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Summary

Temporal changes, as well as differences in distribution, in concentrations of 24 amino acids in plasma and whole blood of neonatal foals were determined from birth to 2 days of age. In addition, differences in concentrations of amino acids in plasma between mare and foal pairs were determined at birth. Significant (P < 0.05) hypoaminoacidemia existed for 15 amino acids in plasma of foals at birth, compared with mares (paired t-test). Concentrations of 7 amino acids (aspartate, glutamate, glutamine, glycine, hydroxyproline, phenylalanine, proline) in plasma of foals were higher (P < 0.05) at birth than in mares, and concentrations of 2 (taurine, tryptophan) were not different (P > 0.05). Significant (P < 0.05) temporal changes for concentrations of 19 of 24 amino acids in plasma were observed during the 48-hour period. Concentrations of 13 of the 19 amino acids in plasma that had significant changes were higher (P < 0.05) at 48 hours. Significant (P > 0.05) effect of time on concentration of 5 amino acids (alanine, methionine, phenylalanine, taurine, threonine) in plasma was not found after birth. Temporal changes in concentrations of 7 amino acids (alanine, asparagine, glutamine, histidine, hydroxyproline, methionine, and threonine) in whole blood were not significantly (P > 0.05) different from those in plasma. Temporal changes for concentrations of the remaining 17 amino acids in whole blood were significantly (P < 0.05) different, compared with plasma. Distribution of the concentrations of 18 amino acids between whole blood and plasma was significantly (P < 0.05) different. Concentrations of 5 amino acids (citrulline, cystine, glutamine, methionine, tryptophan) were significantly (P < 0.05) lower in whole blood than in plasma, whereas concentrations of 13 amino acids were significantly (P < 0.05) higher in whole blood vs plasma. Concentrations of 6 amino acids (asparagine, isoleucine, leucine, proline, serine, valine) in whole blood were not significantly different from concentrations in plasma. Significant differences in temporal patterns of concentrations of amino adds in plasma and whole blood may be attributable to nutritional or physiologic changes associated with parturition. Significant differences between concentrations of amino acids in whole blood and plasma may be attributable to ontogeny or specificity of transport systems across cell membranes.

Free access
in American Journal of Veterinary Research

Summary

Concentrations of amino acids in plasma and whole blood in response to 10 hours of food deprivation were determined in healthy 2-day-old foals (n = 8) and were compared with control values in foals of the same age (n = 8) allowed free access to suckle. In addition, response of concentrations of amino acids in plasma to 15 minutes of free-access suckling was determined at the end of the 10-hour period in both groups. Response of 13 amino acids in plasma of food-deprived foals was significantly (P < 0.05) different, compared with that in control foals. Concentrations of 3 amino acids (alanine, glycine, and phenylalanine) in plasma increased significantly (P < 0.05), whereas concentrations of 7 amino acids (asparagine, citrulline, histidine, ornithine, proline, tryptophan, and tyrosine) in plasma decreased significantly (P < 0.05) during food deprivation. Response of concentrations of 2 amino acids (glycine and histidine) in whole blood was significantly (P < 0.05) different from that in plasma of food-deprived vs control foals. Refeeding of food-deprived foals resulted in significantly (P < 0.05) different responses for concentrations of all but 2 amino acids (cystine and taurine) in plasma, compared with responses in controls. Changes in concentrations of amino acids in plasma and whole blood of foals in response to food deprivation are similar to those in foals with septicemia and in children with grade 1 or 2 kwashiorkor. The significantly different response of food-deprived foals to refeeding may be attributable to increased protein intake or altered physiologic state.

Free access
in American Journal of Veterinary Research

Abstract

Objective

To evaluate changes in the nutrient and protein composition of cat milk during lactation.

Animals

12 lactating domestic shorthair cats.

Procedure

Milk samples collected on days 1, 3, 7, 14, 28, and 42 after parturition were analyzed for concentrations of nitrogen, nonprotein nitrogen, casein, whey proteins, amino acids, total lipids, lactose, citrate, minerals, and trace elements. Individual milk proteins (caseins and whey proteins) were analyzed by use of polyacrylamide gradient gel electrophoresis.

