Acid-base assessment: when and how to apply the Henderson-Hasselbalch equation and strong ion difference theory

Retrospective evaluation of acid-base imbalances, clinicopathologic alterations, and prognostic factors in hospitalized calves with Eimeria-associated diarrhea

Introduction

After the neonatal period Eimeriosis is one of the most common causes of large intestinal diarrhea in calves. In contrast to neonatal calves with diarrhea, there are very few reports about the clinicopathological alterations in affected animals, which are mainly based on experimental data. The aim of the present study was therefore to characterize acid-base and related clinicopathologic alterations in calves with Eimeria-associated diarrhea and to identify variables associated with in-hospital mortality.

Methods

Retrospective analysis of clinical and clinicopathologic findings extracted from medical records of 118 calves aged 1 to 5 months admitted to a veterinary teaching hospital.

Results

Severely affected calves were profoundly hyponatremic and hypochloremic, with a strong correlation between plasma sodium and chloride concentrations (Spearman's rs  = 0.90). Acidemia was found in 57.6% of calves and was associated with hyperphosphatemia, hyper-L-lactatemia, and the presence of unidentified strong ions. Forty-seven calves (39.8%) did not survive to hospital discharge. Classification tree analysis indicated that hospital mortality was associated with plasma ionized calcium concentrations <1.05 mmol/L, initial leukocyte counts >16 × 109 cells/L, and a poor or cachectic body condition. The resulting sensitivity and specificity for predicting non-survival of this model was 59.6 and 90.1%, respectively. In addition to plasma ionized calcium [Odds ratio (OR) = 0.011] and leukocyte concentrations (OR = 1.08), recumbency (OR = 6.1), albumin (OR = 0.90), and decreased strong ion difference (OR = 0.91) were associated with mortality in a second modeling approach (sensitivity 78.7%, specificity 71.8%).

Conclusion

Calves with Eimeria-associated diarrhea can develop profound clinicopathologic derangements. The identified prognostic factors suggest that advanced disease severity, indicated by an inability to stand and reduced body condition, is associated with a lower chance of survival.

A randomized controlled trial evaluating the effect of providing a rest period during long-distance transportation of surplus dairy calves: Part II. Effect on hematological variables

The objective of this randomized controlled trial was to determine if providing a rest stop including provision of feed and water between periods of continuous transportation mitigates the effect of long-distance transportation on markers of energy status and hydration in calves transported by road for 16 h. This study was conducted between September 2022 to January 2023 and included male and female Holstein and crossbred dairy calves ≥7 d old from 2 commercial dairy farms in Ontario, Canada (n = 96). On the day before transportation, calves were enrolled and randomly assigned to one of 2 treatment groups: (1) continuous transportation by road for 16 h or (2) 8 h of transport, 8 h of rest, and a further 8 h of transport to a single calf-raising facility. Calves that received a rest stop were fed 2 L of milk replacer at the time of unloading for the rest period and again immediately before reloading for the second leg of the journey. Blood samples were collected before and after transportation as well as daily for 3 d following arrival to the calf-raising facility. Serum was analyzed for concentrations of BHB, nonesterified fatty acids (NEFA), haptoglobin, and creatine kinase, and acid-base disturbances were evaluated within 1 h of collection of whole blood to assess glucose, sodium, potassium, ionized calcium, hematocrit, hemoglobin, pH, base excess, partial pressure of oxygen, total carbon dioxide, bicarbonate, partial pressure of carbon dioxide, and oxygen saturation. Mixed linear regression models with repeated measures were built to assess the effect of treatment group, age at transportation, breed, and sex on these parameters. Immediately after transportation, calves that received the rest period had lower BHB (-68.04 μmol/L, 95% CI: -99.59 to -36.49), NEFA (-0.14 mmol/L, 95% CI -0.22 to -0.07), and sodium (-1.10 mmol/L, 95% CI = -2.18 to -0.02), and higher glucose (0.48 mmol/L, 95% CI = 0.21 to 0.74), potassium (0.27 mmol/L, 95% CI = 0.11 to 0.43), ionized calcium (0.06 mmol/L, 95% CI = 0.03 to 0.08), and oxygen saturation (8.76%, 95% CI = 1.61 to 15.91) compared with calves that were continuously transported for 16 h. Additionally, calves transported between 11 and 12 d old had lower hematocrit (-1.22%, 95% CI = -2.19 to -0.25), hemoglobin (-3.07 g/L, 95% CI = -5.70 to -0.43), haptoglobin (-0.13 g/L, 95% CI = -0.23 to -0.02), and potassium (-0.13 mmol/L, 95% CI = -0.22 to -0.04) and higher sodium (0.83 mmol/L, 95% CI = 0.03 to 1.63) than 7 to 8 d old calves. Furthermore, calves that were 13 to 24 d old at transport had lower haptoglobin (-0.16 g/L, 95% CI = -0.27 to -0.06) and potassium (-0.14 mmol/L, 95% CI = -0.23 to -0.05), and higher sodium (1.02 mmol/L, 95% CI = 0.22 to 1.82) and ionized calcium (0.02 mmol/L, 95% CI = 0.002 to 0.035) compared with calves transported at 7 to 8 d old. The results of this trial demonstrate that a rest period improves energy status upon arrival to a calf-raising facility, suggesting that the benefit of a rest period may be mostly related to the provision of mid-journey milk meals.

Reference limits for blood gas analysis performed from coccygeal vessels of multiparous Holstein dairy cows: Effects of stage of lactation and season of sampling

Blood gas analysis is a great support to the diagnostic process of critically ill patients. Its correct application to the medicine of dairy cows depends on the availability of specific reference intervals that are still difficult to find in the literature. They may vary according to the type of blood sampled, the animals' age and production stage, and climatic conditions. This study aimed at calculating the reference limits for some blood gas parameters in the blood collected from the coccygeal vessels of multiparous Holstein dairy cows. This site of sampling implies the risk of withdrawing blood of unknown origin (venous, arterial, or mixed), but it has a high practical interest for easy and quick performance and minimal animal restraint required. Data from 379 cows were used, and reference limits were produced for pH, partial pressure of carbon dioxide, bicarbonate concentration, total carbon dioxide concentration, oxygen saturation (sO2), hemoglobin (Hb), hematocrit (Hct), base excess, glucose, Na, K, and ionized calcium (iCa). The effects of stage of lactation (5-60 vs. >60 DIM) and season of sampling (cold vs. hot) were investigated, and specific reference limits were produced for each variable and each level of the factors whenever a significant effect was detected. The pH, sO2, K, and iCa were not influenced by season or stage of lactation. All the other blood gas parameters were significantly affected by season of sampling, and Hb, Hct, glucose, and Na were also affected by stage of lactation. Reference limits provided in this study are specific to the site of sampling (coccygeal vessels) and the animal category considered. Further studies are needed to produce reference intervals for other blood gas parameters, cow categories, and blood types.

