Effects of dietary sodium chloride intake on renal function and blood pressure in cats with normal and reduced renal function

OBJECTIVE: To determine effects of variations in dietary intake of sodium chloride (NaCl) on systemic arterial blood pressure (ABP) in cats with normal and reduced renal function. ANIMALS: 21 adult cats (7 with intact kidneys [control cats; group C], 7 with unilateral renal infarction with contralateral nephrectomy [remnant-kidney model; group RK], and 7 with unilateral renal infarction and contralateral renal wrapping and concurrent oral administration of amlodipine [remnant-wrap model; group WA]). PROCEDURE: All cats were sequentially fed 3 diets that differed only in NaCl content (50, 100, or 200 mg of Na/kg); each diet was fed for 7 days. The ABP was recorded continuously by radiotelemetry, and renal function (glomerular filtration rate [GFR]) was determined on the sixth day of each feeding period. RESULTS: Dietary supplementation with NaCl did not affect ABP, but it increased GFR in groups C and WA. The renin-angiotensin-aldosterone axis was activated in groups RK and WA at the lowest NaCl intake, but supplementation with NaCl suppressed this activation in group WA. The lowest NaCl intake was associated with hypokalemia and a high fractional excretion of potassium that decreased in response to supplementation with NaCl. Arterial baroreceptor resetting was evident after chronic hypertension but was not modified by dietary supplementation with NaCl. CONCLUSIONS AND CLINICAL RELEVANCE: Low NaCl intake was associated with inappropriate kaliuresis, reduced GFR, and activation of the renin-angiotensin-aldosterone axis without evidence of a beneficial effect on ABP. Therefore, this common dietary maneuver could contribute to hypokalemic nephropathy and progressive renal injury in cats.     

Effects of dietary protein content on renal parameters in normal cats

This study evaluates the effect of dietary protein content on renal parameters in 23 healthy spayed female cats. The objective was to determine if cats eating diets high in protein will have higher serum urea nitrogen (UN) and creatinine values without a detectable change in kidney function, as assessed by urinalysis. A single random cross-over design was used. Cats were fed a standard maintenance diet for at least 1 month prior to the dietary trial. They were fed in two phases. For the first phase, cats were randomly assigned to receive either a high protein [HP=46% metabolizable energy (ME)] or low protein (LP=26% ME) diet. For the second phase, cats were fed whichever diet they were not fed during the phase I period. Blood and urine samples were collected at 2-week intervals for the duration of the study (10 weeks). UN, albumin, alanine aminotransferase and urine specific gravity were significantly higher, and creatinine and phosphorus were significantly lower (P<0.05) when cats were fed the HP diet as compared to when they were fed the LP diet, although none of the mean values were found to be outside of the corresponding reference interval. Dietary intake can result in clinically significant changes in UN and statistically significantly changes in several other biochemical analytes, although all analytes are likely to remain within normal reference intervals. Therefore, an accurate dietary history is necessary to help determine if renal parameters are being influenced by diet in a particular patient.     

NaCl胁迫下苞片对华北驼绒藜种子萌发的影响

对去苞片和带苞片的华北驼绒藜种子在不同的盐浓度下进行处理,带苞片种子的发芽率、发芽指数、活力指数均高于去苞片的。在ＮａＣｌ浓度为７０,１４０,２１０,２８０和４２０ｍｍｏｌ／Ｌ 时,带苞片种子的发芽率显著高于去苞片的（犘＜０．０５）,分别为９０．００％,８９．００％,７９．７５％,６９．２５％,５３．７５％ 和７８．５０％,８１．５０％,７４．００％,６２．２５％ 和３９．２５％。用蒸馏水和４９０ｍｍｏｌ／Ｌ 的ＮａＣｌ溶液对带苞片和去苞片的华北驼绒藜的种子处理１２ｈ,带苞片种子吸水率均低于去苞片的,苞片延缓了种子的吸水率。４９０ ｍｍｏｌ／Ｌ ＮａＣｌ处理华北驼绒藜种子１,３ 和７ｄ后,苞片中Ｎａ＋ 含量显著增加（犘＜０．０５）。说明华北驼绒藜种子的苞片可以吸附一部分Ｎａ＋ ,减少对胚的伤害。苞片对华北驼绒藜在荒漠盐渍环境中的定植具有重要的意义。     

