Estimated antimicrobial dispensing frequency and preferences for lactating cow therapy by Ontario dairy veterinarians.

In this cross-sectional study, data were collected from responses to a questionnaire on dispensing frequencies of antimicrobials used by dairy practitioners in Ontario in dairy cattle in 2001. Data were validated through clinical case scenarios. Respondents reported using antimicrobials across all categories of importance to human medicine (medically important, Categories I to III) with a diversity of treatment combinations and routes of administration. Respondents anticipated that a request for direct veterinary supervision by producers was dependent on case severity, highlighting the importance of on-farm diagnostic and treatment protocols. Knowledge of the antimicrobials used in lactating cow therapy, and their frequency and reasons for use, will provide baseline information and contribute to antimicrobial stewardship in this food-animal production sector.

Estimé de la fréquence de la distribution d'agents antimicrobiens et préférences pour le traitement des vaches laitières par les vétérinaires en Ontario. Cette étude en coupe transversale a été réalisée à partir de réponses recueillies d'un questionnaire qui ciblait les fréquences de dispense d'agents antimicrobiens utilisés chez les vaches laitières par les vétérinaires de la province d'Ontario en 2001. Ces données ont été validées avec l'aide de scénarios de cas cliniques. Les répondants ont indiqué l'utilisation d'antimicrobiens dans toutes les catégories qui sont jugées critiques en médecine humaine (dont les Catégories I à III) avec une diversité de combinaisons de traitements ainsi que de moyens d'administration. Les répondants ont anticipé que ce serait la sévérité d'un cas clinique qui déterminerait si le producteur devait faire une demande de supervision directe d'un vétérinaire sur la ferme. Ceci fait ressortir l'importance des protocoles de diagnostics et de traitements qui se feront dans chaque ferme. La connaissance des sortes d'agents antimicrobiens nécessaires, ainsi que la raison et la fréquence de leur utilisation en thérapie chez la vache laitière lactante, va fournir des renseignements de base et aussi contribuer à la gestion responsable d'agents antimicrobiens dans ce secteur de production animale.(Traduit par les auteurs).

Antimicrobial dispensing by Ontario dairy veterinarians.

This questionnaire-based cross-sectional study was designed to capture the demographics of dairy practitioners in Ontario and to describe aspects of antimicrobial dispensing on-farm and over-the-counter by these veterinarians. The information collected revealed that the prescription status of a drug and the level of veterinary-client-patient relationship were important elements of dispensing policies. Over-the-counter dispensing records were incomplete, while only a small proportion of on-farm dispensing records contained pertinent information and directions as required by the Veterinarians Act. While respondents recognized that antimicrobial use in dairy herds could lead to resistance in cattle, few indicated that this was a significant public health issue. Veterinarians can play a key role in antimicrobial stewardship, part of which is the provision of complete written dispensing instructions to producers for antimicrobial use in dairy cattle.

La distribution des agents antimicrobiens par les vétérinaires qui s'occupent des vaches laitières en Ontario. Cette étude en coupe transversale a été réalisée à partir de réponses recueillies d'un questionnaire qui ciblait les données démographiques des praticiens des fermes laitières de l'Ontario en plus de décrire les habitudes de dispense des doses d'agents antimicrobiens in situ par les vétérinaires ou en vente libre auprès des distributeurs. Cette information nous a permis de reconnaître que le statut de l'agent antimicrobien prescrit et le niveau de relation entre le vétérinaire-client-patient sont des éléments très importants de la politique de dispense. Les données concernant les agents antimicrobiens achetés sans prescription étaient incomplètes dans les points de vente et seulement une petite proportion des données internes à la ferme contenait les informations et les dosages tels que requis par la loi sur les vétérinaires. Les répondants reconnaissaient que l'utilisation des agents antimicrobiens chez les vaches laitières pouvait élever leur résistance à ceux-ci, mais peu d'entre eux mentionnaient que ceci engendrait une réelle inquiétude pour la santé publique. Les vétérinaires ont donc un rôle clé à jouer et ils devront être assidus en fournissant, par écrit, des instructions complètes sur les prescriptions d'agents antimicrobiens aux producteurs de vaches laitières.(Traduit par les auteurs).

Factors associated with survival in the herd for dairy cows following surgery to correct left displaced abomasum.

