Retrospective Evaluation of Method of Treatment, Laboratory Findings, and Concurrent Diseases in Dairy Cattle Diagnosed with Left Displacement of the Abomasum during Time of Hospitalization

Simple Summary Left displacement of the abomasum (LDA) is a common disease in high-producing dairy cattle, resulting in direct and indirect costs, discomfort for the cattle, and death if not treated. The objectives of this retrospective study were to assess the effect of treatment on recovery from LDA during time of hospitalization, to investigate the influence of concurrent diseases on the recovery, and to identify prognostic indicators in laboratory findings. Neither the number of concurrent diseases nor the method of surgery had any influence on the outcome (death or recovery). The most common concurrent disease was metritis/endometritis (38.4% of cows). Conservative treatment (abomasal rolling) was successful in 92.8% of cows, with a recurrence rate of 56.7%. Neither oral nor analgesic therapy had any influence on the recurrence of LDA following abomasal rolling during hospitalization. In cows undergoing surgery, endoscopic abomasopexy as described by Janowitz and right flank laparotomy were performed most often (40.8% and 40.2%, respectively). A significantly (p < 0.01) higher number of cows showed the outcome recovery compared with death. The results of this study indicate that the outcome after surgery for LDA under clinical conditions does not depend on the method of surgery, and that concurrent diseases are often diagnosed in cattle with LDA. Conservative treatment has a high recurrence rate. Left displacement of the abomasum (LDA) is a disease often diagnosed in high-producing dairy cattle, resulting in direct and in indirect costs for the farmer, and discomfort and death for the cows. For the present retrospective study, the aims were to assess the effect of treatment on recovery during the time of hospitalization of the cows, to investigate the influence of concurrent diseases on the recovery, and to identify prognostic indicators in laboratory findings. Metritis/endometritis (38.4% of cows) was the concurrent disease diagnosed most often. Conservative treatment (abomasal rolling) was performed successfully in 92.8% of cows;the recurrence rate was 56.7%. Neither treatment with an oral drench nor treatment with analgesics had any influence on the recurrence of LDA following abomasal rolling during hospitalization. Endoscopic abomasopexy as described by Janowitz was performed more often than right flank laparotomy (40.8% and 40.2%, respectively). A significantly (p < 0.01) higher number of cows had the outcome recovery compared with death. The results of this study show that the outcome after surgery for LDA under clinical conditions does not depend on the method of surgery. Moreover, cows with LDA often suffer from concurrent diseases. If conservative treatment is decided on, farmers should be informed that there is a high recurrence rate, and other treatment options should be discussed

Untersuchungen zum Schmerzausdrucksverhalten bei Kühen nach Klauenoperationen

Schmerzmedikamente werden beim Rind nicht routinemäßig verabreicht, teils aus medizinischen Gründen, wie der Kontrolle der Belastung und der frühzeitigen Erkennung von Komplikationen, vor allem aber aus ökonomischen Gründen. Ziel der Untersuchung war es zu klären, inwieweit die zusätzliche peri-operative Gabe von Schmerzmitteln bei Kühen mit Klauenerkrankungen die Schmerzäußerungen, den Heilungsverlauf und die spätere Nutzung beeinflusst. Im Rahmen einer vergleichenden Doppelblindstudie wurden 36 laktierende Kühe der Rasse Deutsches Fleckvieh untersucht, dabei wurde die gängige Therapieform ohne Schmerzmittel mit der zusätzlichen Gabe eines Analgetikums verglichen. Auf der Suche nach objektivierbaren Verhaltenweisen der Tiere wurde eine Bewertungstabelle entwickelt. Das Schmerzausdrucksverhalten wurde durch 13 ethologische und einen physiologischen Parameter mit Hilfe von Handprotokollen in drei Beobachtungsintervallen pro Tag über einen sechstägigen Zeitraum quantifiziert. Als geeignete Verhaltensweisen, die sich unter Schmerzmitteleinfluss verändern, können besonders der „Mentale Status“ der Tiere, der Gesichtsausdruck mit Ohrenstellung und der Augenausdruck beurteilt werden. Auch die Belastung der erkrankten Gliedmaße im Stehen erwies sich als sehr hilfreich bei der Einschätzung des Schmerzempfindens der Kühe. Die Futteraufnahme und die Kopfhaltung der Tiere mit Schmerzmittel waren gegenüber den Tieren ohne Schmerzmittel deutlich verbessert. Auch Verhaltensauffälligkeiten und Lautäußerungen wurden bei den Tieren mit Schmerzmittel weniger häufig gemacht. Die Parameter Rückenlinie, Liegeverhalten sowie Sozialverhalten in Anbindehaltung und die Atemfrequenz waren dagegen sehr variabel und daher wenig aussagekräftig. Durch einen telemetrischen Halsbandrecorder wurden über Tagesmittelwerte die Bewegungsaktivitäten Fressen, Wiederkauen, Stehen und Ablegen erfasst. Dabei war der Verlauf der Verhaltensaktivitäten in beiden Therapiegruppen gleichsinnig und parallel, wobei der Aktivitätsmodus der Tiere mit Schmerzmitteltherapie vergleichsweise höher lag. Jedoch bestanden hierin keine signifikanten Unterschiede. Zur Differenzierung, inwieweit die Schmerzbelastung für die Tiere auch Stress bedeutete, wurden die Cortisolkonzentrationen in Milch und Blutserum radioimmunologisch bestimmt. Die Milchcortisolkonzentrationen im Morgen- und Abendgemelk boten eine Möglichkeit die Stressbelastung aufgrund der chronischen und akuten Schmerzen zu messen, sie erwiesen sich als nicht geeignet zwischen den Schmerzarten, akut und chronisch, zu differenzieren. Die Untersuchung zeigte, dass durch den operativen Eingriff mit der Beseitigung des schmerzhaften Prozesses allein das Wohlbefinden der Patienten gesteigert werden kann. Allerdings führt die Gabe eines Schmerzmittels in den ersten Tagen nach der Operation zu einer zusätzlichen Verbesserung des Allgemeinbefindens. Wie die Ergebnisse belegen, sind die frühzeitige Behandlung und die Anwendung eines Schmerzmittels zu empfehlen

