Clinical and microbiological characterization of subclinical bacteriuria and sporadic bacterial cystitis in dogs with spontaneous hypercortisolism.

Study's aims were to characterize subclinical bacteriuria (SB) and sporadic bacterial cystitis (SBC) in dogs with spontaneous hypercortisolism (HC). Prospective cross-sectional design divided patients as newly diagnosed (n = 27), poorly controlled (n  = 21), well controlled (n  = 34), and controls (n  = 19). Urine culture positive results were identified by MALDI-TOF and submitted to antibiogram. Escherichia coli was the most common microorganism (36%). The majority of positive cultures in HC were SB (12.2%). All 4.1% SBC cases were in well controlled HC cases. Bacteriuria correlated with low urine specific gravity and low lymphocyte count. HC degree of control correlated with leukocyturia. SB/SBC cases were treated based in antimicrobial susceptibility leading to microbiological cure in 75% of HC cases. Persistent infections occurred only in SB cases, all by E. coli which became more resistant. SB/SBC prevalence in canine HC is actually lower. Further evidence for current ISCAID guideline contraindication for SB treatment due to HC were provided.

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.

Comparison of JC-1 and MitoTracker probes for mitochondrial viability assessment in stored canine platelet concentrates: A flow cytometry study.

Mitochondria perform crucial roles in many biochemical processes, and mitochondrial depolarization is an early sign of platelet apoptosis. The mitochondrial membrane potential is usually evaluated through JC-1 probe, but it can also be assessed with MitoTracker probes. Our aim was to evaluate mitochondrial viability in stored canine platelet concentrates (PCs) with the fluorescent probes JC-1 and MitoTracker. Platelets from 22 canine PCs were stained with JC-1 and MitoTracker probes on days 1, 3, and 5 of storage. Data on metabolic parameters were also collected for correlation studies. Results of JC-1 and MitoTracker revealed a decrease in mitochondrial membrane potential in day 5 of storage compared to days 1 and 3, providing evidence of mitochondrial depolarization, a finding that was confirmed by the data on metabolic parameters. MitoTracker probes also added information regarding platelet swelling. In conclusion, MitoTracker probes offered a more complete mitochondrial analysis in the evaluation of stored canine PCs. © 2018 International Society for Advancement of Cytometry.

Bacterial endocarditis and increased cardiac troponin I levels in a brown howler monkey (Alouatta guariba clamitans) with an interventricular septal defect.

A brown howler monkey (Alouatta guariba clamitans) was presented with lethargy, hyporexia, cough and heart murmur. The complementary tests and necropsy revealed pleuropneumonia, bacterial endocarditis and interventricular septal defect. To the best of our knowledge, this is the first report of increased cardiac troponin I levels in this species.

Variation of cow's milk composition across different daily milking sessions and feasibility of using a composite sampling / Variação da composição do leite de vaca em diferentes turnos diários de ordenha e viabilidade de usar uma amostragem composta

ABSTRACT: This study vised to detect possible changes in chemical and cellular composition of cow's milk at different milking sessions and to test if proportional or composite milk sampling can be used instead of separate milk analysis. Two experiments were conducted: one in cows milked thrice daily and the other one in cows milked twice daily. In both experiments, three milk samples were collected from each cow in each milking session in order to determine milk composition at each milking; to have a composite sample, i.e., a single sample from the same aliquots of milk from each milking session; and to have a proportional sample, i.e., a single sample from each milking session in a volume proportional to milk volume yielded. Fat content and fat to protein ratio were higher in the afternoon on both experiments. Protein content was larger in the afternoon on cows milked twice daily, but not on cows milked thrice daily. Lactose level was not different across the milking sessions in any of the experiments. The urea level was higher in the afternoon and evening milking on cows milked thrice daily, and in the morning milking on cows milked twice daily. Somatic cell count did not differ between milking in any experiment. No difference in milk composition was noted between proportional and composite samples on cows milked thrice or twice daily. The collection of proportional and composite samples is recommended in twice or thrice daily milking sessions so that the analysis of milk components becomes more easy and cheap.

