78 research outputs found

    Role of electrolytes and unmeasured anions in the metabolic acid-base abnormalities in dogs with parvoviral enteritis

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    Background: The strong ion model (SIM) is an alternative paradigm in the characterization of acid‐base disturbances particularly in complex disorders. Hypothesis/Objectives: To compare the acid‐base changes in dogs with parvoviral enteritis (PE) using the Henderson‐Hasselbalch (HH) approach, with 2 strong ion approaches. Animals: Forty‐four dogs with PE, and 16 age‐matched control dogs. Methods: Prospective controlled observational study. Acid‐base status was evaluated using the HH model, Fencl‐Stewart (FS) approach and a validated strong ion model (VDM). The acid‐base changes according to each model were classified and compared. Statistical correlations between pH, CO2, and various SIM variables were performed, as well as between the sum of effects (SOE) of the SIM and the individual variables comprising the SOE. Results: The HH model identified acid‐base disorders in 31/44 cases of which 16/31 were mixed with metabolic acidosis and concurrent respiratory alkalosis the most common (10/31). Using the FS approach, metabolic changes were present 36/42 cases, with changes in free water (FW), chloride, and unmeasured anions (UA) being the most prevalent. Both FW and UA correlated well with pH; however, UA were most consistently abnormal in severe acidemia. Similarly to the HH, the VDM detected acid‐base disturbances in 28/44 cases. Major contributors to the acid‐base changes were hyponatremia, hypochloremia, and Atot acidosis because of elevated globulins and increased UA. Conclusions and Clinical Importance: Acid‐base changes are common and complex in dogs with PE, and were easier to understand using a SIM paradigm. Increases in UA have not been documented in PE in dogs

    Advances in the understanding of the pathogenesis, progression and diagnosis of myxomatous mitral valve disease in dogs

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    A number of key questions remain unanswered in the pathogenesis of myxomatous mitral valve disease (MMVD). As MMVD typically afflicts small-breed dogs, a genetic basis has been implied. In addition, the fact that not all dogs within a risk group develop MMVD is still unexplained. Research into the pathogenesis of MMVD typically falls under three categorical divisions, namely genetic factors, mechanical factors of the valve and systemic factors. Genetic studies have implicated certain loci in the pathogenesis of MMVD. Of particular interest is the insulin-like growth factor (IGF)-1 locus, as IGF-1 is also associated with growth. The mechanical structure and function of the mitral valve have also received much attention in recent years. What has emerged is the notion of a highly complex dynamic structure, which has an uneven distribution of stress and strain according to the flow of blood. Research efforts have also identified a number of systemic factors such as cytokines and signalling pathways that may contribute to the failure of the valve. Serotonin remains an area of interest in this field. Taken together, the amalgamation of research efforts in these three areas will go a long way towards resolving the understanding of this disease. Another area of focus in MMVD has been the development of clinical tests to diagnose the onset of congestive heart failure. To this end, echocardiographic indices and biochemical markers have been investigated. Echocardiographic indices such as left atrial to aortic ratio and the N-terminal of the prohormone brain natriuretic peptide (NT-proBNP) have been identified as specific risk factors to predict progression. Advanced imaging studies such as cardiac magnetic resonance imaging have enabled investigators to determine the earliest remodelling changes that occur in MMVD.http://www.jsava.co.zaam201

    Medical management of myxomatous mitral valve disease : an evidence-based veterinary medicine approach

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    Myxomatous mitral valve disease (MMVD) is the most common heart disease of dogs. The current management of MMVD in dogs is mostly pharmacological, and the recommendations for treatment are based on a number of veterinary studies. Notwithstanding the current consensus regarding the medical management of MMVD, there remains active debate as to which drugs are the most effective. In order to understand how recommendations are constructed in the pharmacological management of diseases, the veterinarian needs to understand the concept of evidence-based veterinary medicine, and how the findings of these studies can be applied in their own practices. This review summarises the current veterinary literature and explains how the consensus regarding the management of MMVD has been reached. This review highlights the limitations of veterinary studies in order to provide veterinary practitioners with a sense of the difficulty there is in establishing the benefit of one treatment over the other. Veterinarians should therefore apply treatment recommendations based on the best evidence, integrated with a pathomechanistic understanding of the disease process and clinical experience.http://www.jsava.co.zaam201

    The central role of chloride in the metabolic acid-base changes in canine parvoviral enteritis

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    The acid–base disturbances in canine parvoviral (CPV) enteritis are not well described. In addition, the mechanisms causing these perturbations have not been fully elucidated. The purpose of the present study was to assess acid–base changes in puppies suffering from CPV enteritis, using a modified strong ion model (SIM). The hypothesis of the study was that severe acid–base disturbances would be present and that the SIM would provide insights into pathological mechanisms, which have not been fully appreciated by the Henderson–Hasselbalch model. The study analysed retrospective data, obtained from 42 puppies with confirmed CPV enteritis and 10 healthy control dogs. The CPV-enteritis group had been allocated a clinical score, to allow classification of the data according to clinical severity. The effects of changes in free water, chloride, L-lactate, albumin and phosphate were calculated, using a modification of the base excess algorithm. When the data were summated for each patient, and correlated to each individual component, the most important contributor to the metabolic acid–base changes, according to the SIM, was chloride (P < 0.001). Severely-affected animals tended to demonstrate hypochloraemic alkalosis, whereas mildly-affected puppies had a hyperchloraemic acidosis (P = 0.007). In conclusion, the acid–base disturbances in CPV enteritis are multifactorial and complex, with the SIM providing information in terms of the origin of these changes.http://www.elsevier.com/locate/tvjlhb201

