Preparing students for careers in food-supply veterinary medicine: a review of educational programs in the United States.

The real and/or perceived shortage of veterinarians serving food-supply veterinary medicine has been a topic of considerable discussion for decades. Regardless of this debate, there are issues still facing colleges of veterinary medicine (CVMs) about the best process of educating future food-supply veterinarians. Over the past several years, there have been increasing concerns by some that the needs of food-supply veterinary medicine have not adequately been met through veterinary educational institutions. The food-supply veterinary medical curriculum offered by individual CVMs varies depending on individual curricular design, available resident animal population, available food-animal caseload, faculty, and individual teaching efforts of faculty. All of the institutional members of the Association of American Veterinary Medical Colleges (AAVMC) were requested to share their Food Animal Veterinary Career Incentives Programs. The AAVMC asked all member institutions what incentives they used to attract and educate students interested in, or possibly considering, a career in food-supply veterinary medicine (FSVM). The problem arises as to how we continue to educate veterinary students with ever shrinking budgets and how to recruit and retain faculty with expertise to address the needs of society. Several CVMs use innovative training initiatives to help build successful FSVM programs. This article focuses on dairy, beef, and swine food-animal education and does not characterize colleges' educational efforts in poultry and aquaculture. This review highlights the individual strategies used by the CVMs in the United States.

Infusion of sodium bicarbonate in experimentally induced metabolic acidosis does not provoke cerebrospinal fluid (CSF) acidosis in calves.

In a crossover study, 5 calves were made acidotic by intermittent intravenous infusion of isotonic hydrochloric acid (HCl) over approximately 24 h. This was followed by rapid (4 h) or slow (24 h) correction of blood pH with isotonic sodium bicarbonate (NaHCO(3)) to determine if rapid correction of acidemia produced paradoxical cerebrospinal fluid (CSF) acidosis. Infusion of HCl produced a marked metabolic acidosis with respiratory compensation. Venous blood pH (mean ± S(x)) was 7.362 ± 0.021 and 7.116 ± 0.032, partial pressure of carbon dioxide (Pco(2), torr) 48.8 ± 1.3 and 34.8 ± 1.4, and bicarbonate (mmol/L), 27.2 ± 1.27 and 11 ± 0.96; CSF pH was 7.344 ± 0.031 and 7.240 ± 0.039, Pco(2) 42.8 ± 2.9 and 34.5 ± 1.4, and bicarbonate 23.5 ± 0.91 and 14.2 ± 1.09 for the period before the infusion of hydrochloric acid and immediately before the start of sodium bicarbonate correction, respectively. In calves treated with rapid infusion of sodium bicarbonate, correction of venous acidemia was significantly more rapid and increases in Pco(2) and bicarbonate in CSF were also more rapid. However, there was no significant difference in CSF pH. After 4 h of correction, CSF pH was 7.238 ± 0.040 and 7.256 ± 0.050, Pco(2) 44.4 ± 2.2 and 34.2 ± 2.1, and bicarbonate 17.8 ± 1.02 and 14.6 ± 1.4 for rapid and slow correction, respectively. Under the conditions of this experiment, rapid correction of acidemia did not provoke paradoxical CSF acidosis.

Factors affecting rectal temperature measurement using commonly available digital thermometers.

Rectal temperature measurement is an essential part of physical examination of cattle and some physiological experiments. Modern digital thermometers are often used to measure rectal temperatures by students; this study describes their reliability and appropriate use. Students measured rectal temperature on 53 occasions using their personal digital thermometer and techniques gained from previous instruction, rectal temperature was also measured by an experienced person using a Cornell mercury thermometer completely inserted in the rectum. Cornell mercury thermometers values were 38.95±0.05°C (mean±1 SE, n=53). Student rectal temperature measurements using their initial technique were nearly 0.5°C lower, 38.46±0.07°C. After receiving instruction to insert the digital thermometer to the window, student obtained values were 38.77±0.06°C; these are significantly higher than with the student's initial technique and closer to those obtained with a Cornell thermometer. In a series of 53 water bath tests, student owned thermometers recorded similar mean values to those of a traceable (reference) digital thermometer, Cornell mercury thermometer readings were 0.2°C higher. 10 individual digital thermometers were repeatedly tested against a traceable thermometer in a water bath, one was inaccurate. In a separate experiment a trained clinician tested the effect of angle of insertion of a digital thermometer on temperature readings and the affect was <0.1°C. We conclude that accurate temperature measurements using digital thermometers are only likely if the thermometer is inserted to the beginning of the window and the thermometer's accuracy is checked periodically.

