Cardiac trauma confirmed by cardiac markers in dogs: two case reports

Correlation between canine biochemical analytes and TRP36 ELISA seropositivity for Ehrlichia canis in Brazil

BACKGROUND

Synthetic peptides of tandem repeat proteins (TRPs) have been employed in the serologic analysis of canine monocytic ehrlichiosis (CME) and used in epidemiological studies in Brazil. Based on molecular studies of TRPs, different genotypes of Ehrlichia canis have been described, but data on their pathogenicity remain unknown.

OBJECTIVES

To correlate hepatic, renal, and muscular alterations in relation to different genotypes of E. canis in naturally exposed dogs using enzyme-linked immunosorbent assay (ELISA) with TRP19 and TRP36 synthetic protein antigens.

METHODS

Two hundred serum samples were subjected to ELISA with the antigens of TRP19 and three genotypes (US, Br, and CR) of TRP36 of E. canis circulating in Brazil. Positive sera were evaluated through eight biochemical parameters, and the results were evaluated by principal component analysis and canonical correlation.

RESULTS

ELISA revealed that 47 (23.5%) serum samples reacted to the BrTRP36 peptide, 36 (18%) reacted to the TRP19 peptide, and 8 (4%) reacted to the USTRP36 and CRTRP36 peptides separately. The most frequent biochemical alterations observed were for CK (59.4%), ALB (31.8%), GLO (28.9%), TP (28.9%), ALP (26%), urea (24.6%), creatinine (14.4%), and ALT (14.4%). The most prominent diagnostic method in canonical correlation analysis was BrTRP36, followed by TRP19, which correlated with hyperglobulinemia and hypoalbuminemia.

CONCLUSIONS

Antibodies that reacted against the Brazilian genotype of E. canis correlated positively with hyperglobulinemia and increases in serum urea and creatinine. According to our results, the Brazilian genotype of E. canis is related to the chronic phase of CME.

Intense exercise and endurance-training program influence serum kinetics of muscle and cardiac biomarkers in dogs

Few data exist on the physiological consequences of an incremental exercise test (IET) and training in dogs. Here we evaluated the effect of an endurance-training program (ETP) on the kinetics of the serum biomarkers: creatine kinase (CK), aspartate aminotransferase (AST), myoglobin, cardiac troponin I (cTnI), and creatine kinase isoenzyme MB (CK-MB). Eighteen Beagle dogs were assigned to three groups: sedentary (S), untrained (U), and trained (T). The dogs from the groups T and U underwent IET, and their lactate threshold (LT) was determined. The LT and velocity corresponding to the LT (VLT) was determined by visual inspection. The VLT was utilized to determine the training intensity level. Thus, the dogs from group T underwent an eight-week aerobic conditioning program with the intensity training set to 70-80% of the VLT. Next, dogs from the groups T and U have submitted to IET again. The group S did not undergo IETs or training. The maximal velocity (Vmax) at which the dog achieves in the IET and heart rate were determined. For biomarkers, venous blood samples were collected before the experimental procedure (baseline) and before and 1, 6, 12, 24, 48, and 72 h after the IETs. VLT and Vmax increased in group T (P < .05), indicating an improvement in dogs' aerobic and anaerobic fitness. CK and AST rose (P < .05), peaking 6 h after both IETs and returning to baseline levels after 12-24 h. Levels of cTnI and myoglobin were unaltered. CK-MB peaked 1 h after the IETs and returned to baseline levels after 12 h (P < .05). We concluded that ETP improved the aerobic capacity of the dogs without any skeletal or cardiac muscle injury.

