Ultrasound Evaluation of Lung Fields in Healthy Dogs: Scanning Technic and Aspects of Normality.

Background: The ultrasound exam has always played a secondary role in pulmonary imaging, with its applicability restricted in emergency care to screen for pleural and/or pericardial effusion, pneumothorax and pulmonary contusion. The recognition of different reverberating artifacts arising from the normal aerated lungs (A lines) and in the presence of lungs with interstitial and/or alveolar infiltrates (B lines) led to wider application of the technique in patients with respiratory syndrome. The objective of this study was to describe the ultrasound imaging methodology and the aspects of the pleura, pleural space and lung fields in healthy dogs.Materials, Methods & Results: Twenty healthy dogs of different breeds and ages, males and females were evaluated in this study; good health status was confirmed by physical examination, electro and echocardiographic assessment, thoracic radiography and systemic arterial blood pressure measurements. Dogs were scanned by a single examiner experienced in diagnostic imaging and previously trained for 6 months in thoracic ultrasound image interpretation. A MyLab 40 with a microconvex multifrequency probe (5-8 MHz) was used in this study.  Evaluation was performed in an orthopneic position (standing or sternal recumbecy) under manual containment. Ultrasound examinations were based on the VetBLUE (Veterinary Bedside Lung Ultrasound Exam) protocol. Lung fields were regionally scanned at the 2nd-3rd, 4-5th, 6-7th and 8-9th intercostal spaces in the right and left hemithorax. A subxiphoid window was added to screen for free fluid in the pleural space and/or pericardial sac. Pleural sliding and A lines, that are hyperechoic parallel equidistant lines arising from the visceral pleura-lung interface could be easily seen at all intercostal spaces in all dogs in this sample, with more difficult visualization at the 2nd-3rd intercostal space. B lines were observed in seven out of twenty dogs (35%). However, this artifact was limited to one intercostal space and a maximum of two lines were detected per field. B line artifacts were more commonly seen in the right hemithorax, at the level of the 8-9th intercostal space however without significant differences. In the subxiphoid window evaluation A lines were not detected.Discussion: The observation of B lines in healthy dogs was previously described and as in our study there were no significant differences relative to B line observation relatively to the intercostal space neither between the right and the left hemithorax. B lines are generally associated with decreased pulmonary aeration in response to interstitial/alveolar infiltration, which generates reflections and comet tail artifacts. The low number of B lines observed in this study may be associated with larger veins or lymphatics vessels, focal interstitial thickening or microatelectasia. The high respiratory frequency does not interfere in the sonographic evaluation. The dyspnea presented for animals with acute respiratory syndromes can be aggravated in stress situations, such as the displacement to the radiology service and manipulation necessary to the radiographic projections. Regional scanning by some acoustic windows allows rapid assessment of the thorax, with significant contributions to decision making in emergency situations. However, ultrasonography does not eliminate the need for other imaging modalities such as radiography and computed tomography and should be seen as a screening tool for patients presenting with acute respiratory syndromes

Pimobendan improves clinical signs in short term compared to digoxin or placebo in dogs with heart failure due to chronic degenerative mitral valve disease