Demographic survey of veterinarians employed in western Canada.

The objective of this study was to generate demographic data on veterinarians working in western Canada. A sample of 551 veterinarians was randomly selected from a population of 2474 veterinarians employed in western Canada, 425 (77.1%) of whom responded to the survey. The respondents were evenly split between males (53.1%) and females (46.9%). More than half (58.0%) of the private practitioners practised exclusively on companion animals (small animals and horses), while 2.9% devoted 100% of their time to food animals. There were 351 respondents who had had > or = 2 employers since graduation; 80% of those who had begun their careers in companion animal (CA) practice had remained in this type of practice, while 54.3% of those who had begun their careers in mixed animal practice had switched to CA practice. Analyses of wage and workload data from 85 full-time veterinary employees showed that CA practitioners worked the fewest hours/week (47.0), had the least number of evenings on-call/month (3.7), and earned the highest hourly wage (35.79 dollars) as compared with non-CA practitioners.

Factors associated with the career path choices of veterinarians in western Canada.

This second of 2 articles, relating to the veterinary profession in western Canada, explores the factors associated with veterinarians' career path choices. Among other factors, companion animal (small animal and equine) (CA) practitioners were less likely to have been raised in, or near to, a small center (< or = 10 000), were more concerned with their workload (hours of work and number of nights on-call), and preferred to work in progressive practices. Food animal (FA) practitioners were more likely to be male, have been raised in a small center, have been raised in the Province of Saskatchewan, and to have self-assessed themselves as having an above average knowledge of agriculture at the time they applied for admission to veterinary college. Mixed animal (MA) practitioners had more factors in common with FA than with CA practitioners. Three main factors were associated with leaving mixed or food animal practice: hours of work and too many nights on-call, the level of remuneration, and lack of support and mentorship.

Factors affecting the career path choices of graduates at the Western College of Veterinary Medicine.

The objective of this study was to describe the demographics of the Class of 2006, Western College of Veterinary Medicine, and to determine which factors influenced the graduates' career path choices. Data were collected via an on-line survey and the response rate was 95.7% (67/70). The majority (57%) of graduates were starting their veterinary career in a food animal-related (FAR) job. Two factors were significantly associated with this choice: 1) those raised in, or near, a small center (population < 10 000) were 3.4 times (P = 0.03) more likely to accept a FAR position than were those raised in a large center (> 10 000), and 2) graduates with a bachelor of science in agriculture (BSc Ag) were 4.5 times (P = 0.04) more likely to begin their career as a FAR practitioner than were those without such a degree. However, 9 of the 16 graduates having a BSc Ag had an urban upbringing.

D-Lactic acid-induced neurotoxicity in a calf model.

