Application of Epidemiological Methods in a Large-Scale Cross-Sectional Study in 765 German Dairy Herds-Lessons Learned.

From 2016 to 2020, the "PraeRi" study, conducted by three German veterinary universities, was aimed at enhancing animal health and welfare in dairy farms. With 765 dairy farms visited and 101,307 animals examined, this study provided a basis for improving animal health and welfare. The study population comprised three different regions representing a broad variety of characteristics. To ensure representative estimates, a sample size of 250 farms was determined for each region, employing a stratified sampling plan based on farm size. According to the information provided by the farmers, the most commonly occurring disease in their herds was mastitis without general disorder (14.2% to 16.3% of the herd-depending on the region). For most disorders, prevalence data were lowest for the region South compared with the two remaining regions. Multivariable regression analyses were performed to identify risk factors for various target variables, and the results were communicated through individual reports and benchmarking flyers to participating farmers. The authors encountered challenges in management and communication due to the project's size in terms of personnel, data, and farms examined. Harmonizing data management and hypothesis testing across all involved parties added complexity.

Pharmacokinetics of metamizole (dipyrone) as an add-on in calves undergoing umbilical surgery.

This preliminary clinical investigation of the pharmacokinetic behavior of the main metamizole (dipyrone) metabolites 4-methylaminoantipyrine (4-MAA) and 4-aminoantipyrine (4-AA) in calves undergoing umbilical surgery is part of an already published main study. A single intravenous dose of metamizole was added to ketamine/xylazine/isoflurane anesthesia. Eight Simmental calves weighing 90 ± 10.8 kg and aged 47.6 ± 10.4 days received 40 mg/kg metamizole intravenously 10 minutes prior to general anesthesia. Blood samples were collected over 24 hours and analyzed for 4-MAA and 4-AA. Meloxicam was additionally given twice: 2.5 hours pre- and 20.5 hours postsurgically. The pharmacokinetic profile of 4-MAA was best fitted to a two-compartment model and was characterized by a fast distribution half-life and slow elimination half-life (t½alpha = 5.29 minutes, t½beta = 9.49 hours). The maximum concentration (Cmax 101.63 µg/mL) was detected at the first measurement time point 15 minutes after administration. In contrast, 4-AA showed fast, high and biphasic plasma peak concentration behavior in five calves (2.54-2.66 µg/mL after 15-30 minutes, and 2.10-2.14 µg/mL after 2-3.5 hours) with a t½beta of 8.87 hours, indicating a rapid distribution and subsequent redistribution from well-perfused organs. Alternatively, three calves exhibited a slower and lower monophasic plasma peak concentration (1.66 µg/mL after 6.5 hours) with a t½beta of 6.23 hours, indicating slow accumulation in the intravascular compartment. The maximum concentration and area under the plasma concentration curve (AUC) of 4-AA were lower than those of 4-MAA. This metabolic behavior supports our already published data on clinical monitoring and plasma cortisol concentrations (PCCs). Compared to those of saline controls, lower PCCs correspond to the t½alpha of 4-MAA. Data on Tmax and t½beta also match these clinical observations. However, further studies are required to assess the exact analgesic mechanism and potency of the metamizole metabolites in calves.

Use of metamizole as an additional analgesic during umbilical surgery in calves.

OBJECTIVE: To investigate the effect of metamizole on physiologic variables in calves undergoing surgical extirpation of the navel during anaesthesia using xylazine, ketamine and isoflurane. STUDY DESIGN: Double-blind, randomized trial. ANIMALS: A total of 26 calves. METHODS: Calves with uncomplicated umbilical hernias and otherwise clinically healthy were randomly allocated to one of two groups: the control group (CG) and metamizole group (MG). All calves were administered meloxicam (0.5 mg kg-1) intravenously (IV) 150 minutes before skin incision (SI). Animals were premedicated with xylazine (0.2 mg kg-1) intramuscularly 50 minutes before SI. Anaesthesia was induced with ketamine (2 mg kg-1) IV 30 minutes before SI and maintained with isoflurane in oxygen. MG calves were given metamizole (40 mg kg-1) IV 60 minutes before SI. CG calves were administered an equivalent volume of saline. Heart rate (HR) and mean arterial blood pressure (MAP) were recorded from 5 minutes before SI until the end of anaesthesia (60 minutes after SI). Blood samples for determination of the plasma cortisol concentration (PCC) were drawn 60 minutes before SI and at 5, 30, 60, 150, and 510 minutes after SI. RESULTS: In both groups, PCC increased during surgery and decreased after surgery. PCC was consistently lower in MG than in CG and was significantly (p = 0.0026) lower at 150 minutes after SI in the MG. Overall, the mean PCC in MG was 10.9 nmol L-1 lower than that in CG (p = 0.01). In both groups, HR decreased during anaesthesia, whereas MAP increased, albeit with no statistically significant (p > 0.05) differences between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Our study results suggest that a single preoperative dose of metamizole may have a positive impact on intra- and immediate postoperative analgesia by reducing PCC when used as an indicator of nociception.

