Introdução à bioquímica clínica veterinária

3. ed. rev. ampl

Metabolic profile of Holstein cows : reference values in herds of Rio Grande do Sul - Brazil

Background: Assessing data from metabolic profile is a complex task depending on individual factors such as breed, age, sex and physiological status and environmental factors such as climate and management. Therefore, reference intervals produced in herds from different geographic regions are not always precise in the local reality. The aim of this study is to compile results of values of the most used parameters in the metabolic profile of healthy Holstein cows, grouped by lactation stage, obtained from studies in Rio Grande do Sul, Brazil, as an effort for the elaboration of regional reference intervals for dairy cattle in this geographic area. Materials, Methods & Results: The research was defined through the PICO strategy, considering multiparous Holstein cows from scientific studies carried out in Rio Grande do Sul, during the period 1996-2021, in which the nitrogen, glycidic, lipidic, enzymatic or mineral metabolic profile was determined. Google Scholar, Scientific Electronic Library and PubMed were the electronic databases selected for the search, using the following descriptors: “profile” and “metabolic” and “metabolic profile” and “dairy” or “cattle” or “cow” and “Brazil” and “southern” or “Rio Grande do Sul”. Studies in Portuguese, English and Spanish languages were considered. The references of the articles initially selected were also verified, through ResearchGate and Google Scholar, in addition to unpublished data, unfinished studies or data in the so called “gray literature”. It was possible to identify a total of 34 publications, which were tabulated to assess the scientific quality and bias risk. Studies were evaluated by a pair of independent reviewers, in order to compare results. Eligibility confirmation was given after the complete reading of the articles, evaluating the presence of all the inclusion selection criteria, such as adequate population and the intervention made. Examples of exclusion criteria for studies were studies or data duplication and methodological flaws that could compromise reliability. Thus, of the 34 studies selected in the initial screening, 14 remained. Thereafter, observational studies were preferably sought for data extraction. In the case of clinical trials, only data from control groups were used, in order to avoid disturbances due to interventions or treatments that could be applied. The reference intervals or means of the evaluated metabolites extracted from these studies were grouped in tables, in order to facilitate the comparison with research results obtained in different regions or even for comparison with future studies in the region of interest. Discussion: This retrospective study obtained mean values and standard deviation of the most used parameters in the metabolic profile of Holstein cows, grouped by lactation stage, obtained from studies performed in the state of Rio Grande do Sul, Brazil. Divergences were observed in several evaluations, especially in values of albumin, beta-hydroxybutyrate, aspartate transaminase and calcium, in spite of all data represented healthy animals from research trials with adequate environment and diet. It is important to consider the risk of time bias in this study, as within this 25-year period there was a very large evolution in dairy farming and some values may not be fully representative of current management systems in Holstein herds. Nevertheless, the results reinforce the importance of using regional reference values for the proper interpretation of metabolic profile results in dairy cows. In addition, the proposing of database index for regional averages or reference intervals, is useful for comparing results of metabolic profiles carried out in different geographic regions, in future studies to be performed in this particular region, or even to be utilized by field practitioners of this particular region

Correlação entre lipidose hepática, variação da condição corporal e analitos hepáticos em bovinos leiteiros

