Ability of hematologic and serum biochemical variables to differentiate gram-negative and gram-positive mastitis in dairy cows.

Medical records of 142 dairy cows with clinical mastitis were examined to determine whether hematologic or serum biochemical results could be used to distinguish between mastitis episodes caused by gram-negative bacteria (n = 78) from those caused by gram-positive bacteria (n = 64). Signalment, historic information, hematologic and serum biochemical results, milk culture results, and outcome (discharged from hospital or died) were obtained from the medical records. Cows with gram-negative mastitis had significantly (P < .

Fumonisin toxicosis in swine: an overview of porcine pulmonary edema and current perspectives.

Fumonisin toxicosis in swine was named porcine pulmonary edema (PPE) after outbreaks of a fatal disease in pigs fed Fusarium verticillioides (F. moniliforme)-contaminated corn screenings from the 1989 corn crop in Iowa, Illinois, and Georgia. Pigs that died had severe pulmonary edema, which has not been identified in other species after exposure to fumonisins.

Factors associated with colostral specific gravity in dairy cows.

The objectives of this study were to identify factors associated with colostral specific gravity in dairy cows, as measured by a commercially available hydrometer (Colostrometer). Colostral specific gravity was measured in 1085 first-milking colostrum samples from 608 dairy cows of four breeds on a single farm during a 5-yr period. Effects of breed, lactation number, and month and year of calving on colostral specific gravity were determined, as were correlations between colostral specific gravity, nonlactating period length, and 305-d yields of milk, protein, and fat.

Fumonisin B(1) is hepatotoxic and nephrotoxic in milk-fed calves.

Fumonisins are a group of mycotoxins that alter sphingolipid biosynthesis and induce leukoencephalomalacia in horses and pulmonary edema in pigs. Experimental administration of fumonisin induces hepatotoxicity in all species, including cattle, as well as nephrotoxicity in rats, rabbits, and sheep. We investigated the hepatotoxicity and nephrotoxicity of fumonisin B(1) to calves.

Fumonisin B(1) increases serum sphinganine concentration but does not alter serum sphingosine concentration or induce cardiovascular changes in milk-fed calves.

Fumonisin B(1) is the most toxic and commonly occurring form of a group of mycotoxins that alter sphingolipid biosynthesis and induce leukoencephalomalacia in horses and pulmonary edema in pigs. Purified fumonisin B(1) (1 mg/kg, iv, daily) increased serum sphinganine and sphingosine concentrations and decreased cardiovascular function in pigs within 5 days. We therefore examined whether the same dosage schedule of fumonisin B(1) produced a similar effect in calves.

Species and organ specificity of fumonisin-induced endothelial alterations: potential role in porcine pulmonary edema.

Fumonisins, mycotoxins that commonly contaminate corn, induce cardiovascular toxicity and pulmonary edema in pigs, leukoencephalomalacia in horses, and nephropathy in rats, rabbits, and lambs. The mechanisms of these species-specific target organ toxicoses are poorly understood. We have previously reported perinuclear accumulation of membranous material in pulmonary capillary endothelial cells of pigs fed fumonisin-containing culture material.

The effects of a hemoglobin-based oxygen carrier (HBOC-301) on left ventricular systolic function in anesthetized dogs.

Objective: To evaluate the effects of a hemoglobin-based oxygen carrier (HBOC-301) on left ventricular preload, afterload, contractility, and ventriculo-arterial coupling in anesthetized dogs.

Study Design: A prospective experimental study.

Animals: Seven adult male dogs weighing 2.

Purified fumonisin B(1) decreases cardiovascular function but does not alter pulmonary capillary permeability in swine.

Fumonisins are mycotoxins produced by Fusarium verticillioides, which induce acute pulmonary edema in swine. We previously reported that ingestion of fumonisin-containing culture material decreases cardiovascular function in swine (1996,a,b; Fundam. Appl.

Effects of endurance training on standard and signal-averaged electrocardiograms of sled dogs.

Objective: To determine the effect of endurance training on QRS duration, QRS-wave amplitude, and QT interval.

Animals: 100 sled dogs in Alaska.

Procedure: Dogs were examined in early September (before training) and late March (after training).

Sequence of cardiovascular changes leading to pulmonary edema in swine fed culture material containing fumonisin.

Objectives: To determine the sequence of cardiovascular and blood gas changes induced by ingestion of fumonisin-containing culture material in swine and to examine the temporal relationship of these changes to plasma sphinganine and sphingosine concentrations.

Animals: 12 healthy castrated pigs (38 to 50 kg).

Procedure: Pigs were instrumented to permit cardiovascular monitoring and collection of blood samples.

Ingestion of fumonisin B1-containing culture material decreases cardiac contractility and mechanical efficiency in swine.

Fumonisins are mycotoxins produced primarily by Fusarium verticillioides, a fungus that commonly contaminates corn. Fumonisin ingestion increases plasma and tissue sphingosine and sphinganine concentrations and causes porcine pulmonary edema, which has been attributed to acute left-sided heart failure or increased vascular permeability. We investigated the effect of short-term ingestion of fumonisin B1-containing culture material on cardiac function in pigs.