Left displaced abomasum (LDA) is a common problem in dairy cows. There have been numerous studies focused on predicting prognosis for right displaced abomasal corrective surgery, but a paucity of studies exist focused on more common LDA surgeries. Our objective was to determine if survival to 60 d or 1 yr after surgery could be predicted from the physical exam findings, periparturient disease status, and a biochemical profile from a blood sample obtained at the time of LDA diagnosis. Blood ß-hydroxybutyrate (BHBA) concentrations were measured immediately using a hand-held meter. Data obtained from CanWest DHI (Guelph, ON, Canada) for all of the study subjects (n=179 cases, by 24 veterinarians from 4 clinics), including cull date, cull reason, and test-day milk production. Cows were classified based on whether or not they were culled within 60 d or 1 yr of surgery. Based on logistic regression, cows that had dystocia [odds ratio (OR)=13, 95% confidence interval (CI)=7-26] or were not ketotic (blood BHBA<1.2 mmol/L; OR=3, 95% CI=1.03-9) at the time of corrective surgery were more likely to be culled within 60 d. Higher serum concentrations of BHBA (OR=0.95, 95% CI=0.92-0.98), nonesterified fatty acids (OR=0.81, 95% CI=0.75-0.88), and Mg (OR=0.49, 95% CI=0.35-0.68) all had a protective effect against culling within 1 yr of LDA surgery. Based on survival analysis, longevity in the herd for 365 d following corrective surgery was associated with higher BHBA and Mg at the time of LDA diagnosis before surgery, as well as milk production following surgery.

Evaluation of the effects of treating dairy cows with meloxicam at calving on retained fetal membranes risk.

Some non-steroidal anti-inflammatory drugs increase the risk of retained fetal membranes. This is the first study to investigate the effects of meloxicam on the risk of retained fetal membranes. Administration of meloxicam to dairy cattle immediately following calving revealed no differences in the incidence of retained fetal membranes between meloxicam-treated and untreated animals. There was no difference between the 2 groups in the incidence of periparturient diseases following calving. Meloxicam can be used on the day of calving in lactating cows without increasing the risk of retained fetal membranes.

L'évaluation des effets d'une injection de méloxicam immédiatement après le vêlage chez la vache laitière sur le risque de rétention des membranes foetales. Certains médicaments inflammatoires non-stéroïdiens augmentent le risque de rétention de membranes fœtales. Cette étude est la première à examiner les effets du méloxicam quant au risque de rétention de membranes fœtales. Aucune différence n'a été notée dans le cas de rétention de membranes fœtales lors du vêlage chez la vache laitière entre les vaches qui ont reçu une injection de méloxicam immédiatement après le vêlage et celles qui n'ont rien reçu. De plus, il n'y avait aucune différence d'incidence de maladies périnatales observées suite au vêlage entre les deux groupes. On peut donc administrer du méloxicam aux vaches laitières le jour du vêlage sans augmenter le risque de rétention de membranes fœtales.(Traduit par les auteurs).

An investigation of the effects of ketoprofen following rumen fistulation surgery in lactating dairy cows.

Post-operative pain management following rumen surgery is not common practice. We examined the effect of providing the pain medication ketoprofen to dairy cattle following the first stage of a rumen cannulation surgery, which involves an incision in the body wall and exteriorizing and clamping the rumen. The results of this study provide clear evidence that the first stage of the surgery was painful and ketoprofen at the time of and 24 h following surgery, alleviated some, but not all, of the post-surgical pain. Pain mitigation should be included when performing flank surgery in cattle.

Une enquête sur les effets du kétoprofène administré à des vaches laitières après une chirurgie de fistulisation du rumen. Ce n'est pas pratique courante d'administrer des analgésiques suite à la chirurgie du rumen. Cette étude a examiné les effets du médicament kétoprofène chez les vaches laitières après la première étape d'une chirurgie de fistulisation du rumen. Cette chirurgie consiste à faire une incision sur le côté gauche de l'abdomen pour ensuite sortir une partie du rumen de l'abdomen et de le fixer avec une attache. Les résultats de cette étude démontrent que la première étape était douloureuse et que l'administration du kétoprofène, à la fin de la chirurgie, ainsi qu'après 24 h, a atténué une partie de la douleur chirurgicale sans toutefois l'enlever complètement. L'administration d'analgésiques devrait faire partie intégrante du traitement lors des chirurgies abdominales chez les bovins.(Traduit par les auteurs).

Short communication: a comparison of 2 nonsteroidal antiinflammatory drugs following the first stage of a 2-stage fistulation surgery in dry dairy cows.