Liver lipidosis is a metabolic disorder mostly observed in high yielding dairy cattle, especially during the transition period. The aim of this study was to determine the correlation between hepatic lipid infiltration, biochemical indicators of liver function, and body condition score (BCS) variation in dairy cows. Fifty-one multiparous Holstein cows raised in a confined system were evaluated. Liver biopsies and blood samples were collected, and BCS was measured on days 3 and 28 postpartum. Lipid infiltration was determined by histologic examination. The plasma activity of aspartate aminotransferase, alkaline phosphatase, and gamma-glutamyl transferase and concentration of beta-hydroxybutyrate, non-esterified fatty acids, albumin, total bilirubin, and cholesterol were determined. BCS was measured using objective (camera) and subjective (visual) methods. Mild lipid infiltration was found in 3.92% of cows sampled on day 3 and 5.88% on day 28. Bilirubin was significantly higher on day 3 than on day 28 postpartum, and cholesterol was significantly higher on day 28 than on day 3 in all cows. There was no difference in biochemical analytes between cows with and without lipidosis. On day 3, mean subjective BCS was 3.10 and objective BCS was 3.16, while on day 28, these scores were 2.91 and 2.99, respectively. The calculated liver function index (LFI) was found to be a more sensitive indicator of liver function than the hepatic analytes evaluated. No correlation between BCS variation and lipid infiltration was found. Cholesterol and bilirubin levels showed the most remarkable changes during the early postpartum period. LFI is a potential indicator of postpartum liver function.A lipidose hepática é um distúrbio metabólico principalmente observado nos bovinos de leite de alto rendimento, especialmente no período de transição. O objetivo deste estudo foi determinar a correlação entre infiltração lipídica hepática, indicadores bioquímicos de função hepática e variação da condição corporal em bovinos leiteiros. Foram avaliadas cinquenta e um vacas multíparas de raça Holandesa em confinamento. Coletaram-se biopsias de fígado e amostras de sangue, e a condição corporal (BCS) aferiu-se nos dias 3 e 28 pós-parto. A infiltração lipídica determinou-se mediante avaliação histológica. Mensuraram-se a atividade da aspartato aminotransferase, fosfatase alcalina e da gama-glutamil transferase, concentração de beta-hidroxibutirato, ácidos graxos não esterificados, albumina, bilirrubina total e colesterol. A BCS mediu-se utilizando método objetivo (câmera) e subjetivo (visualmente). Observou-se discreta infiltração lipídica em 3,92% dos bovinos amostrados no dia 3 e 5,88% no dia 28. Em todos os bovinos a bilirrubina foi significativamente mais alta no dia 3 do que no dia 28 e o colesterol foi superior no dia 28 do que no dia 3. Não houve diferença nos analitos bioquímicos dos bovinos com e sem lipidose. No dia 3, a média subjetiva da BCS foi 3,10 e a objetiva 3,16, enquanto no dia 28, obtiveram-se valores de 2,91, e 2,99 respectivamente. O índice calculado de função hepática mostrou ser um indicador mais sensível da função hepática do que os analitos avaliados individualmente. Não houve correlação entre a variação do BCS e infiltração lipídica

SEROLOGICAL EVIDENCE OF LEPTOSPIRA SPP. IN THE LAMI TUCO-TUCO RODENTS (CTENOMYS LAMI)

Although rodents are reportedly the major reservoirs of Leptospira spp. in the wildlife of Brazil, the role of the widely distributed native tuco-tuco rodent (Ctenomys lami) has yet to be determined. Accordingly, a total of 40 serum and eight urine samples from wild C. lami were collected from June to September 2008 in the city of Porto Alegre, Southern Brazil. The serum samples were screened using the Microscopic Agglutination Test against 13 Leptospira spp. pathogenic serovars. A polymerase chain reaction (PCR) was performed to detect the presence of leptospiral DNA in the urine samples. Five (12.5%) of the serum samples had >100 antibody titer levels against one or more of the serovars. None of the urine samples yielded a positive PCR amplification; however, all of the source animals were also negative. In conclusion, although C. lami may be exposed to Leptospira spp., infection may be occasional because no detectable leptospiruria was found

Cardiovascular indicators and mitral valve disease in dogs with spontaneous hypercortisolism : prospective evaluation