Background: Chronic degenerative mitral valve disease (CDMVD) continues to be the most common cause of heart failure (HF) in small breed dogs. Pimobendan (PIMO) is a mixed action drug with inotropic and vasodilator properties and is widely used to treat heart disease in dogs. Therefore, PIMO increases cardiac output, reduces both preload and afterload and increases myocardial contractility without increasing energy consumption and myocardial oxygen. Digoxin (DIG) is a cardiac glycoside acting through inhibition of the sarcolemmal Na+/K+ ATPase pump, hence increasing intracellular calcium. It exerts benefi cial effects on left ventricular function, symptoms and exercise tolerance. The purpose of this prospective, randomized, double blind clinical trial was to evaluate the clinical response and QoLQ in heart failure (HF) dogs treated with digoxin or pimobendan in addition to conventional therapy (furosemide and benazepril). Materials, Methods & Results: Inclusion criteria: dogs in class III or stabilized class IV (NYHA). Exclusion criteria: use of positive inotrope and antiarrhythmic, presence of atrial fi brillation, renal or hepatic disease or neoplasia. Thirty three dogs were included and randomly assigned to DIG (n = 11), PIMO (n = 14) and placebo (PL) (n = 8) and followed up weekly. Data was evaluated for days zero, 7, 14 and 28. Increasing score was assigned to each variable depending on worsening of clinical evaluation (history and physical exam, QoLQ and echocardiogram (echo).Three dogs died during treatment due to worsening of HF, one of PL group and two of DIG group; furthermore, one of PIMO group was censored due to worsening of heart failure. There was no signifi cant difference between and within groups for echo and radiography. PL and DIG groups did not show any signifi cant difference throughout the 28 days of treatment. PIMO group showed lower physical exam score and increased early mitral infl ow velocity on day 28. Serum creatinine increased on days 14 and 28 compared to baseline, but within normal limits. The groups were similar within each evaluation day. Discussion: This is the fi rst short term prospective randomized double blind study comparing PIMO to DIG or PL additionally to conventional therapy (ACEi and furosemide) for dogs with HF due to CDMVD. It was observed an early signifi cant clinical improvement in dogs receiving PIMO compared to those receiving DIG or PL. The increase in early mitral infl ow velocity (E-wave) on day 28 for PIMO group is suggestive of diastolic dysfunction improvement, but this is only one variable related to diastolic function. Creatinine concentration increased in PIMO group, although it remained within normal range. In the present study, although all the three groups received furosemide, only PIMO group showed increase in blood creatinine between baseline and days 7 and 28. This result must be explored in later studies. Regarding the exercise intolerance assessment in a QoLQ, it must be aware that the owner evaluation is strongly infl uenced by the level of exercise that the dog is regularly submitted. Considering that most of the times, small breed dogs in a more advanced age is probably more sedentary and this fact surely precludes the owner to assess the exercise capacity. A more objective evaluation of the exercise tolerance should be considered in further clinical trials. Probably because of the small number of animals included in this study, differences in other studied variables were not found. The short-term follow-up of these patients may also have infl uenced the lack of differences among groups. Considering that stronger clinical evidence is needed to guide clinical decisions, longer prospective studies are also needed to compare the effects of DIG and PIMO, as well as to consider the benefi ts of the use or not of DIG associated with PIMO for dogs in HF due to CDMVD.Funding. This project was fi nancially supported by FAPESP - São Paulo Research Foundation, process number 08/57620-2

Cardiac biomarkers in Maine Coon cats genetically tested for hypertrophic cardiomyopathy

