Biomedical subjects

J H Foreman

Publications and source records attributed to J H Foreman.

At least 19 recordsLinked to original sources

PubMed2002

Forelimb skeletal scintigraphy responses in previously untrained Thoroughbreds undergoing initial treadmill training.

Scintigraphy has been used in numerous clinical settings to examine horses to determine the origin of lameness problems, but it has not been used previously to monitor prospectively the skeletal responses of a group of similarly-trained racehorses. Our hypothesis was that in naïve Thoroughbred (TB) racehorses, initial treadmill training induces increased radiopharmaceutical uptake in high-motion joints and in the dorsal third metacarpal bone (MC3). Eight previously-untrained TB racehorses underwent sequential skeletal scintigraphic examinations as they exercised daily for 9 weeks on an inclined treadmill. At the end of Weeks 0 (pre-training), 3 (trotting at 4.2 m/s and initial galloping), 6 (galloping at 7.5 m/s), and 9 (sprinting 600 m at 12.5 m/s), horses received 140 mCi 99m Technetium-methylene diphosphonate i.v. followed by a standard skeletal scintigraphic forelimb examination 2 h later. Views were graded for increased radiopharmaceutical uptake by 3 co-investigators who were blinded to horse identification, breed, sex, date, and clinical findings. Results were compared before and after training for each skeletal location using the Mann-Whitney Rank Sum Test with the level of significance set at P<0.05. Initial treadmill training resulted in increased radiopharmaceutical uptake in the carpus (P = 0.031), metacarpophalangeal joint (P = 0.021), proximal phalanx (P = 0.035), and distal phalanx (P = 0.003). Training did not affect dorsal MC3 radiopharmaceutical uptake (P>0.05).

Animals↗

PubMed2001

Technical note: using calcium carbonate as an osmolar control treatment for acid-base studies in horses.

The efficacy of using calcium carbonate as an osmolar control treatment for acid-base studies in horses receiving alkalizing compounds was evaluated. Six mares were nasogastrically intubated with isomolar quantities of sodium or calcium as sodium bicarbonate or calcium carbonate or with water during three treatment periods. Doses of the carbonic acid salts were 500 mg/kg sodium bicarbonate mixed with 4 L of distilled water (positive control) and 595 mg/kg calcium carbonate mixed with 2 L of distilled water to yield isoosmolar treatments. Four liters of distilled water served as the negative control. Jugular venous blood samples were drawn before intubation and at hourly intervals for 6 h after intubation. The serum electrolytes Na+ and K+, blood pH, and HCO3- were determined. The sodium bicarbonate treatment increased blood pH and HCO3- (P < 0.01) above both the water and CaCO3 treatments. No differences (P > 0.05) were found between the water and CaCO3 treatments. These data indicate that calcium carbonate may serve as a suitable osmolar control treatment for studying the effects of treatments that affect acid-base status of horses.

Acid-Base Equilibrium↗

PubMed2000

Short- and long-term survival and prevalence of postoperative ileus after small intestinal surgery in the horse.

The records of 74 horses that recovered from anaesthesia after surgery for a small intestinal lesion from 1994 to 1999 were reviewed. Sixty-three horses (85%) had a strangulating lesion and 43 of these (68%) had a resection and anastomosis. Four of 11 horses (36%) without a strangulating lesion had a resection and anastomosis. Sixty-three horses (85%) survived to discharge, with a survival rate of 53/63 in horses with a strangulating lesion (84%) and 10/11 (91%) in others. For all lesions, short-term survival for all end-to-end anastomoses (91%; 21/23) and for no resection (92%; 23/25) were superior (P < 0.05) to survival for jejunocaecal anastomosis (76%; 19/25). Fourteen horses (19%) had a repeat abdominal surgery during hospitalisation; 9 of these (64%) survived short-term. Postoperative ileus developed in 7/70 horses (10%) after surgery for a problem other than proximal enteritis, and all had a strangulating lesion. Postoperative ileus (POI) was more likely after a jejunocaecostomy than after other procedures, and did not develop after a jejunojejunostomy. Survival > 7 months was 52/69 (75%) and for > 12 months was 39/57 (68%). The estimated prevalence of adhesions was 13%. Short-term survival was poorest in horses that had a jejunocaecostomy, but long-term survival was less affected by the anastomosis used. The sharpest decline in survival was during the first postoperative week and postoperative mortality then declined over time after surgery. A postoperative protocol that allowed early postoperative feeding was well tolerated. The results confirm that the overall prognosis after small intestinal surgery in horses is improved over earlier findings.

