Topic:Dehydration
Dehydration in horses refers to a state where there is an insufficient amount of water in the body to maintain normal physiological functions. This condition can result from inadequate water intake, excessive fluid loss due to sweating, diarrhea, or other factors affecting fluid balance. Dehydration affects various bodily systems, including the circulatory, digestive, and muscular systems, and can impact a horse's performance and overall health. Signs of dehydration in horses may include dry mucous membranes, decreased skin elasticity, and an elevated heart rate. This page compiles peer-reviewed research studies and scholarly articles that explore the causes, effects, detection, and management of dehydration in equine populations.
Responses of hematological parameters, beta-endorphin, cortisol, reactive oxygen metabolites, and biological antioxidant potential in horses participating in a traditional tournament. Several concerns have been raised over the health of animals used in equestrian games that have their origins in historical or religious events and are currently held in many countries. This study investigated physiological stress response and health status of horses participating in the Sartiglia, a historical horse tournament held in the city of Oristano, Italy, which is principally based on the attempts of masked horsemen at a gallop to run a sword through a hole in a suspended silver star. Blood samples were collected from 21 horses the day before the tournament (D0), during the tournament...
Effects of oral powder electrolyte administration on packed cell volume, plasma chemistry parameters, and incidence of colic in horses participating in a 6-day 162-km trail ride. This study evaluated the effects of administering oral powder electrolytes on packed cell volume (PCV), plasma chemistry parameters, and incidence of colic in horses participating on a 6-day 162-km trail ride in which water was not offered ad libitum. Twenty-three horses received grain with powder electrolytes daily while 19 control horses received grain only. Horses were ridden approximately 32 km a day at a walk or trot. Packed cell volume and plasma chemistry parameters were analyzed daily. Episodes of colic were diagnosed and treated by a veterinarian unaware of treatment group allocation....
Rapid weight-loss impairs simulated riding performance and strength in jockeys: implications for making-weight. Despite the performance concerns of dehydration in other sports, there are currently no data on the effects of rapid weight-loss on the physical and cognitive performance of jockeys in a sport-specific context. In a randomised crossover design, eight Great Britain (GB) male licensed jockeys were assessed for chest strength, leg strength, simulated riding performance (assessed by maximum pushing frequency on a mechanical riding simulator during the final two furlongs of a simulated 2 mile race) and simple reaction time after performing 45 min of exercise, during which euhydration was maintained...
[Examination of horses with acute colic – clinical pathology and diagnostic imaging]. The article summarizes the relevant clinical pathological assessment of horses with acute colic. A minimal laboratory evaluation should include the patient's haematocrit (or packed cell volume), total protein, and lactate concentration in the blood. Haematocrit and total protein provide an indication of the severity of dehydration (haematocrit < 0.45 l/l is evidence of no to mild dehydration whereas > 0.5 l/l points to a severe dehydration). The degree of dehydration is often associated with the severity of the colic. Additionally, the blood lactate concentration rises with increasing intesti...
Physicochemical interpretation of acid-base abnormalities in 54 adult horses with acute severe colitis and diarrhea. The quantitative effect of strong electrolytes, pCO2 , and plasma protein concentration in determining plasma pH and bicarbonate concentrations can be demonstrated with the physicochemical approach. Plasma anion gap (AG) and strong ion gap (SIG) are used to assess the presence or absence of unmeasured anions. Objective: The physicochemical approach is useful for detection and explanation of acid-base disorders in horses with colitis. AG and SIG accurately predict hyperlactatemia in horses with colitis. Methods: Fifty-four horses with acute colitis and diarrhea. Methods: Retrospective study. Ph...
Systemic, renal, and colonic effects of intravenous and enteral rehydration in horses. Intravenous (IV) and intragastric (IG) administration of fluid therapy are commonly used in equine practice, but there are limited data on the systemic, renal, and enteric effects. Objective: IV fluid administration will increase intestinal and fecal hydration in a rate-dependent manner after hypertonic dehydration, but will be associated with significant urinary water and electrolyte loss. Equivalent volumes of IG plain water will result in comparatively greater intestinal hydration with less renal loss. Methods: Six Thoroughbred geldings. Methods: Experimental study. 6 by 6 Latin square desi...
