The pathophysiology of uncontrolled hemorrhage in horses.

Background: Hemorrhagic shock in horses may be classified in several ways. Hemorrhage may be considered internal versus external, controlled or uncontrolled, or described based on the severity of hypovolemic shock the patient is experiencing. Regardless of the cause, as the severity of hemorrhage worsens, homeostatic responses are stimulated to ameliorate the systemic and local effects of an oxygen debt.

Collection and administration of blood products in horses: Transfusion indications, materials, methods, complications, donor selection, and blood testing.

Background: Blood transfusion is a lifesaving treatment for horses with acute hemorrhage and other causes of anemia. Transfusions improve oxygen delivery to the tissues via increased blood volume and hemoglobin concentration. Certain aspects of equine blood transfusion are challenging, especially in the field situation, and practitioners may be unfamiliar or feel overwhelmed with the process.

Abdominocentesis techniques in horses.

Background: Abdominocentesis is commonly used to evaluate the abdominal cavity of the horse. This technique provides valuable diagnostic information as well as the means to monitor patients with abdominal diseases being managed medically and to determine their need for surgical management. Complications are uncommon and include trauma to the gastrointestinal tract or spleen, septic peritonitis, or abdominal wall infection.

Interpreting abdominal fluid in colic horses: Understanding and applying peritoneal fluid evidence.

Background: Interpreting changes in peritoneal fluid helps clinicians manage colic and other diseases in horses. During abdominal problems in the horse, abdominal fluid characteristics such as color, turbidity, total nucleated and red blood cell counts, cytology, total protein, and l-lactate change in predictable ways, helping the clinician characterize the disease.

Description: Normal abdominal fluid in horses is odorless, clear to light yellow in color, and transparent.

Calculating and selecting fluid therapy and blood product replacements for horses with acute hemorrhage.

Background: Blood products, crystalloids, and colloid fluids are used in the medical treatment of severe hemorrhage in horses with a goal of providing sufficient blood flow and oxygen delivery to vital organs. The fluid treatments for hemorrhage will vary depending upon severity and duration and whether hemorrhage is controlled or uncontrolled.

Description: With acute and severe controlled hemorrhage, treatment is focused on rapidly increasing perfusion pressure and blood flow to vital organs.

Agreement of Bioreactance Cardiac Output Monitoring With Thermodilution in Healthy Standing Horses.

Bioreactance is the continuous analysis of transthoracic voltage variation in response to an applied high frequency transthoracic current and was recently introduced for non-invasive cardiac output measurement (NICOM). We evaluated NICOM compared to thermodilution (TD) in adult horses. Six healthy horses were used for this prospective, blinded, experimental study.

Clinical Assessment of an Ipsilateral Cervical Spinal Nerve Block for Prosthetic Laryngoplasty in Anesthetized Horses.

The nociceptive blockade of locoregional anesthesia prior to surgical stimulation can decrease anesthetic agent requirement and thereby potential dose-dependent side effects. The use of an ipsilateral second and third cervical spinal nerve locoregional anesthetic block for prosthetic laryngoplasty in the anesthetized horses has yet to be described. Anesthetic records of 20 horses receiving locoregional anesthesia prior to laryngoplasty were reviewed and compared to 20 horses of a similar patient cohort not receiving locoregional anesthesia.

Clinical Pathology of the Racehorse.

The assessment of blood analytes in racehorses can provide useful data on performance and health. The horses' adaptive responses to training that occur to optimize performance should be considered when interpreting alterations seen on laboratory results. Similarly, the alterations observed in laboratory test results can identify subclinical and clinical disease and be helpful for identifying organ dysfunction and, in many cases, monitoring progress and response to treatment.

Sudden death of a horse with supraventricular tachycardia following oral administration of flecainide acetate.

Objective: To describe a case of supraventricular tachycardia and sudden death in a horse following administration of flecainide acetate.

Case Summary: An 8-year-old Hanoverian warmblood gelding was treated for chronic, naturally occurring, supraventricular tachycardia with digoxin, procainamide hydrochloride, quinidine sulfate, and flecainide acetate. After oral administration of flecainide, polymorphic ventricular tachycardia (torsades de pointes) and ventricular fibrillation developed, leading to cardiovascular collapse and death.