Investigating nutritional strategies during a rest period to improve health, growth, and behavioral outcomes of transported surplus dairy calves

The objective of this study was to investigate the effects of feeding surplus dairy calves a milk replacer (MR) or one of 2 different oral rehydration solutions (ORS) during a midtransportation rest period on metabolic and clinical health indicators, growth, and behavioral outcomes after arrival at a calf-raising facility. Surplus dairy calves (n = 128) were transported in 4 cohorts from February to July 2022 for 12 h to a holding facility, rested for 8 h, then transported for an additional 6 h to a calf-raising facility. Upon arrival at the holding facility, calves were randomly assigned to 1 of 3 treatments: MR (n = 43), a high-sodium ORS developed for diarrhea (ORS-D; n = 43), or a high-potassium ORS developed for transportation (ORS-T; n = 42). The exact age of calves at transportation was unknown; however, all calves were less than 14 d of age. Calf BW at enrollment was 43.9 ± 5.9 kg, 43.7 ± 6.5 kg, and 45.0 ± 4.5 kg for calves fed MR, ORS-D, and ORS-T, respectively. Calves were fed 2.0 L of their treatment twice, once upon arrival and once before leaving the holding facility. At unloading and reloading at the holding facility, calves were weighed and blood samples were obtained. Calves were also health scored at unloading at the holding facility. After arrival at the calf-raising facility, calves were weighed, health scored, and blood samples were taken. Blood samples were collected at 24 and 48 h and BW was recorded at 24 h, 48 h, 72 h, 5 d, 7 d, 14 d, and at 8 wk after arrival at the calf-raising facility. Calves were also health scored daily for 14 d; health scoring included fecal consistency scoring and evaluating the presence or absence of respiratory disease. Lying time, lying bouts, and activity index were measured during transportation and from 3 d relative to transportation using accelerometers. At arrival to the calf-raiser, calves fed ORS-D had higher concentrations of nonesterified fatty acids (NEFA) and BHB than calves fed MR. Furthermore, calves fed ORS-T had higher concentrations of BHB at arrival to the calf raiser compared with calves fed MR. In the 14 d after arrival at the calf-raiser, there was evidence that calves fed ORS-T had a higher proportion of days with diarrhea and respiratory disease compared with those fed MR. During transportation, calves fed ORS-T had a lower activity index than calves fed MR, suggesting that ORS-T calves had lower overall activity. In addition, on the day of transportation (d 0), ORS-T and ORS-D calves had a lower activity index than calves fed MR. There were no treatment effects on growth outcomes. The results of this study suggest that feeding MR rather than an ORS during a midtransportation rest period could minimize fat mobilization and can potentially improve diarrhea and respiratory disease but does not affect growth outcomes after arrival at calf-raisers.

Construction of various lipid carriers to study the transdermal penetration mechanism of sinomenine hydrochloride

OBJECTIVE

To investigate the transdermal mechanisms and compare the differences in transdermal delivery of Sinomenine hydrochloride (SN) between solid lipid nanoparticles (SLN), liposomes (LS), and nanoemulsions (NE).

METHODS

SN-SLN, SN-LS and SN-NE were prepared by ultrasound, ethanol injection and spontaneous emulsification, respectively. FTIR, DSC, in vitro skin penetration, activation energy (Ea) analysis were used to explore the mechanism of drug penetration across the skin.

RESULTS

The particle size and encapsulation efficiency were 126.60 nm, 43.23 ± 0.48%(w/w) for SN-SLN, 224.90 nm, 78.31 ± 0.75%(w/w) for SN-LS, and 83.22 nm, 89.01 ± 2.16%(w/w) for SN-LS. FTIR and DSC showed the preparations had various levels of impacts on the stratum corneum's lipid structure which was in the order of SLN > NE > LS. Ea values of SN-SLN, SN-LS, and SN-NE crossing the skin were 2.504, 1.161, and 2.510 kcal/mol, respectively.

CONCLUSION

SLN had a greater degree of alteration on the skin cuticle, which allows SN to permeate skin more effectively.

Water, mineral, and blood acid-base balance in calves with naturally occurring diarrhea receiving two alternative oral rehydration solutions or a placebo

Quantifying the water and mineral losses in feces is essential to determine the optimal composition of oral rehydration solutions (ORS) for diarrheic animals. In a randomized complete block design, this study evaluated water, mineral, and blood acid-base balance of calves with naturally occurring diarrhea receiving ORS or a placebo. On d 0, 45 calves (age: 18 ± 3.2 d; mean ± SD) were selected based on the presence of visual signs of diarrhea, such as dirty tail or wet feces, along with clinical symptoms evaluated by measuring the skin turgor and the degree of enophthalmos. On d 1, calves were divided into blocks of 3 animals based on blood base excess (BE) measured at 0900 h, and within each block, calves were randomly assigned to 1 of 3 treatments (15 calves per treatment) including (1) a hypertonic ORS (HYPER; Na+ = 110 mmol/L; 370 mOsm/kg; strong ion difference [SID] = 60 mEq/L), (2) a hypotonic ORS with low Na+ (HYPO; Na+ = 77 mmol/L; 278 mOsm/kg; SID = 71 mEq/L), and (3) a placebo consisting of lukewarm water with 5 g/L of whey powder (CON). Milk replacer (MR) was fed through teat buckets twice daily at 0630 h and 1700 h in 2 equally sized meals of 2.5 L from d 1 to 3 and of 3.0 L on d 4 and 5. Treatments consisting of 2.0 L lukewarm solutions were administered between milk meals from d 1 to 3 at 1200 h and 2030 h through teat buckets. Refusals of MR and treatments were recorded daily, and blood samples were collected from the jugular vein once daily at arrival in the afternoon of d 0 and at 0900 h from d 1 to 5 after arrival. Urine and feces were collected quantitatively over a 48-h period from 1200 h on d 1 to 1200 h on d 3, and a representative sample of each 24-h period was stored. In addition, the volume of extracellular fluid was evaluated on d 2 by postprandial sampling over a 4-h period relative to the injection of sodium thiosulfate at 1300 h. Total daily fluid intake (MR, treatment, and water) from d 1 to 3 was greater in HYPER (LSM ± SEM; 8.9 ± 0.36 L/d) and HYPO (7.8 ± 0.34 L/d) than in CON (6.6 ± 0.34 L/d). This resulted in a greater water balance (water intake - fluid output in urine and feces) in calves receiving ORS (59.6 ± 6.28 g/kg BW per 24 h vs. 39.6 ± 6.08 g/kg BW per 24 h). Fecal Na+ losses were greater in HYPER than in the other treatments (81 ± 12.0 mg/kg BW per 24 h vs. 24 ± 11.8 mg/kg BW per 24 h). Blood pH was higher in HYPO (7.41 ± 0.016) than CON (7.35 ± 0.016) over the 5 monitoring days, whereas HYPER (7.37 ± 0.017) did not differ with other treatments. In this experimental model, diarrheic calves were likely unable to absorb the high Na+ load from HYPER, resulting in greater Na+ losses in feces, which might have impaired the alkalinizing capacity of HYPER. In contrast, HYPO significantly sustained blood acid-base balance compared with CON, whereas HYPER did not. This suggests that low tonicity ORS with a high SID are more suitable for diarrheic calves.

