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1.
OBJECTIVE: To determine whether plasma, urine, and fecal electrolyte and mineral concentrations differ between clinically normal horses and Thoroughbreds with recurrent exertional rhabdomyolysis (RER) after consumption of diets varying in cation-anion balance. ANIMALS: 5 Thoroughbred mares with RER and 6 clinically normal mixed-breed mares. PROCEDURE: Each of 3 isocaloric diets designated as low, medium, and high on the basis of dietary cation-anion balance (DCAB) values of 85, 190, and 380, respectively, were fed to horses for 14 days. During the last 72 hours, 3 horses with RER and 3 control horses had daily urine and fecal samples obtained by total 24-hour collection. Remaining horses had urine samples collected daily by single catheterization. RESULTS: For each diet, no differences existed between horses with RER and control horses in plasma pH, electrolyte concentrations, and creatine kinase activity or in urine pH and renal fractional excretion (FE) values. Plasma pH, strong ion difference, bicarbonate and total carbon dioxide concentrations, and base excess decreased and plasma chloride and ionized calcium concentrations increased with decreasing DCAB. Urine pH decreased with decreasing DCAB. The FE of chloride and phosphorus were greatest for horses fed the low diet. The FE values for all electrolytes exept magnesium did not differ between urine samples obtained by single catheterization and total 24-hour collection. Daily balance of calcium, phosphorus, sodium, chloride, and potassium did not differ significantly among horses fed the various diets. CONCLUSIONS: In clinically normal horses and in horses with RER, the DCAB strongly affects plasma and urine pH and the FE of sodium, potassium, chloride, and phosphorus.  相似文献   

2.
Four mares and four geldings of Quarter Horse and Thoroughbred breeding were used in two simultaneous 4x4 Latin square experiments to study the effects of dietary cation-anion balance (DCAB), defined as meq ((Na+K)-C1)/kg dry matter, on urinary pH and mineral excretion in exercised horses. Diets consisted of a pelleted concentrate of corn, soybean meal and cottonseed hulls fed with bermudagrass hay. Treatments with DCAB of +5 (Low, L), +107 (Medium Low, ML), +201 (Medium High, MH) and +327 (High, H), meq ((Na+K)-Cl)/kg dry matter were formed by supplementing diet L with calcium chloride and ammonium chloride, diet ML with calcium chloride and diet H with sodium bicarbonate and potassium citrate (Table 1). Diet MH was not supplemented and served as the control treatment. Horses were conditioned aerobically for 6 weeks using long, slow, distance (LSD) workouts. During the experimental periods, horses were subjected to a combined exercise regimen alternating LSD with an interval-training protocol 6 days/week. There was a significant (P<.01) treatment effect on urine pH; least squares means for L, ML, MH and H were 6.73, 7.17, 7.38, and 7.92. Horses consuming diet L excreted more calcium in the urine (P<.05) than those consuming MH or H. Least squares means for daily urine calcium excretion tended to be linear across treatments and ranged from 19.66 g/day for diet L to 9.12 g/day for diet H. Urinary chloride excretion was higher (P<.05) for L than for MH or H. Horses fed diet H excreted more sodium (P<.05) in urine than horses fed the other diets. Lowering DCAB, increases urinary calcium loss; depending on the level of calcium intake, this could lead to negative calcium balance in exercising horses.  相似文献   