Anastomosis, Surgical↗

PubMed1999

Parietal hernia of the small intestine into the epiploic foramen of a horse.

A 12-year old 573-kg (1,261-lb) Quarter Horse gelding was referred with colic of 12 hours' duration and with poor response to medical treatment. On the basis of physical and laboratory findings, a pelvic flexure impaction was suspected. The horse was treated medically. Because signs of mild abdominal pain persisted and the heart rate had increased, an exploratory celiotomy was performed 30 hours after signs of colic were first noticed. At surgery, the ileum was found partially entrapped within the epiploic foramen, in a left-to-right direction, to form a parietal hernia. The entrapped intestinal segment was reduced but not resected, and the horse recovered fully. In retrospect, the delay before surgery in this horse was tolerated because this was a parietal hernia and, therefore, did not cause complete ileal obstruction. This horse had an unusual form of small-intestinal strangulation in the epiploic foramen that might not cause sufficient obstruction initially to allow early detection.

Animals↗

PubMed1999

Equine respiratory pharmacology.

Differentiation of diseases of the equine respiratory tract is based on history, clinical signs, auscultation, endoscopy, imaging, and sampling of airway exudate. Upper respiratory therapies include surgical correction of airway obstructions; flushing of localized abscesses (strangles), guttural pouch disease, or sinusitis; and oral or parenteral antibiotic and anti-inflammatory therapy if deemed necessary. Pneumonia usually is treated with antimicrobials, anti-inflammatories, and bronchodilators. Pleural drainage is indicated if significant pleural effusion is present. The most commonly used therapies for early inflammatory and chronic allergic obstructive conditions include bronchodilators and anti-inflammatories. Acute respiratory distress, particularly acute pulmonary edema, is treated with diuretics (usually furosemide), intranasal oxygen, bronchodilators, corticosteroids, and alleviation of the underlying cause. Furosemide also had been used in North America as a race-day preventative for exercise-induced pulmonary hemorrhage (EIPH), but recent data have shown that furosemide may be a performance-enhancing agent itself.

Animals↗

PubMed1999

Environmental stress and 3-day eventing: effects of altitude.

Three-day event horses are subject to various external environmental stresses including changes in ambient temperature, humidity, altitude, and test severity. Considerable research on the adverse effects of increased heat and humidity preceded the 1996 Olympic Summer Games in Atlanta, Georgia USA, but no research has been done previously on the effects of altitude on 3-day eventing. Physical and venous blood gas data were collected on horses (n = 24) competing in the High Prairie Preliminary (CCN*) and Intermediate (CCN**) 3-day events and Preliminary Horse Trials in Parker, Colorado (1900 m above sea level). Despite the increased altitude, only post exercise rectal temperature and pH were higher (P < 0.05) whereas heart rate (HR), [K+], and ionized calcium (ICa++) were lower (P < 0.05) in 3-day event horses compared to horse trial horses. All other variables (respiratory rate [RR], PCV, [Hb], PCO2, [tCO2], [HCO3-], BE, and [Na+]) were not different between groups (P > 0.05). When these preliminary horse trial horses in Colorado were compared to those previously studied at preliminary horse trials at sea level in Arizona, post exercise HR and RR were higher (P < 0.05) and pH, PCO2, [tCO2], [HCO3-], BE and [iCa++] were lower (P < 0.05) at altitude. These data show that increased altitude (1900 m above sea level) was more stressful for 3-day event horses, but did not result in the severe physiological changes and inability to complete prescribed exercise tests seen in previous studies with increased heat and humidity. It is clear from these and previous data that increased heat and humidity are the more important environmental stressors in 3-day eventing.

Animals↗

PubMed1999

Necrotizing mycotic vasculitis with cerebral infarction caused by Aspergillus niger in a horse with acute typholocolitis.