RESUMO: Este estudo visou detectar possíveis mudanças na composição química e celular do leite de vaca em diferentes sessões de ordenha, e testar se a amostragem de leite proporcional ou composta pode ser usada em vez de uma análise separada do leite. Dois experimentos foram conduzidos: um em vacas ordenhadas três vezes ao dia e outro em vacas ordenhadas duas vezes ao dia. Em ambos os experimentos, três amostras de leite foram coletadas de cada vaca em cada ordenha: para determinar a composição do leite em cada ordenha; ter uma amostra composta, isto é, uma única amostra das mesmas alíquotas de leite de cada sessão de ordenha; e ter uma amostra proporcional, ou seja, uma única amostra de cada sessão de ordenha em um volume proporcional ao volume de leite produzido. O conteúdo de gordura e a relação gordura:proteína foram maiores no período da tarde nos dois experimentos. O conteúdo de proteína foi maior à tarde nas vacas ordenhadas duas vezes ao dia, mas não nas vacas ordenhadas três vezes ao dia. O nível de lactose não foi diferente nas sessões de ordenha em nenhum dos experimentos. O nível de ureia foi maior à tarde e à noite, nas vacas ordenhadas três vezes ao dia e, pela manhã, nas vacas ordenhadas duas vezes ao dia. A contagem de células somáticas não diferiu entre as ordenhas em nenhum experimento. Não houve diferença na composição do leite entre as amostras proporcionais e compostas em vacas ordenhadas três vezes ao dia. Recomenda-se a coleta de amostras proporcionais e compostas em duas ou três sessões diárias de ordenha, para que a análise dos componentes do leite se torne mais fácil e barata.

Hemato-biochemical profile of meat cattle submitted to different types of pre-loading handling and transport times.

Pre-loading handling and conditions of transport are related to welfare, disease risk and product quality of production animals. These steps continue to be one of the major animal management problems in Brazil. This study evaluated the effects of different types of pre-loading handling and road transport times on the haematological and biochemical traits of cattle. Eighteen male cattle were submitted to three travel times (24, 48 and 72 h) in a truck soon after load using different types of pre-loading handling: traditional (rough handling), training (gentle handling) and use of flags to movement cattle. Haematological traits, blood biochemical measures as well as blood and faecal cortisol were analysed in order to assess animal welfare and physiological status. The traditional management showed to be more stressful, also had animals with a greater number of neutrophils and lower numbers of lymphocytes than handling with flags, showing that animals submitted to more stressful situations can have compromised immune system. Serum aspartate aminotransferase concentrations were within the reference levels and when taken together with increased creatine kinase patterns observed indicate muscle damage in traditional management. Decrease in glucose concentrations over time from traditional management to flag management was observed, while fructosamine was increased in traditional management with 72 h of travel. When taken together, all reported factors, immune, enzymatic, energetic and hormonal, indicate that the quality of pre-loading handling and time of transport were determinant for animal welfare, its homeostatic balance and sanitary conditions.

Milk composition of Holstein cows: a retrospective study / Caracterização da composição do leite de vacas Holandesas: estudo retrospectivo

ABSTRACT: Worldwide, milk analysis is an satisfactory measurement of milk quality on dairy farms. Milk composition is the base for payment systems, so knowledge of its characteristics at different periods is essential for modern dairy producer. The aim of the study was to evaluate the effects of year, season, stage of lactation, and lactation number on variations in milk yield and composition of Holstein cows (n=148,604). Milk yield estimated by multiple regression was 25,50L/cow/day. Winter was the season with the highest milk yield and the highest protein and lactose content. Milk fat was highest in the fall, in cows in late lactation and also in primiparous cows. Lactating cows from 6 to 60 days in lactation and those in 2nd or 3rd lactation showed the highest milk yield. Lactose concentration was positively correlated with milk yield. Somatic cell score was negatively correlated with milk yield and with lactose concentration. Most important variations in milk characteristics occur among seasons, lactation stages and parities. Mammary gland health is yet the greatest challenge to be overcome.

