Fluid Therapy In Horses Research Articles

Clinical effects of immunization, bleeding, and albumin-based fluid therapy in horses used as immunoglobulin source to produce a polyspecific antivenom (Echitab-plus-ICP) towards venoms of African snakes.

During the production of snake antivenoms, the animals used as immunoglobulin source are subjected to processes that could deteriorate their physical condition. Therefore, these conditions must be carefully designed and validated. In this work, the immunization and bleeding protocols applied to horses used to produce the African polyspecific antivenom EchiTAb-plus-ICP were evaluated regarding their effects on the horses' health. The study focused on horses that had been previously immunized with venoms and then received periodic booster venom injections for antivenom production. It was found that the periodic immunization with 5mg of a mixture of venoms of Bitis arietans, Echis ocellatus, Dendroaspis polylepis, and Naja nigricollis did not induce systemic signs of envenomation, and only caused mild swelling at the injection site, which did not evolve to abscesses, fistulas, or fibrosis. Three consecutive days of bleeding, collecting 6-8L of blood per day, and self-transfusing the red blood cells (RBC) in the second and third days, did not induce evident cardiorespiratory alterations. However, this procedure caused significant reductions in RBC, hematocrit, hemoglobin, and total plasma protein values. Seven weeks after bleeding, these parameters were recovered, and horses were ready for the next immunization/bleeding cycle. The intravenous administration of equine albumin, at a dose of 2g/kg body weight, increased the apparent plasma volume and the albumin concentration. However, this procedure induced early adverse reactions and transient alterations of the serum levels of the enzyme gamma-glutamyl transferase (GGT), thus suggesting some degree of hepatic injury. It was concluded that immunization and bleeding as described in this work do not cause significant clinical alterations in the horse's health, except for a transient drop in some hematological parameters. The albumin-based fluid therapy used does not hasten the recovery after bleeding but instead induces adverse events in the animals.

Comparative Trial of Continuous Flow Enteral and Intravenous Fluid Therapy in Horses.

Continuous flow enteral fluid therapy with isotonic and hypotonic enteral electrolyte solutions are as safe and effective as intravenous fluid therapy. The aim of this study was to carry out a comparative assessment between continuous flow enteral and intravenous (IV) fluid therapy in adult experimentally dehydrated horses. Six experimentally dehydrated adult mares were used in a study carried out in a 6 × 3 crossover design, which each animal received three different treatments (isotonic enteral fluid therapy—EsISO, hypotonic enteral fluid therapy—EsHYPO and intravenous fluid therapy with Lactate Ringer Solution—LR IV, all in continuous flow). Solutions were administered at a rate of 15 mL−1.kg−1.h−1 for 8 h, after 36 h of water and food deprivation. Serum and urinary biochemical assessment; urinary volume, pH and specific gravity; and blood gas analysis were measured at −36, 0, 2, 4, 6, and 8 h. The dehydration period (DP) caused discrete hydroelectrolytic and acid base imbalances. The EsISO, EsHYPO and LR IV increased blood volume. Enteral solutions restored the imbalances yielded by the DP and all treatments increased urine volume. Also, the EsHYPO and LR IV showed no effects in acid base balance, while EsISO showed slightly acidifying effect. The present study certifies the efficacy and safety of isotonic and hypotonic continuous flow enteral fluid therapy in comparison to IV fluid therapy in dehydrated horses.

Current Concepts in Fluid Therapy in Horses.

Despite the frequent inclusion of fluid therapy in the treatment of many conditions in horses, there are limited studies available to provide evidenced-based, species-specific recommendations. Thus, equine fluid therapy is based on the application of physiology and extrapolation from evidence in other veterinary species and human medicine. The physiologic principles that underly the use of fluids in medicine are, at first glance, straightforward and simple to understand. However, in the past 20 years, multiple studies in human medicine have shown that creating recommendations based on theory in combination with experimental and/or small clinical studies does not consistently result in best practice. As a result, there are ongoing controversies in human medicine over fluid types, volumes, and routes of administration. For example, the use of 0.9% NaCl as the replacement fluid of choice is being questioned, and the theoretical benefits of colloids have not translated to clinical cases and negative effects are greater than predicted. In this review, the current body of equine research in fluid therapy will be reviewed, connections to the controversies in human medicine and other veterinary species will be explored and, where appropriate, recommendations for fluid therapy in the adult horse will be made based on the available evidence. This review is focused on the decisions surrounding developing a fluid plan involving crystalloids, synthetic colloids, and plasma.

