Topic:Water
The relationship between water and horses encompasses the study of hydration, water intake, and the physiological roles of water in equine health. Water is essential for maintaining various bodily functions in horses, including thermoregulation, digestion, and cellular processes. Horses require adequate water intake to support their metabolic needs and overall well-being. Factors influencing water consumption in horses include diet, environmental conditions, and activity levels. This page compiles peer-reviewed research studies and scholarly articles that explore the physiological importance of water, factors affecting water intake, and the implications of water balance on equine health and performance.
Molecular dynamics simulation of equine infectious anemia virus Tat protein in water and in 40% trifluoroethanol. Two molecular dynamics (MD) simulations were performed in order to increase the understanding of the dependence of protein conformation on solvent environment. The protein used for these simulations is the transcriptional activator of the equine infectious anemia virus (EIAV-Tat). The structure of this protein has been determined by nuclear magnetic resonance (NMR) in aqueous solution (Willbold et al., Science 264, 1584 (1994)) and in 40% (v/v) trifluoroethanol (TFE) (Sticht et al., Eur. J. Biochem., submitted) showing considerable differences in the stability of the secondary structure elemen...
Measurement of gastric emptying of water in foals by impedance epigastrography. Impedance epigastrography was used to measure gastric emptying rates on two occasions in each of three foals. After smoothing of the raw data, emptying of water appeared to obey an exponential model. The mean emptying rate constant (SEM) was 0.171 +/- 0.038 min-1 (mean emptying half time 4.9 +/- 1.0 min).
[Possibilities for the all-year free-range raising of horses]. The ethological concept concerning supply of needs an avoidance of damage is mentioned as a possibility for the evaluation of welfare aspects related to animal management. The 250 Dülmen horses kept on 300 ha by the Duke of Croy show what must be provided for horse-keeping in a semi-natural environment: Sufficient food and water, efficient shelter as well as adequate structures for the needs of horses concerning social and comfort behaviour. A catalogue of factors, functions and facilities for this kind of horse-keeping is presented.
Gastric emptying of four liquid meals in pony foals. Water, saline and a saline/Intralipid mixture (lipid concentration 1.25 per cent) emptied very rapidly from the stomach in neonatal pony foals, and obeyed an apparently exponential pattern. Cisapride did not significantly modify the emptying of the saline/Intralipid mixture. Equine milk emptied more slowly. The data indicated that the lipid component of milk was not an important factor. Milk caused deviation from an exponential pattern in two of four foals: an initial lag phase appeared, which could represent a phase of intragastric processing. However, the rate was still rapid compared with r...
The role of sweat in maintaining the stimulation of effort homeostasis in horses. Sweat secretion was analyzed quantitatively and qualitatively in 20 horses after a 5 min. gallop at 450 m/min. The analysis revealed concentration of proteins 63.3 +/- 6.47 g/l, mainly albumins, a high level of sodium 254.43 +/- 62.84 mM/,l chloride 268.68 +/- 98.46 mM/l, potassium 98.95 +/- 49.62 mM/l and calcium 4.14 +/- 0.8 mM/l. A dependence was found between the protein concentration in serum and its quantity in sweat and between the level of potassium in sweat and its loss from the cells within a range 8.6 to 25.8 mM/l. The hypertonic horse sweat protects organism for excessive water los...
Effects of dehydration and rehydration on plasma vasopressin and aldosterone in horses. We have investigated the change in plasma vasopressin and aldosterone concentrations in Namib (desert-adapted) and in control horses from a subtropical region, during an acute 12% dehydration and during rehydration, while food was available. During dehydration, vasopressin concentrations increased significantly in both groups of horses, but the increase was significantly greater in Namib horses than in control horses. During rehydration, vasopressin levels fell, but fell significantly less in Namib horses. The change in vasopressin concentration correlated significantly with plasma osmolality ...
[Riding arenas and different riding track surfaces in relation to the airway contamination in horses. Laboratory studies on riding surfaces]. 29 samples of commonly used surfaces were tested for their water characteristics (litre weight, water capacity, water binding, water evaporation) and their contribution to airborne fungal spores (dust formation, dust setting). The results are discussed in comparison to the literature with regard to the environment. The results are: 1. Any surface--no matter of what material--eventually causes air pollution with fungal spores and dust. 2. Correct watering prevents air pollution by any surface. 3. Artificial products have no advantage over natural materials in the parameters tested. 4. The quest...
