Bovine Endotoxicosis-some aspects of relevance to production diseases. A review. Acta vet. scand. 2003. Suppl. 98, 141-155.-This review describes some circumstances where endotoxins of Gram negative bacteria may be related to the pathogenesis of some common production diseases. Decisive evidence for the pathogentical role of endotoxins remains scarce, and therefore an interdisciplinary background covering epidemiological, biological, biochemical, clinical and experimental aspects is given. Several authors have suggested that endotoxins play a significant role for the development of diseases such as laminitis, abomasal displacement, sudden death syndrome of feed-lot steers ect. While the biological, biochemical and clinical pictures of bovine endotoxicosis is quite well known, and certainly may resemble the clinical and biochemical pictures seen in some of the before mentioned diseases, it is however still not clear how or when endotoxins would gain parenteral access. This review describes excerpts of the biology of endotoxins, key clinical signs and the biochemistry associated to these. It is described how ruminal acidosis may facilitate the translocation of endotoxin from the intestinal/ ruminal contents to the portal and eventually the systemic bloodstream. The function of the liver hence becomes central, and the role of hepatic fatty infiltration around parturition is discussed. The review finally suggest that acute ruminal acidosis may be viewed as an analogue to the human syndrome Gut-Derived Infectious Toxic Shock (GITS), where shock is propagated primarily by the translocation of bacterial endotoxin from the gut.
Orthopedic disorders are common among horses, often leading to euthanasia, which often could have been avoided with earlier detection. These conditions often create varying degrees of subtle long-term pain. It is challenging to train a visual pain recognition method with video data depicting such pain, since the resulting pain behavior also is subtle, sparsely appearing, and varying, making it challenging for even an expert human labeller to provide accurate ground-truth for the data. We show that a model trained solely on a dataset of horses with acute experimental pain (where labeling is less ambiguous) can aid recognition of the more subtle displays of orthopedic pain. Moreover, we present a human expert baseline for the problem, as well as an extensive empirical study of various domain transfer methods and of what is detected by the pain recognition method trained on clean experimental pain in the orthopedic dataset. Finally, this is accompanied with a discussion around the challenges posed by real-world animal behavior datasets and how best practices can be established for similar fine-grained action recognition tasks. Our code is available at https://github.com/sofiabroome/painface-recognition.
Horses have the ability to generate a remarkable repertoire of facial expressions, some of which have been linked to the affective component of pain. This study describes the facial expressions in healthy horses free of pain before and during transportation and social isolation, which are putatively stressful but ordinary management procedures. Transportation was performed in 28 horses by subjecting them to short-term road transport in a horse trailer. A subgroup (n = 10) of these horses was also subjected to short-term social isolation. During all procedures, a body-mounted, remote-controlled heart rate monitor provided continuous heart rate measurements. The horses’ heads were video-recorded during the interventions. An exhaustive dataset was generated from the selected video clips of all possible facial action units and action descriptors, time of emergency, duration, and frequency according to the Equine Facial Action Coding System (EquiFACS). Heart rate increased during both interventions (p<0.01), confirming that they caused disruption in sympato-vagal balance. Using the current method for ascribing certain action units (AUs) to specific emotional states in humans and a novel data-driven co-occurrence method, the following facial traits were observed during both interventions: eye white increase (p<0.001), nostril dilator (p<0.001), upper eyelid raiser (p<0.001), inner brow raiser (p = 0.042), tongue show (p<0.001). Increases in ‘ear flicker’ (p<0.001) and blink frequency (p<0.001) were also seen. These facial actions were used to train a machine-learning classifier to discriminate between the high-arousal interventions and calm horses, which achieved at most 79% accuracy. Most facial features identified correspond well with previous findings on behaviors of stressed horses, for example flared nostrils, repetitive mouth behaviors, increased eye white, tongue show, and ear movements. Several features identified in this study of pain-free horses, such as dilated nostrils, eye white increase, and inner brow raiser, are used as indicators of pain in some face-based pain assessment tools. In order to increase performance parameters in pain assessment tools, the relations between facial expressions of stress and pain should be studied further.