An 18-year-old Morgan mare was presented to the Veterinary Medical Teaching Hospital, University of Illinois, with a 10-day history of watery diarrhea, depression, and dysphagia. On admission, the animal was severely dehydrated, depressed, and unable to swallow and had no clinical signs of diarrhea. The respiratory and heart rate and body temperature were within normal limits. Following fluid therapy, the mare developed severe watery diarrhea and continued to be depressed, incoordinated, and dysphagic. The animal died on the fourth day after admission and was sent to the Laboratories of Veterinary Diagnostic Medicine for necropsy. Gross postmortem findings were consistent with an acute cerebral infarction in the right cerebral hemisphere, an acute necrotizing typhlocolitis, multifocal petechial and ecchymotic hemorrhages, enlarged and congested pars intermedia of the pituitary gland, and marked bilateral adrenocortical hyperplasia with multifocal areas of necrosis and hemorrhage. Histologic evaluation of the affected brain demonstrated an area of coagulative necrosis of the gray matter, with hemorrhage, vasculitis, and thrombosis. There were many fungal hyphae 3.5-6.0 microm, pale basophilic, septate, and occasionally branching at 45 degrees present in the arterial walls and throughout the necrotic tissue. Immunohistochemical analysis revealed Aspergillus niger as the etiologic agent responsible for the mycotic vasculitis and infarction in the brain. Bacteria culture and immunohistochemical staining of the colon and cecum failed to demonstrate specific pathogens.

Acute Disease↗

PubMed1999

Techniques for evaluation of right ventricular relaxation rate in horses and effects of inhalant anesthetics with and without intravenous administration of calcium gluconate.

OBJECTIVES: To determine the most repeatable method for evaluating right ventricular relaxation rate in horses and to determine and compare effects of isoflurane or halothane with and without the added influence of intravenously administered calcium gluconate on right ventricular relaxation rates in horses. ANIMALS: 6 Thoroughbred horses from 2 to 4 years old. PROCEDURE: 6 models (2 for monoexponential decay with zero asymptote, 3 for monoexponential decay with variable asymptote, and 1 for biexponential decay) for determining right ventricular relaxation rate were assessed in conscious and anesthetized horses. The 2 methods yielding the most repeatable results then were used to determine right ventricular relaxation rates in horses anesthetized with isoflurane or halothane before, during, and after i.v. administration of calcium gluconate. Right ventricular pressure was measured, using a catheter-tip high-fidelity pressure transducer, and results were digitized at 500 Hz from minimum rate of change in ventricular pressure. RESULTS: 2 models that used monoexponential decay with zero asymptote repeatedly produced an estimate for relaxation rate and were used to analyze effects of anesthesia and calcium gluconate administration on relaxation rate. Isoflurane and halothane each prolonged right ventricular relaxation rate, with greater prolongation evident in halothane-anesthetized horses. Calcium gluconate attenuated the anesthesia-induced prolongation in right ventricular relaxation rate, with greater response obtained in isoflurane-anesthetized horses. CONCLUSIONS AND CLINICAL RELEVANCE: Right ventricular relaxation rate in horses is assessed best by use of a monoexponential decay model with zero asymptote and nonlinear regression. Intravenous administration of calcium gluconate to isoflurane-anesthetized horses best preserves myocardial relaxant function.

Anesthetics, Inhalation↗

PubMed1999

Hemodynamic effects of ionized calcium in horses anesthetized with halothane or isoflurane.

OBJECTIVES: To evaluate the effects of halothane and isoflurane on cardiovascular function and serum total and ionized calcium concentrations in horses, and to determine whether administration of calcium gluconate would attenuate these effects. ANIMALS: 6 clinically normal adult Thoroughbreds. PROCEDURE: Catheters were inserted for measurement of arterial blood pressures, pulmonary arterial blood pressures, right ventricular pressure (for determination of myocardial contractility), right atrial pressure, and cardiac output and for collection of arterial blood samples. Anesthesia was then induced with xylazine hydrochloride and ketamine hydrochloride and maintained with halothane or isoflurane. An i.v. infusion of calcium gluconate was begun 75 minutes after anesthetic induction; dosage of calcium gluconate was 0.1 mg/kg of body weight/min for the first 15 minutes, 0.2 mg/kg/min for the next 15 minutes, and 0.4 mg/kg/min for an additional 15 minutes. Data were collected before, during, and after administration of calcium gluconate. RESULTS: Halothane and isoflurane decreased myocardial contractility, cardiac index, and mean arterial pressure, but halothane caused greater depression than isoflurane. Calcium gluconate attenuated the anesthetic-induced depression in cardiac index, stroke index, and maximal rate of increase in right ventricular pressure when horses were anesthetized with isoflurane. When horses were anesthetized with halothane, a higher dosage of calcium gluconate was required to attenuate the depression in stroke index and maximal rate of increase in right ventricular pressure; cardiac index was not changed with calcium administration. CONCLUSIONS AND CLINICAL RELEVANCE: I.v. administration of calcium gluconate may support myocardial function in horses anesthetized with isoflurane.

Anesthesia, Inhalation↗

PubMed1999

Hemodynamic effects of thyroidectomy in sedentary horses.

