Search Results

You are looking at 81 - 90 of 1,507 items for :

  • Refine by Access: All Content x
Clear All

Summary

The stability of blood ionized calcium (Ca2+) and acid-base variables in equine, bovine, ovine, and canine venous blood samples (n = 15, in each group) stored at 4 C for 3, 6, 9, 24, or 48 hours was studied. Variables included blood Ca2+ and standard ionized calcium (Ca2+ corrected to pH 7.4) concentrations, pH, blood carbon dioxide and oxygen tensions, base excess, bicarbonate concentration, and total carbon dioxide content. Results indicate that storage of blood samples at 4 C for up to 48 hours, despite appreciable acid-base changes, is associated with <1.5% change in equine, bovine, and ovine blood Ca2+ concentrations. Similar changes were observed in canine blood during the first 9 hours' storage. After 24 and 48 hours' storage, clinically relevant decrease (10.5 and 15.5%) in canine blood Ca2+ concentration was measured. Therefore, Ca2+ concentration in equine, bovine, and ovine venous blood samples stored up to 48 hours, and in canine blood samples stored up to 9 hours at 4 C is of diagnostic use.

Free access
in Journal of the American Veterinary Medical Association

Summary

Stability of ionized calcium (Ca2+) concentration and pH values in bovine and ovine venous samples (n = 12 in each group) stored at 4 C for 3, 9, 24, and 48 hours (blood, plasma, and serum) or for 240 hours (plasma and serum), and at −20 C for 240 hours (plasma and serum), was studied. Storage of bovine and ovine blood, plasma, and serum samples at 4 C for up to 48 hours and of ovine serum samples at 4 C for up to 240 hours, despite appreciable pH changes, was associated with < 2.0% change in blood, plasma, and serum Ca2+ concentrations. Therefore, Ca2+ concentration in bovine and ovine venous blood, plasma, and serum samples stored up to 48 hours, and in ovine serum samples stored up to 240 hours, at 4 C is of diagnostic use.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To assess the effect of dietary potassium citrate supplementation on the urinary pH, relative supersaturation of calcium oxalate and struvite (defined as the activity product/solubility product of the substance), and concentrations of magnesium, ammonium, phosphate, citrate, calcium, and oxalate in dogs.

Animals—12 healthy adult dogs.

Procedure—Canned dog food was fed to dogs for 37 days. Dogs were randomly allocated to 3 groups and fed test diets for a period of 8 days. Study periods were separated by 6-day intervals. During each study period the dogs were fed either standard diet solus (control) or standard diet plus 1 of 2 types of potassium citrate supplements (150 mg potassium citrate/kg of body weight/d) twice daily. Urinary pH, volume and specific gravity, relative supersaturation of calcium oxalate and struvite, and concentrations of magnesium, ammonium, phosphate, calcium, oxalate, and citrate were assessed for each treatment.

Results—Mean urine pH was not significantly affected by dietary potassium citrate supplementation, although urine pH did increase by 0.2 pH units with supplementation. Diets containing potassium citrate maintained a higher urine pH for a longer part of the day than control diet. Three Miniature Schnauzers had a significantly lower urinary relative calcium oxalate supersaturation when fed a diet supplemented with potassium citrate, compared with control diet.

Conclusions and Clinical Relevance—Dietary potassium citrate supplementation has limited effects on urinary variables in most healthy dogs, although supplementation results in maintenance of a higher urine pH later in the day. Consequently, if supplementation is introduced, dogs should be fed twice daily and potassium citrate should be given with both meals or with the evening meal only. (Am J Vet Res 2000;61:430–435)

Full access
in American Journal of Veterinary Research

Abstract

Objectives

To determine the most repeatable method for evaluating right ventricular relaxation rate in horses and to determine and compare effects of isoflurane or halothane with and without the added influence of intravenously administered calcium gluconate on right ventricular relaxation rates in horses.

Animals

6 Thoroughbred horses from 2 to 4 years old.

Procedure

6 models (2 for monoexponential decay with zero asymptote, 3 for monoexponential decay with variable asymptote, and 1 for biexponential decay) for determining right ventricular relaxation rate were assessed in conscious and anesthetized horses. The 2 methods yielding the most repeatable results then were used to determine right ventricular relaxation rates in horses anesthetized with isoflurane or halothane before, during, and after IV administration of calcium gluconate. Right ventricular pressure was measured, using a catheter-tip high-fidelity pressure transducer, and results were digitized at 500 Hz from minimum rate of change in ventricular pressure.