The course of plasma cortisol concentration after three different doses of ketamine in xylazine-premedicated calves.

OBJECTIVE: To investigate the influence of ketamine on plasma cortisol concentration (PCC) in calves. STUDY DESIGN: Prospective, randomized experimental study. ANIMALS: A total of 41 healthy, predominantly cross-bred calves, aged 3-4 months. METHODS: Calves were premedicated with intramuscular xylazine (0.2 mg kg-1) and randomly divided into four groups. The control group (CONT) received saline (after 10, 20 and 30 minutes), whereas groups K1, K2 and K3 were injected intravenously once, twice or thrice, respectively, with 4 mg kg-1 of ketamine at 10 minute intervals. Blood samples were collected at fixed time points and analysed to determine the PCC; furthermore, the plasma concentrations of ketamine and norketamine were assessed after a single ketamine administration in group K1. The pharmacokinetic parameters of ketamine and norketamine were calculated as plasma concentrations versus time. RESULTS: All groups showed significant (p < 0.0001) increases in PCC compared with the baseline value; however, for the first 60 minutes, PCC was significantly higher in the ketamine-treated groups (time × dose effect; K1: p < 0.0001; K2: p = 0.0008; K3: p = 0.0135) than in the CONT group. The group receiving triple ketamine administration exhibited the greatest increase in PCC compared with the baseline level (121.17 ± 33.25 nmol L-1), whereas in the CONT group, the increase in PCC was smaller than the baseline cortisol level (82.67 ± 36.86 nmol L-1). The plasma concentration of ketamine decreased with a half-life of approximately 12 minutes, which was longer than the dose interval. The increase in PCC after triplicate administration might, therefore, have resulted from ketamine/norketamine accumulation rather than from the total dosage. CONCLUSIONS AND CLINICAL RELEVANCE: Our results showed that ketamine increases the plasma concentration of cortisol in xylazine-treated calves. Thus, the previous treatment of subjects needs to be considered in studies using plasma/serum cortisol concentrations as an indicator of pain.

[Herd health problems with a focus on potential involvement of Clostridium botulinum in dairies in Bavaria. - A survey among veterinarians]. / Bestandsprobleme mit möglicher Beteiligung von Clostridium botulinum in bayerischen Milchkuhbetrieben.

OBJECTIVE: To evaluate the perceptions of Bavarian bovine practitioners in regard to ailments that could potentially be associated with chronic Clostridium botulinum infections. MATERIAL AND METHODS: A questionnaire-based survey consisting of two parts was conducted via telephone. The questionnaire contained five main inclusion criteria and seven further criteria for inclusion in the second, special part of the study. The main focus was on diseases suspected to be associated with chronic Clostridium botulinum infections. For the interview in the special part, for each practice, the farm that fulfilled the most of the main criteria was selected. RESULTS: In the general section of the questionnaire, 38 (37%) of the 104 participants stated not to have farms with any of the previously indicated disease patterns in their practice. A total of 532 operations (5% of all managed dairies) were classified as a problem facility that had to deal with the aforementioned main inclusion criteria diseases. The most frequently stated on-farm problems were an increased number of recumbent cows (73 %), lameness or cases of ataxia (70 %), udder problems (69 %), metabolic disorders (68 %), high incidence of chronically ill animals (66 %) and high culling rates (66 %). The housing conditions of dairy cows were assessed to be "mediocre" or "poor" in 49 % of dairies. Feeding management was regarded as "moderately good", "good" or "very good" by 91 % of participants. Testing for Clostridium spp. was performed on 11 farms and positive results were found in seven cases. CONCLUSION: Livestock veterinarians in Bavaria are frequently confronted with an abundance of animal health-related issues on dairy farms. However, even on farms on which there were signs according to the literature of clostridial infection, rather husbandry-related problems were suspec -ted in most cases.