Background: Canine hypercortisolism (HC) is the most prevalent endocrinopathy in dogs in southern Brazil. The prognosis depends on several factors including the general health status, owners´ commitment, and the development of disease complications and comorbidities occurrence, such as cardiovascular complications including mitral valve disease (MVD), systemic arterial hypertension, and left ventricular hypertrophy. The main objective of the present study was to assess cardiovascular parameters in canine HC, based on investigating survival-related variables. The study also aimed to evaluate the influence of concurrent preclinical (MVD) on dogs` survival and the impact of HC on MVD progression. Materials, Methods & Results: A total of 25 dogs with spontaneous HC were enrolled and divided into 2 subgroups accordingly to their echocardiographic findings: group HC (normal echocardiography at first evaluation, n = 16); and group HC + MVD (concurrent presence of stages B1 and B2 MVD diagnosed at the first evaluation, n = 9). The patients were evaluated at diagnosis (T0); 6 months after treatment begging (T1); and after 12 months of treatment (T2). The owners were further contacted by phone or e-mail for 1 more year after T2 regarding survival information. A control group (CG, n = 20) was also evaluated at T0 and T1. At each evaluation, dogs were submitted to a complete clinical evaluation and physical exam, associated with a minimum database (CBC, serum biochemistry, and urine analysis) and cardiovascular evaluation composed of systolic blood pressure determination, electrocardiogram (ECG), and echodopplercardiography. In the HC group, 11/16 dogs underwent the evaluation at T2, while 4/9 dogs from the HC + MVD group and 17/20 dogs from the CG underwent the evaluation at T2. Five dogs (31.25%) from the HC group and 4 dogs (44.44%) from the HC + MVD group died before the end of the follow-up period. In the control group, only 1 dog (5.26%) died before the end of the study. Despite the higher mortality in the HC + MVD group during the follow-up period, there was no significant difference (P = 0.632) in survival when compared with the HC group. The MVD of 4 dogs included in the HC + MVD group was classified as stage B1, while the other 5 dogs were classified as stage B2. Only 1 dog from the CG developed stage B1 MVD in the period studied; however, progression of the MVD stage was documented in 1/4 of dogs in the HC + MVD group and MVD development was documented in 3/11 of dogs from the HC group from T0 to T2. The odds ratio (OR) and respective 95% confidence interval (95%CI) for HC as a risk factor for MVD progression were 4.267 (0.4268 - 42.65; P = 0.342). Exercise intolerance (12/16 dogs) and dyspnea (6/16 dogs) were the cardiorespiratory clinical signs with the highest incidence in the HC group at T0. When compared to the control group, both exercise intolerance (P < 0.001) and dyspnea (P = 0.03) occurrence were significantly higher in the HC group. The age (P = 0.001) and the occurrence of dyspnea (P = 0.036) at diagnosis were significantly higher in dogs with HC that died during the follow-up than those that remained alive. Regarding the occurrence of cardiac arrhythmias verified by ECG, no statistically significant differences were observed among groups. Discussion: The study suggests that systemic hypertension and altered echocardiographic measurements did not interfere with dogs’ survival; however, dyspnea was associated with a worse prognosis. Finally, it is possible to conclude that mitral valve degeneration is a common comorbidity in dogs with HC, however, it was not evidenced their interference in the survival of dogs with this endocrine disease or even a role of the HC in the progression of the MVD

Perfil metabólico de cordeiros fêmeas em pastagem de azevém manejada sob diferentes intensidades e métodos de pastejo