Accidental monensin poisoning in goats

Sodium monensin is the most frequently used ionophore as a growth promoter in ruminant diets. It has numerous benefits; however its toxic effects have also been observed in several animal species. Naturally occurring cases have not yet been reported in goats. This study describes an outbreak of accidental poisoning, characterizing its clinical, laboratory and pathological findings. Thirty-seven of 40 Anglo Nubian goat kids became intoxicated after receiving a diet that was erroneously supplemented with sodium monensin. They ingested an estimated toxic dose between 25 and 39 mg/kg BW. Clinical evolution was monitored (n = 27), followed by serum creatine kinase (CK) and aspartate aminotransferase (AST) activities measurements, and blood gas analysis. Postmortem examinations were performed between 1 and 8 days of evolution (n = 14). Clinical signs began 5 h after ingestion and included reticuloruminal hypomotility, lethargy, anorexia, tachycardia, cardiac arrhythmia, wet cough, pulmonary and tracheal crackles, and serous nasal discharge. The morbidity and lethality rates were 92.5 and 62.1%, respectively. CK and AST activities increased, reaching median values of 10,860 and 1596 U/L, respectively; the hyperchloremic metabolic acidosis was mild. The lesions were characterized by degeneration and necrosis of the cardiac and skeletal muscles, pulmonary congestion and edema, and passive liver congestion. The kids essentially developed cardiomyopathy with left and right congestive heart failures. Unlike in other ruminant species, skeletal muscle functional disability was infrequent. It can be concluded that monensin is toxic to goats and should be used with caution in their diet.

Enteral hydration in cows: Comparison between continuous flow and bolus administration

BACKGROUND

Enteral hydration in cattle is most commonly performed as a bolus (B) via the ororuminal route, although continuous flow (CF) administration via the nasoesophageal route represents a viable alternative. Currently, no study has compared the effectiveness of these two methods. This study aimed to compare the efficiency of enteral hydration using CF and B to correct water, electrolyte and acid-base imbalances in cows.

METHODS

Protocols for the induction of dehydration were applied twice to eight healthy cows, with an interval of 1 week. In a crossover design, two types of enteral hydration were performed using the same electrolyte solution and volume equal to 12% of bodyweight (BW): CF (10 mL/kg/h, between 0 and 12 hours) and B (6% BW, twice, at 0 and 6 hours). Clinical and blood variables were determined at -24, 0, 6, 12 and 24 hours and compared using repeated-measures ANOVA.

RESULTS

Induced moderate dehydration and hypochloremic metabolic alkalosis were corrected after 12 hours using the two hydration methods, with no differences observed between the methods.

LIMITATIONS

The study was conducted with induced rather than natural imbalances, so the findings should be interpreted cautiously.

CONCLUSION

Enteral CF hydration is as effective as B hydration in reversing dehydration and correcting electrolyte and acid-base imbalances.

A randomized controlled trial investigating the effect of transport duration and age at transport on surplus dairy calves: Part II. Impact on hematological variables

Surplus dairy calves often arrive at veal and dairy-beef rearing facilities with health and blood metabolite level abnormalities, which can affect their welfare and performance, predisposing them to future health challenges. The objective of this randomized controlled trial was to investigate the effects of transport duration and age at the time of transport on blood parameters in surplus dairy calves following 6, 12, or 16 h of continuous road transportation. All surplus calves from 5 commercial dairy farms in Ontario were enrolled and examined daily before transport (n = 175). On the day of transportation, calves were weighed, blood sampled, and randomly assigned to 6, 12, or 16 h of transportation. Blood samples were then collected immediately after transportation, as well as 24, 48, and 72 h thereafter. Serum was analyzed at a provincial diagnostic laboratory for nonesterified fatty acids (NEFA), β-hydroxybutyric acid (BHBA), creatine kinase (CK), cholesterol, and haptoglobin. In addition, blood gas and electrolyte values were also assessed at the time of sample collection. Mixed models with repeated measures were used to assess the effects of transport duration, breed, sex, transfer of passive immunity status, weight before transportation, and age at transportation on blood parameters. Immediately following transportation, NEFA and BHBA were greater for calves transported for 12 h (Δ = 0.22 mmol/L NEFA, 95% CI = 0.15 to 0.30; Δ = 0.04 mmol/L BHBA, 95% CI = 0.02 to 0.06) and 16 h (Δ = 0.35 mmol/L NEFA, 95% CI = 0.27 to 0.42; Δ = 0.10 mmol/L BHBA, 95% CI = 0.08 to 0.11) compared with calves transported for 6 h. Glucose was lower immediately following transportation in calves transported for 16 h compared with 6 h (Δ = -15.54 mg/dL, 95% CI = -21.54 to -9.54). In addition, pH and HCO3- were lower in calves transported for 12 (Δ = -0.09 pH, 95% CI = -0.13 to -0.05; Δ = -1.59 mmol/L HCO3-, 95% CI = -2.61 to -0.56) and 16 h (Δ = -0.07 pH, 95% CI = -0.12 to -0.03; Δ = -1.95 mmol/L HCO3-, 95% CI = -2.95 to -0.95) compared with calves transported for 6 h. Calves transported between 15 and 19 d of age had a higher concentration of cholesterol and CK (Δ = 0.27 mmol/L cholesterol; 37.18 U/L CK) compared with 2- to 6-d-old calves, and calves 12 to 14 d old had greater reduction in HCO3- (Δ = -0.92 mmol/L) compared with 2- to 6-d-old calves. These findings show that transporting calves for long distances results in lower glucose concentration and suboptimal energy status, and that this effect varies based on the calf's age.