Factors Associated With Lameness in Tie Stall Housed Dairy Cows in South Germany

Lameness remains a major concern for animal welfare and productivity in modern dairy production. Even though a trend toward loose housing systems exists and the public expects livestock to be kept under conditions where freedom of movement and the expression of natural behavior are ensured, restrictive housing systems continue to be the predominant type of housing in some regions. Factors associated with lameness were evaluated by application of multiple logistic regression modeling on data of 1,006 dairy cows from 56 tie stall farms in Bavaria, South Germany. In this population, approximately every fourth cow was lame (24.44% of scored animals). The mean farm level prevalence of lameness was 23.28%. In total, 22 factors were analyzed regarding their association with lameness. A low Body Condition Score (BCS) (OR 1.54 [95%-CI 1.05-2.25]) as well as increasing parity (OR 1.41 [95%-CI 1.29-1.54]) entailed greater odds of lameness. Moreover, higher milk yield (OR 0.98 [95%-CI 0.96-1.00]) and organic farming (OR 0.48 [95%-0.25-0.92]) appeared to be protectively associated with lameness. Cows with hock injuries (OR 2.57 [95%-CI 1.41-4.67]) or with swellings of the ribs (OR 2.55 [95%-CI 1.53-4.23]) had higher odds of lameness. A similar association was observed for the contamination of the lower legs with distinct plaques of manure (OR 1.88 [95%-CI 1.14-3.10]). As a central aspect of tie stall housing, the length of the stalls was associated with lameness; with stalls of medium [(>158-171 cm) (OR 2.15 [95%-CI 1.29-3.58]) and short (171 cm). These results can help both gaining knowledge on relevant factors associated with lameness as well as approaching the problem of dairy cow lameness in tie stall operations

Traumatic odontoid process synchondrosis fracture with atlantoaxial instability in a calf: clinical presentation and imaging findings

A 6-week-old female Simmental calf was evaluated for acute non-ambulatory tetraparesis. Physical and laboratory examinations revealed no clinically relevant abnormalities. Neurological findings were consistent with acute, progressive and painful cervical myelopathy. Radiographs displayed a fractured odontoid process (dens axis) and vertebral step misalignment at the fracture site. A traumatic origin was suspected. Advanced diagnostic imaging was considered to allow better planning of potential surgical stabilisation and to exclude any additional lesions of the cervical vertebral column. However, during trailer transportation to the advanced diagnostic imaging and surgery site, the calf deteriorated neurologically and was humanely euthanised. Magnetic resonance imaging (MRI) and computed tomography (CT) were performed immediately post-mortem for scientific reasons. The MRI examination reflected the radiographic findings and confirmed severe spinal cord compression at the fracture site. In addition, a T2W-hyperintense signal change within the paravertebral soft tissue dorsal to the fracture site was indicative of a traumatic event. CT identified the fracture site at the synchondrosis between the odontoid process and the body of the axis, and this finding was confirmed by post-mortem examination. Advanced diagnostic imaging and post-mortem examination did not identify any other cervical lesion. In summary, this calf was diagnosed with a traumatic odontoid process synchondrosis fracture, which has not been reported previously in calves but presents a challenging and well-known fracture type in young children. This case report indicates that the odontoid process synchondrosis is a potential predisposed injury site and that traumatic odontoid process synchondrosis fractures should be considered as a potential differential in calves with acute cervical pain and/or signs of a cervical myelopathy

