Epidemiology and risk factors of cecal dilatation/dislocation and abomasal displacement in dairy cows]

The aims of the study were to determine the prevalence of cecal dilatation/dislocation (CDD) and abomasal displacement (DA) in Switzerland, to identify risk factors for both diseases, and to compare directly their epidemiologic situation. The epidemiologic study included 158 cases of CDD and 149 cases of DA from the cases referred to both University Clinics of Berne and Zurich. The results showed that DA was associated with nutrition-related risk factors: use of minerals and sodium chloride, inadequate concentrate feeding and beginning of the feeding. Furthermore, breed was significantly associated with DA, but not with CDD. Finally, milk yield and pasture were also significantly included in the models. For CDD, nutrition-related risk factors were also found: pasture in summer, use of corn pellets and corn silage in winter. In the final model, protein concentrate was also included. Although both diseases were found at comparable frequencies, the results of this study indicate marked differences between the epidemiology of occurrence of CDD and DA. Therefore, the hypothesis of a common etiopathogenesis appears unlikely.     

Concentration of volatile fatty acids in digesta samples obtained from healthy cows and cows with cecal dilatation or dislocation

OBJECTIVE: To compare concentrations of acetic, propionic, butyric, and i- and n-valerianic acids in digesta samples obtained from the rumen, cecum, proximal loop of the ascending colon (PLAC), and rectum of healthy cows and cows with cecal dilatation or dislocation (CDD). ANIMALS: 20 cows with CDD and 20 healthy cows. PROCEDURE: Samples were collected from all sites during surgical correction of CDD and also from the rectum 1, 2, and 3 days after surgery (group CDD). Samples from healthy (control) cows, matched on the basis of diet and milk yield, were obtained at a slaughterhouse. Concentrations of volatile fatty acids (VFA) were analyzed by use of gas chromatography. Absolute concentration of each VFA was additionally corrected for pH to allow calculation of the concentration of undissociated VFA. RESULTS: Absolute concentration and concentration of the undissociated form of all analyzed VFA were significantly increased in samples collected from the cecum and PLAC of cows in group CDD, compared with concentrations for control cows. Within 3 days after surgery, significant decreases of the absolute concentration of butyric, i- and n-valerianic acids, and undissociated i- and n-valerianic acids were evident in samples obtained from the rectum of group-CDD cows. Concentrations of VFA in samples obtained from the rectum during surgery correlated with corresponding VFA concentrations in samples obtained from the PLAC. CONCLUSIONS: Concentrations of VFA are increased in the cecum and PLAC of cows with CDD. However, the role of increased concentrations of VFA in the etiopathogenesis of CDD is unknown.     

Effects of xylazine on cecal mechanical activity and cecal blood flow in healthy horses

Mechanical activity of the cecal body, lateral cecal arterial blood flow, carotid arterial pressure, and heart rate were measured in 6 conscious healthy horses 30 minutes before and for 120 minutes after IV administration of xylazine at dosages of 1.1 mg/kg of body weight, 0.55 mg/kg, and 0.275 mg/kg. Xylazine at a dosage of 1.1 mg/kg reduced the mean motility index (the product of the mean amplitude of contractions and the total duration of contractile activity divided by the recording time) of the circular and longitudinal muscle layers for the first, second, third, and fourth 30-minute periods after administration of xylazine. Xylazine at a dosage of 0.55 mg/kg reduced the motility index of the circular and longitudinal muscle layers for the first and second 30-minute periods after administration of xylazine. Xylazine at a dosage of 0.275 mg/kg reduced the motility index of the circular and longitudinal muscle layers for the first 30-minute period after administration of xylazine. Mean lateral cecal arterial blood flow was significantly (P less than 0.05) lower than the base-line value at 2 and 4 minutes after administration of all 3 xylazine dosages and at 8 minutes after administration of xylazine dosages of 1.1 mg/kg and 0.55 mg/kg. All dosages of xylazine caused transient hypertension and bradycardia, followed by hypotension.     

Comparison of thelotomy and theloscopic triangulation for the treatment of distal teat obstructions in dairy cows--a retrospective study (1994-1998)

The medical records of 56 cows suffering from teat obstructions in the area of the rosette of Fürstenberg were reviewed; 22 were treated by thelotomy and 34 by theloscopic triangulation and the long-term results were reviewed by telephone conversations with the owners up to four years after the surgery. The milk flow at the fourth milking session after surgery was significantly better in the cows treated by theloscopy and, as a result, fewer of these cows required the teat sphinder to be cut. The cows treated by theloscopy also stayed in hospital for a significantly shorter period and suffered fewer episodes of mastitis.     