A cardiomiopatia hipertrófica (CMH) é a cardiopatia mais diagnosticada em felinos e responsável por morbidade e mortalidade elevadas. A desorganização do sarcômero no miocárdio de gatos afetados com a CMH tem relação com a mutação do gene miosina ligado à proteína C (MYBPC3). A concentração plasmática de biomarcadores cardíacos como o aminoterminal peptídeo natriurético atrial (NTproANP) e o aminoterminal peptídeo natriurético tipo B (NT-proBNP) liberados, respectivamente, secundária ao estresse da parede miocárdica dos átrios e ventrículos; a troponina I cardíaca (cTnI), liberada secundariamente à lesão miocárdica; e a endotelina tipo 1 (ET-1), um peptídeo vasoconstrictor potente cuja concentração plasmática aumenta em pacientes com insuficiência cardíaca, tem incrementado o diagnóstico de cardiopatias em humanos. A CMH é diagnosticada pela ecocardiografia convencional pela evidenciação de hipertrofia cardíaca (HC) segmentar ou difusa. Este estudo utilizou 57 gatos da raça Maine Coon, testados geneticamente para a mutação (M), que foram separados em quatro grupos: GIA com M e com HC (n= 4); GIB com M e sem HC (n= 10); GIIA sem M e com HC (n= 5); GIIB sem M e sem HC (n= 38) e avaliados por meio de ecocardiografia convencional e determinação dos biomarcadores cardíacos NT-proANP, NTproBNP, cTnI e ET-1. A prevalência da mutação nos gatos estudados foi de 24,56%. Diferenças estatísticas significantes foram observadas nos valores de NT-proBNP entre os grupos GIA e GIIB e GIA e GIB; de cTnI entre GIA e GIIB. Quando considerado apenas a presença ou ausência da mutação ou da hipertrofia, foram encontrados valores maiores de NT-proBNP em animais com HC e de cTnI em animais com mutação. Com base na metodologia utilizada, estabeleceu-se um ponto de corte para o NT-proBNP, considerando a presença de hipertrofia de 189,9 pmol/L, com sensibilidade de 77,8%, especificidade de 81,3%, valor preditivo positivo de 43,8% e valor preditivo negativo de 95,1 para o NT-proBNP, e o outro ponto de corte de 0,015 ng/mL, com sensibilidade de 64,3%, especificidade de 81,4%, valor preditivo positivo de 52,9% e valor preditivo negativo de 87,5% para a cTnI. A perspectiva para novos estudos concerne à cTnI e sua relação com a presença da mutação MYBPC3.Hypertrophic cardiomyopathy (HCM) is the most common feline heart disease and is responsible for high morbidity and mortality rates. Sarcomere disorganization in the affected myocardium of cats with HCM is related to the myosin binding protein C (MYBPC3) gene mutation. The plasma concentration of cardiac biomarkers such as atrial aminoterminal natriuretic peptide (NT-proANP) and Type B aminoterminal natriuretic peptide (NT-proBNP) released, respectively, by atrial and ventricular myocardium secondary to wall stress; cardiac troponin I (cTnI), released secondary to myocardial injury; and type 1 endothelin (ET-1), a potent vasoconstrictor peptide have been increasingly used for evaluation of human heart disease which are increased in patients with heart failure (HF). HCM is diagnosed by the presence of segmental or diffuse cardiac hypertrophy (CH) through conventional echocardiography. This study enrolled 57 Maine Coon cats screened for mutation (M) that were assigned to four groups: GIA with M and with CH (n= 4); GIB with M and without CH (n= 10); GIIA without M and with CH (n= 5); GIIB without M and without CH (n= 38) and evaluated by conventional echocardiography and cardiac biomarkers NT-proANP, NT-proBNP, cTnI and ET-1 measurements. The prevalence of the mutation in this study was 24.56%. Statistically significantly differences were observed in NT-proBNP among GIA and GIIB groups and among GIA and GIB groups; and in cTnI between GIA and GIIB groups. When considering only mutation and CH presence or absence, higher values of NT-proBNP were found in CH cats, and higher values of cTnI in those with mutation. Based on proposed methodology, cut-off value to NT-proBNP considering CH presence of 189.9 pmol/L had a sensitivity of 77.8%, specificity of 81.3%, predictive positive value of 43,8% and predictive negative value of 95,1% and the cut-off value of 0.015 ng/mL for cTnI considering mutation presence had a sensitivity of 64.3%, specificity of 81.4%, predictive positive value of 52,9% and predictive negative value of 87,5%. This study opened new perspectives to studies related to cTnI and MYBPC3 mutation

Standardization of echocardiographic, electrocardiographic, radiographic, and systolic blood pressure parameters in Dachshund dogs