Fluid therapy in horses: how much is too much?

Fluid therapy in horses: how much is too much?

Enteral Fluid Therapy in Horses: Effects of Maintenance Hypotonic Electrolyte Solutions Containing Maltodextrin, Sucrose, or Dextrose Administered in Continuous Flow

To evaluate the effects of maintenance hypotonic electrolyte solutions containing carbohydrates administered by nasoesophageal tube in continuous flow in horses during 12 hours on body weight, waist circumference, water intake, aspect and moisture content of the stool, frequency of defecation, urine density and urinary glucose, sodium, potassium, chloride, urea and creatinine, and urinary volume in horses. We used six mares randomly divided into three treatments in two Latin squares 6 × 3, concurrent, in mixed model. All solutions had the same composition (5 g of NaCl, 0.5 g of KCl, 200 mg of magnesium pidolate, and 1 g of calcium gluconate, diluted in 1,000 mL of water), only differing in power source and osmolarity, ESMaltodextrin—electrolyte solution plus 15 g of maltodextrin (measured osmolarity of 203 mmol L−1); ESSucrose—electrolyte solution plus 15 g of sucrose (measured osmolarity of 234 mmol L−1); and ESDextrose—electrolyte solution plus 15 g of dextrose (measured osmolarity of 264 mmol L−1). The electrolyte solutions were administered at a dose of 15 mL kg−1 h−1 for 12 hours in continuous flow. Maintenance hypotonic electrolyte solutions containing maltodextrin, dextrose, and sucrose were effective in promoting diuresis and decreasing urinary density, without presenting adverse effects. ESSucr was more effective in softening the stool.

Effects of a new intravenous electrolyte solution for veterinary therapy on the electrolyte and acid-base balances of healthy horses

ABSTRACT: The effects of a new intravenous electrolyte solution for veterinary therapy on electrolyte and acid-base balances of horses were evaluated, assessing the potential of the use of this solution as a rational alternative in fluid therapy. Eight healthy adult horses, including 4 males and 4 females, received two treatments in a cross-over design: isotonic saline solution (IS) and a test solution (TS) containing 145mEq of Na+, 5mEq of K+, 4mEq of Ca++, 2mEq of Mg++, 96mEq of Cl-, 60mEq of lactate, 50g of dextrose, and 4mg of cyanocobalamin per liter. Solutions were IV infused in a volume corresponding to 5% of BW, over 3 hours. Venous blood samples were taken 5 times before and after the infusion (at 0, 3, 6, 9 e 24h), for pHv, pCO2v, HCO3 -v, BEv, Na+, K+, Cl-, Ca++, Ca, P, Mg, glucose and L-lactate measurements, and AG and SID calculations. The data were analyzed through repeated measures ANOVA. The IS caused mild acidifying effect by increasing Cl- and decreasing plasma SID. In contrast, the TS induced mild and transient hypochloremia without changes in acid-base balance. Hyperglycemia was present at the end of the TS infusion and reversed 6 hours later. The horses did not exhibit any clinical changes. We concluded that TS is an option for fluid therapy in horses.

Evaluation of Equine Albumin Solution in Fluid Therapy in Horses with Colic

Equine albumin solution can be a good therapeutic option in fluid replacement for treatment of horses with colic. The purpose of this study was to evaluate the effects of initial fluid therapy with equine albumin solution in horses presenting with colic and mild-to-moderate dehydration, and to compare this therapy with fluid therapy based on crystalloids alone. Nineteen horses of both genders presenting with colic and mild-to-moderate dehydration were used. Animals were randomly assigned to one of two groups (control: fluid therapy based on crystalloid solutions; experimental: fluid therapy based on equine albumin and crystalloid solutions). Physical examination, hematocrit determination, blood gas analysis, serum biochemistry, blood and peritoneal lactate assessment, and measurement of colloid osmotic and arterial pressure were performed at predetermined times. Good results were obtained with equine albumin solution. More fluid is attracted into and maintained in the intravascular compartment, despite infusion of small volumes, as indicated by higher arterial pressure, lower capillary refill time, lower hematocrit and serum protein concentrations, lower colloid osmotic pressure, and better skin turgor. Equine albumin solution has good oncotic action and is a safe fluid therapy option for horses with colic and mild-to-moderate dehydration. Our results suggest it can be a good choice of fluid for correction of severe dehydration, although further research is necessary to determine the adequate dose in such cases.