Behavior of renin angiotensin aldosterone axis during pulling exercises in euhydrated and dehydrated horses. The influence of hydration prior to exercise on hormonal response to exercise was investigated in horses, divided into two groups, control (n=11) and dehydrated (n=53). They were also classified according to their body weight in A (≈ 350 kg), B (351-450 kg) and C (≈ 451 kg). Horses covered 60 m on a track pulling a carriage loaded with 2, 2.25 and 2.5 times their body weight, for A, B and C. Blood samples were taken at rest, after exercise and during recovery. Electrolytes, albumin, renin, angiotensin and aldosterone concentrations were measured. Dehydrated and control horses had higher al...
Osmotic stress and membrane phase changes during freezing of stallion sperm: mode of action of cryoprotective agents. The aim of this study was to determine how different membrane-permeable and -impermeable cryoprotective agents modulate tolerance of stallion sperm to osmotic stress and stabilize membranes during cryopreservation. Special emphasis was on hydroxyl ethylene starch (HES), which exposes cells to minimal osmotic stress due to its large molecular weight. Percentages of motile sperm post-thaw were found to be similar when glycerol, sucrose, and HES were used at their optimal concentrations. Percentages of plasma membrane intact sperm after return to isotonic medium were highest for HES. Fourier tran...
An alternative dietary strategy to make weight while improving mood, decreasing body fat, and not dehydrating: a case study of a professional jockey. Professional jockeys are unique among weight-making athletes, as they are often required to make weight daily and, in many cases, all year-round. Common methods employed by jockeys include dehydration, severe calorie restriction, and sporadic eating, all of which have adverse health effects. In contrast, this article outlines a structured diet and exercise plan, employed by a 22-yr-old professional National Hunt jockey in an attempt to reduce weight from 70.3 to 62.6 kg, that does not rely on any of the aforementioned techniques. Before the intervention, the client's typical daily energy intak...
Membrane phase behavior during cooling of stallion sperm and its correlation with freezability. Stallion sperm exhibits great male-to-male variability in survival after cryopreservation. In this study, we have investigated if differences in sperm freezability can be attributed to membrane phase and permeability properties. Fourier transform infrared spectroscopy (FTIR) was used to determine supra and subzero membrane phase transitions and characteristic subzero membrane hydraulic permeability parameters. Sperm was obtained from stallions that show differences in sperm viability after cryopreservation. Stallion sperm undergoes a broad and gradual phase transition at suprazero temperatures...
A comparison of hypertonic (7.2%) and isotonic (0.9%) saline for fluid resuscitation in horses: a randomized, double-blinded, clinical trial. Hypertonic saline solution (7.2%) (HSS) can quickly replace intravascular volume deficits. HSS more recently has been advocated in the treatment of traumatic brain injury, but its use in dehydrated patients remains controversial. Objective: Hypertonic saline solution will show a significant improvement in both clinical and laboratory hydration parameters as compared to isotonic (0.9%) saline solution (ISS). Methods: Endurance horses eliminated from the 2009 Western States 100-mile (220-km) endurance ride and requiring IV fluid therapy were eligible for enrollment in the study. Methods: Twenty-...
Metabolic changes in four beat gaited horses after field marcha simulation. Mangalarga-Marchador is a popular 4-gaited Brazilian horse breed; however, there is little information about their metabolic and physiological response to exercise. Objective: To measure physiological and metabolic responses of the Mangalarga-Marchador to a simulated marcha field test and to compare these responses between 2 types of marcha gaits (picada and batida). Methods: Thirteen horses were used in the study and randomly assigned to either the picada or batida gait for the simulated marcha field test (speed ∼ 3.2 m/s; 30 min; load ∼ 80 kg). Methods: Included body composition, heart r...
Dehydration, electrolyte imbalances and renin-angiotensin-aldosterone-vasopressin axis in successful and unsuccessful endurance horses. Limited information exists concerning the defence of homeostasis during endurance competitions and the relationship with performance. Objective: This research analysed renin (REN), angiotensin II (ANG), aldosterone (ALD) and vasopressin (AVP) in horses covering different distances, assesses differences between successful and eliminated horses and evaluates correlations between hydration status, renal function, electrolytes, REN, ANG, ALD and AVP. Methods: Packed cell volume (PCV), velocity and serum concentrations of REN, ANG, ALD, AVP, Na, K, Cl, Ca, Mg, P, creatine kinase, aspartate aminotra...