Comparison of the effects of intragastric infusions of equal volumes of water, dioctyl sodium sulfosuccinate, and magnesium sulfate on fecal composition and output in clinically normal horses. A Latin square design was used to compare the effects of laxatives and a corresponding volume of water on gastrointestinal tract function in 4 healthy horses. Horses were intragastrically infused with each of the following: dioctyl sodium sulfosuccinate (DSS; 50 mg/kg of body weight); magnesium sulfate (0.5 g/kg--low dosage); magnesium sulfate (1.0 g/kg--high dosage); and an equal volume of water (6 L) given as a control infusion. From 5 to 33 hours after the high dosage of magnesium sulfate, feces were slightly softer than usual in all horses. In 1 horse, DSS caused mild colic, hyperpnea, and...
Milk and water intakes of foals sucking grazing mares. Intakes of milk and milk nutrients were determined for 8 foals at 11-18 days of age and for 10 foals at 30-44 days and 60-74 days of age while sucking grazing mares. Water intakes (sources other than milk) of the foals were determined at 30-44 days and 60-74 days of age. Five of the 10 mares were fed a protein supplement (24% crude protein) in addition to grazing during the stud season. The protein supplement did not influence foal intakes of milk and milk nutrients, milk composition, weight gains of the mares or the growth rate of the foals. Foal milk intakes increased (P less than 0.05) from...
Thirst and salt appetite in horses treated with furosemide. When a preliminary experiment in sodium-replete ponies revealed an increase, but not a significant increase, in salt consumption after furosemide treatment, the experiment was repeated using sodium-deficient horses in which aldosterone levels might be expected to be elevated to test the hypothesis that a background of aldosterone is necessary for salt appetite. Ten Standardbred mares were injected intravenously with furosemide or an equivalent volume of 0.9% sodium chloride as a control to test the effect of furosemide on their salt appetite and blood constituents. Sodium intake and sodium los...
Effect of whole-body potassium depletion on plasma, erythrocyte, and middle gluteal muscle potassium concentration of healthy, adult horses. The effects of whole-body potassium depletion induced by food deprivation on plasma, erythrocyte, and middle gluteal muscle K concentrations was quantified in 16 healthy, adult horses before, during, and at the end of a 7-day period of food deprivation during which water and sodium chloride were available ad libitum. Potassium concentrations were determined by atomic absorption spectroscopy. Plasma K concentration remained constant (3.49 +/- 0.09 mM K/L of plasma; mean +/- SEM) throughout the study. Erythrocyte potassium concentration decreased from 93.10 +/- 1.94 mM K/L of erythrocytes on day...
Water homeostasis in desert-dwelling horses. This study set out to investigate tolerance of the body water pool to short-term water deprivation in horses and, in particular, to assess whether feral horses from the Namib Desert showed tolerance to dehydration superior to Transvaal. Hydration status was compared in six feral horses from the Namib Desert and in six Boerperd farm horses under conditions of normal hydration and after 72 h of dehydration. Under normal hydration, the two groups did not differ significantly in water intake, plasma sodium and potassium concentrations, plasma osmolality, hematocrit, total plasma protein, body wate...
Vibrational modes of hemoglobin in red blood cells. Equine red blood cells were washed in saline heavy water (2H2O) to exchange the hydrogen atoms of the non-hemoglobin components with deuterons. This led to novel neutron scattering measurements of protein vibrations within a cellular system and permitted a comparison with inelastic neutron scattering measurements on purified horse hemoglobin, either dry or wetted with 2H2O. As a function of wavevector transfer Q and the frequency transfer v the neutron response typified by the dynamic structure factor S(Q, v) was found to be similar for extracted and cellular hemoglobin at low and high tempera...