Results

2 models that used monoexponential decay with zero asymptote repeatedly produced an estimate for relaxation rate and were used to analyze effects of anesthesia and calcium gluconate administration on relaxation rate. Isoflurane and halothane each prolonged right ventricular relaxation rate, with greater prolongation evident in halothane-anesthetized horses. Calcium gluconate attenuated the anesthesia-induced prolongation in right ventricular relaxation rate, with greater response obtained in isoflurane-anesthetized horses.

Conclusions and Clinical Relevance

Right ventricular relaxation rate in horses is assessed best by use of a monoexponential decay model with zero asymptote and nonlinear regression. Intravenous administration of calcium gluconate to isoflurane-anesthetized horses best preserves myocardial relaxant function. (Am J Vet Res 1999;60:872–879)

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine whether breed, age, sex, or reproductive status (ie, neutered versus sexually intact) was associated with the apparent increase in prevalence of calcium oxalate (CaOx) uroliths and the decrease in prevalence of magnesium ammonium phosphate (MAP) uroliths in cats over time.

Design—Case-control study.

Animals—Case cats consisted of cats with CaOx (n = 7,895) or MAP (7,334) uroliths evaluated at the Minnesota Urolith Center between 1981 and 1997. Control cats consisted of cats without urinary tract disease admitted to veterinary teaching hospitals in the United States and Canada during the same period (150,482).

Procedure—Univariate and multivariate logistic regression were performed.

Results—British Shorthair, Exotic Shorthair, Foreign Shorthair, Havana Brown, Himalayan, Persian, Ragdoll, and Scottish Fold cats had an increased risk of developing CaOx uroliths, as did male cats and neutered cats. Chartreux, domestic shorthair, Foreign Shorthair, Himalayan, Oriental Shorthair, and Ragdoll cats had an increased risk of developing MAP uroliths, as did female cats and neutered cats. Cats with CaOx uroliths were significantly older than cats with MAP uroliths.

Conclusions and Clinical Relevance—Results suggest that changes in breed, age, sex, or reproductive status did not contribute to the apparent reciprocal relationship between prevalences of CaOx and MAP uroliths in cats during a 17-year period. However, cats of particular breeds, ages, sex, and reproductive status had an increased risk of developing CaOx and MAP uroliths. (J Am Vet Med Assoc 2000;217:520–525)

Full access
in Journal of the American Veterinary Medical Association

Objective

To assess the effect of oral administration of CaCl2 gel on blood mineral concentrations, parturient disorders, reproductive performance, and milk production of dairy cows with retained fetal membranes (RFM).

Design

Randomized field trial.

Animals

20 cows that calved normally and were not treated with CaCl2 gel (group 1), 20 cows with RFM that were treated with CaCl2 gel (group 2), and 20 cows with RFM that were not treated with CaCl2 gel (group 3).

Procedure

Group-2 cows were treated orally with CaCl2 gel (54 g of calcium) 24 and 48 hours after parturition.

Results

Administration of CaCl2 gel 24 and 48 hours after parturition did not have a significant effect on serum normalized calcium, total calcium, magnesium, or phosphorus concentrations or on incidence of metritis or left displacement of the abomasum, days to first insemination, pregnancy status after first insemination, or milk production.

Conclusions and Clinical Relevance

Administration of CaCl2 gel 24 and 48 hours after parturition did not have significant effect on blood mineral concentrations, parturient disorders, reproductive performance, and milk production in dairy cows with RFM. (J Am Vet Med Assoc 1999;215:72-76)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate an electrolyte analyzer for measurement of ionized calcium (Cai) and magnesium (Mgi) concentrations in blood, plasma, and serum; investigate the effect of various factors on measured values; and establish reference ranges for Cai and Mgi in dogs.

Animals—30 healthy adult dogs of various breeds.

Procedure—Precision in a measurement series, day-to-day precision, and linearity were used to evaluate the analyzer. The effects of exposure of serum samples to air, type of specimen (blood, plasma, or serum), and storage temperature on sample stability were assessed. Reference ranges were established with anaerobically handled serum.