The aim of this study was to evaluate the effect of grazing methods and intensities on the metabolic profile of lambs grazing ryegrass. This study was performed in Eldorado do Sul (RS). The treatments consisted of two grazing intensities with rotational and continuous stocking methods: moderate and low. The experimental design was a randomized block arranged in a factorial scheme with four replicates. To evaluate the metabolic and nutritional conditions of the lambs, blood samples were collected to evaluate phosphorus, albumin, glucose, magnesium, globulin, cortisol, urea and total proteins. The highest blood urea value was observed in the month of September in lambs kept in continuous method grazing. There was no statistical difference between the grazing intensities and grazing methods for albumin, glucose, magnesium, globulin, cortisol and total protein levels in profile lambs. The cortisol values suggested that the animals were not subjected to high stress levels. In conclusion, rearing female lambs on ryegrass, irrespective of grazing methods or intensities, allowed the maintenance of body homeostasis and did not cause any metabolic unbalances, nutritional unbalances or stress.O objetivo deste estudo foi avaliar o efeito dos métodos e das intensidades de pastejo no perfil metabólico de cordeiros. Este estudo foi realizado em Eldorado do Sul (RS). Os tratamentos consistiram em duas intensidades de pastejo (moderada e baixa), com métodos lotação rotativa e lotação contínua. O delineamento experimental foi em blocos ao acaso, em esquema fatorial com quatro repetições. Para avaliar as condições metabólicas e nutricionais dos cordeiros, foram coletadas amostras de sangue para avaliar fósforo, albumina, glicose, magnésio, globulina, cortisol, ureia e proteínas totais. O maior valor de ureia no sangue foi observado no mês de setembro nos cordeiros mantidos em pastejo contínuo. Não houve diferença estatística entre as intensidades de pastejo e os métodos de pastejo para albumina, glicose, magnésio, globulina, cortisol e níveis de proteína total nos cordeiros perfilados. Os valores de cortisol sugeriram que os animais não foram submetidos a altos níveis de estresse. Concluindo, a criação de cordeiros em azevém, independentemente dos métodos ou das intensidades de pastejo, permitiu a manutenção da homeostase corporal e não causou desequilíbrios metabólicos, desequilíbrios nutricionais ou estresse

Produção e composição do leite em vacas com desordens no pós-parto

This study aimed to determine the impact of different post-partum disorders on milk yield and composition. One hundred and fifteen Holstein cows from a commercial dairy farm located in the state of Rio Grande do Sul in southern Brazil were monitored up to 62 days post-partum. During this period, body condition score evaluation and animal clinical examination were conducted. Percentages of fat, protein, and lactose, as well as somatic cells score, were determined in milk samples. The AST activity and concentrations of NEFA, calcium, and BHBA, were analyzed in blood samples. The occurrence of clinical disorders was identified in 30 (26%) cows. Subclinical disorders were identified in 64 (56%) cows. Only 21 (18%) cows did not suffer any kind of disorder within the studied period. In this study, no significant differences were found in milk production, protein, and somatic cell count in clinical, subclinical, and healthy cows. Milk fat and the fat: protein quotient (F:P) were higher in cows with clinical disorders and the 6 to 21 days in milk, and lactose were lower in cows with clinical disorders and the 22 to 42 days in milk (P<0.05).O objetivo deste estudo foi determinar o impacto de diferentes distúrbios após o parto na produção de leite e em sua composição. Cento e quinze vacas Holandesas de uma fazenda de gado leiteiro, localizada em estado da região Sul do Brasil, foram monitoradas até 62 dias após o parto. Durante esse período, foram realizadas avaliações do escore de condição corporal e exame clínico nos animais. As porcentagens de gordura, proteína e lactose, bem como o escore de células somáticas, foram determinadas nas amostras de leite. A atividade do AST e as concentrações de NEFA, cálcio e BHBA foram analisadas em amostras de sangue. A ocorrência de distúrbios clínicos foi identificada em 30 (26%) vacas, os distúrbios subclínicos foram identificados em 64 (56%) vacas. Apenas 21 (18%) vacas não sofreram nenhum tipo de distúrbio ao longo do período estudado. Neste estudo, não foram encontradas diferenças significativas na produção do leite, proteína e na contagem de células somáticas em vacas com doenças clínicas, subclínicas e saudáveis. No leite, a gordura e o quociente gordura e proteína (G:P) foram maiores em vacas com doença clínica no período de seis a 21 dias de lactação, e a lactose foi menor em vacas com doença clínica no período de 22 a 42 dias de lactação (P<0,05)

Clinical and laboratory aspects of a bovine with left displacement of the abomasum

