Borehole Temperatures and a Baseline for 20th-Century Global Warming Estimates

Lack of a 19th-century baseline temperature against which 20th-century warming can be referenced constitutes a deficiency in understanding recent climate change. Combination of borehole temperature profiles, which contain a memory of surface temperature changes in previous centuries, with the meteorological archive of surface air temperatures can provide a 19th-century baseline temperature tied to the current observational record. A test case in Utah, where boreholes are interspersed with meteorological stations belonging to the Historical Climatological Network, yields a noise reduction in estimates of 20th-century warming and a baseline temperature that is 0.6° ± 0.1°C below the 1951 to 1970 mean temperature for the region.     

Anatomy of the patent ductus venosus in the cat

The biplanar mesenteric vein portovenograms of 10 cats with left divisional intrahepatic portosystemic shunts consistent with a patent ductus venosus (PDV) were reviewed. A corrosion cast of the hepatic portal vasculature was made post mortem from one individual that died post operatively following surgical attenuation of the shunting vessel. On the basis of the combined surgical, post mortem and imaging data, these left divisional shunts were found to have consistent anatomy, each having a straight vessel which drained into a venous ampulla before draining into the caudal vena cava at the level of the diaphragm. The left phrenic vein and left hepatic vein both entered the ampulla independently of the shunting vessel. The anatomical similarity between these findings in the cat and the PDV in the dog suggest that it is appropriate to describe this particular portosystemic shunt as a PDV.     

Cholelithiasis and hyperthyroidism in a cat

A 14-year-old domestic short-hair cat presented with a history of intermittent malaise and increased drinking. A diagnosis of hyperthyroidism and cholelithiasis was made by a combination of blood testing, radiography and ultrasonography. After medical management of hyperthyroidism, thyroidectomy and cholecystectomy were successfully performed. Removed choleliths were comprised of calcium carbonate and bilirubinate. Histopathological analysis of tissue suggested low grade pancreatic and hepatobiliary disease, as well as hyperthyroidism, might have contributed to stone formation.     

The effect of different combinations of lignocaine,ketoprofen, xylazine and tolazoline on the acute cortisol response to dehorning in calves

AIMS: The aims of this study were (a) to evaluate the effect of xylazine and tolazoline, with and without lignocaine, on the cortisol response of calves following amputation dehorning and (b) to assess the effect of a non-steroidal anti-inflammatory drug (ketoprofen) and local anaesthesia on the cortisol response of calves to amputation dehorning.

METHODS: Plasma cortisol concentrations were measured in 100 dehorned or non-dehorned 3-month-old calves over an 8-h period following five different sedative/analgesic or control treatments. Sedative/analgesic treatments were: control (no anaesthesia); local anaesthesia and ketoprofen; local anaesthesia and xylazine; local anaesthesia, xylazine and tolazoline; and xylazine only. Within each sedative/analgesic treatment group, half the calves (n=10 per group) were amputation dehorned and half were not dehorned.

RESULTS: The change in plasma cortisol concentrations in calves dehorned after being given ketoprofen and local anaesthesia did not differ significantly from that of non-dehorned control calves for at least 8 h. In contrast, the cortisol response of dehorned calves not given analgesic drugs peaked 30 min after dehorning and lasted >4 h. Xylazine injected before dehorning significantly reduced but did not eliminate the peak of the cortisol response. When both xylazine and local anaesthesia were administered before dehorning the peak in the cortisol response was virtually eliminated. In the dehorned calves that received xylazine with or without local anaesthesia, cortisol concentration increased significantly 3 h after dehorning and did not return to baseline until at least 5 h later. When tolazoline was administered shortly after xylazine, it caused a marked cortisol response, higher than the response to any other treatment.

CONCLUSIONS: Combining ketoprofen and local anaesthesia minimised the cortisol response, and by inference the pain- induced distress, following amputation dehorning in calves. Xylazine reduced the initial cortisol response to dehorning but not as much as when local anaesthesia was also given. The increase in cortisol concentration from 3–8 h after dehorning in calves given xylazine alone or in combination with local anaesthesia suggests that calves experienced pain-induced distress during this time and that xylazine had no long-term analgesic effect. Tolazoline, used to reverse the sedative effects of xylazine, caused a marked cortisol response in calves via a mechanism which remains unclear.     

The physiological and physical status of single calves at birth in a dairy herd in New Zealand

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.     

Eliciting conditioned taste aversion in lizards: Live toxic prey are more effective than scent and taste cues alone

Conditioned taste aversion (CTA) is an adaptive learning mechanism whereby a consumer associates the taste of a certain food with symptoms caused by a toxic substance, and thereafter avoids eating that type of food. Recently, wildlife researchers have employed CTA to discourage native fauna from ingesting toxic cane toads (Rhinella marina), a species that is invading tropical Australia. In this paper, we compare the results of 2 sets of CTA trials on large varanid lizards (“goannas,” Varanus panoptes). One set of trials (described in this paper) exposed recently‐captured lizards to sausages made from cane toad flesh, laced with a nausea‐inducing chemical (lithium chloride) to reinforce the aversion response. The other trials (in a recently‐published paper, reviewed herein) exposed free‐ranging lizards to live juvenile cane toads. The effectiveness of the training was judged by how long a lizard survived in the wild before it was killed (fatally poisoned) by a cane toad. Both stimuli elicited rapid aversion to live toads, but the CTA response did not enhance survival rates of the sausage‐trained goannas after they were released into the wild. In contrast, the goannas exposed to live juvenile toads exhibited higher long‐term survival rates than did untrained conspecifics. Our results suggest that although it is relatively easy to elicit short‐term aversion to toad cues in goannas, a biologically realistic stimulus (live toads, encountered by free‐ranging predators) is most effective at buffering these reptiles from the impact of invasive toxic prey.     

Effect of hCG on Early Luteal Serum Progesterone Concentrations in PG600‐Treated Gilts

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.     

Surgical Treatment of Colic Results in 181 Horses

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.