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21.
AIM: To determine the physiological status of calves at birth and the perinatal factors that might predispose newborn calves to debility and death, using criteria previously established for newborn lambs.

METHODS: Friesian mixed-aged cows and heifers on a dairy farm in New Zealand that were close to calving were separated from the main herd and observed 24 h a day until they calved. Cows in which labour did not progress for over 1 h or which were in distress were assisted. About 12–13 min after birth, rectal temperature was measured and a blood sample was taken from each calf. The packed cell volume (PCV) and plasma lactate, glucose and fructose concentrations were determined. The time to stand for each calf and the air temperature and weather conditions at birth were recorded.

RESULTS: The parameters measured were within normal ranges for newborns for the majority of calves. Calves sired by an Angus bull and born to heifers (AngusX) had significantly higher plasma lactate and fructose concentrations than Friesian calves born to cows, but there were no significant differences between the two breeds in any of the other parameters measured. Calves of both breeds born with assistance had significantly higher plasma lactate concentrations than those born without. Friesian calves that were assisted at birth had significantly lower PCvs and took significantly longer to stand than calves born without assistance. Assisted AngusX calves were significantly heavier than their unassisted counterparts. Calves born during windy and wet weather and when air temperatures were below 10°C had lower rectal temperatures, took longer to stand and had higher plasma glucose concentrations than those born in dry weather and when air temperatures were above 10°C.