Results—The coefficient of variation for precision in a measurement series was ≤ 1.5% for both electrolytes at various concentrations. The Cai and Mgi concentrations were significantly lower in aerobically handled serum samples, compared with anaerobically handled samples. The Cai and Mgi concentrations differed significantly among blood, plasma, and serum samples. In anaerobically handled serum, Cai was stable for 24 hours at 22°C, 48 hours at 4°C, and 11 weeks at –20°C; Mgi was stable for 8 hours at 22°C, < 24 hours at 4°C, and < 1 week at –20°C. In anaerobically handled serum, reference ranges were 1.20 to 1.35 mmol/L for Cai and 0.42 to 0.58 mmol/L for Mgi.

Conclusions and Clinical Relevance—The electrolyte analyzer was suitable for determination of Cai and Mgi concentrations in dogs. Accurate results were obtained in anaerobically handled serum samples analyzed within 8 hours and kept at 22°C. (Am J Vet Res 2004;65:183–187)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To study the musculoskeletal development of Great Dane puppies fed various dietary concentrations of calcium (Ca) and phosphorus (P) in fixed ratio by use of dual energy x-ray absorptiometry (DEXA), determination of serum insulin-like growth factor I and parathyroid hormone concentrations, radiography, and blood chemistry analysis results.

Animals—32 purebred Great Dane puppies from 4 litters.

Procedure—At weaning, puppies were assigned randomly to 1 of 3 diets. Blood was collected for biochemical analyses and hormone assays, and radiography and DEXA were performed through 18 months of age. Changes in body weight, bone mineral content, fat tissue weight, lean mass, result of serum biochemical analyses, hormonal concentrations, and radius lengths were analyzed through 18 months of age.

Results—Bone mineral content of puppies correlated positively with Ca and P content of the diets fed. Significant differences between groups in bone mineral content, lean mass, and body fat were apparent early. The disparity among groups increased until 6 months of age and then declined until body composition was no longer different at 12 months of age. Accretion rates for skeletal mineral content, fat, and lean tissue differed from each other and by diet group.

Conclusions and Clinical Relevance—Ca and P concentrations in the diet of young Great Dane puppies are rapidly reflected in the bone mineral content of the puppies until 5 to 6 months of age, after which hormonal regulation adjusts absorption and excretion of these minerals. Appropriate Ca and P concentrations in diets are important in young puppies < 6 months of age. (Am J Vet Res 2002;63:1036–1047)

Full access
in American Journal of Veterinary Research

calcium) of extracellular calcium. *Significant ( P < 0.05) difference between groups. Effects of diltiazem on contractile responses of laminar arteries and veins to phenylephrine, 5-HT, and ET-1 —Preincubation of laminar arteries with diltiazem (10

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate the effect of an osteoconductive resorbable calcium phosphate cement (CPC) on the holding power of bone screws in canine pelvises and to compare the effect with that for polymethylmethacrylate (PMMA).

Sample Population—35 pelvises obtained from canine cadavers.

Procedure—Each pelvis was sectioned longitudinally. Within each pair of hemipelvises, one 4.0-mm cancellous screw was placed in the sacroiliac (SI) region and another in the iliac body. Similar regions on the contralateral- matched hemipelvis were assigned 1 of 3 augmentation techniques (CPC-augmented 4.0-mm cancellous screws, PMMA-augmented 4.0-mm cancellous screws, and CPC-augmented 3.5-mm cortical screws). Pullout force was compared between matched screws and between treatment groups prior to examination of cross sections for evaluation of cement filling and noncortical bone-to-cortical bone ratio.

Results—CPC and PMMA augmentation significantly increased pullout force of 4.0-mm screws inserted in the SI region by 19.5% and 33.2%, respectively, and CPC augmentation significantly increased pullout force of 4.0-mm cancellous screws inserted in the iliac body by 21.2%. There was no difference in the mean percentage augmentation between treatment groups at either location. Cement filling was superior in noncortical bone, compared with filling for cortical bone. Noncortical bone-to-cortical bone ratio was significantly greater in the sacrum (6.1:1) than the ilium (1.3:1).

Conclusions and Clinical Relevance—CPC and PMMA improve the ex vivo holding strength of 4.0-mm cancellous screws in the SI and iliac body regions and SI region, respectively. Cement augmentation may be more effective in areas with greater noncortical bone-to-cortical bone ratios. (Am J Vet Res 2005;66:1954–1960)

Full access
in American Journal of Veterinary Research