OBJECTIVE: To investigate hemodynamic effects of thyroidectomy in horses at rest. ANIMALS: 6 healthy aged Quarter Horse mares. PROCEDURE: Horses were monitored for 5 months before and 4 weeks after thyroidectomy and for an additional 4 weeks after administration of thyroid hormone supplement (2.5 microg of thyroxine/kg of body weight, PO, q 12 h, and 0.6 microg of triiodothyronine/kg, PO, q 12 h). Responses to thyroid-stimulating hormone (TSH) were measured before and 4 weeks after thyroidectomy. Other variables monitored daily were resting rectal temperature (T), heart rate (HR), respiratory rate (RR), and body weight (BW). Monthly cardiac output (Q), blood volume (BV), plasma volume (PV), standard electrocardiographic measures, systolic and right ventricular blood pressure, and HR responses were determined after IV administration of isoproterenol and phenylephrine. Variables were analyzed by use of repeated-measures ANOVA. RESULTS: Complete thyroidectomy was confirmed by minimal response to TSH 4 weeks after surgery. Resting HR, RR, T, Q, and beta-adrenergic responsiveness to isoproterenol decreased significantly after thyroidectomy. Resting T, Q, and beta-adrenergic responsiveness increased after administration of supplement and was not significantly different from euthyroid values. Blood volume and PV increased significantly after thyroidectomy but did not return to euthyroid values despite administration of supplement. Response to phenylephrine was minimally different between treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Thyroidectomy in horses caused decreased resting HR, RR, T, Q, and isoproterenol responsiveness and increased BV, PV, PQ interval, and QT interval corrected for HR. Some of these surgically induced changes appeared to be partially reversed by administration of thyroid hormone supplement.

Adrenergic alpha-Agonists↗

PubMed1998

Comparison of hypertonic saline-dextran solution and lactated Ringer's solution for resuscitating severely dehydrated calves with diarrhea.

OBJECTIVE: To determine effectiveness of rapid i.v. administration of hypertonic saline-dextran (HSD) solution combined with oral administration of isotonic electrolyte solution for resuscitating severely dehydrated calves and to compare the resuscitative response with that of a conventional treatment of lactated Ringer's solution (LRS) i.v. and orally administered isotonic electrolyte solution. DESIGN: Prospective study. ANIMALS: 15 male dairy calves 3 to 10 days old. PROCEDURE: Baseline data were obtained. Osmotic diarrhea and severe dehydration were induced for 48 hours. Calves were then allocated to 3 treatment groups. The control group (group C) did not receive fluids, a second group (group H) received hypertonic saline (7.2% NaCl) solution with 6% dextran 70 and isotonic electrolyte solution, and a third group (group L) received LRS and isotonic electrolyte solution. Physical examinations were performed every 8 hours. RESULTS: Calves developed diarrhea, lethargy, severe dehydration (mean, 14% of body weight), azotemia, hyperkalemia, and mild acidemia. Group-C calves remained lethargic and severely dehydrated during the 24-hour treatment phase. Calves treated with HSD and LRS were effectively resuscitated; however, response for most variables was more rapid and sustained for the HSD-treated group. Cardiac output was greater in LRS- than HSD-treated calves 1, 2, and 8 hours after initiation of treatment because of continued i.v. administration of fluids. CLINICAL IMPLICATIONS: A combination of HSD and isotonic electrolyte solution was a rapid and effective method for resuscitation of severely dehydrated calves. It was similar in effectiveness to conventional treatment in which LRS and isotonic electrolyte solution were used for resuscitating calves with severe dehydration.

Administration, Oral↗

PubMed1998

Clinical and laboratory assessment of hydration status of neonatal calves with diarrhea.

OBJECTIVE: To develop accurate, objective guidelines for assessing hydration status of neonatal calves with diarrhea. DESIGN: Prospective study. ANIMALS: 15 male dairy calves 3 to 10 days old. PROCEDURE: Dehydration and diarrhea were induced by administration of diuretic agents (i.e., furosemide, spironolactone, hydrochlorothiazide) and sucrose solution. Linear regression was used to examine the relationship between potentially useful factors for evaluating hydration status (extent of enophthalmos; skin-tent duration on neck, thorax, and upper and lower eyelids; heart rate; mean central venous pressure; peripheral [extremity] and core [rectal] temperatures; core-peripheral [rectal-extremity] temperature difference; PCV; and hemoglobin and plasma protein concentrations) and degree of dehydration, as determined by change in body weight. RESULTS: Best predictors of degree of dehydration were extent of enophthalmos, skin elasticity on neck and thorax, and plasma protein concentration. CLINICAL IMPLICATIONS: These experimentally determined guidelines provide practitioners with a simple, inexpensive, and practical method for evaluating hydration status of neonatal calves with diarrhea.