Os cães da raça Dachshund apresentam acondroplasia/hipocondroplasia, considerada uma condição fisiológica da raça, resultando num corpo longo com os membros curtos, arqueados e musculosos, esterno largo e proeminente, caixa torácica oval e ampla. Essas condições podem dificultar a realização e interpretação de alguns exames. A hipótese desse trabalho é que os cães da raça Dachshund tenham valores ecocardiográficos, eletrocardiográficos, radiográficos e pressóricos diferenciados. Para isso, foram estudados 69 cães adultos e sadios da raça Dachshund, sendo 28 (40,6%) machos e 41 (59,4%) fêmeas; com idade variando de 18 meses a 10 anos de idade; e peso médio de 8,4±2,3 kg. Foram realizados exames ecocardiográfico, eletrocardiográfico, radiográfico, bem como determinação de pressão arterial sistêmica em todos os animais. Para a análise dos resultados, os animais foram categorizados, segundo, gênero, presença ou ausência de castração, faixa etária (A: >1 a ≤ 3 anos, B: >3 a ≤ 6 anos e C: >6 a ≤ 10 anos), peso (< 8 kg e ≥ 8 kg) e circunferência torácica (> 45 cm e ≥ 45 cm). Foram estabelecidos, em cães adultos e sadios da raça Dachshund, os valores de ecocardiografia convencional, eletrocardiografia, radiografia e de pressão arterial sistêmica por meio do método Doppler Os resultados ecocardiográficos principais, com a média e intervalo de confiança de 95% foram: septo interventricular em diástole SIVd (6,5 [6,3-6,7] cm), parede livre de ventrículo esquerdo em diástole PLVEd (6,3 [6,1-6,4] cm), diâmetro interno de ventrículo esquerdo na diástole DIVEd (2,5 [2,5-2,6] cm), diâmetro interno de ventrículo esquerdo na sístole DIVEs (1,2 [1,2-1,3] cm), fração de encurtamento - FE -(51,32 [49,79-52,84]%), fração de ejeção do ventrículo esquerdo Fej (0,84 [0,82-0,85]). Não houve diferença estatística para gênero ou castração. Mas quando os cães foram separados pela faixa etária, houve diferença estatística significativa entre os grupos A e B (p = 0,0073) para SIVd e PLVEd; sendo que os valores para o grupo A foram de: SIVd (6,2 [5,9-6,5] cm) e PLVEd (6,0 [5,7-6,2] cm). Os valores para o grupo B foram: SIVd (6,9 [6,5-7,3] cm) and PLVEd (6,5 [6,3-6,8] cm). Não houve diferença entre o grupo C e os grupos A e B; os valores para o grupo C foram: SIVd (6,4 [5,9-6,8] cm) e PLVEd (6,4 [6,1-6,7] cm). Portanto, cães adultos da raça Dachshund possuem espessura maiores de SIVd e PLVEd quando comparados com valores padronizados para outras raças. Quando os animais foram divididos pelo peso (>8 kg e ≥ 8 Kg), houve diferenças significativas para DVEd (2,44±0,26 cm; 2,64±0,27 cm; p>0,001), como também para circunferência torácica (> 45 cm e ≥ 45 cm), com valores de 2,43±0,25 cm e 2,63±0,27 cm (p>0,001). Também foram estabelecidos valores ecocardiográficos para tamanho do átrio esquerdo, nos eixos látero-lateral e ápico-basilar, respectivamente, iguais a 2,24±0,31 cm e 2,17±0,31 cm; bem como os valores de Doppler tecidual do anel valvar mitral lateral: onda E`=0,11±0,02 m/s, onda A´=0,10±0,02 m/s e razões E´/A´=1,12±0,33 m/s e E/E´=5,91±1,21 m/s. Cães adultos e sadios da raça Dachshund podem apresentar prolapso valvar mitral (40,58%). O valor de pressão arterial sistêmica por meio do método Doppler na cauda