Effects of dexamethasone on selected parameters of the bovine immune system

The synthetic glucocorticoid, dexamethasone, has been used by investigators studying bovine immune mechanisms to either exacerbate infectious processes or simulate stress-induced steroid-influenced immunosuppression. Considerable differences exist in the literature concerning the effect of dexamethasone on the bovine immune response.The purpose of our study was to clarify the reported effects of dexamethasone on bovine T-lymphocyte function. Therefore, we designed experiments to evaluate cellular and humoral aspects of the bovine immune response under the influence of dexamethasone. The experiments took into consideration the pharmacokinetics of dexamethasone and optimal and suboptimal doses of selected mitogens. The data suggest little variation in hematological parameters that occurred with the administration of dexamethasone. Leukocyte counts were slightly elevated at two observations, and this was believed to be the result of an increase in peripheral blood neutrophils. T-lymphocytes (erythrocyte rosetting) were not selectively depleted. However, suppression of T-lymphocyte function was noted, particularly in response to suboptimum doses of phytohaemagglutinin (PHA) and Concanavalin A (Con A). Antibody production to the T-dependent antigen, KLH, was suppressed in those animals receiving dexamethasone. These data suggest that the immunosuppressive effect of dexamethasone in the bovine is dependent upon the dose of dexamethasone administered, the pharmacological level of dexamethasone in vivo, physiological adaptation of the host, mitogen dose used in evaluation, and the time of evaluation post drug administration. The study points out the importance of considering these variables when interpreting the effects of dexamethasone on the bovine immune response.     

Effects of high dietary sodium chloride content on performance and sodium and potassium balance in growing pigs

Thirty castrated male Moo Lath pigs (6–8 weeks of age) were used in a 15-week growth trial to study the effect of high dietary sodium chloride (NaCl) content on feed and water intake, performance, sodium (Na) and potassium (K) balance, and plasma aldosterone concentration. The pigs were randomly allocated (ten per treatment) to diets containing 0.24 % Na (Na0.24), 0.28 % Na (Na0.28), and 0.32 % Na (Na0.32) per kg diet. Feed and water was provided ad libitum, and water consumption, feed offered, and feed residues were recorded daily. Every third week, the pigs were weighed, blood samples were collected, and a 3-day total collection of urine and feces was performed. Water intake was higher (P?=?0.001) in pigs fed with diets Na0.28 (3.7 L/day) and Na0.32 (3.9 L/day) than in pigs fed with diet Na0.24 (3.4 L/day), and dry matter (DM) intake was higher on diet Na0.32 (P?=?0.041) than on the other diets. The average daily body weight (BW) gain was higher on diet Na0.32 than on the other diets (P?=?0.031). The feed conversion ratio (in kilogram feed DM to kilogram BW gain) was 4.6, 4.6, and 4.1 on treatments Na0.24, Na0.28, and Na0.32, respectively (P?=?0.14). The highest Na balance was observed on diet Na0.32 followed by diets Na0.28 and Na0.24 (P?<?0.001), while there was no treatment-related pattern for the K balance. The Na/K ratio in feces and urine increased (P?<?0.001), and the K/Na ratio in feces (P?<?0.001) decreased with increasing Na content in the diet. Plasma aldosterone concentration decreased (P?<?0.001) with increasing dietary content of Na. These results indicate that high NaCl intake and free access to water will increase Na balance but do not negatively influence feed intake and performance of growing local pigs.     