Validation of a blood gas device for ionized calcium analysis in Holstein cows

BACKGROUND

Accurate analysis of ionized calcium (iCa) is critical for the detection of hypocalcemia or subclinical hypocalcemia. The Edan i15 Vet (EDAN) blood gas device has not been validated for iCa in dairy cows.

OBJECTIVES

We aimed to validate the EDAN blood gas device against the Gem Premier 3000 (GEM) analyzer by measuring iCa concentrations and evaluating the ability of these measurements, compared with serum total calcium (TCa) concentrations, to diagnose subclinical hypocalcemia.

METHODS

iCa concentrations were measured with the EDAN and GEM devices, and serum TCa concentrations were measured with a wet biochemistry method with blood from 125 lactating Holstein cows between calving to day 27 postpartum.

RESULTS

Bland-Altman plots showed a mean and total bias of 0.05 and 0.24 mmol/L for the EDAN device, respectively. The intercept did not include zero, but the slope included 1.0 in the Passing-Bablok regression. The sensitivity and specificity (Se/Sp) of the EDAN device were 93/94%, 93/90%, 91/93%, and 85/95% for iCa cut-off values of <1.00, 1.05, 1.10, and 1.15 mmol/L, respectively, as determined with the GEM device. The Se/Sp were 57/82% and 72/80% for EDAN and 57/80% and 72/79% for GEM at serum TCa cut-off points <2.15 and <2.00 mmol/L, respectively. The average iCa concentrations analyzed with the GEM and EDAN devices were 1.04 ± 0.18 and 1.09 ± 0.17, respectively.

CONCLUSIONS

The EDAN device did not have satisfactory agreement with GEM and could not be used interchangeably, but it had satisfactory Se/Sp to diagnose subclinical hypocalcemia compared with the GEM-derived iCa cut-off points. Serum TCa concentration cut-off values were not suitable for diagnosing subclinical hypocalcemia because of unsatisfactory Se/Sp compared with iCa concentrations analyzed by the GEM and EDAN devices. The iCa values analyzed using the EDAN and GEM devices were consistent with previously reported data.

Does postprandial lipemia interfere with blood gas analysis and assessment of acid-base status in dogs?

To evaluate the interference of postprandial lipemia on blood gas parameters and to assess the acid-base status by the quantitative approach of the strong ion model blood samples of 15 healthy dogs were collected during fasting (0 h) and at one (1 h), three (3 h) and five (5 h) hours after the induction of lipemia with a hypercaloric diet. Total cholesterol (TC) and triglyceride (TG) levels were used to assess lipemia and these were correlated with the parameters evaluated accordingly. Anion gap decreased at 5 h without correlation with TC and TG, whereas other parameters measured by the blood gasometer did not change. In the evaluation of the acid base state, the apparent strong ion difference (SIDa) and the strong ion gap (SIG) showed a decrease at 5 h without correlation with lipemia. Lipid levels correlated with the effective strong ion difference (SIDe), the concentration of total non-volatile weak acids (A_tot), albumin, phosphate, and magnesium. The SIDe increased at 1 h and at 3 h; the A_tot at 1 h, 3 h, and 5 h; albumin increased at 1 h and 3 h; phosphate increased at 1 h, 3 h and 5 h; and magnesium decreased at 5 h. Though postprandial lipemia does not interfere with blood gas analysis, it can cause errors in the variables used to assess the acid-base status, which are dependent on biochemical analytes. Therefore, caution is required when interpreting electrolyte disturbances that result from the postprandial state.

Effectiveness of oral electrolyte solutions with different compositions for the treatment of neonatal calves with induced osmotic diarrhea

ABSTRACT In a randomized controlled trial, we evaluated the effects of five oral electrolyte solutions (OESs) with different compositions of water, electrolyte, and acid-base balances of diarrheal neonatal calves. Osmotic diarrhea and dehydration were induced with sucrose in milk, spironolactone, and hydrochlorothiazide for 48 h in thirty 10-day old Holstein healthy calves with 43.5 ± 3.80 kg BW who were fed with natural milk. They were allocated to five treatment groups (n=6) based on the administered OES (commercial: OES A, B, C, D; and non-commercial: OES UEL). On the day of treatment, the calves received 6L of OES in two doses apart from milk intakes. Venous blood samples were collected at -48h (start of induction), -24h, 0h (start of the treatment day), 8h, 16h, 24h, 48h, and 72h. TPP, glucose, D-lactate, L-lactate, pH, pCO2, HCO3 -, BE, Na+, K+, Cl-, SID3, SIG, AG, Atot and percentage change in plasma volume (%PV) were measured or calculated and analyzed by two-way repeated measures ANOVA. All the calves developed osmotic diarrhea, mild to moderate dehydration, hyponatremia, relative hyperchloremia, and moderate to severe metabolic acidosis. The tested OESs were well accepted by the calves and effective in reversing dehydration, electrolyte imbalances, and metabolic acidosis. OES D did not completely correct hyponatremia, and SEO B caused transient hyperglycemia. It has been concluded that all the tested OESs are safe and effective for the treatment of diarrhea in calves with moderate degrees of dehydration and metabolic acidosis, which indicates that they have proper compositions for this purpose.