3.
Eight geldings and four mares were randomly assigned treatments within three 4x4 Latin square design experiments to study the effects of dietary cation-anion balance (DCAB) on mineral balance and dry matter digestibility in sedentary and anaerobically exercised horses. Four diets with an average DCAB (calculated as meq ((Na+K+) - Cl-)/kg of diet dry matter) of +24 (Low, L), +127 (Medium Low, ML), +227 (Medium High, MH) and +352 (High, H) were fed for a 21 day adjustment period followed by a 72 hour collection period. Diets consisted of a pelleted base concentrate of com, soybean meal and cottonseed hulls fed with either native prairie grass or bermuda grass hay in a 60:40 ratio. Diet L was formed by adding calcium chloride and ammonium chloride to the base concentrate, diet ML was formed by adding calcium chloride, and diet H was formed by adding potassium citrate and sodium bicarbonate. Diet MI-I received no supplementation and served as the control. Representative samples of feed, feces and urine were analyzed for mineral content and mineral balances were calculated by difference. Fecal output was greater (p <.05), and thus, dry matter digestibility was lower in exercised homes consuming diet L versus diet H. Sodium balance was greater (p <.05) in sedentary horses consuming diet MH as compared to those consuming diets ML and L Sodium balance was greater (p <.05) in exercised homes consuming diet H as compared to those consuming diets ML and L Potassium balance was greater (p <.05) in sedentary horses consuming diet H as compared to those horses consuming diet ML, however, potassium balance was not affected by DCAB in exercised horses. No significant differences were detected in chloride or magnesium balances in the sedentary horses, although chloride balance was greater (p <.05) and magnesium balance was lower (p <.05) in exercised homes consuming diet L as compared to all other diets. In sedentary homes, phosphorus balance was reflective of intake with differences (p <.05) observed between all treatments. However, in exercised homes, phosphorus balance was lower (p <.05) oniy for those consuming diet L. Calcium balance decreased significantly as DCAB decreased between all treatments in sedentary horses, while calcium balance in exercised homes was greater (p <.05) for homes consuming diet H as compared to those consum- ing diet L.Previous research from our laboratory has shown that both exercised and sedentary horses consuming diets with a low DCAB experience a nutritionally induced metabolic acidosis. The current data indicate that anaerobically exercised and sedentary horses consuming these diets excrete significantly more calcium in the urine resulting in decreased calcium balances. Prolonged consumption of diets with a low DCAB may lead to a significant demineralization of bone and a subsequent weakening of the skeleton.  相似文献   

4.
This study demonstrated that the feeding of treatment diets with calculated dietary cation-anion balances (DCAB) of +370.43 (H) and -25.69 (L) did not have significant effects on blood pH, pCO2, and HCO3-. Serum Ca2+, P, Na+, and Cl- as well as plasma PTH did not differ (P > .05) between the two treatment groups. Serum K+ was higher (P< .05) in horses fed diet H rather than diet L. The DCAB of the diet significantly affected urinary Ca2+, P, Na+, K+, and Cl- excretion in the young growing horse. Urine Ca2+ and Cl- levels were higher (P < .01) in horses fed diet H versus diet L. Furthermore, levels of P, Na+, and K+ in the urine were higher (P < .01) in horses on diet H as opposed to diet L. Results of this study indicate that horses were able to maintain acid-base status regardless of diet. However, these data imply that growing horses consuming diets low in DCAB may be predisposed to abnormal bone mineralization due to the increase in calcium excretion which could lead to a weakening of the skeletal system.  相似文献   

5.
SUMMARY Studies were made to determine if a practical assessment of the calcium and phosphorus nutrition of horses could be obtained from an analysis of urine samples. The concentrations of Ca and P in urine samples changed markedly when groups of 4 mares were fed diets containing from 1.0 to 3.9 g Ca/kg and from 1.5 to 6.1 g P/kg, but serum concentrations of Ca and P remained relatively constant. The concentrations in single urine samples were considered unreliable indicators of excretion of the minerals because of variations in water excretion, and two methods to overcome this problem were examined. In one method, the creatinine clearance ratios (%Cr) of Ca and P were calculated. The other method was simpler, and concentrations of the minerals were expressed as the ratio of the total solute concentration. Both of these methods appeared to give reliable estimates of the excretion of Ca and P in urine, and there were significant relationships between the values obtained for horses fed diets containing a wide range of Ca and P. When the horses were fed adequate Ca, the Ca-%Cr was greater than 2.5% and P-%Cr was less than 4%. The corresponding ratios of mineral concentration to solute concentration were greater than 15 μmole Ca/mosmole and less than 15 μmole P/mosmole. When a low Ca (1.0 g/kg) and high P (4 g/kg) diet was fed, the excretion of Ca and P had changed markedly after 3 days and could be monitored in single samples of urine by either method. It was concluded that a practical assessment of the Ca and P nutrition of horses could be obtained from an analysis of urine samples to determine if the diet is either low, adequate or high in Ca, and high in P.  相似文献   