Effects of crude protein and sodium intake on water turnover in cats fed extruded diets

The comprehension of strategies to increase urine production may be important, especially in kibble diets to prevent urolithiasis in cats. The effects of increasing amounts of crude protein (CP) and sodium on the water turnover of cats were evaluated using the water balance (WB) method and the deuterium dilution technique. The study followed a randomized block design, with three blocks of eight cats, two cats per food type in each block, and six cats per food. Four extruded diets with different amounts of CP and sodium were evaluated (on DM basis): 28% CP and 0.58% sodium; 39% CP and 0.64% sodium; 52% CP and 0.76% sodium; and 64% CP and 0.87% sodium. Cats were individually housed in cages for 8 days to measure WB, urea excretion, and faecal and urine characteristics. Deuterium oxide was used to evaluate water turnover, and during the period cats were housed in a collective cattery. The data were analysed by an F test, and the means were compared by polynomial contrasts. The ɑ level of significance was set at 0.05. The methods were compared by Pearson correlation, and Bland and Altman analysis. The increase in the CP content elevated linearly the renal excretion of urea (p < .001), and, together with the higher sodium intake, elevated the renal solute load, which resulted in a linear increase in urine production and water intake (p < .01). The urine density, metabolic water, and faecal and insensible water losses did not differ (p > .05). The water flux increased linearly when using the deuterium method (p < .001), but the obtained values were 20.85 ± 11.11 ml/cat/day higher than those verified using the WB method (p = .001). Higher CP and sodium amounts in dry diets increased the urine production and water consumption of cats, and this can be explored as a possible option to increase urination.     

Effects of a single injection of methylprednisolone acetate on serum biochemical parameters in 11 cats

BACKGROUND: Therapeutic use of corticosteroids has been implicated in a variety of serum biochemical abnormalities in dogs; however, the effects in cats are less well characterized. OBJECTIVE: The objective of this brief communication is to report serum biochemical changes in response to methylprednisolone acetate (MPA) in adult cats. METHODS: Serum biochemical profiles were performed on 11 cats with dermatologic diseases at baseline, 3-6 days, and 16-24 days after a single intramuscular dose of 5 mg/kg MPA. RESULTS: Median serum albumin and bicarbonate concentrations and amylase activity were increased compared to baseline at both post-treatment time points; aspartate aminotransferase activity and magnesium concentration were increased at 3-6 days post-treatment only; and alkaline phosphatase activity and total calcium concentration were increased at 16-24 days post-treatment only. Median serum creatinine concentration was decreased compared to baseline at both post-treatment time points. Examination of data from individual cats revealed significant variability in serum biochemical changes in response to MPA. No adverse clinical reactions to the drug were reported. CONCLUSIONS: A single dose of MPA results in significant changes in some serum biochemical values in cats, although individual responses will vary.     

Effects of aqua-treadmill exercise on selected blood parameters and on heart-rate variability of horses

The objectives of the present study were to investigate the effects of Aquatraining of horses (aqua-treadmill exercise; treadmill manufactured by Equitech - L.u.S. Equipment, Warendorf, Germany) on selected blood parameters [lactic acid concentration (mmol/l), haemoglobin content (g/l)] and on heart-rate variability (HRV) [heart rate (beats per min; b.p.m.), standard deviation of all NN-intervals (SDNN; ms), normalized power of the low and high frequency band (LFnorm, Hfnorm; au), % recurrence, % determinism and ratio(corr)]. Seven horses performed six exercise tests with different work loads (walking (x = 1.56 +/- 0.08 m/s) and trotting (x = 2.9 +/- 0.13 m/s): dry, water above the carpus and water above the elbow). The standardized test-protocol was: 5 min warm-up at walk while the water was pumped in, followed by the 20-min exercise period at walk or trot, followed by a 5-min walk while pumping out the water. Blood samples were taken prior to each test at rest in the stable, as well as exactly 5 min after the end of the 20-min exercise period. Electrocardiograms were recorded during rest and the 20-min exercise period. Compared to rest, neither the chosen velocities, the two water levels, nor the dry tests led to a significant increase of the lactic acid concentration in any horse. The haemoglobin content showed a significant increase as a result of exercise. Significant differences could be found between the heart rates at rest and the six exercise tests and between the mean of the levels 'walking' and the mean of the levels 'trotting'. An exercise-induced change of HRV was characterized by a decreasing SDNN, a significantly higher LFnorm (sympathetic influence) combined with a significantly lower HF(norm) power (parasympathetic activity) and a rising degree of order (significantly higher % determinism and nearly unchanged % recurrence) and stability (significantly rising ratio(corr)) of the recurrence plot. In conclusion, the used training-protocol for aqua-treadmill exercises only represents a medium-sized aerobic work load for horses, but the different levels of burden were indicated especially by changes in HRV.     

