tan, nodules were observed in the lungs, air sacs, peritoneum, livers, spleens and kidneys. On histopathology, mixed populations of zygomycetes and Aspergillus hyphae were observed in the granulomas in the lungs, and zygomycete hyphae were observed in the granulomas in the air sacs, peritoneum, livers, spleens and kidneys. No bacteria were isolated from any of the lesions. Aspergillus fumigatus was isolated from the lung lesions only and hyphae that were consistent with those of a Rhizopus spp. were isolated from the lesions in several organs. Pullets, which were kept together with the cockerels from the day they were hatched, were not affected. The absence of infection in the pullets, which were kept together with the cockerels, suggests that the cockerels were either infected during incubation, with the fungi penetrating the egg shell, or that they were infected during hatching before they were mixed with the pullets.     

Levels of insulin and glucose in calves during the first 6 months of life]

Twenty-four calves of the Holstein-Friesian breed were included into a trial. The trial was performed from April (when the calves were born) to October. The objective of the study was to investigate variations in insulin and glucose levels over a longer time period of the postnatal development of calves. The blood was sampled by the jugular vein puncture at the age of 1, 2, 3, 5, 14, 21, 28, 35, 49, 63, 91, 118, 147 and 175 days. The calves were housed in a prophylactorium calf-house till the age of 21 days: till the age of 14 days they were housed individually and then in groups of 2-3 calves in a small pen. The calves were fed milk till the age of 26 or 28 days, after a fortnight the feed intake was increased from the previous 3 litres to 5-6 litres per head/day. At the age of 21 days the calves were transferred to pens in the calving room. At the age of 26 days twelve calves were transferred to a barn for young cattle rearing, the remaining twelve calves were transferred at the age of 28 days; here they were housed by 10-12 head per pen and they were fed a commercial milk replacer diluted at a 1:10 ratio, the feed intake being 6-8 litres a day, and a commercial pelleted calf starter TKS at the amount of 1.0-1.1 kg.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ultrastructure of the intraerythrocytic stage of Cytauxzoon felis

The erythrocytes of 2 cats experimentally infected with Cytauxzoon felis were examined by light and electron microscopy. In stained blood smears, parasitized erythrocytes usually contained a single, roundish organism, but occasionally up to 4 were present in a cell. Chains of these roundish organisms also were seen. Elongated parasites, sometimes with ear-like projections, were present in a few erythrocytes. By electron microscopy, the parasite contained a poorly defined nucleus, rough endoplasmic reticulum, ribosomes, nonplicated mitochondria, food vacuoles, and a cytostome on its limiting membrane. Usually, the parasite was oval, but budding forms also were evident. Crystalloid inclusions were present in parasitized and nonparasitized erythrocytes.     

Effect of feeding frequency on bacterial and fungal concentrations, pH, and other parameters in the rumen.

Three sheep were fed a pelleted high-roughage diet either once, 6, or 24 times per day in a 3 x 3 Latin square trial. During each 21-d period, 14 d were allowed for adaptation followed by a 7-d collection period, in which samples for microbial counts were taken on d 1 and 5 and several rumen parameters were measured on d 2 and 6. Bacterial concentrations were not different between feeding frequencies on the first sampling day but were higher (P < 0.05) on the second sampling day when the sheep were fed 24 times a day. Fungal concentrations were not different among feeding frequencies on either sampling day. No effects of feeding frequency were observed for the concentration of cellulolytic bacteria or fungi. On d 2, ruminal volume was larger (P < 0.05) with six feedings than with one feeding and fluid volume turnover was greater (P < 0.05) when sheep were fed 24 times per day. Rumen pH values were higher (P < 0.01) on both d 1 and 5 when the sheep were fed once a day and the percentage of rumen dry matter was highest (P < 0.02) with 24 feedings. These findings would suggest that if the same amount of a given diet is fed daily, the number of feedings does not markedly affect microbial concentrations, rumen volume, or liquid turnover time.     

Controlled clinical trial of the effect of a homoeopathic nosode on the somatic cell counts in the milk of clinically normal dairy cows

Cows in a 250-cow Holstein-Friesian herd were allocated at random to be treated with either a homoeopathic nosode or a negative control, both treatments being applied by means of an aerosol spray to the vulval mucous membranes. A total of six treatments were given over a period of three days and milk samples were taken for the determination of somatic cell counts (SCC) on days -3, 3, 7, 9, 14, 21 and 28. Individuals applying the treatments or carrying out the SCC determination were unaware of which animals were receiving which treatment. Owing to the wide natural variations in SCC, the trial had only a 71 per cent possibility of detecting a 30 per cent difference in SCC between the two groups. There were no significant differences between the SCC of the two groups on any sample day, but there were significant variations between the SCC on different days (P=0.003) in both groups.     

Diagnosis, therapy and endocrinologic parameters of persistent follicles in mares in comparison with preovulatory follicles]

During the 1997 breeding season persistent follicles were diagnosed in 17 mares. In 16 of these mares a total of 17 follicles were transabdominally punctured and the steroids oestradiol, progesterone and testosterone were measured in the follicular fluid and in blood serum. In ten mares serving as a control group preovulatory follicles were punctured. The follicular fluid of the persistent follicles revealed a very high variability of the steroid concentrations. Depending on the steroid ratio within the follicles, eight follicles were rated as being intact, three follicles were undergoing atresia and five follicles were luteinized. Because of the high oestradiol levels of the follicular fluid within the control group, all of these follicles were considered to be intact. In both groups, no correlation of the steroid concentration between serum and follicular fluid was detectable. This fact argues against a passive diffusion of the steroids through the follicular wall. By puncturing the persistent follicles it was possible to bring the affected mares back into a physiological oestrus cycle within a normal dioestrus period.     