6.
OBJECTIVE: To determine effects of experimentally induced hypercalcemia on serum concentrations and urinary excretion of electrolytes, especially ionized magnesium (iMg), in healthy horses. ANIMALS: 21 clinically normal mares. PROCEDURES: Horses were assigned to 5 experimental protocols (1, hypercalcemia induced with calcium gluconate; 2, hypercalcemia induced with calcium chloride; 3, infusion with dextrose solution; 4, infusion with sodium gluconate; and 5, infusion with saline [0.9% NaCl] solution). Hypercalcemia was induced for 2 hours. Dextrose, sodium gluconate, and saline solution were infused for 2 hours. Blood samples were collected to measure serum concentrations of electrolytes, creatinine, parathyroid hormone, and insulin. Urine samples were collected to determine the fractional excretion of ionized calcium (iCa), iMg, sodium, phosphate, potassium, and chloride. RESULTS: Hypercalcemia induced by administration of calcium gluconate or calcium chloride decreased serum iMg, potassium, and parathyroid hormone concentrations; increased phosphate concentration; and had no effect on sodium, chloride, and insulin concentrations. Hypercalcemia increased urinary excretion of iCa, iMg, sodium, phosphate, potassium, and chloride; increased urine output; and decreased urine osmolality and specific gravity. Dextrose administration increased serum insulin; decreased iMg, potassium, and phosphate concentrations; and decreased urinary excretion of iMg. Sodium gluconate increased the excretion of iCa, sodium, and potassium. CONCLUSIONS AND CLINICAL RELEVANCE: Hypercalcemia resulted in hypomagnesemia, hypokalemia, and hyperphosphatemia; increased urinary excretion of calcium, magnesium, potassium, sodium, phosphate, and chloride; and induced diuresis. This study has clinical implications because hypercalcemia and excessive administration of calcium have the potential to increase urinary excretion of electrolytes, especially iMg, and induce volume depletion.  相似文献   

7.
OBJECTIVE: To evaluate the diagnostic value of serum concentrations of total magnesium (tMg) and ionized magnesium (iMg), concentrations of magnesium (Mg) in muscle, intracellular Mg (icMg) concentrations, urinary Mg excretion (EMg), Mg clearance (CMg), and fractional clearance of Mg (FCMg) in horses fed diets with Mg content above and below National Research Council recommendations. ANIMALS: 9 young female horses. PROCEDURES: 6 horses were fed a reduced-Mg diet for 29 days followed by an Mg-supplemented diet for 24 days. Control horses (n = 3) were fed grass hay exclusively. Blood, urine, and tissue samples were collected, and an Mg retention test was performed before and after restriction and supplementation of Mg intake. Serum tMg, serum iMg, muscle Mg, icMg, and urine Mg concentrations were measured, and 24-hour EMg, CMg, and FCMg were calculated. RESULTS: Reductions in urinary 24-hour EMg, CMg, and FCMg were evident after 13 days of feeding a reduced-Mg diet. Serum tMg and iMg concentrations, muscle Mg content, and results of the Mg retention test were not affected by feeding the Mg-deficient diet. Spot urine sample FCMg accurately reflected FCMg calculated from 6- and 24-hour pooled urine samples. Mean +/- SD FCtMg of horses eating grass hay was 29 +/- 8%, whereas mean FCtMg for horses fed a reduced-Mg diet for 29 days was 6 +/- 3%. CONCLUSIONS AND CLINICAL RELEVANCE: The 24-hour EMg was the most sensitive indicator of reduced Mg intake in horses. Spot sample FCMg can be conveniently used to identify horses consuming a diet deficient in Mg.  相似文献   