Lactic acidosis (DAC) occurs as a complication of short-bowel syndrome in humans and in a variety of other gastrointestinal disorders in monogastrics and ruminants. DAC is associated with signs of impaired central nervous system (CNS) function including ataxia and coma. The objective of this experiment was to determine whether either acidification of nervous tissue or d-lactic acid is responsible for decreased neurological function. Eight Holstein calves (32 +/- 11 days, 70 +/- 10 kg) were surgically catheterized with indwelling intravenous jugular and atlanto-occipital space cerebrospinal fluid (CSF) catheters and infused for 6 h in random order with isomolar dl-lactic acid (dl-LA), l-lactic acid (l-LA), hydrochloric acid (HCl), or saline. dl-LA induced ataxia after 4 h of infusion and produced the greatest obtunding of CNS function (at 7 h, score 8.0 +/- 0.4), whereas the other infusions caused neither ataxia nor scores over 1.5 (P < 0.01 from dl-LA). dl-LA induced significantly less acidemia than HCl (at 6 h pH 7.13 +/- 0.06 and 7.00 +/- 0.04, base excess -16 +/- 1 and -23 +/- 3 mmol/l, bicarbonate 11 +/- 1 and 8 +/- 1 mmol/l respectively, all P < 0.01) but greater than l-LA and saline (P < 0.01). CSF changes followed a similar but less pronounced pattern. Although HCl infusion produced a severe acidemia and CSF acidosis, only minor effects on neurological function were evident suggesting that d-lactate has a direct neurotoxic effect that is independent of acidosis. Conversely, l-LA produced only minor neurological changes.

The effects of feeding and fasting on gastrointestinal sounds in adult horses.

The effect of changes in feed intake on auscultatable gastrointestinal sounds has not been systematically studied. Disagreement also is present in the literature about variation in sounds according to the quadrant of auscultation. Gastrointestinal sounds were recorded over the center of the left dorsal, left ventral, right ventral, and right dorsal quadrants and over the middle of the right abdominal flank. During 24 hours (n = 4) or 48 hours (n = 5) of fasting, there was a reduction in the intensity of gastrointestinal sounds as assessed by analysis of sound recordings. There was also a reduction in the number of mixing-like and propulsive-like sounds heard by 2 blinded observers. After refeeding, there was a marked increase in sound. Sound intensity varied among abdominal quadrants, but blinded observers did not notice significant differences in the number of mixing-like sounds. The left dorsal quadrant was quieter than others during fasting and refeeding. The right ventral quadrant appeared to be least affected by fasting, and sounds were louder over the right ventral and right middle quadrants than over the others. The blinded observers' perceptions of sound correlated poorly with one another and with objective measures of sound intensity. This experiment demonstrates the effectiveness of computerized analysis of abdominal sound in detecting a reduction in the intensity of gastrointestinal sounds during fasting and their return during refeeding. The left dorsal quadrant was quieter than other quadrants, likely because of its position over the small colon. There was considerable observer variation in the number of intestinal sounds heard.

Obstruction of the small intestine by a trichobezoar in cattle: 15 cases (1992-2002).

OBJECTIVE: To determine historical and clinical findings, treatment, and outcome for cattle with small intestinal obstruction caused by a trichobezoar. DESIGN: Retrospective case series. ANIMALS: 15 cattle. PROCEDURES: Medical records of cattle with a diagnosis of small intestinal obstruction by a trichobezoar from 1992 to 2002 were reviewed. Information pertaining to various aspects of diagnosis, treatment, and outcome was collected from records. RESULTS: Trichobezoars were more common in young cattle, and affected cattle did not deteriorate clinically as rapidly as cattle with other types of intestinal obstruction. The most common initial owner complaints included decreased or absent fecal output, inappetance, abdominal distension, and signs of abdominal pain. Common clinical findings were dehydration, decreased or absent rumen motility, signs of depression, splashing sounds during succussion of the abdomen, and a pinging sound on percussion of the abdomen. The jejunum was obstructed in 10 cattle. Hypochloremic metabolic alkalosis and chronic inflammation were common laboratory findings. All 4 cattle that underwent abdominocentesis had peritonitis. The obstructing trichobezoar was removed surgically in 9 cattle, of which 7 survived and 2 died. The 6 cattle treated medically died or were euthanized. CONCLUSIONS AND CLINICAL RELEVANCE: Obstruction of the small intestine by a trichobezoar is uncommon, but it should be considered as a differential diagnosis in cattle with signs of intestinal obstruction, particularly if they are younger than 4 years of age and have a history of nonacute signs of intestinal obstruction. Surgical removal appears to be a favorable method of treatment and should be considered when this condition is suspected.

Evaluation of traditional instruction versus a self-learning computer module in teaching veterinary students how to pass a nasogastric tube in the horse.