Animals↗

PubMed1998

The exhausted horse syndrome.

Exhaustion occurs in most equestrian sports, but it is more frequent in events that require sustained endurance work such as endurance racing, three-day eventing, trial riding, and hunting. Exhaustion is also more likely when an unfit, unacclimatized, or unsound horse is exercised. Mechanisms that contribute to exhaustion include heat retention, fluid and electrolyte loss, acid-base imbalance, and intramuscular glycogen depletion. Clinical signs include elevated temperature, pulse, and respiratory rate; depression; anorexia; unwillingness to continue to exercise; dehydration; weakness; stiffness; hypovolemic shock; exertional myopathy; synchronous diaphragmatic flutter; atrial fibrillation; diarrhea; colic; and laminitis. Treatment includes stopping exercise; rapid cooling; rapid large volume intravenous or oral fluid administration; and nonsteroidal anti-inflammatory drug administration.

Acclimatization↗

PubMed1998

Use of peripheral temperature and core-peripheral temperature difference to predict cardiac output in dehydrated calves housed in a thermoneutral environment.

OBJECTIVE: To investigate the relation between cardiac output (CO) and peripheral (fetlock) temperature (PT) and core-peripheral (rectal-fetlock) temperature difference (CPTD) in dehydrated calves housed in a thermoneutral environment. ANIMALS: 28 male dairy calves 3 to 10 days old. PROCEDURE: Severe dehydration and watery diarrhea were induced by administering diuretics (furosemide, hydrohlorothiazide, spironolactone) and sucrose solution. Cardiac output was measured by means of thermodilution, core temperature was determined by placing a digital thermometer in the rectum, and PT was measured by taping a thermistor to the left hind fetlock and insulating the thermistor from ambient air. RESULTS: In thermoneutral ambient temperatures (10 to 24 C), PT and CPTD were constant and independent of CO at normal or high CO values but were linearly dependent on CO below a critical value (78% of normal CO output). Regression equations were developed that predicted CO from measured PT or CPTD. At ambient temperatures below the lower critical temperature for neonatal calves (8 to 10 C), normal values for PT and CPTD in healthy calves were significantly different from those at thermoneutral ambient temperatures. CONCLUSIONS AND CLINICAL RELEVANCE: Peripheral temperature and CPTD are practical, noninvasive, and inexpensive but only moderately useful methods for predicting CO in hemodynamically stable calves housed in a thermoneutral environment. Thus, these parameters are of some value in daily monitoring of the response to treatment and in determining need for i.v. fluid administration in dehydrated calves housed at a dry still-air temperature of 10 to 24 C but are of minimal to no value in calves housed at < 10 C.

Animals↗

PubMed1998

A reliable, practical, and economical protocol for inducing diarrhea and severe dehydration in the neonatal calf.

Fifteen healthy, colostrum-fed, male dairy calves, aged 2 to 7 d were used in a study to develop a diarrhea protocol for neonatal calves that is reliable, practical, and economical. After instrumentation and recording baseline data, diarrhea and dehydration were induced by administering milk replacer [16.5 mL/kg of body weight (BW), PO], sucrose (2 g/kg in a 20% aqueous solution, p.o.), spironolactone and hydrochlorothiazide (1 mg/kg, PO) every 8 h, and furosemide (2 mg/kg, i.m., q6h). Calves were administered sucrose and diuretic agents for 48 h to induce diarrhea and severe dehydration. Clinical changes after 48 h were severe watery diarrhea, severe depression, and marked dehydration (mean, 14% BW loss). Cardiac output, stroke volume, mean central venous pressure, plasma volume, thiocyanate space, blood pH and bicarbonate concentration, base excess, serum chloride concentration, and fetlock temperature were decreased. Plasma lactate concentration, hematocrit, and serum potassium, creatinine, phosphorus, total protein and albumin concentrations were increased. This non-infectious calf diarrhea protocol has a 100% response rate, while providing a consistent and predictable hypovolemic state with diarrhea that reflects most of the clinicopathologic changes observed in osmotic/maldigestive diarrhea caused by infection with rotavirus, coronavirus or cryptosporidia. Limitations of the protocol, when compared to infectious diarrhea models, include failure to induce a severe metabolic acidosis, absence of hyponatremia, renal instead of enteric loss of chloride, renal as well as enteric loss of free water, absence of profound clinical depression and suspected differences in the morphologic and functional effect on intestinal epithelium. Despite these differences, the sucrose/diuretic protocol should be useful in the initial screening of new treatment modalities for calf diarrhea. To confirm their efficacy, the most effective treatment methods should then be examined in calves with naturally-acquired diarrhea.