Cardiac Troponins in Dogs and Cats

Cardiac troponins are sensitive and specific markers of myocardial injury. The troponin concentration can be thought of as a quantitative measure of the degree of injury sustained by the heart, however, it provides no information on the cause of injury or the mechanism of troponin release. Conventionally, the cardiac troponins have been used for diagnosis of acute myocardial infarction in humans and have become the gold standard biomarkers for this indication. They have become increasingly recognized as an objective measure of cardiomyocyte status in both cardiac and noncardiac disease, supplying additional information to that provided by echocardiography and ECG. Injury to cardiomyocytes can occur through a variety of mechanisms with subsequent release of troponins. Independent of the underlying disease or the mechanism of troponin release, the presence of myocardial injury is associated with an increased risk of death. As increasingly sensitive assays are introduced, the frequent occurrence of myocardial injury is becoming apparent, and our understanding of its causes and importance is constantly evolving. Presently troponins are valuable for detecting a subgroup of patients with higher risk of death. Future research is needed to clarify whether troponins can serve as monitoring tools guiding treatment, whether administering more aggressive treatment to patients with evidence of myocardial injury is beneficial, and whether normalizing of troponin concentrations in patients presenting with evidence of myocardial injury is associated with reduced risk of death.

CREATINAFOSFOQUINASE-ISOENZIMA MB MASSA (CK-MB MASSA) E TROPONINA I (cTnI) EM CÃES (<italic>Canis familiaris</italic>)

<title>Resumo</title><p>Os marcadores cardíacos, sobretudo a CK-MB massa e a cTnI, tem demonstrado um papel essencial seja em cardiologia clínica ou cirúrgica veterinária e humana, permitindo um diagnóstico mais preciso e acurado nas lesões miocárdicas. O objetivo deste trabalho foi mensurar os marcadores cardíacos em tela na Medicina Veterinária, aprimorar sua utilização e obter informações sobre estes métodos laboratoriais não invasivos que permitem o monitoramento da integridade da célula miocárdica. A quantificação dos parâmetros foi feita do soro de cães saudáveis atendidos na rotina do setor de Clínica Médica de Pequenos Animais do Hospital Veterinário da Universidade Estadual do Norte Fluminense Darcy Ribeiro. O kit de ensaio imunométrico por quimioluminescência turbo (IMMULITE Turbo, Siemens®) humano mostrou-se eficaz na avaliação na espécie canina, tanto para CK-MB massa quanto cTnI. Além disso, os valores encontrados para CK-MB massa e cTnI contribuirão significativamente para a rotina clínica ou para os trabalhos experimentais em cães.</p>

Tei index (myocardial performance index) and cardiac biomarkers in dogs with parvoviral enteritis

Tei index (myocardial performance) and cardiac biomarkers were evaluated in dogs with parvoviral enteritis (PVE). Tei index was calculated as isovolumic contraction time plus isovolumic relaxation time divided by ejection time. Myocardial and skeletal muscle damages were assessed by serum levels of cardiac troponin I (cTnI), creatine (phospho) kinase, lactate dehydrogenase and aspartate aminotransferase. Serum magnesium level was also determined. According to treatment response, dogs were divided into the survivor (n=20) and non-survivor groups (n=23). Seven healthy dogs served as controls. The mean value of the Tei index was higher in non-survivors, compared with survivors (p<0.02) and healthy controls (p<0.01). Serum level of cTnI in non-survivors was higher than that of survivors and controls (p<0.05). Tei index showed the highest sensitivity and specificity to predict mortality. The findings of an elevated Tei index and an increase in serum cTnI are factors associated with a poor prognosis in cases of canine parvovirosis.

Assessment of serum enzymatic markers of cardiomyocytes injury in female dogs submitted to ketamine S(+), atropin and xylazine association

PURPOSE

To assessment of the aspartate aminotransferase (AST), creatine kinase (CK) and creatine kinase isoenzyme fraction MB (CK-MB) serum activity in female dogs anesthetized with ketamine S (+), atropine and xylazine in several associations.

METHODS

Twenty three healthy female dogs randomly distributed in four groups named as GI (n=6), GII (n=6), GIII (n=6) and GIV (n=5) were treated respectively with atropine and ketamine S(+) (0.04 mg/kg; 10 mg/kg); ketamine S(+) (10 mg/kg); atropine, xylazine and ketamine S(+) (0.04 mg/kg; 1.1 mg/kg; 10 mg/kg) and xylazine and ketamine S(+) (1.1 mg/kg; 10 mg/kg). AST, CK and CK-MB serum activity measurement before pre-medication (M0) and one, two, three, six, 12, 24, 36 hours after.