Infrared thermography of the udder after experimentally induced Escherichia coli mastitis in cows.

The study aimed to use infrared thermography (IRT) to evaluate the changes in udder surface temperature after induction of Escherichia coli mastitis in the right hind quarter. Over a time period of 24 h before to 24 h post-inoculation, thermograms of both hind quarters were taken every 2 h to determine maximum (Tmax) and average (Tavg) temperatures. Differences in both maximum and average temperatures (DTmax and DTavg) were calculated, as well as temperature differences between both hind quarters. All cows developed signs of clinical mastitis with a significant increase in DTmax and DTavg with Tmax at 13 h post-inoculation for the (non-infected) left hind quarters. The results demonstrate that detection of mastitis using IRT is possible if the interval between examinations does not exceed 2 h.

Developing an accurate method for estimating thyroid volume in calves using ultrasonography.

Diseases of the thyroid gland with struma formation can occur in calves suffering from iodine deficiency. The aim of the study was to develop a guideline for standardized ultrasonographic examination of the thyroid gland in order to determine its volume. Sonographic measurements of the thyroid lobes were carried out on three standardized axes in calves up to 3 months of age (n = 83). Total volume (V SON ) was calculated using the formula for an ellipsoid body. Forty three of the enrolled animals were euthanized. The lobes of their thyroid glands were dissected and measured with a slide gauge, and V SLG was calculated accordingly. In addition, thyroid volume was measured using the method of water displacement (V AQU ) and this was used as a gold standard in correlation and regression analyses with sonographic and slide gauge values. Intraobserver variability of sonographic measurements was dependent on side and axis, and ranged between 3.04% and 7.35%. In the euthanized calves with a body mass of 52.4 ± 17.1 kg, V SLG was 4.5 ± 1.4 ml, V SON was 6.5 ± 1.7 ml, and V AQU was 7.9 ± 2.4 ml (mean ± standard deviation). Instead of the formula for ellipsoid bodies which underestimates thyroid volume, we developed a new formula derived from regression analysis. Body mass and thyroid volume correlated significantly. With the formula presented, thyroid volume of calves can be estimated by ultrasonographic measurement of three axes and compared to predicted values based on body mass.

Infrared thermography of the udder surface of dairy cattle: characteristics, methods, and correlation with rectal temperature.

Thermograms of the caudal udder surface were taken of five healthy cows before and after inoculation of Escherichia coli into the right hind quarter. Images in clinically normal udder quarters from cows without fever (CN) were compared with those post inoculation when cows had fever (⩾ 39.5°C) and showed elevation of somatic cell counts (⩾ 400,000 cells/mL) in the inoculated quarter (CM). Using graphic software tools, different geometric analysis tools (GATs: polygons, rectangles, lines) were set within the thermographic images. The following descriptive parameters (DPs) were employed: minimum value ('min'), maximum value ('max'), range ('max-min'), and arithmetic mean ('am'). Surface temperatures in group CN were between 34.1°C ('polygons'/'min') and 37.9°C ('polygons'/'max'), and in group CM between 34.5°C ('polygons'/'min') and 40.0°C ('polygons'/'max'). The greatest differences in the temperatures between CN and CM (2.06°C) were found in 'polygons' and 'rectangles' using 'max'. The smallest coefficient of variation in triplicate determinations was found in GAT 'polygons' with DP 'max' (Tmax) (0.15%), and the relationship to the rectal body temperature (Tr) could be described by Tr=5.68+0.874*Tmax. The results show that significant changes can be displayed best using the GAT 'polygons' and the DP 'max'. These methods should be considered for automated monitoring of udder health in dairy cows.