8.
将36头干奶后期中国荷斯坦奶牛随机分为对照组、试验Ⅰ组、试验Ⅱ组（每组12头）．分别饲喂常规日粮、阴离子型日粮及在此基础上朴Ca日粮，探讨其对奶牛体内代谢状况、健康状况及生产性能的影响。与饲喂常规日粮相比，饲喂阴离子型日粮可降低奶牛尿液pH值（P〈0．01）和血液HCO2^-浓度（P〉0．05）；增加奶牛产后12h（P〈0．05）、2d（P〈0．05）血清总钙含量．对血清无机磷、镁含量没有显著影响；明显降低奶牛亚临床性低血钙率（33％）、胎衣不下率（33％）和乳房水肿率（17％）；增加牛奶乳糖率（P〈0．05），对其他奶成分和奶产量没有显著影响（P〉0．05）。在阴离子型日粮中补Ca后．与饲喂阴离子型日粮相比．除增加奶牛产后血清镁含量外（P〈0．05）．对其他各项指标没有明显影响。  相似文献   

9.
Urine (U) and serum (S) were obtained every 2 hours during a 12- or 24-hour period from eight healthy 96-hour-old pony or horse foals. Dams' milk samples were obtained concurrently. Urine volume was measured during this 12- or 24-hour period. The mean amount of urine produced was 148 +/- 20 ml/kg/day. Baseline urinalyses were evaluated on all foals at two days of age, before any manipulation. Urine generally was dilute (less than 1.008) but the specific gravity was as high as 1.027 in one normal foal. Continuous (12 or 24 hour) urinary catheterization resulted in bacteriuria but not white blood cells in the urine. Prolonged catheterization did not cause foals to become febrile or exhibit clinical signs of cystitis or other illness. Urinary electrolyte excretion, urinary electrolyte clearances, and fractional electrolyte excretions (FE) were measured. When compared with normal values reported in adult horses, excretion, clearance, and FE were similar for sodium (Na) but higher for potassium (K), phosphorus (P), and calcium (Ca). There were no significant differences between data collected during different time periods, and it was concluded that the use of single sample urine/serum estimates of fractional excretion in the neonatal foal was an appropriate indicator of the renal handling of electrolytes, and when viewed in conjunction with urinalysis and other serum parameters, a valuable aid to evaluating renal function.  相似文献   

10.
The fractional excretion (FE) of a constituent by the kidney is the fraction of the amount filtered by the glomerulus, which is excreted into urine. It is mostly determined for electrolytes, and is expressed as the ratio of the clearance of a given electrolyte to creatinine clearance. The main physiologic factors affecting FE variation are species, age, and the alimentary supply of electrolytes. The value of FE tests in the diagnosis of kidney disease is limited, except in canine Fanconi's syndrome. FEs of many constituents often are increased in chronic kidney disease, but their diagnostic value is no greater than that of plasma creatinine concentration. FEs also are altered in nonrenal diseases such as diabetes mellitus and rhabdomyolysis, and during treatment with xylazine, rehydration fluids, and diuretics. FEs, especially of calcium, phosphates, and magnesium, are useful in clinical nutrition to assess mineral balance. FE is difficult to measure, so its use should be limited to nutritional investigations and nephrology research.  相似文献   

11.
ABSTRACT

Aims: To compare urine urinary pH, blood pH and concentration of electrolytes in blood of healthy horses fed an anionic salt supplement to achieve diets with a dietary cation-anion difference (DCAD) of ?40 or 0?mEq/kg DM, with horses a fed a diet with a DCAD of 85?mEq/kg DM.