[Several physiologic aspects of the reactions of foals in the first three days after weaning]. Changes have been observed in nine foals, six months of age, after weaning for the time of three days, namely in the intake of drinking water, hematocrit, sedimentation of erythrocytes and three minerals Na+, K+ and Cl-. Foals respond to weaning immediately, lowering significantly their consumption of drinking water and increasing high significance of Na+ and Cl-. Changes of level K+, hematocrit and sedimentation don't show any significant variations. The results reached are to be considered as an introductory information for further inquiry on the more extensive methodical basis.
Gastric rupture in horses: 50 cases (1979-1987). A computer-based search was conducted of medical and necropsy records of horses admitted to the teaching hospital from Jan 1, 1979, to Dec 31, 1987, to obtain the records of all horses admitted to the hospital for colic and subsequently found to have gastric rupture. Fifty cases of gastric rupture were found. The records were reviewed to obtain data regarding peritoneal fluid analysis. Cell counts of these samples were often erroneous because debris and clumps of bacteria were counted when most WBC were lysed. A cross-sectional study of gastric rupture cases versus all other colic cases regard...
Stimuli of thirst in donkeys (Equus asinus). A study of the stimuli of thirst was conducted on six feral donkeys. Donkeys were found to be stimulated to drink by overnight water deprivation, by the diuretic furosemide, and by hypertonic saline infusion, all in the absence of heat stress or work. Donkeys compensate accurately for the fluid deficit caused by overnight water deprivation. After 19 hr without water, they drank 8.8 +/- 2.4 (mean +/- SE) liters within 60 min. Their undeprived overnight intake was 8.4 +/- 1.5 liters. However, latency was longer and water intake was less than that of ponies with the same changes in blood paramete...
Changes in articular cartilage after intra-articular injections of methylprednisolone acetate in horses. Eight mature horses with no prior signs of joint disease or history of intra-articular therapy were treated with 8 weekly intra-articular injections of methylprednisolone acetate. Treatments were given at a dose of 120 mg/joint into the right radiocarpal and intercarpal joints, with the left joints as untreated controls. Articular cartilage samples were obtained at necropsy 1, 4, and 8 weeks after the last injection. Compared with controls, cartilage from injected joints had a loss of hematoxylin basophilia and decreased intensity of staining in safranin O fast green dye. Chondrocyte necrosis ...
Large colon resection. With large colon resection and anastomosis, up to 95 per cent of the length of the large colon has been successfully removed. A hand-sewn end-to-end anastomosis is effective for lesions in the left dorsal colon and pelvic flexure. Transection and a side-to-side anastomosis with stapling equipment is most effective for extensive resections (greater than 50 per cent). Horses with extensive colon resection (95 per cent) have permanent deficiencies of water absorption and digestion of cellulose and protein. Fermentative capacity is reduced, owing to decreased particulate matter retention time in t...
Vasopressin in dehydrated and rehydrated ponies. Six pony mares deprived of water for 24 hours showed significant increases in plasma vasopressin (2.8 pg/ml) and osmolality (9 mosmol/kg). When water was made available the ponies drank rapidly (5 of 6 drank to satiety within 90 seconds) and corrected their fluid deficits precisely. Vasopressin did not return to predehydration levels until osmolality did after 15 minutes of access to water. The horse differs from rodents and humans, but is similar to pigs in that vasopressin levels do not fall before osmolality returns to normal. Oropharyngeal factors, therefore, may not be as important in vas...
Effect of water vapor-saturated air therapy on bronchoalveolar lavage and tracheal mucus transport rate in clinically normal horses. Water vapor-saturated air was delivered to 12 healthy, housed horses for 2 hours daily for 5 days. Treatment had no effect on tracheal mucus transport rate, bronchoalveolar lavage total and differential cell counts, blood cell counts, or plasma fibrinogen concentration.
Digestion, fecal, and blood variables associated with extensive large colon resection in the horse. Nutritional alterations were evaluated in 9 horses before surgery and 3 weeks, 3 months, and 6 months (4 total trials) after sham operation (group 1; n = 3) or extensive large colon resection (group 2; n = 6). Feed and fecal analyses were performed to determine apparent digestion of dry matter, organic matter, crude protein, calcium, phosphorus, magnesium, potassium, manganese, zinc, copper, and iron, and true digestion of dry matter, organic matter, crude protein, total plant cell wall, hemicellulose, cellulose, and lignin. Additional fecal and metabolic variables included the percentage of f...