Medical treatment of right-sided dilatation of the abomasum in cows

Twenty-two cows with right-sided displacement of the abomasum were treated with hyoscine-n-butyl bromide and dipyrone (Buscopan compositum; Boehringer Ingelheim). Within 24 hours 11 had recovered completely, three had improved, six had shown no improvement and two had been slaughtered. Within 48 hours 17 of the cows had recovered completely and five had been slaughtered.     

Difference in the length of the medial and lateral metacarpal and metatarsal condyles in calves and cows--a post-mortem study

Measurements were taken in the metacarpal and metatarsal bones in 42 calves and 10 dairy cows post-mortem to determine whether there are anatomical differences in bone length. Manual and digital measurements of various bone length parameters were taken. There was a significant difference in the mean length of the condyles of the metacarpal and the metatarsal bones in calves and cows, the lateral condyle being longer than the medial. In all but one metatarsal bone (98.8%), the lateral condyle was longer than the medial. In the metacarpal bones, the lateral condyle was longer in only 52.4% of the bones, in 21.2%, they had the same length and in 27.4% the medial condyle was longer. These intrinsic anatomical differences can help distinguish between the left and right metacarpal and metatarsal bones, for instance, in anatomical and archaeological studies. Knowledge of these differences might be useful for studies on digit function and on the possible predisposition of cattle to claw diseases in the lateral claws of the hind limbs.     

手术治疗犬胃扩张扭转

胃扩张扭转是胃绕其轴线扭转,使胃大弯向腹部右侧移位,造成胃韧带拉伸延长,并最终变松弛,幽门向前背侧移位至体中线左侧,空气存于腔中,增加胃内压力,减少静脉血流过腹腔,导致门脉高压,全身低血压及心内性休克。胃扩张扭转发病急且危及生命。最常见发生于大型深胸中年至老龄犬。临床症状包括腹部膨胀、干呕、不安及过度流涎。     

Effects of dopamine administration on cecal mechanical activity and cecal blood flow in conscious healthy horses

Lateral cecal arterial blood flow, carotid arterial pressure, heart rate, and mechanical activity of the circular and longitudinal muscle layers of the cecal body were measured in 7 conscious healthy horses during IV infusion of physiologic saline solution for 60 minutes (control), during a 60-minute IV infusion of dopamine (at dosages of 1, 2.5, and 5 micrograms/kg/min), and for 60 minutes after IV infusion of dopamine. The mean values for lateral cecal arterial blood flow during IV infusion of dopamine at a dosage of either 1 or 2.5 micrograms/kg/min were not significantly different from the mean values for lateral cecal arterial blood flow during IV infusion of saline solution. The mean values for lateral cecal arterial blood flow, however, were significantly greater during IV infusion of dopamine at a dosage of 5 micrograms/kg/min than the mean values for lateral cecal arterial blood flow during IV infusion of saline solution. Intravenous infusion of dopamine at 1 and 2.5 micrograms/kg/min did not significantly change the mean values for carotid arterial pressure. In contrast, the mean values for carotid arterial pressure were significantly less during IV infusion of dopamine at dosages of 2.5 and 5 micrograms/kg/min than during infusion of saline solution. The mean values for heart rate were not significantly altered by infusion of dopamine at a dosage of either 1 or 2.5 micrograms/kg/min, but infusion of dopamine at a dosage of 5 micrograms/kg/min significantly increased heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)     

Incidence of intramammary infections during the dry period without or with antibiotic treatment in dairy cows--a quantitative analysis of published data

The study was aimed at summarising the literature that compares the incidence levels of spontaneously occurring intramammary infections (IMI) during the dry period, without versus with antibiotic dry cow treatment (DCT). A meta-analytic relative risk (RR) calculation was implemented when a priori relevant. Two main categories of comparison were used in the 36 selected papers. In the first category, the udder quarters were randomly allocated (at quarter or cow level) to an untreated or a treated group. Quarter incidence averaged 12.8% (weighted mean) in untreated quarters, and depending on the DCT used, from 6.6 to 8.0% in treated quarters. The meta-analytic RR of new IMI for untreated versus treated quarters varied from 1.54 to 1.94, depending on the DCT used. DCT was mainly found effective against IMI due to streptococci and coagulase-positive staphylococci. Based on only a few papers, the application of an internal teat sealer was associated to a quite similar (or possibly better) protection against IMI than DCT, but only in a subpopulation of particular (selected) cows. In the second category of studies, a selective dry cow or quarter antibiotic-treatment (selective DCT or DQT), according to cow or quarter selection criteria, was compared to blanket DCT. The meta-analytic RR of new IMI was 1.71 for selective DCT versus blanket DCT. Selective DQT seemed to be more at risk than selective DCT, but consisted of treating a much lower proportion of quarters. The summary-results provided by our meta-analysis should only be used with caution, due to possibly low external validity. More research seems to be relevant on the risk factors of new IMI during the dry period to make the outcomes of omission of DCT in selected cows more predictable under field conditions.     