Background: Abomasal diseases of dairy cattle are mainly associated with stress conditions, nutritional disorders and metabolic disorders. Dairy cattle that develop left or right abomasal displacement generally lose their appetite and have 30 to 50% drop in milk production. The objective of this work is to report the clinical and laboratorial aspects of a high yielding Holstein cow suffering left abomasal displacement in Rio Grande do Sul, southern Brazil. Case: The cow was part of a research project of the Veterinary Faculty of the Federal University of Rio Grande do Sul and was monitored weekly. The animal showed decreased milk production, anorexia, prostration, tremors, diarrhea, smelly metritis and a body score of 3 in a scale of 1-5. In the clinical examination, the animal presented respiratory rate of 26 movements per minute (RV: 26-35), heart rate of 71 beats per minute (RV: 48-84), body temperature of 38.5°C (RV: 38- 39.3), normocorate mucosa, moderate dehydration and no ruminal movements. In the abdominal auscultation the animal presented metallic sound in the left flank. Blood concentration of beta-hydroxybutyrate was 8.3 mmol/L (RV: < 1.2 mmol/L). The cow underwent surgery for correction of left abomasum displacement. After surgery, the animal showed improvement of the clinical condition and ate hay, pasture and silage. Feeding with concentrate was avoided for a week. The animal had satisfactory evolution, being monitored for more 4 weeks and afterward was discharge Discussion: Genetic improvement in milk cattle has led to the selection of animals with higher milk production through the selection of animals with deeper body capacity, which may allow more space in the abdomen for abomasal movement. In the present case, clinical ketosis was confirmed through the presence of ketonuria and ketonemia. Ketosis is caused by excess ketone bodies in organic fluids, with or without clinical signs. The impact of their disorder may be related to weight loss of the animal and occurrence of secondary diseases, as abomasal displacement. The blood activity of AST, an enzyme used as an indicator of liver damage, was increase (352 U/L; RV: < 132). Elevated activity of this enzyme is related to a greater tendency to problems such as retention of placenta and hypocalcemia, among others. In the present case, the most likely is that the animal had a high body score at the time of calving, and reduced dry matter intake. After that, the cow probably initiated a hepatic lipidosis, which is common in cases of ketosis. A decrease in the production of cholesterol occurred (68 mg/dL; RV: 80-120) further aggravated by the hepatic steatosis. With ketosis the animal decreased further the dry matter intake, anad as a consequence of all of the aforementioned factors, retention of placenta and subsequent metritis may occurred, further reducing feed ingestion. Finally, all the associated problems caused the abomasum displacement worsening the condition of the animal. This clinical case confirms the importance of having good pre and postpartum management. The animal presented interrelated diseases that are frequently cause and effect for the overall picture

Quality control in veterinary blood banks : evaluation of canine platelet concentrates stored for five days

Background: Platelets undergo structural, biochemical and functional alterations when stored, and platelet storage lesions reduce platelet function and half-life after transfusion. The objective of this study was to evaluate stored canine platelet concentrates with platelet aggregation, flow cytometry and biochemistry assays. Twenty-two bags of canine platelet concentrates were obtained by the platelet-rich plasma method and were assessed on days 1, 3 and 5 after collection. Parameters such as platelet counts, residual leukocytes, platelet swirling, glucose, lactate, pH, CD62P expression (platelet activation), JC-1 (mitochondrial function) and annexin V (apoptosis and cell death) were assessed. Results: Over the five days of storage there was a significant decrease in glucose, HCO3, pCO2, ATP, pH, swirling and mitochondrial function, associated with a significant increase in lactate levels and pO2. At the end of storage pH was 5.9 ± 0.6 and lactate levels were 2.8 ± 1.2 mmol/L. Results of the quality parameters evaluated were similar to those reported in human platelets studies. The deleterious effects of storage were more pronounced in bags with higher platelet counts (> 7.49 × 1010/unit), suggesting that canine platelet concentrates should not contain an excessive number of platelets. Conclusions: Quality parameters of canine platelets under standard storage conditions were similar to those observed in human platelets. Our results have potential to be used for the routine evaluation and quality control in veterinary blood banks