RESULTS

There was no significant change in AST, CK e CK-MB serum activity among groups. However, CK serum activity in relation to moments within the groups was increased in all groups over the time in spite of treatment, except GI. In relation to CK-MB activity, in the moments within the group, it was observed an increase compared to baseline in all groups.

CONCLUSION

Creatine kinase and creatine kinase fraction MB isoenzyme showed changes in their mean values remained higher than baseline for a longer time in GIII and GIV.

Perfis eletrocardiográfico e ecodopplercardiográfico de ovinos após ingestão da suspensão aquosa de Mascagnia rigida Griseb. (Malpighiaceae)

Estudou-se o perfil eletrocardiográfico e ecodopplercardiográfico de ovinos intoxicados experimentalmente pela Mascagnia rigida Griseb (Malpighiaceae). Quinze ovinos machos da raça Santa Inês, com sete meses de idade e pesando, em média, 27kg, foram distribuídos em três grupos (G) com cinco animais cada: No G1 (controle), os animais receberam apenas água; nos G2, receberam 20g/kg de M. rigida durante três dias; e no G3, 20g/kg de M. rigida, durante sete dias. As folhas de M. rigida foram trituradas com água e administradas na forma de suspensão, por via oral, por meio de sonda. M. rigida promoveu aumento da FC em repouso e, principalmente, durante o esforço físico e diminuiu a fração de ejeção e o percentual de encurtamento sistólico do ventrículo esquerdo.

Intoxicação natural e experimental por Nerium oleander (Apocynaceae) em bovinos no Rio Grande do Sul

Descreve-se a intoxicação natural e experimental por Nerium oleander em bovinos no Rio Grande do Sul, Brasil. Dois de oito bovinos morreram subitamente após consumirem folhas de galhos de N. oleander que haviam sido podados e jogados no piquete onde os animais eram mantidos. Não foram observados sinais clínicos em uma vaca, mas um terneiro de 4 meses de idade apresentou decúbito lateral, movimentos de pedalagem, vocalização e morte. As alterações macroscópicas mais importantes observadas na vaca morta naturalmente e em duas novilhas intoxicadas experimentalmente ocorreram no coração que apresentava petéquias e equimoses no átrio esquerdo, coágulos e hemorragias no endocárdio do ventrículo esquerdo e áreas levemente pálidas no septo interventricular e em porções do miocárdio dos ventrículos. Na histologia, havia necrose de coagulação de fibras cardíacas individuais e de pequenos agrupamentos, caracterizada por aumento de eosinofilia citoplasmática e núcleos picnóticos. Essas lesões eram mais acentuadas no músculo papilar. O diagnóstico foi fundamentado na presença da planta no potreiro onde estavam os animais, quadro clínico-patológico compatível e reprodução experimental em dois bovinos nas doses de 0,5 e 1,0g/kg de folhas frescas da planta.

Intoxicação experimental com extratos de Mascagnia rigida (Malpighiaceae) em camundongos

Foi realizado o fracionamento químico do extrato aquoso da Mascagnia rigida Griseb., uma importante planta tóxica no Brasil, para se obter cinco substratos ricos em diferentes grupos químicos - alcalóides, flavanóides, taninos, saponinas e açúcares, ácidos orgânicos e aminoácidos -, e investigar a toxicidade dessas frações, exceto a última, em 75 camundongos. Os animais, distribuídos aleatoriamente em cinco grupos, receberam: grupo I - alcalóides; grupo II - flavanóides; grupo III - taninos; grupo IV - saponinas e grupo V - placebo, este último funcionando como controle negativo. Todos os grupos, com exceção do grupo-controle, redistribuídos em três subgrupos, A, B e C, com cinco animais cada, receberam, respectivamente, 9g/kg, 18g/kg e 27g/kg de cada substrato. As frações foram fornecidas via oral, diariamente, por sete dias; no sétimo dia, foi coletado sangue para o estudo do perfil sangüíneo e dosagem de enzimas musculares. As frações de alcalóides e taninos foram capazes de causar alteração no perfil enzimático-muscular, com aumento significativo da enzima miocárdica. Observou-se, também, aumento significativo na porcentagem da CK-MB após a administração das frações de saponinas e taninos, comprovando a ação tóxica da M. rigida sobre a fibra muscular cardíaca.