Equine intradermal test threshold concentrations for house dust mite and storage mite allergens and identification of stable acari fauna.

Background: House dust mite (HDM) and storage mite (SM) stable fauna and their associated equine intradermal test (IDT) threshold concentrations (TCs) for the midwestern region of the USA are unknown.

Hypothesis/objectives: To determine IDT TCs and serum IgE concentrations for two HDM and three SM species in clinically normal horses over two seasons, and to identify the mite taxa and habitats in a stable.

Animals: Thirty-eight clinically normal horses.

An ex vivo model to evaluate the effect of cyclical adductory forces on maintenance of arytenoid abduction after prosthetic laryngoplasty performed with and without mechanical arytenoid abduction.

Objectives: To (1) develop a model of cyclical adduction force on an abducted left arytenoid cartilage that mimics swallowing or coughing; (2) determine if arytenoid abduction by a clamp before knot tying will improve the maintenance of abduction under cyclical adduction testing.

Study Design: Experimental.

Sample Population: Cadaveric equine larynges (n = 14).

Serum protein concentrations as predictors of serum immunoglobulin G concentration in neonatal foals.

Objective: To determine the predictive value of serum concentrations of total protein (sTP), albumin (sAlb), and globulin (sGlob) measured by automated calorimetric assays to estimate serum immunoglobulin G (sIgG) concentrations in neonatal foals and identify failure of transfer of passive immunity when compared to turbidoimmunometric assay determinations of sIgG.

Design: Retrospective and prospective analysis of laboratory data.

Setting: University tertiary care facility.

Direct intra-abdominal pressures and abdominal perfusion pressures in unsedated normal horses.

Objectives: To determine whether direct intra-abdominal pressures (IAP) and calculated direct abdominal perfusion pressures (APP) are location dependent within the abdomen of standing horses. We hypothesize that IAP will be increased and calculated APP will be decreased at a ventral abdominal location (V) when compared to values obtained from the left (LFl) or right flank (RFl).

Design: Prospective experimental design.

Hypothalamic-pituitary gland axis function and dysfunction in horses.

Hypothalamic-pituitary (HP) dysfunction has been documented in a limited capacity in horses and foals associated with critical illness, stress, and pain. This article reviews species-specific details of anatomy, function, hormones, receptors, and testing of the HP axis in the horse. A discussion of critical care medicine relevant to HP dysfunction in the horse with some reference to current understanding in human medicine is made, focusing primarily on current and relevant literature.

Multicentric mast cell tumors in a horse.

A 6-year-old female Rocky Mountain horse was presented for evaluation of draining tracts and distal limb subcutaneous edema on the left front and left hind limbs that had been present for 2 weeks. Direct smears of fluid collected by fine-needle aspiration of subcutaneous fluid from both limbs were highly cellular with a predominance of eosinophils accompanied by numerous, moderately atypical, variably granulated mast cells. The cytologic diagnosis was mast cell tumor (MCT) with prominent eosinophilic infiltration with a differential diagnosis of eosinophilic granuloma.

Isolation of Campylobacter fetus subspecies fetus in a two-year-old quarterhorse with chronic diarrhea of an undetermined etiology.

A 2-year-old quarterhorse was evaluated for chronic diarrhea and weight loss of 5 weeks duration after numerous diagnostic tests failed to identify an underlying cause. Historically, the horse was housed at pasture where human household waste vehicles were routinely cleaned and the effluent could run onto the field. Physical examination revealed poor body condition and frequent high-volume diarrhea.

Poorly differentiated leiomyosarcoma of the urogenital tract in a horse.

Case Description: A 2-year-old Thoroughbred filly was evaluated because of hemorrhage from the vulva and suspected hematuria of 5 days' duration.

Clinical Findings: A primary coagulopathy was ruled out on the basis of results of hematologic testing. Vaginoscopy and cystoscopy revealed a large bleeding mass in the bladder that extended into the vagina, causing marked obliteration of normal urogenital structures and difficulty in urination.