Comparison of metrics to assess antibiotic use in small ruminants at a university referral clinic between 2005 and 2019.

BACKGROUND: Monitoring antibiotic use is essential to provide a framework enabling veterinarians to use antibiotics prudently. METHODS: Electronic medical records from the University of Veterinary Medicine's Clinic for Ruminants in Vienna were analysed with respect to sheep and goat antibiotic doses administered over a 15-year period (2005-2019). Antibiotic use was assessed using total milligrams per kilogram (mg/kg), total milligrams, number of doses administered, defined daily doses (DDD) for cattle and estimated DDD for sheep. RESULTS: A total of 5113 antibiotic doses were recorded over the 15-year period. Urinary tract disorders required the highest number of doses administered per animal (mean 16.9; median 16.0). Antibiotic use patterns varied according to the metrics used for analysis. By mg/kg, the largest proportion of antibiotics administered were penicillin/streptomycin (43.0% of the total mg/kg), followed by tetracyclines (17.3%) and sulphonamide/trimethoprim combinations (15.2%). By number of doses administered, the most frequently used antibiotics were penicillins (excluding combinations with streptomycin) (33.9% of total number of doses administered), fluoroquinolones (25.1%), third/fourth-generation cephalosporins (13.6%) and penicillin/streptomycin (13.4%). LIMITATIONS: As the university clinic was a city-based referral centre, this analysis cannot be compared directly with antibiotic use in commercial herds or flocks. CONCLUSIONS: The considered choice of antibiotic use metrics is essential for an effective and meaningful analysis of the responsible use of antibiotics by veterinarians in practice.

Most common diagnoses and antibiotics used in South American Camelid patients at a university clinic in Austria.

Knowledge of common diseases and their treatment in minor species, such as llamas and alpacas, is growing, but frequently drugs are not licensed in these species. Our aim was to evaluate frequent diagnoses and commonly applied antibiotics in patients of a university clinic with a particular focus on EMA Category B antibiotics, which are critically important for human health. We retrospectively analyzed anonymized patient records between 2005 and 2019 regarding the causes for antibiotic treatment and choice of antibiotic substance. The most frequent indications for antibiotic treatment were diseases of the digestive tract and perioperative prophylaxis for castrations. The number of applications of EMA Category B antibiotics initially increased with the number of patients treated, then remained stable, while the use of Category D drugs increased over time. Most Category B antibiotics were used for diseases of crias and diseases of the digestive tract, primarily dental disease. The use of EMA Category B antibiotics cannot be completely avoided based on the types of cases treated. However, antibiotic stewardship guidelines should be followed wherever possible.

Benchmarking Based on Regularly Recorded Claw Health Data of Austrian Dairy Cattle for Implementation in the Cattle Data Network (RDV).

While benchmarking is already used for the assessment of performance gaps in cattle herd management and welfare concerns, its application to quantifying claw health performance is relatively new. The goal here was to establish a benchmarking system for claw health in Austrian dairy cattle. We used electronically registered claw health data of cows from 512 dairy herds documented by professional hoof trimmers, culling data from the same herds, and locomotion scores taken at regular milk performance testings in 99 dairy herds during 2020. Mean, median and the 10th, 25th, 75th, and 90th percentiles of the incidences of risk of lameness, 13 common claw lesions, and the annual culling risk directly related to claw and limb disorders were used as key performance indicators. Only validated data sets were used and participating trimmers and locomotion scorers had to pass interobserver reliability tests with weighted Cohen's kappa values ≥ 0.61 indicating substantial interobserver agreement. This claw health benchmarking system is intended to be used henceforth in the transnational cattle data network (RDV) by all participating farmers and is also available for veterinarians and consultants, with the agreement of respective farmers.

Emergence of Parafilaria bovicola in Austria.

Veterinarians reported cases of cutaneous bleeding in cattle in Austria in the spring and summer of 2020. It was our goal to confirm the tentative diagnosis of parafilariosis by identifying Parafilaria bovicola in exudate samples using molecular methods for the first time in Austria. We asked veterinarians in the field to collect exudate from typical lesions on cattle. We performed polymerase chain reactions (PCRs) and sequenced a 674-bp section of the mitochondrial cytochrome oxidase subunit I in all positive samples. Overall, in 57 of 86 samples, P. bovicola was confirmed by PCR in cattle from Lower Austria, Upper Austria, Styria, Salzburg, Carinthia, and Tyrol. Sequencing detected four different haplotypes or genotypes, respectively, indicating multiple routes of introduction. We conclude that parafilariosis has spread in Austria and we expect that the number of reports of clinical signs and losses due to carcass damage will increase in the future.

The Antibiotic Treatment of Calf Diarrhea in Four European Countries: A Survey.