    Haemangiosarcoma of the os penis in a dog : the most common neoplasm of the canine penis

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    A castrated 9-year-old intact male boerboel cross-breed dog was presented with a month-long history of stranguria. On physical examination, a mass was noted at the caudal extremity of the os penis. Haematology, serum chemistry and urinalysis were all unremarkable. Abdominal and urethral ultrasound demonstrated an enlarged bladder and a dilated urethra, which was followed to the caudal extremity of the os penis. A hyperechoic, roughly spherical, vascularised mass was noted at the caudal os penis, which resulted in obstruction of the penile urethra. Radiographs demonstrated a soft tissue mass with osteolysis of the os penis. Cytology suggested an osteosarcoma. Treatment included amputation of the penis and adjuvant doxorubicin with carboplatin. Histopathology of the penis confirmed a haemangiosarcoma. The patient survived for 20 months. This is only the second published case report describing a penile haemangiosarcoma, and the first published report demonstrating the treatment and outcome of a case of haemangiosarcoma of the os penis. Based on published and unpublished reports, haemangiosarcoma appears to be the most common neoplasm of the canine penis.http://www.jsava.co.zaam201

    Haematological and biochemical reference intervals for wild green turtles (Chelonia mydas): a Bayesian approach for small sample sizes

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    Animal health is directly linked to population viability, which may be impacted by anthropogenic disturbances and diseases. Reference intervals (RIs) for haematology and blood biochemistry are essential tools for the assessment of animal health. However, establishing and interpreting robust RIs for threatened species is often challenged by small sample sizes. Bayesian predictive modelling is well suited to sample size limitations, accounting for individual variation and interactions between influencing variables. We aimed to derive baseline RIs for green turtles (Chelonia mydas) across two foraging aggregations in North Queensland, Australia, using Bayesian generalized linear mixed-effects models (n=97). The predicted RIs were contained within previously published values and had narrower credible intervals. Most analytes did not vary significantly with foraging ground (76%, 22/29), body mass (86%, 25/29) or curved carapace length (83%, 24/29). Length and body mass effects were found for eosinophils, heterophil:lymphocyte ratio, alkaline phosphatase, aspartate transaminase and urea. Significant differences between foraging grounds were found for albumin, cholesterol, potassium, total protein, triglycerides, uric acid and calcium:phosphorus ratio. We provide derived RIs for foraging green turtles, which will be helpful in future population health assessments and conservation efforts. Future RI studies on threatened species would benefit from adapting established veterinary and biomedical standards

    Is High Blood Pressure Self-Protection for the Brain?

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    Rationale: Data from animal models of hypertension indicate that high blood pressure may develop as a vital mechanism to maintain adequate blood flow to the brain. We propose that congenital vascular abnormalities of the posterior cerebral circulation and cerebral hypoperfusion could partially explain the etiology of essential hypertension, which remains enigmatic in 95% of patients. Objective: To evaluate the role of the cerebral circulation in the pathophysiology of hypertension. Methods and Results: We completed a series of retrospective and mechanistic case-control magnetic resonance imaging and physiological studies, in normotensive and hypertensive humans (n=259). Interestingly, in humans with hypertension, we report a higher prevalence of congenital cerebrovascular variants; vertebral artery hypoplasia and an incomplete posterior circle of Willis, which were coupled with increased cerebral vascular resistance, reduced cerebral blood flow and a higher incidence of lacunar type infarcts. Causally, cerebral vascular resistance was elevated before the onset of hypertension and elevated sympathetic nerve activity (n=126). Interestingly, untreated hypertensive patients (n=20) had a cerebral blood flow similar to age-matched controls (n=28). However, participants receiving anti-hypertensive therapy (with blood pressure controlled below target levels) had reduced cerebral perfusion (n=19). Finally, elevated cerebral vascular resistance was a predictor of hypertension suggesting it may be a novel prognostic and/or diagnostic marker (n=126). < Conclusions: Our data indicate that congenital cerebrovascular variants in the posterior circulation and the associated cerebral hypoperfusion may be a factor in triggering hypertension. Therefore lowering blood pressure may worsen cerebral perfusion in susceptible individuals

    Mapping Public Engagement with Research in a UK University

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    Notwithstanding that ‘public engagement’ is conceptualised differently internationally and in different academic disciplines, higher education institutions largely accept the importance of public engagement with research. However, there is limited evidence on how researchers conceptualise engagement, their views on what constitutes engagement and the communities they would (or would not) like to engage with. This paper presents the results of a survey of researchers in the Open University that sought to gather data to fill these gaps. This research was part of an action research project designed to embed engagement in the routine practices of researchers at all levels. The findings indicate that researchers have a relatively narrow view of public engagement with research and the communities with which they interact. It also identified that very few strategically evaluate their public engagement activities. We conclude by discussing some of the interventions we have introduced with the aim of broadening and deepening future researcher engagement
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