Equine viral arteritis control scheme: a brief review with emphasis on laboratory aspects of the scheme in New Zealand

AIM: To review laboratory aspects of the equine viral arteritis (EVA) control scheme in New Zealand between 1989 and 2002. METHODS: The optimisation and performance of the virus neutralisation test (VNT) for equine arteritis virus (EAV) antibody, and the cell culture test to detect EAV in semen were analysed. Laboratory data and control scheme results were reviewed. RESULTS: Using optimised tests, it has been shown that antibody prevalence in Standardbred horses has steadily declined from 54% to <20%. Prevalences in Thoroughbred horses have remained at a low level of around 3%. The number of horses shedding EAV (all Standardbreds) has steadily declined from a maximum at any one time of 20 to the current figure of three. CONCLUSION: Eradication of EVA from the horse population in New Zealand is achievable in the near future.     

The duration of expulsion and the separation of the afterbirth in breeding cows--a contribution to the improvement of parturition monitoring

The objective of this study was to obtain data on the duration of the expulsion and afterbirth stages and on the rate of contractions of the abdominal muscles in dams with eutocia (n = 81; heifers: 11; cows: 70). We also looked into the questions of whether and at which stage of expulsion there were differences in these parameters between cows and heifers as well as purebred Simmental (n = 49) and Simmental X Limousin (n = 21). The total period of expulsion (period from appearance of the phalanxes in the rima vulvae until the complete expulsion of the calf) was 19.7 +/- 2.1 minutes. It took 17.3 +/- 2.3 minutes for the head to emerge. Further expulsion required 1.9 +/- 1.7 minutes. At an average of 40.1 +/- 1.5 minutes, the expulsion stage was longer in heifers than in cows, in which it lasted 18 +/- 2.1 minutes (p < 0.01). The differences are due to the time that the head took to emerge. While this stage of labor lasted 15.3 +/- 2.3 minutes in cows, this interval was clearly longer in heifers, lasting 38.1 +/- 1.5 minutes (p < 0.01). No statistically significant difference was observed in the course of further expulsion and there were not any differences detected between purebred Simmental and Simmental X Limousin. An average of 67.5 +/- 1.6 abdominal contractions were required for complete expulsion, 56.5 +/- 1.7 contractions of the abdominal muscles were necessary until the head appeared. After 9.3 +/- 1.6 abdominal presses, the calf had completely emerged. There was a statistically significant difference between cows (52.8 +/- 1.7) and heifers (93.3 +/- 1.6) until the expulsion of the head (p < 0.01). No breed-specific differences were observed. Separation of the afterbirth was observed in 95.0% of the animals up to the eighth hour post partum. Retarded separation and retained placenta were recorded in 2.5% of the animals in each case. 82.7% of the animals performed placentophagy. No placentophagy was observed when the placenta was retarded. No differences were detected between heifers and cows and the breeds with regard to the separation of the afterbirth and the incidence of placentophagy.     

Effects of xylazine butorphanol on cecal arterial blood flow, cecal mechanical activity, and systemic hemodynamics in horses

A chronic model with an ultrasonic transit time blood flow probe and strain gauge force transducers implanted on the cecum was used to evaluate cecal mechanical activity and cecal arterial blood flow in 4 conscious adult horses. Intravenous administration of xylazine (1.1 mg/kg of body weight) significantly decreased heart rate and cardiac output, but significantly increased diastolic pulmonary arterial pressure, mean pulmonary arterial pressure, carotid arterial pressure, and central venous pressure. Lateral cecal arterial blood flow after xylazine administration was decreased substantially more than was cardiac output, suggesting that xylazine caused constriction of the cecal vasculature. This effect of xylazine may have resulted from either a direct effect of xylazine on the cecal vasculature or from reflex vasoconstriction attributable to reduced cardiac output. Intravenous administration of butorphanol tartrate (0.1 mg/kg) did not significantly alter the hemodynamic responses to xylazine. Cecal mechanical activity, as measured by the motility index, was decreased for 120 minutes after administration of xylazine and for 150 minutes after administration of xylazine/butorphanol.