Methods: Eight healthy horses received each of three diets in a randomised crossover design. Diets consisted of grass hay and concentrate feed, with a varying amount of an anionic supplement to achieve a DCAD of 85 (control), 0 or ?40?mEq/kg DM. They were fed for 14 days each with a washout period of 7 days between. Urine pH was measured daily and blood samples were collected on Days 0, 7 and 14 of each study period for the measurement of pH and concentration of electrolytes.

Results: Four horses voluntarily consumed the anionic supplement with their feed, but four horses required oral supplement administration via dose syringe. During the study period mean urine pH was lower in horses fed diets with a DCAD of 0 (6.91; SD 0.04) and ?40 (6.83; SD 0.04) mEq/kg DM compared to the control diet (7.30; SD 0.04). Compared with horses fed the control diet, mean urine pH was lower in horses fed the 0 and ?40?mEq/kg DM diets on Days 1–12 and 14 (p?<?0.05) of the study period. On Day 13 it was only lower in horses fed the ?40?mEq/kg DM diet (p?<?0.01). Urine pH was similar for horses fed the 0 and ?40?mEq/kg DM diets (p?=?0.151). The DCAD of the diet had no effect on blood pH, ionised Ca or anion gap. Mean concentrations of bicarbonate in blood were affected by diet (p?=?0.049); they were lower when horses were fed the 0?mEq/kg diet relative to the control diet on Day 14.

Conclusions and clinical relevance: The anionic supplement reduced urine pH in horses fed diets with a DCAD of 0 or ?40?mEq/kg DM compared with 85?mEq/kg DM. However as urinary pH did not fall below pH 6.5, the pH below which calcium carbonate uroliths do not form, this reduction in urine pH is unlikely to be clinically significant. The supplement was variably palatable and showed minimal promise as an effective urinary acidifier at the doses administered in this study.  相似文献   

12.
OBJECTIVE: To evaluate the efficacy of using serum total and ionized magnesium (Mg) concentrations and urine Mg concentrations to identify Mg deficiency in cats. ANIMALS: 6 healthy castrated male cats. PROCEDURE: A Mg-replete diet was fed for 37 days, followed by a Mg-deficient diet for 37 days. On days 1, 3, and 7 of the last week of each diet, serum ionized and total Mg concentrations were determined; in addition, urine Mg concentration was determined each day of the last week. Serum total and ionized Mg concentrations were compared with urine Mg concentration, amount of Mg excreted during 24 hours (24-hour urine Mg excretion), ratio of urine Mg concentration to urine creatinine concentration (Umg:Ucr), and urinary fractional excretion of Mg (FEmg) to determine which variable best predicted Mg status. RESULTS: Cats fed Mg-deficient diets had significantly lower serum total and ionized Mg concentrations and 24-hour urine Mg excretion values, compared with cats fed Mg-replete diets. Serum total Mg concentration was the best predictor of Mg status. Twenty-four-hour urine Mg excretion was a repeatable, reliable measurement and had the best correlation with serum total Mg concentration. Serum total Mg concentration also correlated with urine Mg concentration, Umg:Ucr, and FEmg. CONCLUSIONS AND CLINICAL RELEVANCE: Serum total and ionized Mg concentrations can be used to identify cats with dietary-induced Mg deficiencies. Twenty-four-hour urine Mg excretion and urine Mg concentration correlated best with serum total Mg concentration and, therefore, may be the most useful urine variables for identifying Mg deficiency.  相似文献   