Ursache, Verbreitung und evidenzbasierte Therapie sowie Prävention der peripartalen Hypokalzämie

Die peripartale Hypokalzämie ist eine weit verbreitete Stoffwechselstörung, dessen klinische Form etwa 7 % der Milchkühe und dessen subklinische Form fast jede 2. multipare Kuh betrifft. Obwohl sich hinsichtlich Diagnostik und Therapie in den letzten 30 Jahren kaum etwas verändert hat, herrscht bei Landwirten und Tierärzten Unklarheit über die Prävalenz und den Risikozeitraum dieser Stoffwechselstörung. Darüber hinaus gibt es sehr unterschiedliche Angaben darüber, wieviel Kalzium einer Kuh mit klinischer Hypokalzämie substituiert werden sollte. Ziel dieses Übersichtsartikels ist es, die Entstehung und Verbreitung von Hypokalzämie evidenzbasiert darzustellen. Des Weiteren werden die Ergebnisse älterer und neuer Studien zusammengefast, mit dem Ziel eine möglichst genaue Empfehlung zur Behandlung von klinischer Hypokalzämie zu geben. Da in einer 2017 durchgeführten Studie gezeigt wurde, dass der überwiegende Teil deutscher Milchviehbetriebe keine Prophylaxe gegen Hypokalzämie betreibt, werden in dem letzten Teil dieser Arbeit die verschiedenen Prophylaxekonzepte, unter Berücksichtigung der aktuellen Literatur, dargestellt.

Intravenous and Oral Fluid Therapy in Neonatal Calves With Diarrhea or Sepsis and in Adult Cattle

Optimal fluid therapy protocols in neonatal calves and adult cattle are based on consideration of signalment, history, and physical examination findings, and individually tailored whenever laboratory analysis is available. Measurement of the magnitude of eye recession, duration of skin tenting in the lateral neck region, and urine specific gravity by refractometry provide the best estimates of hydration status in calves and cattle. Intravenous and oral electrolyte solutions (OES) are frequently administered to critically ill calves and adult cattle. Application of physicochemical principles indicates that 0.9% NaCl, Ringer's solution, and 5% dextrose are equally acidifying, lactated Ringer's and acetated Ringer's solution are neutral to mildly acidifying, and 1.3-1.4% sodium bicarbonate solutions are strongly alkalinizing in cattle. Four different crystalloid solutions are recommended for intravenous fluid therapy in dehydrated or septic calves and dehydrated adult cattle: (1) lactated Ringer's solution and acetated Ringer's solution for dehydrated calves, although neither solution is optimized for administration to neonatal calves or adult cattle; (2) isotonic (1.3%) or hypertonic (5.0 or 8.4%) solutions of sodium bicarbonate for the treatment of calves with diarrhea and severe strong ion (metabolic) acidosis and hyponatremia, and adult cattle with acute ruminal acidosis; (3) Ringer's solution for the treatment of metabolic alkalosis in dehydrated adult cattle, particularly lactating dairy cattle; and (4) hypertonic NaCl solutions (7.2%) and an oral electrolyte solution or water load for the rapid resuscitation of dehydrated neonatal calves and adult cattle. Much progress has been made since the 1970's in identifying important attributes of an OES for diarrheic calves. Important components of an OES for neonatal calves are osmolality, sodium concentration, the effective SID that reflects the concentration of alkalinizing agents, and the energy content. The last three factors are intimately tied to the OES osmolality and the abomasal emptying rate, and therefore the rate of sodium delivery to the small intestine and ultimately the rate of resuscitation. An important need in fluid and electrolyte therapy for adult ruminants is formulation of a practical, effective, and inexpensive OES.

Enteral electrolytic solutions administered in continuous flow via naso-ruminal route in adult goats

This study aimed to investigate the effects of maintenance enteral electrolytic solutions administered naso-ruminally in continuous flow in adult goats subjected to water and food restriction. Six adult non-pregnant and non-lactating female goats, aged between two and five years old, were used in a crossover (6 × 2) study. Solution 1 (SEE1) comprised: 4.5 g sodium chloride (NaCl); 1 g potassium chloride (KCl); 0.5 g magnesium chloride (MgCl); 1 g calcium chloride in 1,000 ml of water (measured osmolarity: 202 mOsm/l). Solution 2 (SEE2) comprised: 4.5 g of NaCl; 1 g of KCl; 0.5 g of MgCl; 2 g of calcium acetate in 1,000 ml of water (measured osmolarity: 212 mOsm/l). The solutions were administered naso-ruminally at a dose rate of 15 ml/kg/hr, for 12 hr. The animals were evaluated at times T-24, T0, T4, T8, T12, and T24. Both enteral electrolytic solutions were effective in expanding blood volume. SEE1 showed a low-intensity acidifying potential, while SEE2 showed behavior of a neutral enteral electrolytic solution.

Tonicity of oral rehydration solutions affects water, mineral and acid-base balance in calves with naturally occurring diarrhoea

Recommendations for composition of oral rehydration solutions (ORS) for calves, particularly concerning Na⁺, glucose, and their combined effect on tonicity, are not in line with guidelines for humans. Thus, this study aimed to determine the effect of ORS tonicity on water, mineral and acid–base balance. Seventy‐two calves were selected based on the severity of dehydration and blood base excess (BE) on day 0. Five calves that did not develop diarrhoea were removed post‐inclusion from the study. Calves were allocated to blocks of four animals based on blood BE on day 1. Within each block, calves were randomly assigned to one of four treatments: (a) hypotonic ORS with low Na⁺ and lactose (HYPO); (b) isotonic ORS with low Na⁺and glucose (ISO); (c) hypertonic ORS with high Na⁺ and glucose (HYPER); and (d) control consisting of warm water including 5 g/L of whey powder (CON). Treatments were administered twice daily over a 3‐day period, in which calves were offered 2.0 L of treatment at 1300 and 2100 hr. Calves were fed 2.5 L of milk replacer at 0700 and 1630 hr from day 1 to 3 and 3.0 L from day 4 to 5, and had access to water. Calves were monitored for 5 days in which measurements included intakes, BW, blood sampling and collection of faeces on day 1 and urine from day 1 to 3. All ORS treatments maintained normal serum Na⁺, whereas CON did not. Calves in the HYPER group had lower blood pH and greater faecal Na⁺ losses than HYPO and ISO. Plasma expansion relative to baseline was higher in low tonicity ORS (+4.8%) when compared with CON (+1.0%). Urine osmolality was 30% higher in HYPER calves. In this experiment, low tonicity ORS were more effective at restoring water, mineral and acid–base balance than the hypertonic ORS.