Neonatal calves are commonly affected by diarrhea caused by different pathogens, but not always bacteria. Yet, antibiotics are routinely used as a treatment to an unknown extent. It was our goal to survey antibiotic use for the treatment of neonatal calf diarrhea in different countries and to identify influencing factors. A total of 873 farmers and veterinarians in Austria, Belgium, Portugal, and Scotland participated in a voluntary online survey. The data were analyzed using classification and regression tree analyses and chi2 tests. Overall, 52.5% of the participants stated that they use antibiotics when treating neonatal calf diarrhea. Of those, 27% use them always, and 45% use highest priority critically important antibiotics. The most important factor differentiating antibiotic use practices was the country the participants were from, which could be due to regulatory differences between the countries. All antibiotic products stated were licensed for use in cattle, but several were not licensed for the treatment of diarrhea in calves. Our study shows that there is an urgent need for more scientific evidence to define best practices for the treatment of neonatal calf diarrhea. Furthermore, consensual criteria for antibiotic therapy must be defined, and targeted training for farmers and veterinarians must be provided.

Septic Tenosynovitis of the Digital Flexor Tendon Sheath in 83 Cattle.

Septic tenosynovitis of the digital flexor tendon sheath (DFTS) is the second most prevalent infection of deeper structures of the distal limb in cattle, after septic arthritis of the distal interphalangeal (DIP) joint. Depending on the type of infection and the involvement of adjacent anatomical structures, various surgical techniques may be used for therapy: Incising the DFTS to resect one or both digital flexor tendons (RDFT), additional resection of the DIP joint (RDIP) or additional digital amputation (RAMP). Our goal was to describe clinical findings and outcome in cattle patients (euthanasia vs. treatment) and the success of surgical methods including improvement of locomotion and postoperative survival time (POST). Data of eighty-three cattle with a mean age of 4.3 years were reviewed in this retrospective study. Overall, 57.7% of tenosynovitis cases were in the lateral DFTS of a hind limb. Fifty-five cattle were treated surgically; the remaining 28 cattle were euthanized following diagnosis. The median cumulative POST was 17.3, 83.1, and 11.9 months for RDFT, RDIP, and RAMP, respectively. Fatal postoperative complications occurred in three cattle. We conclude that the applied methods were successful and allowed the animals to almost reach the average life expectancy of an Austrian dairy cow.

Measuring sucrose in blood after oral administration to detect abomasal ulcers in calves.

Abomasal ulcers are common in cattle, especially in calves, and to date, there is no reliable antemortem method for diagnosis, to our knowledge. We assessed if measuring sucrose in blood after oral administration in calves could be used to identify animals with abomasal ulcers. Terminally ill calves (n = 12; part A) and calves designated for slaughter (n = 123; part B) were given a sucrose solution per os, and blood samples were taken 15, 30, 60, 90, and 120 min (part A) or 30 and 60 min (part B) after administration. The calves were then euthanized or slaughtered, and their abomasa were examined. Serum samples were analyzed using highperformance liquid chromatography-mass spectrometry, and data were analyzed using general linear mixed models. Calves both with and without affected abomasa had increasing sucrose values over time without significant differences. Also, there was no relationship between the size of the mucosal lesion and sucrose values.

Aspects of lameness in pasture based dairy systems.

Pasture-based dairy systems are implemented all over the world. Access to pasture is perceived to be advantageous for animal welfare in western societies. However, the benefits of grazing on lameness are not uniformly verifiable. This is related to the challenges that grazing cows face which are different from zero-grazing systems to some extent, but may nevertheless be deleterious. The distribution of lesion types comparing housed and pastured cattle differs between studies. This may be caused by differences in how strongly certain risk factors apply in these studies. Major risk factors for lameness in grazing cattle are related to the risk of trauma, for example from long walking distances and lack of track maintenance, and cow factors such as the adaptability of certain breeds to the grazing lifestyle. The consequences of lameness are similar to zero-grazing cattle and negatively affect animal welfare and productivity.

Abomasal and Third Compartment Ulcers in Ruminants and South American Camelids.

Abomasal ulcers are frequent incidental findings in necropsies of domestic ruminants and South American Camelids (SAC) or in slaughter animals and are a frequent cause of death in the most affected group of cattle, veal calves. Their true prevalence and significance is unknown owing to limitations in diagnosing the condition in live animals. This article discusses types of ulcers, possible causes of ulceration, and the clinical consequences, symptoms, and differential diagnoses, as well as further diagnostics in cattle, small ruminants and SAC. The limited treatment options and possibilities for prevention are reviewed.

[Abomasal ulcers in cattle]. / Labmagengeschwüre beim Rind.

Abomasal ulcers lead to several problems. They cause pain resulting in a decrease in productivity and even the possible loss of the animal. Because they are frequently difficult to diagnose, information on their prevalence is variable. Additionally, therapeutic options are limited. Abomasal ulcers are graded as type 1 through 4, type 1 being a superficial defect and type 2 an ulcer where a large blood vessel has been eroded, leading to substantial blood loss. Types 3 and 4 are perforated abomasal ulcers leading to local and diffuse peritonitis, respectively. Causes of abomasal ulcers are multifactorial, for example, mistakes in feeding that lead to gastrointestinal disturbances or other diseases that induce stress. Ulcers can also result from side effects of nonsteroidal anti-inflammatory drugs. In principal, the pathophysiological cause is the disturbance of the balance between protective and aggressive mechanisms at the abomasal mucosa due to stress. Clinical symptoms vary and are mostly non-specific. Fecal occult blood tests, hematology and blood chemistry as well as ultrasonographic examination and abdominocentesis can help to establish the diagnosis. Ulcers can be treated symptomatically, surgically and medically. To prevent abomasal ulcers, animals should be kept healthy by providing adequate nutrition and housing as well as early and effective medical care. Stressful management practices, including transport and commingling, should be avoided.