[Comparison of three different anesthesia procedures in calves with respect to possible pain-associated reactions]. / Vergleich von drei verschiedenen Anästhesieverfahren bei Kälbern hinsichtlich möglicher schmerzassoziierter Reaktionen.

The objective of this study was to compare the effects of three anaesthetic protocols with respect to possible pain-associated reactions: injection (INJE) with xylazine (0.2 mg/kg), ketamine (5 mg/kg) and local anaesthesia (procain 2%); a combination of injection and inhalation (KOMB) with xylazine (0.2 mg/kg), ketamine (2 mg/kg), and isoflurane (1.5-3.0 vol%); and inhalation with isoflurane (control group [o]) surgery. During the trial, the anaesthetic level was controlled, and signs of response to surgical stimulation or spontaneous movements, changes in heart rate, mean arterial pressure, plasma L-lactate and cortisol levels were recorded. The dosage of 5 mg ketamine/kg body mass was rarely sufficient to obtain surgical tolerance in group INJE. In order to attain surgical tolerance, it was necessary to administer an average of 8.4 mg ketamine/kg body mass. All animals of the INJEc/o groups started to show signs of spontaneous movements or response to surgical stimulation between five and twelve minutes after the last administration of ketamine. Signs of response to surgical stimulation at the time of skin incision were significantly most frequent (37%) in the INHAc group, while agitation or response to surgical stimulation at least once during the entire time of anaesthesia was significantly (p <0.01) most frequent in the INJEc group (100%). Changes in heart rate and mean blood pressure were not found to be related to surgical stress situations.Ten minutes after the incision, the highest increases in plasma cortisol levels above basal levels of the previous day were determined in the groups INJEc and INJEo (53.5 and 57.7 nmol/l, respectively). However, a significant increase of plasma cortisol levels between the previous day and ten minutes after incision was only found between INHAc and INHAo (30.1 versus 7.5 nmol/l, p < 0.01) but not in the other pairs of groups (INJEc/o and KOMBdc/o). Within the three experimental groups the increase of plasma cortisol levels between the previous day and ten minutes after incision was only significant between INJEc and KOMBc (53.5 versus 28.3 nmol/l, p < 0.01). Among the protocols tested in this study, the combination anaesthesia (KOMB) was associated with the least amount of pain-associated reactions by the calves. Therefore, this protocol should be used preferred to the other two protocols in order to minimise stress and pain for the animals as much as posssible.

[Euthanasia of cattle: a clinical comparison of T 61 and pentobarbital (Eutha 77)]. / Euthanasie des Rindes--ein klinischer Vergleich von T 61 und Pentobarbital (Eutha 77).

The objective of this study was a comparison of pentobarbital and T 61 in the euthanasia of cattle. 397 cattle of different ages and breeds which had to be euthanised in the Clinic for Ruminants were enrolled. Following clinical examination, euthanasia was performed by intravenous injection of either 40 mg pentobarbital per kg body weight (BW) (0.1 ml Eutha 77) or 0.1 ml T 61/kg BW. The intervals between the beginning of injection and the following events were noted: collapse of the animal, cessation of respiration, cessation of cardiac action, disappearance of the palpebral and corneal reflexes, and maximum dilatation of the pupils. These post-injection events occurred significantly earlier with Eutha 77. In addition, events like excitations and vocalisations were recorded. Excitations occurred twice as often with T 61 (in 34% of cases) than with Eutha 77 (17%), and strong excitations (grade 3 of 3) were also more frequent with T 61 (9.8%) than with Eutha 77 (3%). Vocalisations were less frequent (30%) with T 61 than with pentobarbital (39%), but this difference was not significant. Severe vocalisations occurred very rarely. With both drugs, intervals between the beginning of injection until cessation of reflexes were longer in older animals. Following injection of Eutha 77, cessation of the corneal reflex and maximal dilatation of the pupils occurred earlier in cattle with severe disturbance of the general condition than in cattle with lesser disturbance; in the T 61-group this difference was only significant for the interval until cessation of the corneal reflex. In anaesthetized patients euthanized with T 61 cessation of cardiac action and respiration occurred earlier than in patients that were not under general anaesthesia when euthanized; in the Eutha 77 group, the difference was significant only for the interval until cessation of cardiac action.