Determining the predictive capability of a Clinical Assessment Scoring Chart to differentiate severity of the clinical consequences of neonatal calf diarrhea relative to gold-standard blood gas analysis

Neonatal calf diarrhea (NCD) is a major problem to calf health worldwide, in terms of both morbidity and mortality. A five-point ordinal scale clinical assessment scoring (CAS) chart was utilized to assess calves suffering from NCD-related clinical abnormalities (acidosis and dehydration) on commercial farms. The objective of this research was to determine the predictive capability of this CAS chart against gold standard blood gas parameters, designed to assist farmers in the accurate assessment of the clinical consequences of NCD. A total of 443 diarrheic and non-diarrheic calves were enrolled in the study. The CAS chart rated a calf’s health from no clinical signs to varying degrees of clinical severity on a 0 (clinically normal) to 4 (grave) scale, based on clinical indicators including calf demeanour, ear position, mobility, suckle reflex, desire-to-feed, and enophthalmos. Blood gas analysis was conducted for individual calves, consisting of pH, base excess, Na⁺, K⁺, Ca²⁺, Cl⁻, glucose, total hemoglobin, bicarbonate, anion gap, and strong ion difference. Statistical evaluation was performed by comparison of the CAS score with blood gas profiles using ordinal logistic regression and a non-parametric estimation of the Receiver Operating Characteristics (ROC). The ROC analysis indicated that the CAS chart had acceptable specificity (>95%) with low sensitivity (<60%) in differentiating clinically normal from acidotic/dehydrated cases. Assessment of individual severity classes indicated that the chart can predict and differentiate both clinically normal and advanced cases from the other severity classes (peak estimations >80%) but had reduced accuracy in differentiating mild and moderate cases (peak estimations >50%). The chart, as presented, provides a simple tool to differentiate clinically normal from calves suffering the consequences of diarrhea, but fails to accurately differentiate severity for NCD related acidosis and dehydration. Further efforts are required to enhance the sensitivity and differential diagnostic value of this type of chart.

Identifying hydric, electrolytic and acid-base imbalances through traditional and quantitative approaches in dogs with hemorrhagic gastroenteritis

ABSTRACT Vomiting and diarrhea are two important clinical signs that can cause significant electrolytic and acid-base imbalances. The purposes of this study were to characterize hydric, electrolytic and acid-base disorders presented by puppies with hemorrhagic gastroenteritis and to compare the traditional and quantitative approaches to acid-base status interpretation. Sixty-one animals with a history of vomiting and/or diarrhea were used in this study and the following tests were performed: complete blood count, total plasma protein concentration and hemogasometry. Mean, standard deviation and Kappa values were calculated. The imbalances characterized by both approaches were: 42 (69%) animals without imbalance, 17 (28%) with metabolic alkalosis and 2 (3%) with metabolic acidosis by the traditional approach and 17 (28%) dogs without imbalance, 26 (43%) with metabolic alkalosis and 18 (29%) with metabolic acidosis by the quantitative approach. The agreement calculated between two approaches coincide in 28 cases, with a moderate Kappa value equivalent to 0.459. The most found imbalances were metabolic alkalosis, hypokalemia, and mild dehydration. Most of acid-base disturbances were not identified by the traditional approach, whereas by the quantitative approach, they were easily determined. Thus quantitative approach proved to be superior in identification of possible acid-base imbalances.

Treatment of acute rumen lactic acidosis with intravenous hypertonic sodium chloride or bicarbonate solutions followed by intraruminal water

The effectiveness of 7% hypertonic saline solution (HSS) and 6% hypertonic bicarbonate solution (HBS) followed by intraruminal water administration for the treatment of acute rumen lactic acidosis (ARLA) has not been evaluated yet. The hypothesis of the study is that treatment with HBS causes a faster correction of imbalances and clinical recovery than treatment with HSS. ARLA was induced in six healthy mature female sheep with sucrose twice. The sheep received both treatment regimens in a cross over design. After 18 h of induction, rumen lavage was performed and IV infusion of 7% HSS (4 mL/kg BW) or 6% HBS (6.7 mL/kg BW) was done over 5 min, followed by intraruminal administration of water (8% BW). The solutions provided 4.8 mmol/kg BW of sodium. Physical and laboratory tests were performed for 168 h. Both treatments increased plasma volume. After HSS treatment, pH and HCO₃^- returned to baseline values at 144 h and BE at 168 h. With HBS treatment, pH returned to baseline at 24 h, and HCO₃^- and BE at 48 h. In both treatments, the ruminal motility and the maximum hay intake were restored at 96 and 120 h, respectively. In conclusion, administration of HSS or HBS followed by intraruminal water corrects dehydration and mild-to-moderate metabolic acidosis in sheep with ARLA. Treatment with HBS promoted a faster correction of metabolic acidosis and could be indicated for the most severe cases.

Comparative analysis of acid-base balance in patients with severe sepsis and septic shock: traditional approach vs. physicochemical approach

Introduction: The evaluation of metabolism and the diagnostic classification of acid-base disorders has generated great controversy. Acid-base balance (ABB) is approached by means of the physicochemical and Henderson’s models.Objective: To compare two diagnostic approaches to ABB in patients with severe sepsis.Materials and methods: Prospective, descriptive study conducted in patients with severe sepsis. ABB was analyzed within the first 24 hours. The diagnosis was compared according to each model and the causes of the disorders were compared according to the physicochemical model.Results: 38 patients were included in the study, of which 21 (55%) were women; the mean age was 49 years, the median APACHE II, 13.28, and the mortality at 28 days, 24.3%. The traditional approach identified 8 patients with normal ABB, 20 with metabolic acidosis, and 10 with other disorders. Based on the physicochemical model, all subjects had acidosis and metabolic alkalosis. Increased strong ion difference (SID) was the most frequently observed disorder.Conclusion: The physicochemical model was useful to diagnose more patients with acid-base disorders. According to these results, all cases presented with acidosis and metabolic alkalosis; the most frequent proposed mechanism of acidosis was elevated SID. The nature of these disorders and their clinical relevance is yet to be established.