RESUMO: A determinação da qualidade do leite nas fazendas é um parâmetro mundialmente aceito e utilizado como base para os sistemas de pagamento. Os produtores modernos utilizam o conhecimento das características do leite para adotar medidas que visam melhorar produtividade e qualidade. O objetivo do estudo foi avaliar os efeitos do ano, estação, estágio de lactação e número de lactação sobre as variáveis produção e composição do leite de vacas Holandesas (n=148,604). A produção de leite estimada por regressão múltipla foi de 25,50L/vaca/dia. O inverno foi à estação com a maior produtividade e os maiores teores de proteína e lactose. A gordura de leite foi maior no outono em vacas primíparas e no final da lactação. As vacas com estágio de lactação entre 6 a 60 dias e aquelas que se encontram na segunda ou terceira lactação apresentaram a maior produtividade. A concentração de lactose correlacionou-se positivamente com a produção de leite. O escore das células somáticas correlacionou-se negativamente com a produtividade e com a concentração de lactose. As variações mais importantes nas características do leite ocorrem entre estações, estágios de lactação e número de partos. A saúde da glândula mamária ainda é o maior desafio a superar.

Canine diabetes mellitus risk factors: A matched case-control study.

Different subtypes of canine diabetes mellitus (CDM) have been described based on their aetiopathogenesis. Therefore, manifold risk factors may be involved in CDM development. This study aims to investigate canine diabetes mellitus risk factors. Owners of 110 diabetic dogs and 136 healthy controls matched by breed, sex, and age were interviewed concerning aspects related to diet, weight, physical activity, oral health, reproductive history, pancreatitis, and exposure to exogenous glucocorticoids. Two multivariate multivariable statistical models were created: The UMod included males and females without variables related to oestrous cycle, while the FMod included only females with all analysed variables. In the UMod, "Not exclusively commercial diet" (OR 4.86, 95%CI 2.2-10.7, P<0.001) and "Overweight" (OR 3.51, 95%CI 1.6-7.5, P=0.001) were statistically significant, while in the FMod, "Not exclusively commercial diet" (OR 4.14, 95%CI 1.3-12.7, P=0.01), "Table scraps abuse" (OR 3.62, 95%CI 1.1-12.2, P=0.03), "Overweight" (OR 3.91, 95%CI 1.2-12.6, P=0.02), and "Dioestrus" (OR 5.53, 95%CI 1.9-16.3, P=0.002) were statistically significant. The findings in this study support feeding not exclusively balanced commercial dog food, overweight, treats abuse, and diestrus, as main CDM risk factors. Moreover, those results give subside for preventive care studies against CDM development.

Hemoplasma prevalence and hematological abnormalities associated with infection in three different cat populations from Southern Brazil.

Three hemoplasma species are recognized in domestic cats: Mycoplasma haemofelis, 'Candidatus Mycoplasma haemominutum' and 'Candidatus Mycoplasma turicensis'. We report the prevalence and hematological abnormalities of hemoplasma infection in 369 domestic cats from three different populations (blood donors, hospitalized cats and shelter cats) from Southern Brazil. Complete blood counts were performed at the time of blood collection, and DNA was extracted and tested by conventional PCR for each hemoplasma species. A total of 79 samples (21.40%) were positive for at least one species. The most prevalent hemoplasma was 'Candidatus Mycoplasma haemominutum', with 50/369 (13.55%) positive cats, followed by 'Candidatus Mycoplasma turicensis', 10/369 (2.71%), and Mycoplasma haemofelis, 8/369 (2.16%). Mycoplasma haemofelis and 'Candidatus Mycoplasma haemominutum' coinfection was observed in 4/369 (1.08%), whereas 'Candidatus Mycoplasma haemominutum' and 'Candidatus Mycoplasma turicensis' in 5/369 (1.35%). Three cats (0.81%) were infected with all three hemoplasmas. There was no association between infection and the different populations. Anemia was associated with Mycoplasma haemofelis and 'Candidatus Mycoplasma haemominutum', but not with 'Candidatus Mycoplasma turicensis'. Male cats and cats with outdoor access were more likely to be infected. Although 'Candidatus Mycoplasma haemominutum' is believed to cause minimal or no hematological alterations, the infected cats studied herein were more likely to be anemic.