OBJECTIVE: To evaluate the effectiveness of a self-learning computer module (SLCM) versus traditional instruction in teaching how to pass a nasogastric tube (NG) in the horse. DESIGN: A double-blind, monocentric study. SAMPLE POPULATION: 52 third-year students in the DVM program were randomly assigned to two groups: traditional instruction (N = 25) or SLCM instruction (N = 27). PROCEDURE: Traditional instruction consisted of an instructor and live demonstration; SCLM students were given a CD-ROM each. Both sessions lasted one hour. The students were then united in one session to practice passing the NG tube. Their performance was videotaped and evaluated by two evaluators. Students were then given a multiple-choice knowledge quiz. One week later, a second demonstration of the same procedure by the two methods was administered, and students were allowed to choose either method of instruction. A Likert-scale questionnaire about their comfort, their confidence, and the appropriateness of the teaching method was given after the second demonstration. Data were analyzed by non-parametric tests. A focus-group study was conducted to determine students' perception of each teaching method. Nine participants in the experiment volunteered for these focus-group sessions. The sessions were audiotaped and transcribed. RESULTS: Students in the SLCM group performed significantly better on the test of knowledge than traditionally instructed students. The questionnaire found significant perceived benefits to computer-based instruction, including a preference for the computer-based module, better learning, and greater preparedness. In hands-on skill, time to pass the NG tube on the successful attempt was significantly shorter in the SLCM group than in the traditionally instructed group. The data from focus-group sessions suggest that while participants expressed satisfaction with both modes of instruction, the SLCM group reported somewhat higher levels of confidence in their skills prior to performing the procedure. Whereas the traditional group reported a strong preference for continued live demonstrations of the procedure, the SLCM group stated that the computer-assisted module alone provided them with effective instruction. CONCLUSION: Computer-assisted learning is an acceptable and effective method of training students to pass an NG tube with potential welfare, proficiency, and knowledge advantages.

Lactobacillus GG does not affect D-lactic acidosis in diarrheic calves, in a clinical setting.

D-lactate, produced by gastrointestinal fermentation, is a major contributor to metabolic acidosis in diarrheic calves. Lactobacillus rhamnosus GG survives gastrointestinal transit in the neonatal calf and does not produce D-lactate. To determine whether this probiotic reduces gastrointestinal D-lactate production or severity of diarrhea or both, 48 calves (mean, 11 days old; range, 2-30 days) admitted to the clinic for treatment of diarrhea were randomly allocated to 2 groups. The experimental group was given Lactobacillus rhamnosus GG (1 x 10(11) cfu/d) PO, dissolved in milk or oral electrolyte solution, in addition to clinic treatment protocols; the other group served as a control. Serum and fecal samples were obtained at admission and at 24 and 48 hours after initial administration of Lactobacillus rhamnosus GG. All samples were analyzed for D- and L-lactate by using high-pressure liquid chromatography. Feces were also analyzed for pathogens, Lactobacillus rhamnosus GG recovery, and dry matter. D-lactic acidemia (>3 mmol/L) was present in 37/48 calves at admission. Lactobacillus rhamnosus GG was recovered in the feces of 13 experimental calves and 0 control calves 24 hours after administration. No difference in serum or fecal D- or L-lactate between the groups was detected at any time point. After therapy, D-lactic acidosis was absent at 48 hours in all but 1 calf. No relation between fecal pathogen (viral, bacterial, or protozoal) and degree of D-lactic acidosis was observed. The reduction in mortality and greater fecal dry matter in Lactobacillus rhamnosus GG-treated calves was not statistically significant.

Comparison of surgical versus medical treatment of nephrosplenic entrapment of the large colon in horses: 19 cases (1992-2002).