13.
There is an apparent reciprocal relationship between magnesium ammonium phosphate (MAP, struvite) and calcium oxalate (CaOx) urolithiasis incidence rate in cats. The number of struvite uroliths submitted for analysis over the past 35 years has been decreasing, with an increase in CaOx urolith submissions. Commercial diets aimed to dissolve struvite uroliths are typically acidified, and it has been suggested that dietary acidification increases urinary calcium excretion and the risk of CaOx crystallization. The objective of this study was to assess the effect of urine acidification on the relative supersaturation (RSS) of CaOx in cats, as a representation of crystallization risk. Four diets were extruded to contain identical nutrient contents, but with gradual acidification (0, 0.6, 1.3 and 1.9% sodium bisulphate substituted sodium chloride in diets A, B, C and D respectively). Thirteen adult cats were fed each diet sequentially for a minimum of 10 days. Average urine pH was 6.4, 6.2, 6.0 and 5.9 on diets A, B, C and D respectively (p < 0.0001). Struvite RSS decreased on diets inducing more acidic urine pH (p < 0.0001). Urinary calcium excretion and concentration increased with diets inducing lower urine pH (p < 0.0001), but oxalate excretion and concentration decreased (p < 0.001). CaOx RSS was not different between diets (p = 0.63). These results suggest that a lower diet base excess and resulting urine pH to support struvite dissolution do not increase the risk for CaOx crystallization in the range of urine pH representative of most commercial feline diets. Long-term studies are needed to confirm this.  相似文献   

14.
Effect of diet on struvite activity product in feline urine   总被引：2，自引：0，他引：2  
Groups of male specific-pathogen-free cats were fed a basal, purified diet (A), with or without 0.45% added magnesium (MgCl2, diet B; MgO, diet C) or 1 of 2 commercial diets (D,E). Urine samples collected for 48 hours after 2 weeks of feeding were analyzed for calcium, magnesium, sodium, potassium, ammonium, sulfate, phosphate, oxalate, and citrate content. Concentrations were used to calculate the negative logarithm of the struvite activity product (pSAP), using a microcomputer-based program for calculation of supersaturation of the urine with crystal solutes. The pSAP value for all samples also was hand-calculated by use of an equation. Consumption of diet B caused a significant (P less than 0.05) increase in urine calcium concentration. Total urine phosphate concentration was lower in urine from cats fed diets A, B, or C than in urine from cats fed diets D or E. For the various diets, urine PO4(-3) was: 5.3 microM for diet A; 6.3 microM for diet C; 0.9 microM for diet E; 36 nM for diet D, and 0.5 nM for diet B. Consumption of diets B and C caused significant increases in urine magnesium concentration (53.1 nM and 49.1 mM, respectively). Ammonium ion concentration was highest in urine from cats fed diets B and D, 116.2 mM and 100.3 mM, respectively. When the pSAP, hand-calculated assuming ionic strength u = 0.2, was regressed on that calculated by use of the microcomputer program, the coefficient of determination was 0.96 (P less than or equal to 0.01).  相似文献   

15.
Summary

In a 4×4‐vvk cross‐over study, eight adult cats were given four moist diets containing identical amounts of calcium (13.9 mmol/MJ) but with different ratios of calcium carbonate to calcium chloride, the calcium salts providing half of the total dietary calcium. Increasing amounts of calcium chloride were substituted for equimolar amounts of calcium carbonate. Higher intakes of calcium chloride caused significantly lower pH values in postprandial and 24‐h urine samples. The urinary excretion of ammonium and titratable acid rose with increasing calcium chloride intake. The urinary concentrations of calcium and magnesium were not affected by the type of calcium salt, but the urinary excretion and concentration of phosphorus were significantly depressed when the amount of calcium chloride in the diet was increased. The results are discussed in the context of dietary prevention of and therapy for struvite urolithiasis in cats.  相似文献   

16.
Endogenous creatinine clearance and renal excretion of phenylbutazone, osmotically active material, and compounds contributing to the urinary refractive index were studied in 12 Thoroughbred mares after no treatment, after water administration, or after furosemide administration. Urine was quantitatively collected, using urinary bladder catheters. On average, urine flow of the mares was 9 microliters/min/kg without treatment and increased to about 50 microliters/min/kg after water administration and to about 70 microliters/min/kg after furosemide administration. Water administration increased creatinine clearance values and excretion of phenylbutazone. Furosemide administration increased urinary excretion of osmotically active compounds and compounds contributing to urinary refractive index and decreased excretion of phenylbutazone.  相似文献   