Hemoplasma prevalence and hematological abnormalities associated with infection in three different cat populations from Southern Brazil / Prevalência da infecção por hemoplasmas e alterações hematológicas associadas à infecção em três diferentes populações de gatos do sul do Brasil

Three hemoplasma species are recognized in domestic cats: Mycoplasma haemofelis, ‘Candidatus Mycoplasma haemominutum’ and ‘Candidatus Mycoplasma turicensis’. We report the prevalence and hematological abnormalities of hemoplasma infection in 369 domestic cats from three different populations (blood donors, hospitalized cats and shelter cats) from Southern Brazil. Complete blood counts were performed at the time of blood collection, and DNA was extracted and tested by conventional PCR for each hemoplasma species. A total of 79 samples (21.40%) were positive for at least one species. The most prevalent hemoplasma was ‘Candidatus Mycoplasma haemominutum’, with 50/369 (13.55%) positive cats, followed by ‘Candidatus Mycoplasma turicensis’, 10/369 (2.71%), and Mycoplasma haemofelis, 8/369 (2.16%). Mycoplasma haemofelis and ‘Candidatus Mycoplasma haemominutum’ coinfection was observed in 4/369 (1.08%), whereas ‘Candidatus Mycoplasma haemominutum’ and ‘Candidatus Mycoplasma turicensis’ in 5/369 (1.35%). Three cats (0.81%) were infected with all three hemoplasmas. There was no association between infection and the different populations. Anemia was associated with Mycoplasma haemofelis and ‘Candidatus Mycoplasma haemominutum’, but not with ‘Candidatus Mycoplasma turicensis’. Male cats and cats with outdoor access were more likely to be infected. Although ‘Candidatus Mycoplasma haemominutum’ is believed to cause minimal or no hematological alterations, the infected cats studied herein were more likely to be anemic.

Três espécies de hemoplasmas são reconhecidas em gatos domésticos: Mycoplasma haemofelis, ‘Candidatus Mycoplasma haemominutum’ e ‘Candidatus Mycoplasma turicensis’. A prevalência e alterações hematológicas associadas à infecção por hemoplasmas foi estudada, em 369 gatos domésticos de três populações distintas (doadores de sangue, hospitais e gatos de abrigo) do Sul do Brasil. Foram realizados hemogramas completos no momento da coleta de sangue e as amostras tiveram seu DNA extraído e testado por PCR convencional para cada espécie de hemoplasmas. Setenta e nove amostras (21,40%) foram positivas para pelo menos uma espécie. O mais prevalente foi ‘Candidatus Mycoplasma haemominutum’ com 50/369 (13,55%) gatos positivos, seguidos por ‘Candidatus Mycoplasma turicensis’ com 10/369 (2,71%) e Mycoplasma haemofelis com 8/369 (2,16%). Coinfecção por Mycoplasma haemofelis e ‘Candidatus Mycoplasma haemominutum’ foi observada em 4/369 (1,08%), enquanto ‘Candidatus Mycoplasma haemominutum’ e ‘Candidatus Mycoplasma turicensis’ coinfectaram 5/369 (1,35%) gatos. Três (0,81%) gatos apresentaram infecção pelos três hemoplasmas. Não houve associação entre a infecção e as diferentes populações. Anemia foi associada com a infecção por Mycoplasma haemofelis e ‘Candidatus Mycoplasma haemominutum’, mas não com ‘Candidatus Mycoplasma turicensis’. Gatos machos e com acesso à rua apresentaram maior probabilidade de serem infectados. Embora se acredite que ‘Candidatus Mycoplasma haemominutum’ possa causar alterações hematológicas mínimas ou ausentes, gatos infectados encontrados neste estudo foram mais propensos à anemia.

Identification, occurrence and clinical findings of canine hemoplasmas in southern Brazil.

Hemoplasmas are ubiquitous pleomorphic and epicellular bacteria detected in erythrocytes in several species. In Brazil, studies on hemoplasmas have not included information on occurrence, clinical signs, and risk factors in dogs. This paper investigates the occurrence of hemoplasmas in dogs, focusing on risk factors and clinical status. Conventional PCR for the four types of canine hemoplasmas was performed in 331 blood samples collected from dogs clinically treated at a teaching veterinary hospital. Of all samples, 17/331 (5.1%) were positive for Mycoplasma haemocanis and 6/331 (1.8%) were positive for a 'Candidatus Mycoplasma haemominutum-like' organism. Risk factors included the presence of vectors, old age, dog bite wounds, and neoplastic diseases. In the multivariate analysis, a 4.40 odds ratio in dogs with vector-borne diseases indicated risk for hemoplasmosis. There was correlation between hemoplasma infection and neoplastic disease, suggesting that neoplastic conditions are a risk factor for hemoplasma infection in dogs.