Effects of 2 different medetomidine infusion rates on selected neurohormonal and metabolic parameters in dogs

The effects of 2 different 8-hour continuous rate infusions (CRIs) of medetomidine on epinephrine, norepinephrine, cortisol, glucose, and insulin levels were investigated in 6 healthy dogs. Each dog received both treatments and a control as follows: MED1 = 2 μg/kg bodyweight (BW) loading dose followed by 1 μg/kg BW per hour CRI; MED2 = 4 μg/kg BW loading dose followed by 2 μg/kg BW per hour CRI; and CONTROL = saline bolus followed by a saline CRI. Both infusion rates of medetomidine decreased norepinephrine levels throughout the infusion compared to CONTROL. While norepinephrine levels tended to be lower with the MED2 treatment compared to the MED1, this difference was not significant. No differences in epinephrine, cortisol, glucose, or insulin were documented among any of the treatments at any time point. At the low doses used in this study, both CRIs of medetomidine decreased norepinephrine levels over the 8-hour infusion period, while no effects were observed on epinephrine, cortisol, glucose, and insulin.     

Prevalence of selected rickettsial infections in cats in Southern Germany

Prevalence of Anaplasma, Ehrlichia, Neorickettsia, and Wolbachia DNA in blood of 479 cats collected in different veterinary clinics in Southern Germany was determined using a previously published conventional PCR using 16S-23S intergenic spacer primers (5′ CTG GGG ACT ACG GTC GCA AGA C 3′ – forward; 5′ CTC CAG TTT ATC ACT GGA AGT T 3′ – reverse). Purified amplicons were sequenced to confirm genus and species. Associations between rickettsial infections, and feline immunodeficiency virus (FIV), as well as feline leukemia virus (FeLV) status were evaluated. Rickettsial prevalence was 0.4% (2/479; CI: 0.01–1.62%). In the two infected cats, Anaplasma phagocytophilum DNA was amplified. These cats came from different environment and had outdoor access. Both were ill with many of their problems likely related to other diseases. However, one cat had neutrophilia with left shift and the other thrombocytopenia potentially caused by their A. phagocytophilum infection. There was no significant difference in the FIV and FeLV status between A. phagocytophilum-negative and -positive cats. A. phagocytophilum can cause infection in cats in Southern Germany, and appropriate tick control is recommended.     

Effect of dietary potassium chloride on feeder pig performance, market shrink, carcass traits and selected blood parameters

A total of 288 commingled crossbred feeder pigs were purchased and transported 1,050 km in two trials to investigate the effect of added dietary potassium chloride in receiving and finishing diets on feeder pig shrink recovery, performance and pre-slaughter shrink. Diets containing 0, .48%, .96% or 1.44% added potassium chloride were fed for 2 wk post-arrival and again from 12 wk post- arrival until slaughter. There was no effect (P greater than .1) on gain (22.9 kg pay weight) or feed conversion or on plasma or red blood cell potassium for the 2-wk post-arrival period due to the inclusion of potassium chloride in the 2-wk receiving diet. Also, there was no effect (P greater than .1) of potassium chloride in diets from 12 wk post-arrival until slaughter on gain, feed conversion, market shrink, carcass dressing percentage and plasma or red blood cell potassium concentration at slaughter. These results suggest that corn-soybean meal-based diets contain sufficient potassium for pigs following a period of stress associated with marketing and transport.     