Postoperative pain and its management following fistulation surgery in cattle are poorly understood. The purpose of this study was to compare 2 nonsteroidal antiinflammatory drugs (NSAID) as potential postoperative pain management treatments following the first stage of a 2-stage fistulation surgery. A randomized complete block design trial was conducted in dry Holstein cows (n=10) following fistulation surgery. Ketoprofen (3mg/kg of body weight i.m.) was administered on the day of surgery and 24 h later, whereas meloxicam (0.5 mg/kg of body weight s.c.) was administered once only on the day of surgery. Outcomes evaluated at 0, 2, 9, 24, 26, and 33 h postsurgery were heart rate, respiration rate, rectal temperature, and infrared temperature around the surgical site. Outcomes evaluated on the day of surgery and d 1 following surgery and compared with the average for the 4d before surgery were lying activity (total lying time, total time spent lying on the left side, and percentage of time lying on the left side) and feed intake. A difference was observed in dry matter intake on d 1 but this effect was not different on d 0 compared with presurgical averages. A difference was observed in time spent lying on the left side and a difference was observed in heart rate following the first stage of fistulation surgery compared with presurgical averages. The infrared temperature readings around the surgical site were significantly greater in the hours following surgery compared with presurgical averages. The respiration rate increased over time after 24h postsurgery compared with presurgical values. Although it was clear that the surgery is painful, the drug effects were more difficult to explain. On d 0 and 1, the meloxicam-treated cows ate 3 kg more but spent 101 min/d less time lying on their left side compared with ketoprofen-treated cows. The first stage of a 2-stage fistulation surgery was considered painful based on changes in heart rate, respiration rate, infrared temperature readings, dry matter intake, and time spent lying on the left side. It is clear that left flank surgery is painful and that NSAID can improve outcomes associated with that pain, but we cannot make recommendations as to which NSAID to choose based on these results.

Effects of meloxicam on milk production, behavior, and feed intake in dairy cows following assisted calving.

Parturition is a necessary event for production in dairy cattle, and assistance at calving is common. There is limited use of nonsteroidal antiinflammatory drugs for the alleviation of calving pain and a paucity of research on the effects of these drugs on postpartum health and performance. This randomized triple blind clinical trial involved Holstein cows (n=42) and heifers (n=61) that experienced an assisted parturition. These animals received either 1 injection of meloxicam (0.5mg/kg of body weight) or placebo subcutaneously 24h following calving. Outcome measures included dry matter intake (DMI) and milk production for the first 14d in milk, blood metabolites sampled over 12d, health events for the first 60d in milk, as well as lying and feeding behavior 24h following injection. Continuous data were analyzed using multivariable regression models. Binary outcomes were analyzed using a mixed logistic model with cow modeled using a random intercept. This study failed to show any significant effects of treatment on DMI, milk production, blood metabolites, or health events. A possible explanation for the lack of treatment differences could be that the meloxicam was administered too late after calving. Meloxicam increased feeding time as well as bunk visit frequency in the 24h following injection. Regardless of treatment, animals that had retained fetal membranes produced less milk and had higher serum haptoglobin concentrations. Future research is warranted to examine the effects of antiinflammatory drugs administered closer to the time of calving on health and production.

Short communication: use of a mechanical brush by Holstein dairy cattle around parturition.

Grooming is a normal behavior that may contribute to relief of stress. The purpose of this study was to investigate the effect of access to a mechanical brush on auto-grooming behavior in parturient cows. The hypothesis was that cows would increase the total time spent scratching using the brush if they had access to a brush around the time of calving, whereas auto-grooming would be lower for the brush group compared with the no-brush group. The use of a mechanical brush was analyzed both in a group-housed pen (72 to 48 h before calving) and in an individual maternity pen (6h before to 6h after calving) in 16 multiparous Holstein cows. In the maternity pen, cows were randomly assigned to have access to the brush or not. The provision of a mechanical brush in the individual maternity pen did not change the amount of time spent auto-grooming but cows did use the brush before calving and after the calf was removed. Despite being housed in pens containing a brush, cows failed to use it when the calf was present. However, cows with access to a brush spent more time licking their calves in the first hour postcalving (ß=8.7 min; 95% confidence interval: 1.5, 15.8) than cows that did not have access to a brush. Regardless of treatment, cows increased the time spent auto-grooming and scratching following separation of their newborn calf (ß=1.4 min; 95% confidence interval: 0.46, 2.3 and ß=0.07 min; 95% confidence interval: 0.02, 0.12, respectively). Further research is warranted to investigate possible benefits of mechanical brush devices at the time of calving, particularly for cows that experience difficult calving and require manual or mechanical assistance.

The effect of administering ketoprofen on the physiology and behavior of dairy cows following surgery to correct a left displaced abomasum.