Hock Lesions in Dairy Cows in Cubicle Housing Systems in Germany: Prevalence and Risk Factors

Hock lesions in dairy cows are an important indicator of animal welfare, in particular housing conditions. The aim of this study was to assess the prevalence of hock lesions in dairy cows kept in cubicle housing systems in three structurally different regions of Germany and to derive recommendations from risk factor analyses. Lactating and dry cows kept in cubicle housing systems were assessed for hock lesions (north: 206 farms with 20,792 cows; south: 156 farms with 8050 cows; east: 192 farms with 37,839 cows). Risk factor analyses were conducted using multi-factorial logistic regression models. The median prevalence of hock lesions (hairless patches, wounds, and/or swelling) at farm level was 79.8% (SD: 25.0; north), 66.2% (SD: 31.0; south), and 78.5% (SD: 26.3; east). The mean prevalence of severe hock lesions (wounds and/or swelling) at farm level was 12.5% (SD: 11.3; north), 8.0% (SD: 13.5; south), and 14.4% (SD: 17.9; east). Cows kept in pens with rubber mats or mattresses (with or without a small amount of litter) had a particularly higher chance of hock lesions compared with cows kept in pens with deep-bedded cubicles (OR: north: 3.1 [2.3–4.2]; south: 8.7 [5.9–13.0], east: 2.0 [1.7–2.4]). The study showed that hock lesions are a widespread problem on German dairy farms with cubicle housing systems. Deep-bedded cubicles are likely to reduce hock lesions and increase cows’ comfort

Identifying cow – level factors and farm characteristics associated with locomotion scores in dairy cows using cumulative link mixed models

Lameness is a tremendous problem in intensively managed dairy herds all over the world. It has been associated with considerable adverse effects on animal welfare and economic viability. The majority of studies have evaluated factors associated with gait disturbance by categorising cows into lame and non-lame. This procedure yet entails a loss of information and precision. In the present study, we extend the binomial response to five categories acknowledging the ordered categorical nature of locomotion assessments, which conserves a higher level of information. A cumulative link mixed modelling approach was used to identify factors associated with increasing locomotion scores. The analysis revealed that a low body condition, elevated somatic cell count, more severe hock lesions, increasing parity, absence of pasture access, and poor udder cleanliness were relevant variables associated with higher locomotion scores. Furthermore, distinct differences in the locomotion scores assigned were identified in regard to breed, observer, and season. Using locomotion scores rather than a dichotomised response variable uncovers more refined relationships between gait disturbances and associated factors. This will help to understand the intricate nature of gait disturbances in dairy cows more deeply

Associations of cow and farm characteristics with cow-level lameness using data from an extensive cross-sectional study across 3 structurally different dairy regions in Germany