Solução concentrada de albumina eqüina na fluidoterapia em eqüinos com desidratação leve a moderada

Avaliou-se o efeito da solução concentrada de albumina eqüina diluída a 5% em solução fisiológica (SF) durante fluidoterapia em eqüinos, após indução de desidratação leve a moderada, utilizando-se cinco eqüinos adultos, sem alterações clínicas. Cada animal passou por dois protocolos de fluidoterapia: apenas com SF (metade sob pressão e metade em fluxo contínuo - grupo-controle); com solução de albumina eqüina e SF (apenas em fluxo contínuo - grupo experimental). Avaliaram-se peso, exame físico geral, hematócrito, osmolalidade plasmática, gasometria, proteína total, albumina, uréia, creatinina, Na, K, débito cardíaco e pressão arterial, e calcularam-se pressão oncótica e volume plasmático. Após a aplicação de metade da SF sob pressão nos animais do grupo-controle, as alterações no hematócrito, na proteína total, na albumina, na pressão arterial e na pressão oncótica foram semelhantes às encontradas nos do grupo experimental após aplicação apenas da solução de albumina. Conclui-se que a solução de albumina eqüina é de fácil preparação e aplicação, não demonstra efeitos deletérios na dose e velocidade utilizadas e é passível de ser utilizada como colóide na fluidoterapia na espécie eqüina.

Estimation of Acute Fluid Shifts Using Bioelectrical Impedance Analysis in Horses

Background: Multi‐frequency bioelectrical impedance analysis (MF‐BIA) has been used to evaluate extracellular fluid volume (ECFV), but not fluid fluxes associated with fluid or furosemide administration in horses. If able to detect acute changes in ECFV, MF‐BIA would be useful in monitoring fluid therapy in horses. Hypothesis: The purpose of this study was to evaluate the ability of MF‐BIA to detect acute fluid compartment changes in horses. We hypothesized that MF‐BIA would detect clinically relevant (10–20%) changes in ECFV. Animals: Six healthy mares were used in the study. Methods: This is an original experimental study. Mares were studied in 3 experiments: (1) crystalloid expansion of normally hydrated subjects, (2) furosemide‐induced dehydration followed by crystalloid administration, and (3) acute blood loss followed by readministration of lost blood. MF‐BIA measurements were made before, during, and after each fluid shift and compared to known changes in volume calculated based on the intravenous fluids that were administered in addition to urinary fluid losses. Mean errors between MF‐BIA estimated change and known volume change were compared using nonparametric analysis of variance. Estimated ECFV pre‐ and post‐fluid administration similarly were compared. The level of statistical significance was set at P < .05. Results: Results of the study revealed a statistically significant change in ECFV and total body water during crystalloid expansion and dehydration. Statistically significant changes were not observed during blood loss and administration. Mean errors between MF‐BIA results and measured net changes were small. Conclusions and Clinical Importance: MF‐BIA represents a practical and accurate means of assessing acute fluid changes during dehydration and expansion of ECFV using isotonic crystalloids with potential clinical applications in equine critical care.

Measurement of extravascular lung water by the double indicator dilution method using heat and sodium in horses under general anesthesia.

Rapid infusion is believed to be harmful to the lung, however, the pathological status of pulmonary edema resulting from excessive fluid therapy in horses has not been clarified because the quantitative diagnosis of pulmonary edema is impossible. To evaluate the precision of the double indicator dilution method using heat and sodium in horses, which allows the quantitative diagnosis of pulmonary edema, we compared extravascular lung water volume measured using a lung water computer based on the theory of the double indicator dilution method with that determined by the direct method. The value of extravascular thermal volume (ETV) determined by the double indicator dilution method was 7.82 +/- 0.62 ml/kg and the detection ratio of ETV to the value of pulmonary extravascular water volume (PEWV) by the direct method was 0.996 +/- 0.038. There was a significant correlation between ETV and PEWV (P < 0.05), and the regression line was Y = 1.23 X - 1.73 with a correlation coefficient of 0.953. The value of extravascular lung water determined by the double indicator dilution method was significantly consistent with that obtained by the direct method, indicating the high precision of the double indicator dilution method in normal horse lungs.

Fluid Therapy in Horses with Acute Diarrhea

Fluid Therapy in Horses with Acute Diarrhea