Hypertonic saline.

A key feature in the successful resuscitation of dehydrated or endotoxemic ruminants is the total amount of sodium administered. Administration of small volumes of HS and HSD offer major advantages over large volumes of isotonic saline because HS and HSD do not require intravenous catheterization or periodic monitoring, and are therefore suitable for use in the field. Hypertonic saline and HSD exert their beneficial effect by rapidly increasing preload and transiently decreasing afterload.

Clinical assessment of acid-base status. Strong ion difference theory.

The traditional approach to evaluating acid-base balance uses the Henderson-Hasselbalch equation to categorize four primary acid-base disturbances: respiratory acidosis (increased PCO2), respiratory alkalosis (decreased PCO2), metabolic acidosis (decreased extracellular base excess), or metabolic alkalosis (increased extracellular base excess). The anion gap is calculated to detect the presence of unidentified anions in plasma. This approach works well clinically and is recommended for use whenever serum total protein, albumin, and phosphate concentrations are approximately normal; however, when their concentrations are markedly abnormal, the Henderson-Hasselbalch equation frequently provides erroneous conclusions as to the cause of an acid-base disturbance.

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.

Acute endotoxemia increases left ventricular contractility and diastolic stiffness in calves.

We investigated the acute effects of endotoxemia on left ventricular (LV) contractility, relaxation, diastolic properties, and mechanical energetics in closed-chest calves. Twelve male calves (4 to 10 days old) were anesthetized with alpha-chloralose and instrumented to measure the LV pressure-volume relationship. Calves (n = 6) in the control group remained hemodynamically stable for 4 h.

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.

Use of mammary gland and colostral characteristics for prediction of colostral IgG1 concentration and intramammary infection in Holstein cows.

Objective: To determine whether mammary gland or colostral characteristics at calving could be used to predict colostral immunoglobulin G1 (IgG1) concentration or intramammary infection (IMI) and whether leakage of colostrum affects IgG1 concentration.

Design: Prospective study.

Animals: 113 multiparous Holstein cows.

Serum biochemistry of captive and free-ranging gray wolves (Canis lupus).

Normal serum biochemistry values are frequently obtained from studies of captive sedentary (zoo) or free-ranging (wild) animals. It is frequently assumed that values obtained from these two populations are directly referable to each other. We tested this assumption using 20 captive gray wolves (Canis lupus) in Minnesota, USA, and 11 free-ranging gray wolves in Alaska, USA.

Clinical assessment of left ventricular relaxation.

Ventricular relaxation is altered in a number of cardiac disorders affecting domestic animals. Clinical determination of the ventricular relaxation rate can provide useful information regarding disease severity and response to therapy. We believe that the current gold standard for assessing left ventricular relaxation requires measurement of ventricular luminal pressure at end-expiration using a high-fidelity catheter.

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.

Sedation with xylazine and lumbosacral epidural administration of lidocaine and xylazine for umbilical surgery in calves.

Objective: To determine whether anesthesia consisting of sedation induced by intramuscular administration of xylazine hydrochloride and lumbosacral analgesia induced by epidural administration of lidocaine and xylazine is useful for umbilical surgery in neonatal calves.

Design: Prospective study.

Animals: 6 neonatal male dairy calves.

Electrocardiographic consequences of a peripatetic lifestyle in gray wolves (Canis lupus).

Cardiac chamber enlargement and hypertrophy are normal physiologic responses to repetitive endurance exercise activity in human beings and domestic dogs. Whether similar changes occur in wild animals as a consequence of increased activity is unknown. We found that free-ranging gray wolves (Canis lupus, n = 11), the archetypical endurance athlete, have electrocardiographic evidence of cardiac chamber enlargement and hypertrophy relative to sedentary captive gray wolves (n = 20), as demonstrated by significant increases in QRS duration, QT interval, and QT interval corrected for heart rate, a tendency towards increased Q, R, and S wave voltages in all leads, and a significant decrease in heart rate.

Effect of endurance training on cardiac morphology in Alaskan sled dogs.

The cardiac morphology of 77 conscious Alaskan sled dogs before and after 5 mo of endurance training (20 km/day team pulling a sled and musher) was studied using two-dimensional and M-mode echocardiography. Subgroups included dogs with at least one season of previous training ("veterans") and dogs undergoing their first season of training ("rookies"). Training resulted in a significant (P < 0.

Characteristics of dairy cows during episodes of bacteriologically negative clinical mastitis or mastitis caused by Corynebacterium spp.

Objectives: To use clinical and lactational characteristics to determine whether bacteriologically negative (BN) clinical mastitis episodes are more apt to be caused by gram-negative or gram-positive bacteria, and to investigate severity of clinical mastitis caused by Corynebacterium spp (COR).

Design: Case series.

Sample Population: 300 clinical mastitis episodes affecting 123 dairy cows vaccinated against lipopolysaccharide core antigens.