17.
Aminoglycoside nephrotoxicosis (AGNT) was induced in ewes by daily SC administration of gentamicin. Changes in urinary indices of renal function during the development of AGNT are reported. Measurements from timed, volume-measured urine samples were made on days 0, 7, and 8 and included creatinine clearance, total excretion (TE) rates of electrolytes (Na, K, Cl, P) and urine volume. Measurements from free-catch urine samples (without volume measurement) were made daily and included fractional excretion (FE) rate of electrolytes, urine osmolality, and urine-to-serum osmolality and urine-to-serum creatinine ratios. With the onset of AGNT, FE rates of Na, K, Cl, and P- increased many fold above baseline values (200x, 4 to 5x, 6 to 9x, and 70 to 95x, respectively, on days 7 and 8), indicating decreased tubular reabsorption or increased tubular secretion. The increased FE rates were not representative of increases in total electrolyte excretion rates. The total excretion of Na (TENa) was mildly increased, TEK was decreased, TECl was unchanged, and TEP was significantly increased on days 7 and 8. Abnormal urinalysis results, glucosuria, and increased FEP preceded appreciable increase in serum creatinine concentration. Other abnormal urinary indices of renal function coincided with or followed the increase in serum creatinine concentration. Urinary indices may help characterize renal function associated with the disease state, but did not provide early indication of AGNT.  相似文献   

18.
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.  相似文献   

19.
Samples of serum and urine were obtained simultaneously from 56 healthy lactating cows to determine ranges of fractional excretion (FE) of calcium (Ca), phosphate (PO4), magnesium (Mg), sodium (Na), potassium (K), and chloride (Cl). Samples were obtained at 3 stages of lactation: period 1 = 1 to 7 days, 2 = 83 to 112 days, and 3 = 175 to 197 days. The FE of electrolytes were significantly different among periods 1, 2, and 3 for Ca (P less than 0.001), PO4 (P less than 0.025) and Mg (P less than 0.025), but were not significantly different for Na, K, and Cl. Least squares mean FE of Ca was lowest in period 1 and not significantly different for periods 2 and 3, whereas mean FE values for PO4 and Mg were highest in period 2 and not significantly different for periods 1 and 3. The mean FE values of Na, K, and Cl did not change with stage of lactation. Age and category of milk production (high, medium, and low) did not influence the FE values of the electrolytes.  相似文献   

20.
Four mature, sedentary geldings were used in a 4x4 Latin square design experiment to study the effects of dietary cationanion balance (DCAB), defined as meq ((Na + K) - C1)/kg of dietary dry matter, on urine pH, blood pH and blood gasses. Four diets with actual DCAB levels of +21 (Low, L), +125 (Medium Low, ML), +231 (Medium High, MH) and +350 (High, H) were fed for a 21-day adjustment period and a 72 hour collection period. Total urine output was collected every 4 hours post feeding for 72 hours, and like times across days were combined for analyses. Arterial and venous blood samples were drawn, via indwelling catheters, hourly for 12 hours beginning at feeding. All samples were analyzed immediately after collection for pH, blood gasses and blood acid-base measures. Urine pH was lower (p<.05) at all measured intervals when geldings consumed diet L than when they consumed diets MI, MH and H. Least squares means for urine pH ranges from 5.40 to 5.86 on diet L, 6.79 to 7.30 on diet ML, 7.35 to 7.63 on diet MH and 7.52 to 8.14 on diet H. Blood pH, pCO2 and HCO3 values were also significantly lower in both arterial and venous samples when geldings consumed diet L than when fed diets MH and H. Results of this trial indicate that horses consuming highly anionic diets may experience a nutritionally-induced metabolic acidosis.  相似文献   

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