CONCLUSIONS: Calves with physiological parameters outside the normal range had experienced difficult labour and/or intrapartum hypoxaemia. Placental insufficiency and maternal undernutrition during late pregnancy did not apparently contribute to neonatal problems in the present study.  相似文献   
22.
Gilt oestrus and ovulation responses to injection of a combination of equine chorionic gonadotrophin (eCG) and human chorionic gonadotrophin (hCG) (PG600) can be unpredictable, possibly reflecting inadequate circulating LH activity. The objective of this study was to determine the effect of PG600 followed by supplemental hCG on gilt ovarian responses. In experiment 1, 212 Hypor gilts (160 day of age) housed on two farms in Spain received intramuscular (i.m.) injections of PG600 (n = 47), or PG600 with an additional 200 IU hCG injected either concurrently (hCG‐0; n = 39), or at 24 h (hCG‐24; n = 41) or 48 h (hCG‐48; n = 45) after PG600. A further 40 gilts served as non‐injected controls. Ovulation responses were determined on the basis of initial blood progesterone concentrations being <1 ng/ml and achieving >5 ng / ml 10 d after the PG600 injection. The incidence of ovulating gilts having progesterone concentrations >30 ng/ml were recorded. During the study period, 10% of control gilts ovulated whereas 85–100% of hormone‐treated gilts ovulated. There were no significant differences among hormone groups for proportions of gilts ovulating. The proportions of gilts having circulating progesterone concentrations >30 ng/ml were increased (p ≤ 0.02) in all hCG treated groups compared with the PG600 group. In experiment 2, a total of 76 Hypor gilts at either 150 or 200 days of age were injected with PG600 (n = 18), 400 IU eCG followed by 200 IU hCG 24 h later (n = 20), PG600 followed by 100 IU hCG 24 h later (n = 17), or 400 IU eCG followed by 300 IU hCG 24 h later (n = 21). Blood samples were obtained 10 days later for progesterone assay. There were no effects of treatment or age on incidence of ovulation, but fewer 150‐day‐old gilts treated with PG600 or 400 IU eCG followed by 200 IU hCG had progesterone concentrations >30 ng / ml. We conclude that hCG treatment subsequent to PG600 treatment will generate a higher circulating progesterone concentration, although the effect is not evident in older, presumably peripubertal, gilts. The mechanism involved and implications for fertility remain to be determined.  相似文献   
23.
A retrospective study was performed of 181 horses that underwent an exploratory celiotomy because of acute abdominal disease. Forty-four horses died or were euthanized during surgery. Of the 137 horses that recovered from anesthesia, 72 died of associated diseases or complications, 86 were discharged from the hospital of which 60 survived at least 7 months. Horses with disorders affecting the small intestine had a significantly lower survival rate. Causes of death early in the postoperative period included long bone fracture, shock, ileus, gastric rupture, and peritonitis. After discharge from the hospital, deaths were attributed to colic of unknown cause, malabsorption syndrome, adhesive small bowel obstruction, small and large intestinal volvulus, perforated bowel, and laminitis. Of the 60 horses that were alive at the time of survey, 93.3% had returned to their previous use. A second occurrence of the initial acute abdominal disease was not documented in any horse.  相似文献   
24.
Serum magnesium (Mg) is an infrequnetly measured electrolyte in small animal patients. Currently, little is known about the prevalence and significance of abnormalities in serum Mg in animals. Therefore, a prospective study was performed to examine the incidence and clinical implications of abnormalities in serum Mg levels in critically ill dogs.
Serum Mg and other electrolytes were measured in 93 normal dogs housed at the Purina Pet Care Center and in 48 ill dogs admitted to a small animal critical care unit. The normal reference range for canine serum Mg was determined to be 1.89 – 2.51 mg/dl. Based on this range, 54% of the critically ill dogs were hypomagnesemic (< 1.89 mg/dl) and 13% were hypermagnesemic (> 2.51 mg/dl). Of the electrolytes measured in these patients, serum Mg had the highest prevalence of abnormal values. Hypomagnesemic patients had a significantly higher incidence of concurrent hypokalemia and hyponatremia (p < 0.05), as well as a longer length of hospitalization (p < 0.05) than their normomagnesemic counterparts. Hypermagnesemic patients were 2.6 times more likely not to survive their illness when compared to patients with normal serum Mg levels.
Abnormalities in serum Mg appear to be common in critically ill dogs. These patients commonly have other concurrent electrolyte abnormalities. Since serum Mg is not routinely measured, the presence of hypokalemia or hyponatremia should alert the clinician to the possibility of coexisting hypomagnesemia. The clinical implications of hypomagnesemia and hypermagnesemia in ill dogs appear to involve prolonged hospitalization and increased mortality, respectively: however, the exact etiology remains undetermined.  相似文献   
25.
Efficacy of intra-muscular analgesics for acute pain in sheep   总被引:1,自引:0,他引:1  
The analgesic action of intramuscularly injected buprenorphine, methadone, flunixin meglumine and xylazine was examined in sheep, using algesimetry based on a leg withdrawal response to an electrical stimulus. No analgesic response was detected for buprenorphine, methadone or flunixin meglumine. Only the αaL2-adrenoceptor agonist, xylazine, produced an analgesic response. The current required to elicit a response increased by 170% (4.5±0.43 mA to 12.23±1.14 mA; mean±SE) after a dose of 0.05 mg/kg xylazine; by 180% (4.73±0.3 mA to 13.28±2.35 mA) after 0.1 mg/kg; and by 510% (4.52±0.29 mA to 27.63±3.89 mA) after 0.2 mg/kg. Intramuscular xylazine appears to be an effective analgesic agent for acute pain in the sheep and further investigation into ideal administration regimens and dosage may provide more detailed information on relationships between dose, analgesic and sedative effects. The findings also suggest that some common analgesic agents, and opioids in particular, may be ineffective for the management of acute pain in sheep and that any analgesic should be administered only on the basis of its proven efficacy in that species.  相似文献   
26.
27.
The aim of this study was to determine the association between the oestrous response of pre‐pubertal gilts to gonadotrophin injection or boar exposure and their subsequent farrowing rate and litter size. At 154 days of age, randomly selected pre‐pubertal gilts received an intramuscular injection of 400 IU equine chorionic gonadotrophin plus 200 IU human chorionic gonadotrophin (PG600®; Merck Animal Health; n = 181). From the remaining pool of animals not treated with hormones, the first gilts showing signs of oestrus were selected to act as controls (n = 201). Boar exposure began at 155 days of age for both groups, and gilts were bred at a weight of approximately 130 kg. Comparisons were made between PG600®‐treated gilts exhibiting oestrus or not within 7 days post‐injection (early and late responders, respectively) and control gilts exhibiting oestrus or not within 30 days after beginning of boar exposure (select and non‐select control gilts, respectively). By 162 days, oestrus was detected in 67.5% of PG600®‐treated gilts compared with 5.7% of control gilts (p < 0.0001). The proportion of animals observed in oestrus at least three times before breeding was greater for select control gilts compared with early and late responder PG600®‐treated gilts (p  0.001). There were no significant differences in farrowing rate and litter size between the four treatment groups. These data indicate that PG600® is an effective tool to induce an earlier oestrus in gilts, that subsequent farrowing rate and born alive litter size compare favourably to that of select gilts and that gilts failing to respond promptly to hormonal stimulation do not exhibit compromised fertility.  相似文献   
28.
To meet weekly breeding targets, it is occasionally necessary to inject exogenous gonadotrophins to induce oestrus in prepubertal gilts. However, the gilt oestrus response to equine chorionic gonadotrophin (eCG) either alone or in combination with human chorionic gonadotrophin (hCG) can be unpredictable. The objective of the present study was to examine possible reasons for this unpredictability. Prepubertal gilts (90 kg and 153 days of age, n = 109) received an injection of either 600 IU eCG or a combination of 400 IU eCG and 200 IU hCG (PG600), or were non-injected controls, and were then exposed to a mature boar for 15 min daily for 7 days for oestrus detection. At the time of injection, real-time ultrasound revealed that the gilt ovaries had primarily 1–2 mm follicles. Blood samples were obtained at time of hormone injection (day 0) and at days 3, 7 and 10 for assay of serum progesterone concentrations. The oestrus responses by 7 days were15.5%, 73.3% and 0%, for eCG, PG600, and control gilts, respectively (p < 0.001). The oestrus response improved (p < 0.05) with increasing body weight. Based on circulating progesterone levels, all oestrous gilts ovulated except for four of the PG600 gilts. Failure to express oestrus in PG600 gilts was not associated with a premature rise in progesterone.  相似文献   
29.
30.
Although techniques for the perioperative management of patients undergoing mitral valve replacement have been well established in humans, the use of these techniques has not been widely accepted in veterinary practice. The purpose of this study is to demonstrate that low morbidity and mortality could be achieved in the dog undergoing mitral valve replacement. Nine mongrel dogs (25-45 kg body weight) were subject to left thoracotomy and mitral valve replacement using cardiopulmonary bypass (CPB). The average time on CPB was 1 hour with an aortic cross-clamping time of 40 minutes using chemically induced cardiac arrest. CPB was performed under conditions of moderate systemic hypothermia (28-30 degrees C) and hemodilution (hematocrit, 25-35%). Operative mortality was 22% (2/9) with one death from excessive bleeding and the other from cerebral air embolism. All other animals recovered and were clinically normal 3 weeks after surgery. The authors conclude that successful mitral valve replacement is possible in the large dog.  相似文献   
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