Prevalence of selected infectious disease agents in cats from Arizona

The objective of this study was to use polymerase chain reaction (PCR) assays to determine the prevalence of Ehrlichia species, Anaplasma phagocytophilum, Mycoplasma haemofelis, 'Candidatus Mycoplasma haemominutum' and Bartonella species from feral and relinquished cats in Phoenix and Nogales, Arizona. DNA from one or more of the organisms was amplified from 31 of 112 blood samples (27.7%). DNA consistent with Bartonella clarridgeiae 15 (13.4%), Bartonella henselae 14 (12.5%), 'Candidatus M haemominutum' 9 (8.0%), and M haemofelis 5 (4.5%) were detected. DNA of Ehrlichia species, Neorickettsia risticii, or A phagocytophilum was not amplified. Failure to amplify DNA of A phagocytophilum may relate to the absence of appropriate tick vectors. Failure to amplify Ehrlichia species DNA suggests that cats were not exposed, exposed but not infected, or infected but the DNA was not detected by the PCR assay used in this study. The Bartonella species and hemoplasma results suggest flea control should be maintained.     

Effects of dietary supplementation with sodium chloride on urinary relative supersaturation with calcium oxalate in healthy dogs

OBJECTIVE: To evaluate the effect of dietary supplementation with sodium chloride (NaCl) on urinary calcium excretion, urine calcium concentration, and urinary relative supersaturation (RSS) with calcium oxalate (CaOx). ANIMALS: 6 adult female healthy Beagles. PROCEDURE: By use of a crossover study design, a canned diet designed to decrease CaOx urolith recurrence with and without supplemental NaCl (i.e., 1.2% and 0.24% sodium on a dry-matter basis, respectively) was fed to dogs for 6 weeks. Every 14 days, 24-hour urine samples were collected. Concentrations of lithogenic substances and urine pH were used to calculate values of urinary RSS with CaOx. RESULTS: When dogs consumed a diet supplemented with NaCl, 24-hour urine volume and 24-hour urine calcium excretion increased. Dietary supplementation with NaCl was not associated with a change in urine calcium concentration. However, urine oxalate acid concentrations and values of urinary RSS with CaOx were significantly lower after feeding the NaCI-supplemented diet for 28 days. CONCLUSIONS AND CLINICAL RELEVANCE: Dietary supplementation with NaCl in a urolith-prevention diet decreased the propensity for CaOx crystallization in the urine of healthy adult Beagles. However, until long-term studies evaluating the efficacy and safety of dietary supplementation with NaCl in dogs with CaOx urolithiasis are preformed, we suggest that dietary supplementation with NaCl be used cautiously.     

Influence of the feed base excess on urine parameters in cats

In this study the base excess (BE) was used as a method to predict the influence of the food on the urinary pH on cats. Nine cat foods (six dry and three canned) were consecutively fed to eight cats. The urine pH, volume, specific gravity and water and food intake were determined daily. The base excess [BE; mmol/kg dry matter (DM)] was calculated from the compounds in the food (BE = 49.9*Ca+82.3*Mg*+43.5*Na+25.6*K-64.6*P-13.4*Met-16.6*Cys-28.2*Cl). The BE of the tested foods was between -287.35 and 133.38 mmol/kg DM. The mean urine pH varied between 5.76 (SD = 0.13) and 7.16 (SD = 0.22). The BE correlated with the mean urine pH (pH = 6.25+0.0023*BE; r = 0.74**). The urine volume (ml/kg BW/day) correlated significantly positive with the K- (r = 0.71**) and significantly negative with the P-content (r = -0.67**), the Ca-content (r = -0.50**) followed by the Mg-content (r = -0.36**) of the food. The correlation coefficients between the anions/cations in the food and the urine pH was for K 0.36**, for P -0.61**, the Met+Cys -0.60** and Cl -0.27**. In practice the correlation between urine pH and BE would help to pre-estimate the effect of food on the urine pH and to prevent urolith formation.