OBJECTIVE: To compare the outcome of horses with nephrosplenic entrapment of the large colon (NSELC) treated surgically or medically by rolling, administration of phenylephrine hydrochloride (or both), and exercise. DESIGN: Retrospective study. ANIMALS: 11 medically treated horses and 8 surgically treated horses with NSELC. PROCEDURE: Medical records of horses with nephrosplenic entrapment between 1992 and 2002 were reviewed. Medically treated horses were included if diagnosis and outcome of treatment of nephrosplenic entrapment were confirmed via transrectal examination and ultrasonographic examination. Surgically treated horses were included if the diagnosis was confirmed by exploratory laparotomy. Horses in which the large colon was entrapped between the spleen and body wall were not included. RESULTS: Significant differences in mean age, heart rate, and duration of colic prior to treatment were not detected between horses treated surgically or medically. Ten medically treated horses recovered without complications, and 1 died. In the surgically treated group, 6 of 8 horses recovered without complications and 2 died. Mortality rate did not differ between treatments. Duration of hospitalization for medically treated horses was significantly shorter and the cost significantly less than for surgically treated horses. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that medical treatment of horses with NSELC via administration of phenylephrine hydro-chloride, rolling during general anesthesia, or both appears to be as effective as and less expensive than surgical treatment.

D-lactate in human and ruminant metabolism.

D-lactate is normally present in the blood of mammals at nanomolar concentrations due to methylglyoxal metabolism; millimolar d-lactate concentrations can arise due to excess gastrointestinal microbial production. Grain overload in ruminants, short-bowel syndrome in humans, and diarrhea in calves can all result in profound D-lactic acidemia, with remarkably similar neurological manifestations. In the past, D-lactate was thought to be excreted mainly in the urine, and metabolized slowly by the enzyme d-alpha-hydroxy acid dehydrogenase. More recent studies reported that mammals have a relatively high capacity for D-lactate metabolism and identified a putative mammalian D-lactate dehydrogenase. A growing body of literature is also emerging describing subclinical elevation of D-lactate as an indicator of sepsis and trauma. This article describes advances in the understanding of D-lactate metabolism, D-lactic acidosis in ruminants and humans, and subclinical elevation of d-lactate.

A retrospective study of the diagnoses and survival of elk admitted to a large animal referral clinic.

Information for veterinarians regarding diseases of farmed elk remains scarce despite an increase in the size of the industry. This retrospective study examines all (n=245) elk cases admitted to the Western College of Veterinary Medicine over an 11-year period (1991 to 2001). Age, gender, date of admission, diagnosis, and outcome were examined. Diarrhea, fractures, and other musculoskeletal problems were most common. Most (76%) cases involved elk under 1 y of age; these were more commonly diagnosed with fractures or diarrheal disease. Elk older than 1 y of age tended to be diagnosed with fractures or noninfectious diseases. Overall, the most common diagnosis was fractures, which were seen mostly as traumatic catastrophic long bone fractures. Fractures and other musculoskeletal problems occurred towards the end of summer and into the fall, while diarrhea and other infectious diseases were diagnosed in young elk in the spring and summer. The in-hospital case fatality rate was 33.5%.

Lactobacillus rhamnosus strain GG is a potential probiotic for calves.

Diarrhea is a common occurrence in neonatal calves. Several veterinary probiotics claiming to prevent or treat calf diarrhea are available, but have not been well studied. This study assessed the capability of Lactobacillus rhamnosus strain GG (LGG) to maintain viability in the gastrointestinal tract of calves. We also determined whether LGG can be administered in an oral rehydration solution (ORS) without compromising the efficacy of the ORS or the viability of LGG, and whether LGG produces D-lactate or not. To investigate the intestinal survival of LGG, 15 calves were randomized into 3 groups and LGG was administered orally with their morning milk feeding on 3 consecutive days at a low (LD), medium (MD), or high (HD) dosage. Fecal samples were collected on days 0 (control), 1, 2, 3, 5, and 7 and incubated for 72 h on deMan, Rogosa, Sharpe agar. Twenty-four hours after the 1st feeding, LGG was recovered from 1 out of 5 calves in the LD group, 4 out of 5 calves in the MD group, and 5 out of 5 calves in the HD group. To determine if LGG caused the glucose levels in the ORS to drop below effective levels, 1.5 L of the ORS was incubated with LGG for 2 h at 37 degrees C and the glucose concentration was measured every 20 min using a glucose meter. This ORS was then further incubated for 10 h and aliquots analyzed by high performance liquid chromatography to determine if D-lactate was produced by LGG. Glucose concentrations did not change over the 2 h of incubation, and no D-lactate was produced after 48 h. The LGG maintained viability in ORS. Therefore, this study demonstrated that LGG survives intestinal transit in the young calf, produces no D-lactate, and can be administered in an ORS.