The effects of hypohydration on central venous pressure and splenic volume in adult horses. Central venous pressure (CVP) is used in many species to monitor right-sided intravascular volume status, especially in critical care medicine. Objective: That hypohydration in adult horses is associated with a proportional reduction in CVP. Methods: Ten healthy adult horses from the university teaching herd. Methods: In this experimental study, horses underwent central venous catheter placement and CVP readings were obtained by water manometry. The horses were then deprived of water and administered furosemide (1 mg/kg IV q6h) for up to 36 hours. Weight, CVP, vital signs, PCV, total protein (...
Muscle damage, hydration, electrolyte balance and vasopressin concentrations in successful and exhausted endurance horses. Arginine vasopressin (AVP) is released in response to depletion of the effective circulating blood volume. Endurance horses might develop exhaustion because loss of water and electrolytes in sweat with hypovolaemia and electrolytes abnormalities. Therefore, AVP should act in the control of volemia in these animals. This research evaluates the differences in AVP, hydration, electrolyte status and serum muscle enzymes in successful endurance horses in comparison with those eliminated from the competition because of exhaustion. Eighteen endurance horses, divided into two groups, successful (n = 1...
The effects of hypertonic dehydration changes on renal function and arginine vasopressin in the horse during pulling exercises. This study investigated the effect of hypertonic dehydration on exercise in horses. Valencian draft horses (n=43) with hypertonic dehydration following water and food deprivation and competing in pulling events (COM), were compared to euhydrated horses (n=11) during a pulling exercise test (PET). Both groups were divided into bodyweight (BW) categories A (≤350 kg), B (351-450 kg), and C (≥451 kg), and pulled 2, 2.25, and 2.5 times BW, respectively. Exercise duration (ED) was 1.3±0.8 min. Heart rate, respiratory rate, rectal temperature and blood samples were taken at rest, after exercise,...
Membrane permeability parameters for freezing of stallion sperm as determined by Fourier transform infrared spectroscopy. Cellular membranes are one of the primary sites of injury during freezing and thawing for cryopreservation of cells. Fourier transform infrared spectroscopy (FTIR) was used to monitor membrane phase behavior and ice formation during freezing of stallion sperm. At high subzero ice nucleation temperatures which result in cellular dehydration, membranes undergo a profound transition to a highly ordered gel phase. By contrast, low subzero nucleation temperatures, that are likely to result in intracellular ice formation, leave membrane lipids in a relatively hydrated fluid state. The extent of free...
Application of the sodium dilution principle to calculate extracellular fluid volume changes in horses during dehydration and rehydration. To apply the principle of sodium dilution to calculate the changes in the extracellular fluid (ECF) volume (ECFV) and intracellular fluid volume (ICFV) that occur during dehydration and rehydration in horses. Methods: 8 healthy horses of various breeds. Methods: Horses were dehydrated over 4 hours by withholding water and administering furosemide. Saline (0.9% NaCl) solution was administered IV during the next 2 hours (20 mL/kg/h; total 40 mL/kg). Horses were monitored for an additional hour following IV fluid administration. Initial ECFV was determined by use of multifrequency bioelectrical i...
Fluid and electrolyte supplementation after prolonged moderate-intensity exercise enhances muscle glycogen resynthesis in Standardbred horses. We hypothesized that postexercise rehydration using a hypotonic electrolyte solution will increase the rate of recovery of whole body hydration, and that this is associated with increased muscle glycogen and electrolyte recovery in horses. Gluteus medius biopsies and jugular venous blood were sampled from six exercise-conditioned Standardbreds on two separate occasions, at rest and for 24 h following a competitive exercise test (CET) designed to simulate the speed and endurance test of a 3-day event. After the CETs, horses were given water ad libitum, and either a hypotonic commercial electrol...
Hepatic diseases in horses. The concept 'liver disease' includes several pathological conditions affecting liver's functions. It can either consist of a temporary impaired functioning of the liver and/or it can progress to its failure. The purpose of this review is to update the knowledge on hepatobiliary diseases and in particular on equine hyperlipaemia. Hepatobiliary disease's aetiology, clinical signs, diagnosis and nutritional management are thus described in the first part of the review the second part being devoted to hyperlypaemia's lipid metabolism, epidemiology, clinical signs, post-mortem observations and nutr...
Validity of indicators of dehydration in working horses: a longitudinal study of changes in skin tent duration, mucous membrane dryness and drinking behaviour. Dehydration is a serious welfare concern in horses working in developing countries. Identification of a valid and practical indicator of dehydration would enable more rapid treatment and prevention. Objective: To examine changes in bodyweight, clinical and blood parameters during rehydration of working horses, identify a 'gold standard' criterion for dehydration and use this to validate a standardised skin tent test, drinking behaviour and mucous membrane dryness as potential field indicators. Methods: Fifty horses with a positive skin tent test, working in environmental temperatures of 30-44 ...