Molecular detection of Ehrlichia canis and Anaplasma platys in dogs in Southern Brazil.

The aims of this study were to determine the occurrence of Anaplasma platys and Ehrlichia canis infection in dogs in Porto Alegre, Southern Brazil; and to investigate their association with hematological abnormalities. Serum samples from 196 dogs were first tested using dot-ELISA for antibodies against Anaplasma spp. and Ehrlichia canis. Peripheral blood samples from 199 dogs were subjected to 16S rRNA nested PCR (nPCR) for A. platys and E. canis, followed by DNA sequencing to ensure pathogen identity. A total of 19/196 samples (9.69%) were positive for Anaplasma spp. using ELISA and 28/199 (14.07%) samples were positive for A. platys by nested PCR. All the dog samples were negative for E. canis, both in anti-E. canis antibody tests and in nested PCR. There were no significant differences in hematological parameters between A. platys-PCR positive and negative dogs and Anaplasma spp. serologically positive dogs, except for basophil counts, which were higher in nPCR-positive dogs. This is the first report showing A. platys presence in dogs in Southern Brazil. In conclusion, hematological parameters may not be sufficient to diagnose A. platys infection in dogs in Southern Brazil, probably due either to low pathogenicity or to chronic infection. On the other hand, E. canis may either have very low occurrence or be absent in dogs in Porto Alegre.

Increase in cardiac troponin I in a lamb with tetralogy of fallot.

This study describes a case of tetralogy of Fallot in a lamb showing failure to thrive and signs of respiratory distress. Physical examination, electrocardiography, thoracic radiographies, echocardiography and cardiac troponin I evaluation were performed. The value of cardiac troponin I was compared with the values of 10 healthy lambs of the same age and breed, and the affected animal demonstrated an increase in cardiac troponin I. Due to the poor prognosis, euthanasia was indicated, and necropsy confirmed the diagnosis. This is the first report of an increase in cardiac troponin I in a lamb with tetralogy of Fallot.

A review of the occurrence of hemoplasmas (hemotrophic mycoplasmas) in Brazil.

Recent studies have been conducted in Brazil using molecular techniques for the detection of hemotrophic mycoplasmas in several mammals. In domestic cats, Mycoplasma haemofelis, "Candidatus M. haemominutum", and "Candidatus M. turicensis" infections have been identified. These species have also been found in free-ranging and captive neotropical felid species. Two canine hemoplasmas, Mycoplasma haemocanis and "Candidatus Mycoplasma haematoparvum", have been identified in dogs. In commercial swine populations, Mycoplasma suis was found to be highly prevalent, especially in sows. Moreover, novel mycoplasma species have been identified in Brazilian commercial pigs and domestic dogs. A hemoplasma infection in a human patient infected with the human immunodeficiency virus (HIV) was also recently documented. In conclusion, hemoplasma species are common and important infectious agents in Brazil. Further studies should be conducted to better understand their impact on pets, production animals, and wildlife fauna, as well as their role as zoonotic agents, particularly in immunocompromised patients.

Prevalência dos tipos sangüíneos A, B e AB em gatos domésticos mestiços da cidade de Porto Alegre, Rio Grande do Sul, Brasil / Prevalence of blood types A, B and AB in mixed breed domestic cats of Porto Alegre, Rio Grande do Sul, Brazil

O presente estudo teve como objetivo determinar a prevalência dos tipos sangüíneos em felinos domésticos, mestiços, da cidade de Porto Alegre, Rio Grande do Sul, Brasil. Foram selecionados aleatoriamente 100 gatos, clinicamente saudáveis, mestiços e sem parentesco entre si. Amostras de sangue foram coletadas da veia jugular e a tipagem sangüínea foi realizada através do teste Rapid Vet H Feline (DMS Laboratories, Flemington, USA) e do teste hemaglutinação em tubo de ensaio. A tipagem reversa foi realizada para confirmar o tipo e a presença de aloanticorpos naturais. No presente estudo encontrou-seprevalência de 97% e 3% de gatos do tipo A e B, respectivamente. Não foram encontrados gatos do tipo AB. Os resultados indicam que no sul do Brasil há uma alta prevalência de gatos domésticos mestiços do tipo A, entretanto a prevalência de gatos do tipo B encontrada no trabalho é mais alta do que aquelas relatadas em alguns países. O conhecimento da prevalência dos tipos sangüíneos da população de gatos de uma região pode auxiliar na determinação dos riscos de reações transfusionais e de ocorrência de isoeritrólise neonatal, e estes podem ser prevenidos através de tipagem sangüínea e teste de compatibilidade sangüínea.