In situ hybridization for the detection of transmissible gastroenteritis virus in pigs and comparison with other methods.

Archived formalin-fixed, paraffin-embedded tissues from 25 pigs naturally infected with transmissible gastroenteritis virus (TGEV) were examined by in situ hybridization for TGEV nucleic acid using a nonradioactive digoxigenin-labeled cDNA probe that targeted the nucleocapsid sequence of TGEV strains. The results of in situ hybridization for the detection of TGEV were compared with virus isolation (VI), a fluorescent antibody test (FAT), and transmission electron microscopy (TEM). VI, FAT, and TEM were tested over a course of time before the in situ hybridization was performed. Positive hybridization signals were detected in duodenal, jejunal, and ileal enterocytes from 21 pigs. Hybridization signals were confined to the cytoplasm. Intestinal specimens from 25 piglets were evaluated by 4 tests. Twenty-one of 25 were positive by in situ hybridization. Of these 21 samples, 5 (24%) were positive for TGEV by all 4 tests, 15 (71%) were positive by FAT, 14 (67%) were positive by VI, and 6 (29%) were positive by TEM. In situ hybridization for the detection of TGEV in formalin-fixed, paraffin-embedded tissues provides a rapid means of confirmation of a histopathological diagnosis of TGEV without virus isolation, or when only formalin-fixed intestinal specimens were available.     

几例猪密螺旋体痢疾的诊治报告

文章收集湖南省洞口县历史上猪密螺旋体痢疾病例7例,存栏猪6475头,发病猪1185头,发病率18.3%;治疗1136头,治愈1051头,治愈率92.5%,共死亡134头,死亡率2.1%,发病致死率11.3%。其中最近病例(2018年5月中旬)洞口县茶铺茶场管理区某大型猪场存栏3978头,发病猪854头,发病率21.5%,死亡78头,死亡率2.0%,用泰妙菌素、泰乐菌素药物治疗,采取隔离消毒和科学饲养管理综合防控措施,治疗831头,治愈776头,治愈率93.4%,仍造成经济损失87960元。     

Surgical correction of pectus excavatum, using external splintage in two dogs and a cat

Two 4-week-old pups and a 7-week-old kitten with respiratory distress and pectus excavatum were treated by external application of a coaptation splint to the ventral aspect of the thorax. Sutures were placed percutaneously around the sternum and through predrilled holes in a piece of moldable splint material that had been contoured to fit a normal-shaped thorax. Correction of the sternal deformity and alleviation of respiratory distress were achieved in all 3 animals. Frontosagittal index and vertebral index were assessed before and after surgery. In all 3 animals, both indices were abnormal before surgery, but were within the normal range after surgery.     

Extracutaneous histologic changes accompanying zinc deficiency in pups

The extracutaneous tissues in pups fed a Zn-deficient diet were examined. Four pups were fed a Zn-deficient diet and 3 littermates were fed a Zn-adequate diet. After 5 weeks, the pups were euthanatized. Lesions found only in pups fed a Zn-deficient diet were located in the buccal mucosa, lymph nodes, spleen, and thymus. In the buccal mucosa, lesions consisted of irregular epithelial hyperplasia and disruption of epithelial cell layers. There was a marked absence of lymphocytes in the thymus and in T-cell areas of the lymph nodes and spleen.     

Safety and efficacy of an oil-adjuvant vaccine against haemorrhagic septicaemia in buffalo calves: cross-protection between the serotypes B:2,5 and E:2,5.

The safety, efficacy and duration of immunity of an improved oil-adjuvant vaccine against haemorrhagic septicaemia, containing inactivated cells of Pasteurella multocida serotype B:2,5, were tested in young buffalo calves in Pakistan. For safety testing, five buffalo calves were vaccinated intramuscularly with twice the normal dose, and six weeks later with a normal dose. Except for a transient rise in rectal temperature at six hours after the vaccinations, no systemic reactions were observed. The buffaloes remained in good condition and had a normal appetite. No local reactions were observed at the injection site. For efficacy testing two trials were carried out. In the first, buffalo calves were vaccinated intramuscularly either with two doses two-and-a-half months apart, or with a single dose, or left unvaccinated. They were challenged subcutaneously with virulent P multocida after eight, 13 or 15 months. After challenge at eight months the four buffaloes given two doses and the buffalo given one dose were protected, whereas the control animal developed the typical signs of the disease. After the challenges at 13 and 15 months, the vaccinated animals were still protected whereas the control animals died. In the second trial, buffalo calves were vaccinated intramuscularly either with two doses two months apart, or with a single dose at two months or left unvaccinated. The buffaloes were challenged after eight or 14 months. After challenge at eight months the four control animals died, whereas three of the four buffaloes given a single dose were protected. After challenge at 14 months, the three control animals died, whereas four of the five buffaloes given two doses and both the buffaloes given a single dose were protected. To test for cross-protection against the heterologous serotypes E:2,5 and B:3,4, groups of mice were vaccinated once or left unvaccinated. Four weeks later, the vaccinated and control groups were challenged with a dilution series of the different challenge cultures. The vaccine appeared to induce protection against challenge with different strains of serotypes B:2,5 and E:2,5 but not against strains of serotype B:3,4.