Use of cecal bypass via side-to-side ileocolic anastomosis without ileal transection for treatment of cecocolic intussusception in three horses. 3 horses were evaluated for signs of colic; cecocolic intussusception was detected. Results: Abnormalities detected included diminished intestinal sounds, inflammatory leukogram, dehydration, unremarkable fi ndings via rectal palpation, and ultrasonographic evidence of large intestine intussusception. Laparotomy revealed cecocolic intussusception. Results: Cecal bypass via side-to-side ileocolic anastomosis without ileal transection was performed in each horse by use of an intraluminal anastomosis stapler device. Postoperative complications were minimal, and all horses recovered rapidly and we...
Probing the role of water in lamellar bone by dehydration in the environmental scanning electron microscope. Water, collagen and mineral are the three major components of bone. The structural organization of water and its functions within the bone were investigated using the environmental scanning electron microscope and by analyzing dimensional changes that occur when fresh equine osteonal bone is dehydrated and then rehydrated. These changes are attributed mainly to loss of bulk and weakly bound water. In longitudinal sections a contraction of 1.2% was observed perpendicular to the lamellae, whereas no contraction occurred parallel to the lamellae. In transverse sections a contraction of 1.4% was o...
Hydration of exercised standardbred racehorses assessed noninvasively using multi-frequency bioelectrical impedance analysis. In human and animal clinical practice, multi-frequency bioelectrical impedance analysis (MF-BIA) is increasingly used as a diagnostic tool to assess hydration of intra-and extracellular fluid compartments. Accurate determination of changes in hydration status within individuals over time has remained problematic due to the requirement for complete impedance-frequency relationships at the time points of interest. Objective: To use MF-BIA in 13 Standardbred racehorses and 7 'endurance' research horses to determine if MF-BIA could be used to track changes in total body water (TBW), intracellular ...
Estimation of acute fluid shifts using bioelectrical impedance analysis in horses. 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. Objective: 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. Methods: Six healthy mares were used in the study. Methods: This is an original ...
Enteral fluid therapy in large animals. Enteral fluids administered alone, or in conjunction with intravenous fluids, are reported to be useful for the treatment of dehydration and electrolyte loss associated with diarrhoea in a number of species, following exercise in horses and for feed impaction of the large intestine of horses. Enteral fluids are suitable for treatment of mild to moderately dehydrated patients with some intact intestinal epithelium and motile small intestine. In patients that will drink voluntarily or tolerate nasal intubation the use of enteral fluids may avoid the complications associated with intravenous flui...
Validity of a behavioural measure of heat stress and a skin tent test for dehydration in working horses and donkeys. Dehydration and heat stress are serious welfare issues for equids working in developing countries. There is a lack of any standardised method or validated interpretation of the skin tent test in horses and donkeys. Owners of dehydrated and heat-stressed animals often depend on veterinary examination for identification of these conditions, leading to delays in treatment and unnecessary reliance on external sources to effect welfare improvement. Objective: To validate a standardised skin tent test for dehydration and a behavioural measure of heat stress in working equids; and to examine the effe...
Diarrhea and hyperammonemia in a horse with progressive neurologic signs. A 2-year-old, Quarter Horse filly was referred to Michigan State University, Veterinary Teaching Hospital with a 2-3 day history of depression and partial anorexia progressing to severe, watery diarrhea with severe neurologic abnormalities, including repetitive muscle fasciculations, muscle stiffening, and collapse. Laboratory findings included severe polycythemia, neutropenia, metabolic acidosis, and electrolyte and fluid loss, consistent with watery diarrhea and endotoxic shock. Increased creatine kinase and aspartate transaminase activities were consistent with recent transport and the musc...
Neurologic signs and hyperammonemia in a horse with colic. A 23-year-old Thoroughbred gelding was referred for the evaluation of acute onset of ataxia and depression, and a 2-day history of fever. On physical examination, the gelding was profoundly depressed and 10-12% dehydrated. The horse appeared very unstable, with a wide-based stance in the hind limbs, severe symmetric ataxia in all 4 limbs, and proprioceptive deficits in both hind limbs. Nasogastric intubation produced 4 L of brown, fetid reflux, and rectal examination revealed mild small intestinal and cecal distention. Hematologic abnormalities included neutropenia with toxic change, compatibl...