Surgical correction of left displaced abomasum (LDA) is common in lactating dairy cattle. Despite the growing acceptance that abdominal surgery is painful, few cows are administered analgesia following LDA surgery. The objective of this research was to examine the effect of administering a label dose of ketoprofen on physiological and behavioral indicators of pain in dairy cattle. Holstein cows were enrolled in a field study following LDA surgery. Surgery was performed using the standing right flank (RF) approach or the paramedian (PARA) approach. Using a triple-blind randomized trial, each animal was assigned to receive either 3mg of ketoprofen/kg of body weight or saline (the equivalent volume) by intramuscular injection immediately following surgery and 24h postoperatively. Physiological parameters (heart rate, respiration rate, and rumen motility), blood ß-hydroxybutyrate (BHBA) levels, and an assessment of cow attitude were measured on the day of surgery, and at 2 follow-up visits (visit 1=3 ± 0.9 d and visit 2=9 ± 1.2 d postsurgery; n=175). Milk production and culling were recorded for all cows enrolled in the study. Producers assessed their cows' attitudes and appetites daily for the first 3 d following surgery. A subset of cows (n=37) were fitted on the day of surgery with a 3-axis accelerometer on the hind leg to assess lying behavior. Continuous and binary outcome data were analyzed using multivariable mixed linear and mixed logistic models, respectively, with cow modeled as a random effect. Ketoprofen did not alter the physiological measures, BHBA levels, or behavioral outcomes measured. Cows subjected to RF surgery had longer lying times [model coefficient ß=228.9 min; 95% confidence interval (CI): 122.2 to 335.6] in the first 3 d following surgery, and lower heart rates (ß=-9.4 beats/min; 95% CI: -12 to -6.9 beats/min) at the follow-up visits, compared with animals that underwent PARA surgery. Regardless of surgical procedure, BHBA decreased from surgery day to visit 1 (ß=-1.9 mmol/L; 95% CI: -2.1 to -1.7) and visit 2 (ß=-2.0 mmol/L; 95% CI: -0.2.2 to -1.8). Producer reports indicated that animals that received ketoprofen were more likely to begin eating when provided fresh feed during the first 3 d following surgery compared with those that received saline (odds ratio=4.8; 95% CI: 0.97 to 23.8). These results indicate that PARA surgery may be more painful relative to lying down than the RF approach. The apparent differences in appetite or attitude in cows that received ketoprofen reported by producers warrant further investigation.

Cardiorespiratory effects and efficacy of morphine sulfate in winter flounder (Pseudopleuronectes americanus).

OBJECTIVE: To assess the cardiorespiratory effects of morphine sulfate and evaluate whether morphine blocks cardiac responses to a noxious stimulus in winter flounder. ANIMALS: 42 winter flounder (Pseudopleuronectes americanus) that were acclimated at 10 degrees C. PROCEDURES: Each fish was fitted with a Doppler flow probe around the ventral aorta; cannulae were placed for injection of drug or saline (0.9% NaCl) solution and assessments of respiration. Selected cardiorespiratory variables were measured in morphine-injected (40 mg/kg, IP [n = 18] or 17 mg/kg, IV [2]) or saline solution-injected (1.6 mL [22]) fish at various intervals. Heart rate and cardiac output (CO) were also measured in flounder that were injected with saline solution (n = 19) or morphine (10) and received a noxious or innocuous stimulus (injection of 5% acetic acid or saline solution SC into a cheek) 50 minutes later. RESULTS: Morphine administration promptly induced marked bradycardia (and a concomitant reduction in CO), followed by prolonged (> 48 hours) increases in CO and heart rate. Morphine injection only transiently affected respiratory rate. Application of a noxious stimulus to control flounder resulted in a significant (10%) but transient (< 5 minutes' duration) increase in CO, which was completely blocked by prior administration of morphine. CONCLUSIONS AND CLINICAL RELEVANCE: Although morphine blocked the response to a noxious stimulus in fish, its cardiovascular effects might preclude its use in many research situations. Investigation of the dose dependency of these cardiovascular effects and their interspecific variation is required to determine the applicability of morphine for use in fish.

Pharmacokinetics of morphine in fish: winter flounder (Pseudopleuronectes americanus) and seawater-acclimated rainbow trout (Oncorhynchus mykiss).

We made a single intraperitoneal (IP) injection of morphine sulfate (40 mg/kg) into winter flounder and seawater acclimated rainbow trout at 10 degrees C and then followed its disposition by measuring the change in plasma morphine concentration for 100 h using a morphine specific ELISA. Disposition also was followed for 6h after a single IV injection of 7.5mg morphine sulfate in winter flounder. Plasma morphine reached a maximum within an hour post-injection IP and then decreased in a bi-exponential fashion with a rapid distribution phase followed by a slower elimination phase. The disposition was slower in flounder than in trout even though the fish were held at the same temperature. For example, plasma clearance was 76 mL h(-)(1) kg(-)(1) in the flounder but was almost twice as much in the trout (153 mL h(-)(1) kg(-)(1)) and mean residence time was 27.9h in the flounder but was 7.0 h in the trout. The present study is the first comprehensive pharmacokinetic analysis for any analgesic in an ectotherm, and our results show that: 1) significant intra-specific variation exists between fishes: and 2) the disposition of morphine in fish is approximately one order of magnitude slower than it is in mammals. These differences may be due in part to mass specific differences in cardiac output.