de cães Dachshund adultos e sadios foi de 134±20 mmHg diferenciando-se estatisticamente (p > 0,0001) dos valores obtidos no membro torácico (155±28 mmHg).Dachshund dogs present achondroplasia/hypochondroplasia, considered a breed physiological condition, that results in a long body with short, arched and muscular limbs, large sternum, oval and wide ribcage and developed heart and lungs. All this factors can difficult exams realization and interpretation. The hypothesis is that Dachshund dogs have differentiated echocardiographic, electrocardiographic, radiographic, and systolic blood pressure parameters. Therefore, 69 adult and healthy Dachshund dogs were studied (28 [40.6%] males and 41 [59.4%] females); from 18 months to 10 years-old, weighting 8.4±2.3 kg. Echocardiographic, electrocardiographic, radiographic and systemic arterial pressure evaluations were performed. Animals were categorized according to gender, neutered or not, age group (A: >1 a ≤ 3 years, B: >3 a 6 years e C: >6 a ≤ 10 years), weight (< 8 kg e ≥ 8 kg) e thoracic circumference (< 45 cm e ≥ 45 cm). The values of conventional echocardiography, electrocardiography, radiography and systemic arterial pressure were established in Dachshund dogs using the Doppler method. The main echocardiographic results, with a mean and 95% confidence interval were: interventricular septum in diastole IVSd (6.5 [6.3-6.7] cm), left ventricular free wall in diástole - LVFWd (6.3 [6.1-6.4] cm), left ventricular internal diameter in diastole LVIDd (2.5 [2.5-2.6] cm), left ventricular internal diameter LVIDs (1.2 [1.2-1.3] cm), shortening fraction SF (51.32 [49.79-52.84]%), left ventricular ejection fraction LVEF (0.84 [0.82-0.85]). There was no statistical difference for gender or castration. But when dogs were categorized by age, there was a statistically significant difference between groups A and B (p = 0.0073) for IVSd and LVFWd.; and the values for group A were: IVSd (6.2 [5.9-6.5] cm) and LVFWd (6.0 [5.7-6.2] cm). The values for group B were: IVSd (6.9 [6.5-7.3] cm) and LVFWd (6.5 [6.3-6.8] cm). There was no difference between group C and groups A and B; The values for group C were: IVSd (6.4 [5.9-6.8] cm) and LVFWd (6.4 [6.1-6.7] cm). Therefore, adult dogs of the breed Dachshund have thickness of IVSd and LVFWd when compared with values standardized for other breeds. When animals were divided by weight (< 8 kg and ≥ 8 kg), there were significant differences for LVIDd (2.44 ± 0.26 cm, 2.64 ± 0.27 cm, p (< 0.001), as well as for thoracic circumference (< 45 cm and ≥ 45 cm), with values of 2.43 ± 0.25 cm and 2.63 ± 0.27 cm (p < 0.001). Echocardiographic values were also established for left atrial size, on the latero-lateral and apical-basilar axes at 2.24 ± 0.31 cm and 2.17 ± 0.31 cm, respectively. In addition, the tissue Doppler values of the lateral mitral valve ring: E\' wave = 0.11±0.02 m/s, A\' wave = 0.10±0.02 m/s and E\'/A\' ratios = 1,12±0.33 m/s and E/E \'= 5.91±1.21 m/s. Adult and healthy Dachshund dogs may present with mitral valve prolapse (40.58%). The Doppler method in the tail of healthy Dachshund dogs was 134 ± 20 mmHg, statistically different (p < 0.0001) from values obtained in left forelimb (155 ± 28 mmHg)