Animals↗

PubMed1996

Metabolic causes of equine exercise intolerance.

Metabolic causes of exercise intolerance can be subtle and difficult to document in horses. Because of increased metabolic rate in exercising muscle, most metabolic causes of exercise intolerance are clinically manifested by muscle abnormalities such as ER. Newer causes of ER are being documented by current research and are summarized in the article on muscular causes of equine exercise intolerance. Endocrine causes of exercise intolerance have been poorly documented, but recent work has shown the detrimental effects of hypothyroidism on exercise tolerance in horses. Many metabolic manifestations of exercise intolerance are cumulative in heat exhaustion; prevention by veterinary monitoring is the best treatment, followed by cold water bathing and oral or intravenous fluid and electrolyte replacement. Several ergogenic aids have been proposed and marketed for use in horses, but each has its own problems and few have been shown clearly to have positive effects on performance.

Acid-Base Equilibrium↗

PubMed1996

Acid-base and electrolyte effects of shortening steeplechase in a three-day-event.

This study was designed to characterise the acid-base and electrolyte effects of shortening the distance required during steeplechase (Phase B) in the face of hot and humid weather conditions during a treadmill-simulated Speed and Endurance test. Eight conditioned Thoroughbred horses underwent 3 randomised permutations of a standardised exercise test on a high speed treadmill. Each test consisted of trotting at 3.7 m/s for 10 min (Phase A); galloping at 11 m/s (Phase B) for 4 (cool laboratory conditions), 3 (hot and humid), or 2 (hot and humid) min; trotting at 3.7 m/s for 30 min (Phase C); and walking at 1.8 m/s for 10 min (Phase X). The treadmill slope was 4% for trotting and galloping and 0% for walking. Cool versus hot and humid conditions were 20 degrees C and 50-60% relative humidity vs. 26-28 degrees C and 80-85% relative humidity, respectively. Pulmonary artery blood samples were obtained at rest prior to exercise (Rest); at the end of Phases A (A10) and B (B2-4); at 10 (C10), 20 (C20) and 30 (C30) min through Phase C; and at 5 min into Phase X (X5). Additional samples for lactate (LA) and glucose (GLC) analysis were obtained 5 min into Phase C (C5) and at the end of Phase X (X10). Samples were analysed for packed cell volume (PCV), haemoglobin (HB), total plasma protein (TP), sodium (Na), potassium (K), chloride (Cl), anion gap (AG), plasma glucose (GLC) and lactate (LA), pH, PCO2, bicarbonate (HCO3) and base excess (BE). Shortening steeplechase distance by 50% under hot and humid conditions (2 min B) resulted in a consistent return to control measurements (4 min B) only for plasma LA. Changes in PCV, HB, TP, K and Cl were related more to the longer galloping distance in the 4 min B trials than to hot vs. cold laboratory conditions. Alternatively, changes in LA, GLC, pH, PCO2 and AG were more related to hot and humid laboratory conditions than they were to galloping distance. These latter variables, when combined with physical measures such as core temperature, bodyweight loss, point of fatigue on Phase C and recovery heart rates may serve as the best monitors of positive responses in future studies of proposed modifications to Phase C, rather than those variables which were more distance than weather-related.

Acid-Base Equilibrium↗

PubMed1995

Case-control study of risk factors for development of pleuropneumonia in horses.

Risk factors for development of pleuropneumonia were determined by reviewing medical records of 45 horses with pleuropneumonia and 180 control horses examined between Jan 1, 1980 and Jan 1, 1990. Factors considered included age, breed, sex, occupation, transport farther than 500 miles within the previous week, racing within the previous 48 hours, viral respiratory tract infection or exposure to horses with viral respiratory tract disease within the previous 2 weeks, and vaccination against influenza or rhinopneumonitis within the previous 6 months. Results indicated that Thoroughbreds were at a greater risk of developing pleuropneumonia than were other horses, and Standardbreds were at a reduced risk. Transport farther than 500 miles and viral respiratory tract disease or exposure to horses with respiratory tract disease were determined to be risk factors for the development of pleuropneumonia.

Animals↗