Results

True protein concentration ranged from 6.3 to 8.6% and was as high in mature milk as in colostrum. Nonprotein nitrogen as a portion of total N was constant (approx 8%), as was the whey-to-casein ratio (approx 50:50). Total lipid concentration was high (9.3%) in colostrum, rapidly decreased, then increased to 9% in mature milk. Lactose concentration was constant at 4%. Milk calcium, iron, and copper concentrations increased markedly during lactation, and magnesium and zinc values remained constant. Colostrum and early milk had a low Ca-to-P ratio of 0.4:0.9. Although calcium concentration increased with time, phosphate concentration also increased so that the Ca-to-P ratio remained constant in mature milk at 1.0: 1.2. The major whey proteins had molecular weights of approximately 14,000, 19,000, 40,000 and 80,000. The 80,000 protein (possibly lactoferrin) decreased in concentration during lactation. Two major casein subunits of approximately 28,000 and 33,000 were found, and both increased during early lactation.

Conclusions

Nutrient composition of cat milk and, thus, provision of nutrients to nursing kittens changes over time. (Am J Vet Res 1997;58:370-375)

Free access
in American Journal of Veterinary Research

Summary

The medical records of 25 horses with intra-abdominal neoplasms and 15 horses with intra-abdominal abscesses were reviewed. Common clinical signs of disease observed by owners of horses in both groups included anorexia, weight loss, fever, signs of colic, and depression. Clinical laboratory abnormalities included leukocytosis, hyperfibrinogenemia, hypoalbuminemia, and hypocalcemia. There was considerable overlap of laboratory test results within and between the 2 groups of horses. Peritoneal fluid was classified as an exudate in 12 of 15 horses with intra-abdominal abscesses and in 14 of 25 horses with intra-abdominal neoplasms. Cytologic examination of peritoneal fluid yielded an accurate diagnosis in 11 of 25 horses with neoplasia and in 3 of 15 horses with abscesses. A mean number of 1.45 cytologic analyses/horse was needed to diagnose neoplasms in the 11 horses in which the analysis was successful in definitively diagnosing the condition.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the pharmacokinetics of DL-α-lipoic acid in dogs when administered at 3 dosages via 3 methods of delivery.

Animals—27 clinically normal Beagles.

Procedures—In a 3 × 3 factorial Latin square design, 3 dosages (2.5, 12.5, and 25 mg/kg) of DL-α-lipoic acid were administered orally in a capsule form and provided without a meal, in a capsule form and provided with a meal, and as an ingredient included in an extruded dog food. Food was withheld for 12 hours prior to DL-α-lipoic acid administration. Blood samples were collected before (0 minutes) and at 15, 30, 45, 60, and 120 minutes after administration. Plasma concentrations of DL-α-lipoic acid were determined via high-performance liquid chromatography. A generalized linear models procedure was used to evaluate the effects of method of delivery and dosage. Noncompartmental analysis was used to determine pharmacokinetic parameters of DL-α-lipoic acid. Nonparametric tests were used to detect significant differences between pharmacokinetic parameters among treatment groups.

Results—A significant effect of dosage was observed regardless of delivery method. Method of delivery also significantly affected plasma concentrations of DL-α-lipoic acid, with extruded foods resulting in lowest concentration for each dosage administered. Maximum plasma concentration was significantly affected by method of delivery at each dosage administered. Other significant changes in pharmacokinetic parameters were variable and dependent on dosage and method of delivery.

Conclusions and Clinical Relevance—Values for pharmacokinetic parameters of orally administered DL-α-lipoic acid may differ significantly when there are changes in dosage, method of administration, and fed status.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To assess effects of foods fortified with docosahexaenoic acid (DHA)–rich fish oil on cognitive, memory, psychomotor, immunologic, and retinal function and other measures of development in healthy puppies.

Design—Evaluation study.

Animals—48 Beagle puppies.

Procedures—Puppies were assigned to 3 groups after weaning (n = 16/group) and received 1 of 3 foods (low-DHA, moderate-DHA, or high-DHA food) as their sole source of nutrition until 1 year of age. Visual discrimination learning and memory tasks, psychomotor performance tasks, and physiologic tests including blood and serum analysis, electroretinography, and dual-energy x-ray absorptiometry were performed at various time points. Anti-rabies virus antibody titers were evaluated 1, 2, 4, and 8 weeks after vaccination at 16 weeks of age.