Comparative Evaluation of the Echocardiographic Parameters of Dogs with Chronic Mitral Valve Regurgitation Treated with Amlodipine or Pimobendan

Background: Chronic mitral valve regurgitation is the most common heart disease in dogs. It is caused by myxomatous mitral valve degeneration, an acquired degenerative disease that can lead to congestive heart failure. Pimobendan is a mixed action drug, with inotropic and vasodilator proprieties, widely used to treat such dogs. Amlodipine is a pure vasodilator drug used as an anti-hypertensive agent, with no inotropic effects. This study aimed to compare  echocardiographic, electrocardiographic and blood pressure parameters between dogs with congestive heart failure treated with pimobendan and those treated with amlodipine in addition to conventional therapy.Materials, Methods & Results: A prospective, randomized, double-blind study was conducted in dogs with stage C chronic mitral valve regurgitation according to the 2009 American College of Veterinary Internal Medicine (ACVIM) guidelines, who weighed up to 15 kg. Randomization was performed using appropriate software and the sealed envelope technique. Blinding of the owner, the main researcher, and the person who performed the clinical analysis was guaranteed by the use of identical capsules and bottles for both pimobendan and amlodipine. Statistical analysis was performed using specialized software. Eligibility was determined by predefined inclusion and exclusion criteria. Dogs with cardiac disease other than mitral and/or tricuspid degeneration, patients already undergoing pharmacological treatment with drugs other than enalapril and furosemide, patients with systolic blood pressure below 100 mmHg, patients with chronic kidney disease in stages III or IV according to International Renal Interest Society staging system for chronic kidney disease (2009), and patients with other systemic debilitating diseases were excluded from the study. The animals were randomized into two groups based on the drug they received. Group A received pimobendan (n = 10) and group B received amlodipine (n = 11). All animals were also treated with furosemide and enalapril maleate and evaluated three times over a period of sixty days (T0, T30, T60). Changes in echodopplercardiographic and electrocardiographic parameters and systolic blood pressure were investigated. There were no significant differences in electrocardiographic parameters or systolic blood pressure between the groups at any time. Among the echocardiographic parameters, only early diastolic myocardial peak velocity (Em) and late diastolic myocardial peak velocity (Am) showed a significant difference between groups.Discussion: This was the first prospective randomized double-blind study comparing pimobendan and amlodipine in the treatment of dogs with stage C chronic mitral valve regurgitation according to the ACVIM consensus statement. The use of pimobendan in these patients has been debated because myocardial inotropism is generally preserved in them. Some authors argue that early use of the drug can even lead to deleterious effects on the heart. In the present study, the groups showed no statistically significant differences in systolic blood pressure or electrocardiographic parameters. Among the echocardiographic parameters, statistically significant differences were only observed in the speed of Em waves between groups at T0, in the speed of Em waves in the amlodipine group between T0 and T60 times, and in the speed of Am waves in the amlodipine group between T30 and T60 times. Both parameters are indices of diastolic function and may indicate a change in early myocardial relaxation. From the findings of this study, we could not conclude whether one drug was superior to the other

Comparative Evaluation of the Echocardiographic Parameters of Dogs with Chronic Mitral Valve Regurgitation Treated with Amlodipine or Pimobendan

Background: Chronic mitral valve regurgitation is the most common heart disease in dogs. It is caused by myxomatous mitral valve degeneration, an acquired degenerative disease that can lead to congestive heart failure. Pimobendan is a mixed action drug, with inotropic and vasodilator proprieties, widely used to treat such dogs. Amlodipine is a pure vasodilator drug used as an anti-hypertensive agent, with no inotropic effects. This study aimed to compare  echocardiographic, electrocardiographic and blood pressure parameters between dogs with congestive heart failure treated with pimobendan and those treated with amlodipine in addition to conventional therapy.Materials, Methods & Results: A prospective, randomized, double-blind study was conducted in dogs with stage C chronic mitral valve regurgitation according to the 2009 American College of Veterinary Internal Medicine (ACVIM) guidelines, who weighed up to 15 kg. Randomization was performed using appropriate software and the sealed envelope technique. Blinding of the owner, the main researcher, and the person who performed the clinical analysis was guaranteed by the use of identical capsules and bottles for both pimobendan and amlodipine. Statistical analysis was performed using specialized software. Eligibility was determined by predefined inclusion and exclusion criteria. Dogs with cardiac disease other than mitral and/or tricuspid degeneration, patients already undergoing pharmacological treatment with drugs other than enalapril and furosemide, patients with systolic blood pressure below 100 mmHg, patients with chronic kidney disease in stages III or IV according to International Renal Interest Society staging system for chronic kidney disease (2009), and patients with other systemic debilitating diseases were excluded from the study. The animals were randomized into two groups based on the drug they received. Group A received pimobendan (n = 10) and group B received amlodipine (n = 11). All animals were also treated with furosemide and enalapril maleate and evaluated three times over a period of sixty days (T0, T30, T60). Changes in echodopplercardiographic and electrocardiographic parameters and systolic blood pressure were investigated. There were no significant differences in electrocardiographic parameters or systolic blood pressure between the groups at any time. Among the echocardiographic parameters, only early diastolic myocardial peak velocity (Em) and late diastolic myocardial peak velocity (Am) showed a significant difference between groups.Discussion: This was the first prospective randomized double-blind study comparing pimobendan and amlodipine in the treatment of dogs with stage C chronic mitral valve regurgitation according to the ACVIM consensus statement. The use of pimobendan in these patients has been debated because myocardial inotropism is generally preserved in them. Some authors argue that early use of the drug can even lead to deleterious effects on the heart. In the present study, the groups showed no statistically significant differences in systolic blood pressure or electrocardiographic parameters. Among the echocardiographic parameters, statistically significant differences were only observed in the speed of Em waves between groups at T0, in the speed of Em waves in the amlodipine group between T0 and T60 times, and in the speed of Am waves in the amlodipine group between T30 and T60 times. Both parameters are indices of diastolic function and may indicate a change in early myocardial relaxation. From the findings of this study, we could not conclude whether one drug was superior to the other