The present study was carried out to determine the prevalence of the blood types in mixed breed domestic cats of Porto Alegre, Rio Grande do Sul, Brasil. A hundred of clinically healthy mixed breed and non related cats were selected. Blood samples were collected from the jugular vein and the blood typing was performed by Rapid Vet H Feline test(DMS Laboratories, Flemington, USA) and by hemagglutination tube test. Reverse blood typing was done to confirm the blood types and the presence of alloantibodies. In the present study the prevalence of blood type A and B in cats were 97% and 3%, respectively. No AB blood type cats were found. These results indicate that there is a high prevalence of blood type A mixed breed domestic cats in the south of Brazil, although the prevalence o B cats found is higher than reported in some countries. The knowledge of feline blood types prevalence in cat population can help to determine the risks of transfusion reactions and neonatal isoerythrolysis, and these can beavoid by blood typing and cross-matching test.

Parâmetros hematológicos e níveis de cortisol plasmático em vacas leiteiras de alta produção no sul do Brasil / Hematological parameters and plasma cortisol levels in high-yielding dairy cows in the South of Brazil

A adaptação metabólica é um processo importante para a produção de leite em vacas de alta produção leiteira. A fisiologia das mudanças hematológicas e endócrinas durante o pós-parto é complexa e muitas respostas homeostáticas são importantes para obter o máximo da produção de leite. O perfil hematológico é uma ferramenta diagnóstica útil nos diferentes estágios do ciclo produtivo de vacas leiteiras. O objetivo deste estudo foi avaliar alguns parâmetros hematológicos em diferentes estágios do ciclo produtivo de vacas leiteiras e correlacioná-los com o cortisol. Foram selecionadas 210 vacas multíparas, distribuídas por semanas: -3, -1 (antes do parto) e 2, 5, 8 e 11 (após o parto). Os parâmetros hematológicos avaliados foram hematócrito, concentração de hemoglobina, contagem total e diferencial de leucócitos. O estresse durante o periparto foi avaliado pela concentração de cortisol analisado através do método de radioinmunoensaio de fase sólida. Todos os parâmetros determinados (hematológicos e cortisol) estavam dentro do intervalo de referência para a espécie. Os maiores valores de cortisol foram observados na segunda semana após o parto. Alterações hematológicas associadas a sinais de alto estresse não foram observadas no presente estudo e isto provavelmente se deve ao estado de saúde satisfatório dos animais durante o período de experimento e às condições adequadas de manejo e nutrição.

The metabolic adaptation is an important process to milk production in high-yielding dairy cows. The physiology of hematological and endocrinal changes during the postpartum period is complex and many homeostatic responses are important to achieve the maximum milk production. The hematological status is an useful diagnostic tool to evaluate the general health and the immune system on different stages of the productive cycle in dairy cows. The objective of this study was to evaluate some hematological parameters in different periods of the productive cycle of dairy cows and correlate them with cortisol. Two hundred and ten multiparous dairy cows were selected to this experiment. The animals were distributed by weeks: -3, -1 (60 and 15 days before calving), 2, 5, 8 and 11 (weeks postpartum). The hematological parameters analyzed were PCV (packed cell volume), hemoglobin concentration, total and differential count of WBC (white blood cells). The stress during the periparturient period was evaluated by cortisol levels analyzed by solid-phase radioimmunoassay method. All the hematological and cortisol values were within the normal range for the species. The highest values for cortisol were found during the second week. Hematological changes associated to high stress signs were not observed in the present study and this is probably due to the satisfactory health state during the experiment period and the adequate nutritional and management conditions.