Results—Foods had similar proximate analysis results but varied in concentration of DHA from fish oil; the high-DHA food also contained higher concentrations of vitamin E, taurine, choline, and l-carnitine than did other foods. The high-DHA group had significantly better results for reversal task learning, visual contrast discrimination, and early psychomotor performance in side-to-side navigation through an obstacle-containing maze than did the moderate-DHA and low-DHA groups. The high-DHA group had significantly higher anti-rabies antibody titers 1 and 2 weeks after vaccination than did other groups. Peak b-wave amplitudes during scotopic electroretinography were positively correlated with serum DHA concentrations at all evaluated time points.

Conclusions and Clinical Relevance—Dietary fortification with fish oils rich in DHA and possibly other nutrients implicated in neurocognitive development following weaning improved cognitive, memory, psychomotor, immunologic, and retinal functions in growing dogs.

Full access
in Journal of the American Veterinary Medical Association

Summary

The concentrations of 23 ammo acids in the plasma of 13 healthy foals were determined before suckling, when foals were 1 to 2 days old, 5 to 7 days old, 12 to 14 days old, and 26 to 28 days old. The ratio of the branched chain amino acids to the aromatic amino acids was also calculated at the 5 time points. Analysis of the concentrations at the 5 ages revealed a significant temporal relationship for each amino acid ranging from a polynomial order of 1 to 4 inclusively. There were significant differences between several concentrations of amino acids in plasma at specific sample times; however, no consistent patterns were revealed. The concentrations of amino acids in healthy foals were markedly different from previously determined values in adult horses. The significant differences in the concentrations of amino acids in plasma of healthy foals at the 5 ages may represent developmental aspects of amino acid metabolism or nutrition.

Free access
in American Journal of Veterinary Research

Summary

Concentrations of amino acids in the plasma of 13 neonatal foals with septicemia were compared with the concentrations of amino acids in the plasma of 13 age-matched neonatal foals without septicemia. Analysis of the results revealed significantly lower concentrations of arginine, citrulline, isoleucine, proline, threonine, and valine in the plasma of foals with septicemia. The ratio of the plasma concentrations of the branched chain amino acids (isoleucine, leucine, and valine) to the aromatic amino acids (phenylalanine and tyrosine), was also significantly lower in the foals with septicemia. In addition, the concentrations of alanine, glycine, and phenylalanine were significantly higher in the plasma of foals with septicemia. Therefore, neonatal foals with septicemia had significant differences in the concentrations of several amino acids in their plasma, compared with concentrations from healthy foals. These differences were compatible with protein calorie inadequacy and may be related to an alteration in the intake, production, use, or clearance of amino acids from the plasma pool in sepsis.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine the prevalence of hypomagnesemia and hypocalcemia in horses with surgical colic.

Animals—35 horses with surgically managed colic.

Procedure—Serum concentrations of total magnesium (tMg 2+ ) and calcium (tCa 2+ ), as well as ionized magnesium (iMg 2+ ) and calcium (iCa 2+ ) were analyzed before surgery and 1, 3, 5, and 7 days following surgery. A lead-II ECG and pertinent clinical data were also obtained at each time.

Results—Preoperative serum tMg 2+ and iMg 2+ concentrations were below the reference range in 6 (17%) and 19 (54%) horses, respectively. Serum concentrations of tCa2+ and iCa2+ were less than the reference range in 20 (57%) and 30 (86%) horses before surgery. Horses with strangulating lesions of the gastrointestinal tract had significantly lower preoperative serum concentrations of iMg2+ and iCa2+, as well as a higher heart rate than horses with nonstrangulating lesions. Horses that developed postoperative ileus had significantly lower serum concentrations of iMg2+ after surgery. Serum concentrations of magnesium and calcium (total and ionized) correlated significantly with the PR, QRS, QT, and corrected QT (QTc) intervals. Horses that were euthanatized at the time of surgery (n = 7) had significantly lower preoperative serum concentrations of iMg2+, compared with horses that survived. Neither serum magnesium nor calcium concentrations were predictors of hospitalization time or survival.

Conclusions and Clinical Relevance—Hypomagnesemia and hypocalcemia were common during the perioperative period, particularly in horses with strangulating intestinal lesions and ileus. Serum concentrations of tMg2+ and tCa2+ were less sensitive than iMg2+ and iCa2+ in detecting horses with hypomagnesemia and hypocalcemia. ( Am J Vet Res 2001;62:7-12)

Full access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association