Acid-base assessment of post-parturient German Holstein dairy cows from jugular venous blood and urine: A comparison of the strong ion approach and traditional blood gas analysis

Evaluating acid-base status is important for monitoring dairy herd health. In a field study, we aimed to compare the acid-base status measured by net acid-base excretion (NABE) in urine with results of venous blood analysis in clinically healthy, but possibly metabolically burdened cows in their transition period. For this, we sampled blood from the jugular vein and urine from 145 German Holstein cows within 1 to 76 days post-partum. In blood, the metabolic parameters non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHB), as well as numerous parameters of the acid-base status were measured. The traditional approach, based on bicarbonate concentration, base excess (BE) and anion gap (AG), was compared to the strong ion approach variables, e.g. acid total (Atot), measured strong ion difference (SIDm), strong ion gap (SIG), and unmeasured anions (XA), respectively. Results of both approaches were set against the outcome of urine analysis, i.e. the NABE, base-acid ratio and pH of urine, in a cluster analysis, which provided 7 moderately stable clusters. Evaluating and interpreting these 7 clusters offered novel insights into the pathophysiology of the acid-base equilibrium in fresh post-partum dairy cows. Especially in case of subclinical acid-base disorders, the parameters of the strong ion difference theory, particularly SIDm, Atot and SIG or XA, provided more in-depth information about acid-base status than the traditional parameters BE, bicarbonate or AG in blood. The acid-base status of fresh cows with protein aberrations in blood could be differentiated in a much better way using the strong ion approach than by traditional blood gas analysis or by the measurement of urinary excretion. Therefore, the strong ion approach seems to be a suitable supplement for monitoring acid-base balance in dairy cattle.

Invited review: Mineral absorption mechanisms, mineral interactions that affect acid-base and antioxidant status, and diet considerations to improve mineral status

Several minerals are required for life to exist. In animals, 7 elements (Ca, P, Mg, Na, K, Cl, and S) are required to be present in the diet in fairly large amounts (grams to tens of grams each day for the dairy cow) and are termed macrominerals. Several other elements are termed microminerals or trace minerals because they are required in much smaller amounts (milligrams to micrograms each day). In most cases the mineral in the diet must be absorbed across the gastrointestinal mucosa and enter the blood if it is to be of value to the animal. The bulk of this review discusses the paracellular and transcellular mechanisms used by the gastrointestinal tract to absorb each of the various minerals needed. Unfortunately, particularly in ruminants, interactions between minerals and other substances within the diet can occur within the digestive tract that impair mineral absorption. The attributes of organic or chelated minerals that might permit diet minerals to circumvent factors that inhibit absorption of more traditional inorganic forms of these minerals are discussed. Once absorbed, minerals are used in many ways. One focus of this review is the effect macrominerals have on the acid-base status of the animal. Manipulation of dietary cation and anion content is commonly used as a tool in the dry period and during lactation to improve performance. A section on how the strong ion theory can be used to understand these effects is included. Many microminerals play a role in the body as cofactors of enzymes involved in controlling free radicals within the body and are vital to antioxidant capabilities. Those same minerals, when consumed in excess, can become pro-oxidants in the body, generating destructive free radicals. Complex interactions between minerals can compromise the effectiveness of a diet in promoting health and productivity of the cow. The objective of this review is to provide insight into some of these mechanisms.

A velocidade de infusão da solução poli-iônica intravenosa contendo 84mEq/L de lactato determina a intensidade do efeito alcalinizante em equinos

RESUMO O objetivo deste trabalho foi verificar os efeitos da solução poli-iônica intravenosa contendo 84mEq/L de lactato (L84) sobre os equilíbrios hidroeletrolítico e ácido-base de equinos, quando administrada de forma rápida ou lenta. Cinco equinos sadios adultos receberam a infusão contínua intravenosa da L84, em volume correspondente a 10% do peso corporal, em duas ocasiões: a) infusão rápida (16,66mL/kg/h) durante seis horas; b) infusão lenta (8,33mL/kg/h) durante 12 horas. Amostras de sangue venoso foram colhidas ao início da infusão (hora zero) e três, seis, nove, 12 e 24 horas após, e amostras de urina nas horas zero, seis, 12 e 24. Determinaram-se pH (sanguíneo e urinário), pCO2, HCO3 -, BE, PPT, lactato L, Na+, K+, Cl-, AG, SID, Atot, VVP, densidade urinária e excreções fracionadas urinárias de lactato L, Na+, K+ e Cl-. A L84 provoca efeito alcalinizante iatrogênico de menor magnitude quando administrada de forma lenta, porque os mecanismos renais, atuantes durante o período de infusão, promovem a correção gradativa do desequilíbrio. Pode-se concluir que a infusão de forma lenta da solução L84 em equinos é recomendável nos casos em que se suspeite de acidose metabólica e não seja possível quantificar o grau do desequilíbrio.

Effect of Intravenously Administered Crystalloid Solutions on Acid-Base Balance in Domestic Animals

Intravenous fluid therapy can alter plasma acid-base balance. The Stewart approach to acid-base balance is uniquely suited to identify and quantify the effects of the cationic and anionic constituents of crystalloid solutions on plasma pH. The plasma strong ion difference (SID) and weak acid concentrations are similar to those of the administered fluid, more so at higher administration rates and with larger volumes. A crystalloid's in vivo effects on plasma pH are described by 3 general rules: SID > [HCO3-] increases plasma pH (alkalosis); SID < [HCO3-] decreases plasma pH (alkalosis); and SID = [HCO3-] yields no change in plasma pH. The in vitro pH of commercially prepared crystalloid solutions has little to no effect on plasma pH because of their low titratable acidity. Appreciation of IV fluid composition and an understanding of basic physicochemical principles provide therapeutically valuable insights about how and why fluid therapy can produce and correct alterations of plasma acid-base equilibrium. The ideal balanced crystalloid should (1) contain species-specific concentrations of key electrolytes (Na+ , Cl- , K+ , Ca++ , Mg++ ), particularly Na+ and Cl- ; (2) maintain or normalize acid-base balance (provide an appropriate SID); and (3) be isosmotic and isotonic (not induce inappropriate fluid shifts) with normal plasma.

Blood acid-base status in impala (Aepyceros melampus) immobilised and maintained under total intravenous anaesthesia using two different drug protocols

BACKGROUND

In mammals, homeostasis and survival are dependent on effective trans-membrane movement of ions and enzyme function, which are labile to extreme acid-base changes, but operate efficiently within a narrow regulated pH range. Research in patients demonstrating a pH shifts outside the narrow regulated range decreased the cardiac output and systemic vascular resistance and altered the oxygen binding to haemoglobin. These cardiopulmonary observations may be applicable to the risks associated with anaesthesia and performance of wildlife ungulates on game farms. The aim of this study was to compare blood pH changes over time in impala immobilised and anaesthetised with two different drug protocols (P-TMP - immobilisation: thiafentanil-medetomidine; maintenance: propofol-ketamine-medetomidine; P-EME - immobilisation: etorphine-medetomidine; maintenance: etorphine-ketamine-medetomidine). Additionally, we discuss the resultant blood pH using both the Henderson-Hasselbalch and the Stewart approaches. Two data collection time points were defined, Time1 before maintenance of general anaesthesia and Time 2 at end of maintenance of general anaesthesia. We hypothesise that blood pH would not be different between drug protocols and would not change over time.