The aim of the present study was to evaluate the associations between milk recording data, body condition score (BCS), housing factors, management factors, and lameness in freestall-housed dairy cows in 3 structurally different regions in Germany. These regions substantially vary regarding herd size, breeds, access to pasture, farm management (family run or company owned), and percentage of organic farms. The data used was collected in a large cross-sectional study from 2016 to 2019. A total of 58,144 cows from 651 farms in 3 regions of Germany (North, East, and South) was scored for locomotion and body condition. Additionally, data on milk yield, milk composition, breed, age, as well as information on housing and management were retrieved. One mixed-logistic regression model was fitted per region to evaluate the association of the data with the target variable “lame” and to allow for a comprehensive reflection across different kinds of farming types. In all regions, undercondition (BCS lower than recommended for the lactation stage; North: odds ratio [OR] 2.15, CI 1.96–2.34; East: OR 2.66, CI 2.45–2.88; South: OR 2.45, CI 2.01–2.98) and mid-lactation stage (102–204 d in milk; North: OR 1.15, CI 1.05–1.27; East: OR 1.24, CI 1.17–1.32; South: OR 1.38, CI 1.18–1.62) were associated with higher odds for lameness, whereas overcondition (BCS higher than recommended for the lactation stage; North: OR 0.51, CI 0.44–0.60; East: OR 0.51, CI 0.48–0.54; South: OR 0.65, CI 0.54–0.77) and parity of 1 or 2 was associated with lower odds (parity 1 = North: OR 0.32, CI 0.29–0.35; East: OR 0.19, CI 0.18–0.20; South: OR 0.28, CI 0.24–0.33; parity 2 = North: OR 0.51, CI 0.47–0.46; East: OR 0.41, CI 0.39–0.44; South: OR 0.49, CI 0.42–0.57), irrespective of the regional production characteristics. Low energy-corrected milk yield was associated with higher odds for lameness in South and North (North: OR 1.16, CI 1.05–1.27; South: OR 1.43, CI 1.22–1.69). Further factors such as pasture access for cows (North: OR 0.64, CI 0.50–0.82; and South: OR 0.65, CI 0.47–0.88), milk protein content (high milk protein content = North: OR 1.34, CI 1.18–1.52; East: OR 1.17, CI 1.08–1.28; low milk protein content = North: OR 0.79, CI 0.71–0.88; East: OR 0.84, CI 0.79–0.90), and breed (lower odds for “other” [other breeds than German Simmental and German Holstein] in East [OR 0.47, CI 0.42–0.53] and lower odds both for German Holstein and “other” in South [German Holstein: OR 0.62, CI 0.43–0.90; other: OR 0.46, CI 0.34 – 0.62]) were associated with lameness in 2 regions, respectively. The risk of ketosis (higher odds in North: OR 1.11, CI 1.01–1.22) and somatic cell count (higher odds in East: increased (>39.9 cells × 1,000/mL): OR 1.10; CI 1.03–1.17; high (>198.5 cells × 1,000/mL): OR 1.08; CI 1.01–1.06) altered the odds for lameness in 1 region, respectively. Cows from organic farms had lower odds for lameness in all 3 regions (North: OR 0.18, CI 0.11–0.32; East: OR 0.39, CI 0.28–0.56; South: OR 0.45, CI 0.29–0.68). As the dairy production systems differed substantially between the different regions, the results of this study can be viewed as representative for a wide variety of loose-housed dairy systems in Europe and North America. The consistent association between low BCS and lameness in all regions aligns with the previous literature. Our study also suggests that risk factors for lameness can differ between geographically regions, potentially due to differences in which dairy production system is predominantly used and that region-specific characteristics should be taken into account in comparable future projects

Targeted Greybox Fuzzing with Static Lookahead Analysis

Automatic test generation typically aims to generate inputs that explore new paths in the program under test in order to find bugs. Existing work has, therefore, focused on guiding the exploration toward program parts that are more likely to contain bugs by using an offline static analysis. In this paper, we introduce a novel technique for targeted greybox fuzzing using an online static analysis that guides the fuzzer toward a set of target locations, for instance, located in recently modified parts of the program. This is achieved by first semantically analyzing each program path that is explored by an input in the fuzzer's test suite. The results of this analysis are then used to control the fuzzer's specialized power schedule, which determines how often to fuzz inputs from the test suite. We implemented our technique by extending a state-of-the-art, industrial fuzzer for Ethereum smart contracts and evaluate its effectiveness on 27 real-world benchmarks. Using an online analysis is particularly suitable for the domain of smart contracts since it does not require any code instrumentation---instrumentation to contracts changes their semantics. Our experiments show that targeted fuzzing significantly outperforms standard greybox fuzzing for reaching 83% of the challenging target locations (up to 14x of median speed-up)

Harvey: A Greybox Fuzzer for Smart Contracts

We present Harvey, an industrial greybox fuzzer for smart contracts, which are programs managing accounts on a blockchain. Greybox fuzzing is a lightweight test-generation approach that effectively detects bugs and security vulnerabilities. However, greybox fuzzers randomly mutate program inputs to exercise new paths; this makes it challenging to cover code that is guarded by narrow checks, which are satisfied by no more than a few input values. Moreover, most real-world smart contracts transition through many different states during their lifetime, e.g., for every bid in an auction. To explore these states and thereby detect deep vulnerabilities, a greybox fuzzer would need to generate sequences of contract transactions, e.g., by creating bids from multiple users, while at the same time keeping the search space and test suite tractable. In this experience paper, we explain how Harvey alleviates both challenges with two key fuzzing techniques and distill the main lessons learned. First, Harvey extends standard greybox fuzzing with a method for predicting new inputs that are more likely to cover new paths or reveal vulnerabilities in smart contracts. Second, it fuzzes transaction sequences in a targeted and demand-driven way. We have evaluated our approach on 27 real-world contracts. Our experiments show that the underlying techniques significantly increase Harvey's effectiveness in achieving high coverage and detecting vulnerabilities, in most cases orders-of-magnitude faster; they also reveal new insights about contract code.Comment: arXiv admin note: substantial text overlap with arXiv:1807.0787