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’ knowledge, the reliability of comparison between axillary and rectal temperatures has not been assessed in veterinary patients in a controlled environment. Authors of a recent veterinary report 10 describe comparison of axillary and rectal temperatures in

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in American Journal of Veterinary Research

SUMMARY

To determine the effects of heat stress and drinking water treatments on physical characteristics of skeletal tissue, tibias of cockerels ranging in age from 4 to 11 weeks were tested for breaking strength. Birds were subjected to either a thermoneutral environment (21 ± 2 C) or a hot environment (37 ± 2 C) and supplied with either tap or carbonated drinking water. Breaking strength of tibias was reduced in the hot environment; however, consumption of carbonated drinking water in the hot environment resulted in bone strength comparable with that associated with thermoneutral environment (both types of water). Also, bones from birds of the carbonated water- 37 C treatment group had less phase breaks and tended to separate with a single break. Results indicate that hot environment and carbonated drinking water not only affect the previously reported morphologic and chemical characteristics of developing bone, but also their physical attributes.

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in American Journal of Veterinary Research

SUMMARY

Objective

To investigate the relation between cardiac output (CO) and peripheral (fetlock) temperature (PT) and core-peripheral (rectal-fetlock) temperature difference (CPTD) in dehydrated calves housed in a thermoneutral environment.

Animals

28 male dairy calves 3 to 10 days old.

Procedure

Severe dehydration and watery diarrhea were induced by administering diuretics (furosemide, hydrohlorothiazide, spironolactone) and sucrose solution. Cardiac output was measured by means of thermodilution, core temperature was determined by placing a digital thermometer in the rectum, and PT was measured by taping a thermistor to the left hind fetlock and insulating the thermistor from ambient air.

Results

In thermoneutral ambient temperatures (10 to 24 C), PT and CPTD were constant and independent of CO at normal or high CO values but were linearly dependent on CO below a critical value (78% of normal CO output). Regression equations were developed that predicted CO from measured PT or CPTD. At ambient temperatures below the lower critical temperature for neonatal calves (8 to 10 C), normal values for PT and CPTD in healthy calves were significantly different from those at thermoneutral ambient temperatures.

Conclusions and Clinical Relevance

Peripheral temperature and CPTD are practical, noninvasive, and inexpensive but only moderately useful methods for predicting CO in hemodynamically stable calves housed in a thermoneutral environment. Thus, these parameters are of some value in daily monitoring of the response to treatment and in determining need for IV fluid administration in dehydrated calves housed at a dry still-air temperature of 10 to 24 C but are of minimal to no value in calves housed at < 10 C. (Am J Vet Res 1998;59:874–880)

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in American Journal of Veterinary Research

day. Pens were routinely scraped clean and bedded with sawdust. Frequency for cleaning and bedding was dependent on weather and amount of animal excretions. The intent was to maintain the environment so that steers remained clean and healthy

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in American Journal of Veterinary Research

Summary

Distribution of blood flow among various respiratory muscles was examined in 8 healthy ponies during submaximal exercise lasting 30 minutes, using radionuclide labeled 15-μm diameter microspheres injected into the left ventricle. From the resting values (40 ± 2 beats/min; 37.3 ± 0.2 C), heart rate and pulmonary arterial blood temperature increased significantly at 5 (152 ± 8 beats/min; 38.6 ± 0.2 C), 15 (169 ± 6 beats/min; 39.8 ± 0.2 C), and 26 (186 ± 8 beats/min; 40.8 ± 0.2 C) minutes of exertion, and the ponies sweated profusely. Mean aortic pressure also increased progressively as exercise duration increased. Blood flow increased significantly with exercise in all respiratory muscles. Among inspiratory muscles, perfusion was greatest in the diaphragm and ventral serratus, compared with external intercostal, dorsal serratas, and scalenus muscles. Among expiratory muscles, blood flow in the internal abdominal oblique muscle was greatest, followed by that in internal intercostal and transverse throacic muscles, in which the flow values remained similar. The remaining 3 abdominal muscles had similar blood flow, but these values were less than that in the internal intercostal, transverse thoracic, and internal abdominal oblique muscles. Blood flow values for all inspiratory and expiratory muscles remained similar for the 5 and 15 minutes of exertion. However, at 26 minutes, blood flow had increased further in the diaphragm, external intercostal, internal intercostal, transverse thoracic, and the external abdominal oblique muscle as vascular resistance decreased. On the basis of our findings, all respiratory muscles were activated during submaximal exercise and their perfusion had marked heterogeneity. Also, blood flow in respiratory muscles was well maintained as exercise duration progressed; in fact, several muscles had a further increase in perfusion late during exercise.

