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  • Author or Editor: Fernando Silveira x
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Objective—To determine the insulin response curve during IV glucose tolerance testing of mature Holstein bulls.

Animals—8 Holstein bulls between 5 and 8 years old and weighing between 911.5 and 1035.5 kg.

Procedure—A 50% glucose solution was rapidly administered IV so that each bull received a mean dose of 258 mg of glucose/kg of body weight. Serum glucose and insulin concentrations were determined before and 30, 60, 120, and 240 minutes after glucose infusion.

Results—Serum glucose concentrations 30 and 60 minutes after infusion were significantly greater than baseline concentration. Concentrations returned to baseline values 120 minutes after infusion. Serum insulin concentration was significantly greater 30 minutes after glucose administration, compared with baseline and 240-minute concentrations.

Conclusions and Clinical Relevance—Intravenous glucose tolerance testing of mature Holstein bulls resulted in a characteristic insulin response curve. Baseline and peak insulin concentrations were higher in these bulls, compared with values reported for mature Norwegian Red cows. (Am J Vet Res 2000; 61:61–63)

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in American Journal of Veterinary Research


Objective—To estimate intraocular pressure (IOP) in eyes of healthy camelids, using applanation tonometry.

Animals—The eyes of 34 camelids (16 llamas [Lama glama] and 18 alpacas [L pacos]) that did not have major abnormalities of the ocular surface or intraocular abnormalities.

Procedure—Tonometry measurements were obtained from each eye 3 times during a 24-hour period. Each measurement was the mean of several corneal applanations obtained by use of an applanation tonometer. Data were analyzed, using an ANOVA for a repeated-measures design.

Results—Mean (± SEM) IOP of llamas and alpacas was 13.10 ± 0.35 and 14.85 ± 0.45 mm Hg, respectively. Range of IOP was 7 to 18 mm Hg for llamas and 11 to 21 mm Hg for alpacas. Mean IOP of llamas was significantly less than the mean IOP of alpacas. Significant differences in IOP were not detected between the right and left eye of animals. Significant differences in IOP were not attributed to sex, age, or time of measurement within llamas or alpacas.

Conclusions and Clinical Relevance—Establishing the mean and range of IOP of clinically normal llamas and alpacas provides a frame of reference that is important for use in a complete ophthalmic examination of camelids, which can assist clinicians in the diagnosis of glaucoma and uveitis. Reasons for the difference in mean IOP between llamas and alpacas are unknown. Although the difference may be unimportant clinically, this finding reiterates the fact that caution must be used when extrapolating IOP among species. (Am J Vet Res 2000;61:1542–1544)

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in American Journal of Veterinary Research