D-lactate production and excretion in diarrheic calves.

The origin of D-lactate, the most important acid contributing to metabolic acidosis in the diarrheic calf, is unknown. We hypothesized that because D-lactate is produced only by microbes, gastrointestinal fermentation is the source. The objective of this study was to determine whether D-lactate production occurs in the rumen, colon, or both, and to measure D- and L-lactate concentrations in urine. Fecal, rumen, blood, and urine samples were obtained from 16 diarrheic and 11 healthy calves. Serum electrolyte concentrations were measured in both groups, and blood gas analyses were performed for diarrheic calves. All samples were analyzed for D- and L-lactate by high performance liquid chromatography (HPLC). Diarrheic calves were generally hyperkalemic with high serum anion gap, depressed serum bicarbonate, and low blood pH. L-lactate was markedly higher in rumen contents (22.7 mmol/ L [median]) and feces (8.6 mmol/L) of diarrheic calves than healthy calves (0.5 mmol/L and 5.1 mmol/L, respectively), but not different in serum or urine. Rumen, fecal, serum, and urine D-lactate concentrations were all significantly higher (P < .05) in diarrheic calves (17.0, 25.4, 13.9, and 19.2 mmol/L, respectively) than in healthy calves (0.5, 9.1, 1.4, and 0.5 mmol/L, respectively). Higher D-lactate concentrations in the rumen and feces of diarrheic calves suggests these sites as the source of D-lactate in blood and urine.

High-performance liquid chromatographic assay of lactic, pyruvic and acetic acids and lactic acid stereoisomers in calf feces, rumen fluid and urine.

To facilitate clinical investigation of metabolic acidosis, a high-performance liquid chromatographic method was adapted and validated for the chiral separation of D-(-) and L-(+)-lactic acid in calf feces, rumen fluid and urine. A non-chiral method was also adapted and validated for the separation of pyruvic, acetic and DL-(+/-)-lactic acids in calf feces and DL-(+/-)-lactic and pyruvic acids in rumen fluid. Separation and quantification were achieved using a reversed phase sulphonated polystyrenedivinylbenzene analytical column for pyruvic, acetic and racemic lactic acids and by a 3 microm octadecylsilane (ODS) packed analytical column coated with N,N-dioctyl-L-alanine as the chiral selector for the separation of lactic acid enantiomers with Cu(II)-containing eluents by stereoselective ligand exchange chromatography. Endogenous analytes were present in validation samples over a range of concentrations (0.2-14.8 mmol/l). For the stereoselective assay, mean intra-day accuracy ranged from 90.6 to 108.4% and intra-day precision from 0.3 to 13.8%. For the non-stereoselective assay, mean intra-day accuracy ranged from 90.4 to 108.8% and intra-day precision from 1.5 to 11.1%. The limit of quantitation was 1.0 mmol/l for D- and L-lactic acid, 0.06125 mmol/l for pyruvic acid, 1.0 mmol/l for DL-lactic acid and 1 mmol/l for acetic acid. These assays can be used to study the role of the gastrointestinal tract and kidney in metabolic acidosis.

Clinical West Nile virus infection in 2 horses in western Canada.

Two horses had a history of ataxia and weakness or recumbency. One recovered and was diagnosed with West Nile virus (WNV) infection by serologic testing. The other was euthanized; it had meningoencephalomyelitis, WNV was detected by polymerase chain reaction. West Nile virus infection is an emerging disease. Year 2002 is the first year in which cases have been seen in Saskatchewan.