RESULTS

Significant differences were detected over time but not between the two drug protocols. Overall, the blood pH decreased over time from 7.37 ± 0.04 to 7.31 ± 0.05 (p = 0.001). Overall, over time arterial partial pressure of carbon dioxide changed from 51.3 ± 7.5 mmHg to 72.6 ± 12.4 mmHg (p < 0.001); strong ion difference from 44.6 ± 2.4 mEq/L to 46.9 ± 3.1 mEq/L (p < 0.001); anion gap from 15.0 ± 3.1 mEq/L to 10.9 ± 2.2 mEq/L (p < 0.001); and total weak acids from 16.1 ± 1.2 mmol/L to 14.0 ± 1.1 mmol/L (p < 0.001). The bicarbonate changed from 29.6 ± 2.7 mEq/L to 36.0 ± 4.1 mEq/L (p < 0.001); and lactate changed from 2.9 ± 1.5 mEq/L to 0.3 ± 0.03 mEq/L (p < 0.001) over time.

CONCLUSIONS

The profound increase in the partial pressure of carbon dioxide that worsened during the total intravenous anaesthesia in both protocols initiated a substantial metabolic compensatory response to prevent severe acidaemia. This compensation resulted in a clinically acceptable mild acidaemic state, which worsened over time but not between the protocols, in healthy impala. However, these important compensatory mechanisms require normal physiological function and therefore when immobilising ill or anorexic wild ungulates their acid-base status should be carefully assessed.

Physicochemical characterization of in situ drug-polymer nanocomplex formed between zwitterionic drug and ionomeric material in aqueous solution

Biocompatible polymeric materials with the potential to form functional structures, in association with different therapeutic molecules, in physiological media, represent a great potential for biological and pharmaceutical applications. Therefore, here the formation of a nano-complex between a synthetic cationic polymer and model drug (ampicillin trihydrate) was studied. The formed complex was characterized by size and zeta potential measurements, using dynamic light scattering and capillary electrophoresis. Moreover, the chemical and thermodynamically stability of these complexes were studied. The ionomeric material, here referred as EuCl, was obtained by equimolar reaction between Eudragit E and HCl. The structural characterization was carried out by potentiometric titration, FTIR spectroscopy, and DSC. The effect of pH, time, polymer concentration and ampicillin/polymer molar ratio over the hydrodynamic diameter and zeta potential were established. The results show that EuCl ionomer in aqueous media presents two different populations of nanoparticles; one of this tends to form flocculated aggregates in high pH and concentrations, by acquiring different conformations in solution by changing from a compact to an extended conformation. Moreover, the formation of an in situ interfacial polymer-drug complex was demonstrated, this could slightly reduce the hydrolytic degradation of the drug while affecting its solubility, mainly under acidic conditions.

NOVA SOLUÇÃO ELETROLÍTICA INTRAVENOSA PARA USO VETERINÁRIO: EFEITOS SOBRE O PERFIL ELETROLÍTICO E ÁCIDO BASE EM BOVINOS ADULTOS HÍGIDOS

Resumo Objetivou-se avaliar os efeitos de uma nova solução hidratante intravenosa sobre os equilíbrios eletrolítico e ácido-base de bovinos. Para tanto, oito animais adultos hígidos, mestiços taurinos foram submetidos a dois tratamentos em delineamento cross-over: solução salina isotônica (SI) e solução teste (ST) composta por 145 mEq de Na+, 5 mEq de K+, 4 mEq de Ca++, 2 mEq de Mg++, 96 mEq de Cl-, 60 mEq de lactato, 50 g de dextrose e 4 mg de cianocobalamina por litro. As soluções foram administradas por via intravenosa, em volume correspondente a 5% do peso corporal, durante três horas de infusão contínua. Amostras de sangue venoso foram colhidas antes da infusão e três, seis, nove e 24 horas após o início da infusão para determinações de glicose, lactato L, Ca, P, Mg, pH, pCO2, HCO3-, BE, Na+, K+, Cl- e Ca++. Os resultados foram analisados por análise de variâncias de medidas repetidas. Ao contrário da SI, que causou hipercloremia e redução da diferença de íons fortes no plasma (SID), determinando efeito acidificante, a ST gerou alcalinização leve e transitória e não provocou alteração das concentrações de Na+ e de Cl-. A hipopotassemia e a hiperglicemia, presentes ao final da infusão da ST, foram transitórias e não determinaram sinais clínicos evidentes. Conclui-se que a ST é uma alternativa segura para a terapia com fluidos em bovinos, tendo a vantagem de provocar alterações iatrogênicas de baixa magnitude.

Effects of alkalinization and rehydration on plasma potassium concentrations in neonatal calves with diarrhea

Background

Increased plasma potassium concentrations (K⁺) in neonatal calves with diarrhea are associated with acidemia and severe clinical dehydration and are therefore usually corrected by intravenous administration of fluids containing sodium bicarbonate.

Objectives

To identify clinical and laboratory variables that are associated with changes of plasma K⁺ during the course of treatment and to document the plasma potassium‐lowering effect of hypertonic (8.4%) sodium bicarbonate solutions.

Animals

Seventy‐one neonatal diarrheic calves.

Methods

Prospective cohort study. Calves were treated according to a clinical protocol using an oral electrolyte solution and commercially available packages of 8.4% sodium bicarbonate (250–750 mmol), 0.9% saline (5–10 L), and 40% dextrose (0.5 L) infusion solutions.

Results

Infusions with 8.4% sodium bicarbonate solutions in an amount of 250–750 mmol had an immediate and sustained plasma potassium‐lowering effect. One hour after the end of such infusions or the start of a sodium bicarbonate containing constant drip infusion, changes of plasma K⁺ were most closely correlated to changes of venous blood pH, plasma sodium concentrations and plasma volume (r = −0.73, −0.57, −0.53; P < .001). Changes of plasma K⁺ during the subsequent 23 hours were associated with changes of venous blood pH, clinical hydration status (enophthalmos) and serum creatinine concentrations (r = −0.71, 0.63, 0.62; P < .001).

Conclusions and Clinical Importance

This study emphasizes the importance of alkalinization and the correction of dehydration in the treatment of hyperkalemia in neonatal calves with diarrhea.