Parâmetros bioquímicos de felídeos selvagens (Panthera leo e Panthera tigris altaica) mantidos em cativeiro

A maioria das populações de felinos selvagens é considerada ameaçada ou em extinção devido à caça indiscriminada e à redução de seu habitat natural causada pelo homem. Devido ao número limitado de animais, essas espécies são vulneráveis às doenças e endogamia, além das alterações metabólicas e comportamentais relacionadas à mudança das condições naturais, habitat e alimentação e, ainda, à condição de cativeiro. Há poucos relatos na literatura sobre a bioquímica sérica em leões e tigres. Este estudo apresenta os parâmetros bioquímicos de 23 leões de cativeiro (Panthera leo) e 10 tigres siberianos de cativeiro (Panthera tigris altaica) do Fundação Parque Zoológico de São Paulo. Ureia; creatinina; AST; ALT; ALP; GGT; bilirrubinas totais, diretos e indiretos; proteína total; albumina; CK; lactato desidrogenase; os níveis de triglicérides, de colesterol e de glicose séricas foram determinados; e também os eletrólitos cálcio, fósforo, cloro, sódio e potássio. Não foram encontradas diferenças de parâmetros bioquímicos relacionados ao sexo de Panthera leo, mas para Panthera tigris altaica foram observados valores mais elevados de albumina em machos. Os valores obtidos neste estudo podem ser usados como referência para os indivíduos em cativeiro de Panthera leo e Panthera tigris altaica.Most populations of wild felines are now considered endangered or near extinction due to the indiscriminate hunting and the reduction of their natural habitat, caused by man. Due to the limited number of animals within a population, these species are especially vulnerable to the impacts of diseases and endogamy. In addition, wild felines are also susceptible to metabolic and behavioral changes related to a change in their natural conditions, habitat, and feeding, when the animal enters into captivity. There are few descriptions in the literature of the serum biochemistries of lions and tigers. This study presents the biochemical parameters of 23 captive lions (Panthera leo) and 10 captive Siberian tigers (Panthera tigris altaica) from the Zoological Park of the Sao Paulo Foundation. Serum urea, creatinine, total protein, albumin, total, direct and indirect bilirubin were measured. In addition, serum levels of ALT, AST, ALP, GGT, glucose, CK, lactate dehydrogenase, cholesterol, and triglycerides were determined, as well as calcium, phosphorus, chlorine, sodium, and potassium. Biochemical parameters did not differ significantly among males and females lions, but higher albumin values were observed in male Panthera tigris altaica in comparison to females. The values obtained in this study may be used as reference for captive individuals of Panthera leo and Panthera tigris altaica