Abomasal ulcers in slaughtered cattle in Austria. / Labmagenulzera bei Schlachtrindern in Österreich.

OBJECTIVE: In this preliminary study, the prevalence of abomasal ulcers in cattle in Austria was evaluated for the first time. Furthermore, possible management factors contributing to the formation of abomasal ulcers and the diagnostic ability of faecal occult blood tests were evaluated. MATERIAL AND METHODS: Abomasa of 91 calves, 33 cows and 91 bulls were examined for abomasal ulcers after slaughter. The ulcers were recorded, abomasal content pH was measured and faeces were examined for occult blood. The carcass classification was recorded and the owners were presented with a voluntary questionnaire targeted at health-, management- and feeding-practices that could influence gastric health. RESULTS: The median abomasal pH was 3.0 in calves, 3.6 in bulls and 3.9 in cows. More than 50% of all animals had abomasal ulcers, all of which belonged to the slightest kind of lesion. Faecal occult blood tests proved not to be suitable for detecting these ulcers. From the questionnaire no clear tendencies as far as causative factors for abomasal ulcers could be determined. CONCLUSION AND CLINICAL RELEVANCE: It can be assumed that cattle management systems in Austria contribute to the formation of low-grade abomasal ulcers. Due to the lack of a suitable in vivo model to research the formation of abomasal ulcers in cattle all further speculations must remain elusive. Further influencing factors, such as bacterial ulcer colonization, and the true economic and animal welfare impact of these findings need further investigation. The results of this study should be corroborated in a larger, prospective trial.

Characterization of mucosa-associated bacterial communities in abomasal ulcers by pyrosequencing.

Abomasal ulcers are important pathological alterations of the gastrointestinal tract in cattle and are exceptionally hard to diagnose in vivo. The microbiome of the abomasum in cattle with or without ulcers has hardly been studied to date, and if so, the studies used culture-dependent methods. In the present study, the bacterial communities associated with abomasal ulcers of slaughter cows, bulls, and calves in Austria were described using 16S rRNA gene pyrosequencing. Sequences were clustered into 10,459 operational taxonomic units (OTUs), affiliating to 28 phyla with Proteobacteria, Firmicutes, Bacteroidetes and Tenericutes dominating (96.4% of all reads). The most abundant genera belonged to Helicobacter, Acetobacter, Lactobacillus, and novel Mycoplasma-like phylotypes. Significant differences between the microbial communities of healthy and ulcerated calves compared to cows and bulls could be observed. However, only few statistically significant differences in the abundances of certain OTUs between healthy and ulcerated abomasal mucosa were found. Additionally, near full-length 16S rRNA gene sequences of the most abundant phylotypes were obtained by cloning and Sanger sequencing (n=88). In conclusion, our results allow the first deep insights into the composition of abomasal mucosal bacterial communities in cattle and describe a hitherto unknown high diversity and species richness of abomasal bacteria in cattle. Our results suggest that bacteria may have only limited involvement in the etiology of abomasal ulcers. However, future research will be needed to verify the contribution of bacteria to abomasal ulcer formation as presence or absence of bacteria does not necessarily correlate with etiology of disease.

A two year BTV-8 vaccination follow up: molecular diagnostics and assessment of humoral and cellular immune reactions.

The compulsory vaccination campaign against Bluetongue virus serotype eight (BTV-8) in Germany was exercised in the state of Bavaria using three commercial monovalent inactivated vaccines given provisional marketing authorisation for emergency use. In eleven Bavarian farms representing a cross sectional area of the state the immune reactions of sheep and cattle were followed over a two year period (2008-2009) using cELISA, a serum neutralisation test (SNT) and interferon gamma (IFN-γ) ELISPOT. For molecular diagnostics of BTV genome presence two recommended real time quantitative RT-PCR protocols were applied. The recommended vaccination scheme led to low or even undetectable antibody titers (ELISA) in serum samples of both cattle and sheep. A fourfold increase of the vaccine dose in cattle, however, induced higher ELISA titers and virus neutralising antibodies. Accordingly, repeated vaccination in sheep caused an increase in ELISA-antibody titers. BTV-8 neutralising antibodies occurred in most animals only after multiple vaccinations in the second year of the campaign. The secretion of interferon gamma (IFN-γ) in ELISPOT after in vitro re-stimulation of PBMC of BTV-8 vaccinated animals with BTV was evaluated in the field for the first time. Sera of BTV-8 infected or vaccinated animals neutralising BTV-8 could also neutralise an Italian BTV serotype 1 cell culture adapted strain and PBMC of such animals secreted IFN-γ when stimulated with BTV-1.