To investigate the prevalence of mastitis in sows suffering from postpartum dysgalactia syndrome (PDS), we examined milk constituents and concentrations of lipopolysaccharides (LPS) obtained from the udder vein (v. epigastrica). As part of a case–cohort study, 109 sows were monitored daily from 60 h antepartum (a.p.) to 36 h postpartum (p.p.). Over time, 38 sows were diagnosed with PDS (PDS+) and were retrospectively matched with 38 healthy sows (PDS−). The study period was divided into 7 smaller time periods (A, B, C, D, E, F, G, H, and E), allowing the studied values, in period B to G, to be compared with period A that served as a baseline, and PDS+ and PDS− sows were compared within the time periods. All sows were subjected to a thorough daily clinical examination and blood was sampled from v. epigastrica for LPS detection. Milk samples were obtained for bacteriological evaluation and detection of N-acetyl-beta-d-glucosaminidase (NAGase), lactate dehydrogenase (LDH), β-glucuronidase (β-glu; for evaluation of mastitis), isocitrate (isoC), free glucose, uric acid (UA; for evaluation of the mammary energy status), β-hydroxybutyrate acid (BHBA; for evaluation of ketosis), and milk urea (for evaluation of the protein status). The results revealed that PDS+ sows had decreased concentrations of UA in milk (P < 0.0001), increased heart rates (P < 0.01), increased mammary edema (P < 0.05), and prolonged capillary refill time in the vulvar mucosa (P < 0.01) compared with PDS− sows. Compared with baseline, feces became more solid 0 to 36 h p.p. (P < 0.0001) and the respiration rate decreased 12 to 24 h p.p. (P < 0.0001) for both PDS+ and PDS− sows. No differences were found between PDS+ and PDS− sows for severe bacterial infections, concentrations of LPS in blood or LDH, NAGase, BHBA, free glucose, isoC, or urea in milk. Concentrations of LPS in blood were not associated with signs of mastitis or edema in the mammary glands. However, a difference over time was seen for redness (P < 0.0001), warmth (P < 0.0001), and hardness (P < 0.05) of the 6 most anterior glands in both PDS+ and PDS− sows from 60 h a.p to 36 h p.p. The PDS− sows had greater concentrations of β-glu than the PDS+ sows, but no change over time was demonstrated for this marker. In conclusion, signs of mastitis were not consistently linked to PDS in sows. However, the cardiovascular system seemed to be compromised in PDS+ sows and the cause should be investigated to elucidate the pathogenesis of PDS.
Endotoxins are structural parts of the Gram negative bacteria membrane. Endotoxins are extremely toxic to cattle in parenteral doses in the range 100 ng per kg bw. The development of endotoxicosis is believed to play a significant role in the pathogenesis of various clinical conditions associated with production diseases, from ruminal acidosis and "sudden death syndrome" in feed-lot cattle, to laminitis in dairy cattle, Gram negative infections, shock and death. Decisive evidence for the presence of endotoxemia in any of these conditions is relatively scarce, but circumstantial evidence is more common, because in many respects the clinical and biochemical symptoms of bovine endotoxicosis-gastrointestinal stasis, diarrhoea, hypocalemia, hypozinemia and leukopenia-are similar to those observed in various of the production diseases mentioned. This review will attempt to discuss the possible sources of endotoxin in the bovine clinic, the exposure routes and the relevance of endotoxin for the development of feeding related production diseases. Some aspects regarding individual susceptibility will be discussed as well. The source of endotoxin is mainly Gram negative infection and or gastrointestinal contents. The exposure routes are infected organs (udder, uterus) but exposure may also take place via translocation through a leaky gastrointestinal barrier. Large quantities of endotoxin are present in the rumen of cattle, and the concentration increases when concentrate is added to a hay diet. When ruminitis is present, the ruminal epithelium may become leaky. In experimentally induced ruminal acidosis endotoxin can be detected in the pre-hepatic and sometimes in the systemic circulation. The endotoxin concentrations of the systemic blood were lower than the pre-hepatic concentrations, demonstrating the clearance effect of the liver. Another study has shown that cows with hepatic lipidosis are relatively incapable of clearing injected endotoxin, when compared to cows with normal livers. Such studies underline the significance of the bovine fatty liver syndrome in the production disease complex. Large variations in susceptibility of cattle to endotoxin are commonly reported and the causative factors are extremely interesting. Failure to detect endotoxins in the blood of clearly sick cows has frustrated many researchers and it has been questioned whether the presence of endotoxemia is necessary for the development of endotoxicosis. With the increased knowledge of the links between immunology, stress, parturition and ocurrence of production diseases, it becomes increasingly important to appreciate that the toxicity of endotoxin is caused by the response of the host organism, rather than by the properties of endotoxin per se. Differences in the bovine response to endotoxin may therefore equally well be ascribed to differences in the immunological line of defense as to factors related to the endotoxin of an invading Gram negative microorganism. Investigation of these interrelationships may provide a basis for the identificati...
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