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in American Journal of Veterinary Research

differ substantially according to the breed and environmental conditions of a given horse. Hoof wall moisture is believed to be important for the health and function of hooves, and some investigators recommend that horses living in dry environments have

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in American Journal of Veterinary Research

males and 7 females) with IC were used. To evaluate the effect of the environment on ASRs in cats with and without IC, 11 healthy neutered cats (5 males and 6 females) and 16 cats with IC (8 males and 8 females) were used. These cats were a subset of

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in American Journal of Veterinary Research

be placed in chambers with a total volume appropriate for their relative body size. The acute exposure to this novel space-restricted environment may cause an increase in stress, which not only raises welfare concerns but also may affect the accuracy

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in American Journal of Veterinary Research

deficiencies in the captive tortoises in the present study, the best advice for dealing with tortoises that are artificially raised is to provide hatchling tortoises an adequate photothermal environment and a natural, plant-based diet without supplemental

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in American Journal of Veterinary Research

Summary

From 2 to 4.5 months of age, 80 crossbred gilts were reared in a conventional grower unit where they were naturally exposed to mycoplasmal and bacterial pathogens that cause pneumonia and atrophic rhinitis. At 4.5 months of age, gilts were moved to environmentally regulated rooms (4.9 × 7.3 m) and assigned at random to 1 of 2 treatment groups: low aerial concentration of ammonia (4 to 12 ppm; mean, 7 ppm) or moderate aerial concentration of ammonia (26 to 45 ppm, mean, 35 ppm).

Low concentration of ammonia was obtained by flushing of manure pits weekly, whereas moderate concentration of ammonia was maintained by adding anhydrous ammonia to manure pits that were not flushed. Gilts were weighed biweekly. Mean daily gain (mdg) was less (P < 0.01) for gilts exposed to moderate concentration of ammonia than for gilts exposed to low concentration of ammonia after 2 weeks in their respective environments. By 4 and 6 weeks, however, mdg was similar between the 2 treatment groups.

After 6 weeks in these environments, 20 gilts from each treatment group were slaughtered, and prevalence and severity of lung lesions and snout grades were determined. At slaughter, body weight was greater (P < 0.01) in gilts exposed to low, rather than moderate, ammonia concentration (94.5 vs 86.8 kg; sem, 3.3 kg). Percentage of lung tissue containing lesions (18 vs 12) and snout grade (2.8 vs 3.1) were similar between gilts exposed to low or moderate concentration of ammonia.

The remaining 20 gilts in each treatment group were maintained in their respective environments, exposed daily to mature boars and bred at first estrus. Age at puberty was similar between gilts exposed to low or moderate concentration of ammonia (208 vs 205 days; sem, 1.3 days), even though weight at puberty was less (P < 0.03) for gilts exposed to low concentration of ammonia than for gilts exposed to moderate concentration of ammonia (109.7 vs 118.2 kg; sem, 4.5 kg). At day 30 of gestation, number of live fetuses (10.6 vs 11.7), fetal length (2.53 vs 2.57 cm), and fetus-to-corpus luteum ratio (0.85 vs 0.78) were similar between gilts at low and moderate ammonia environments. These data indicate that exposure of gilts to mean aerial ammonia concentration of 35 ppm in environmentally regulated rooms depressed mdg for 2 weeks, but failed to alter onset of puberty or litter size at day 30 of gestation.

Free access
in American Journal of Veterinary Research