External balance of water and electrolytes in the horse. The components of the daily external water and electrolyte balances of five normal Standardbred geldings with a mean body weight of 427 kg, were determined over 14 day periods. The mean value of daily total water intake (a summation of free, combined and metabolic water intake) for the group was 27.6 litres, that is, 64.4 ml/kg body weight, while mean values for ambient temperature and humidity ranged from 16 to 25 degrees C and 55.4 to 75.5 per cent, respectively. The mean daily urine volume of 9.9 litres (23.2 ml/kg) for the group, was found to exceed the mean faecal water output of 7.2 litr...
Dietary requirements and athletic performance of horses. There is no clear evidence that the chronic requirement for any non-energy yielding nutrient rises in proportion as the energy requirement increases with hard work. The need for protein, and probably that for calcium, remain a function of bodyweight daily. Some proportionality with energy may exist for certain nutrients, although the evidence has not been adduced. For example, because of an increase in both the proportion and amount of propionic acid in the volatile fatty acids of caecal contents, the tissue requirement for vitamin B12 may rise with an increase in the rate of energy metabolism...
The use of urea as a marker of body water in the nursing foal. Urea, compared with deuterium oxide (D2O) as a reference, was used as a body marker to estimate body water volume in ten 2-month old nursing foals. Plasma urea clearance was regular over 10 h and the R2 of the disappearance curve was between 0.93 and 0.98. Mean urea space was about 4% lower than D2O space, but the standard deviation of the proportion of water in body weight was higher with urea (3.8%) than with D2O (1.6%). Calculated urea entry rate was 49 mg/h/kg LW0.75.
Effect of meal frequency on fluid balance and behavior of ponies. Twelve ponies were fed their total daily ration either as one large meal or divided into six small meals. Pre- and post-feeding behavior was recorded six times a day. Blood samples were taken for 30 min before and two hr after the meal. Plasma protein increased from 7.0 to a peak of 7.3 g/dl with small meals and from 7.3 to 8.1 g/dl with large meals, and returned to pre-feeding levels by 90 min post-feeding. Hematocrit rose from 33.3 to 34.1% with small meals and from 33.0 to 36.0% with large meals. These rapid and short-lived increases indicate a decrease in plasma volume. Plasma osmolality r...
Functional design of horse hoof keratin: the modulation of mechanical properties through hydration effects. Tensile moduli and J-integral fracture toughness values were determined for horse hoof-wall keratin at four hydration levels. The stiffness of hoof-wall was influenced by water content to a greater degree than is the stiffness of other mammalian hard keratins. Young's modulus increased from 410 MPa at 100% relative hydration (RH) to 14.6 GPa at 0% RH. Fracture toughness was maximal (22.8 kJ m-2) at an intermediate hydration (75% RH), which represents a two-fold increase over both fully hydrated and dehydrated material. Maximum fracture toughness occurred at a hydration level which is within th...
Enteroliths in horses. Many cases of enteroliths were reported in the nineteenth century but the number greatly decreased in the early twentieth century. However, in recent years the number of cases in certain parts of the United States such as California has greatly increased. The reasons for the increase are obscure. The intake of nitrogen, magnesium and phosphorus (the primary components of enteroliths) from water and food is likely to be a factor. Arabians may be more likely to develop enteroliths than horses of other breeds. A nidus such as a small stone is needed because a nidus has been found in every enterol...
Some properties of different skeletal muscle fiber types: comparison of reference bases. Several biochemical components of the white portion of the gastrocnemius (WGM), plantaris (PM), and soleus (SM) muscles of the rat and middle gluteal (MGM) muscle of the horse were compared based on wet and dry weight, protein, and total creatine concentrations ([TCr]). The water content was similar for the rat hindlimb muscles, however, the concentrations of protein, ATP, phosphocreatine (PCr), creatine, and glycogen ranked as SM less than PM less than WGM for all reference bases except total creatine. In contrast, concentrations of ATP, creatine, and PCr were similar in all muscles studied w...