G.A.O. Cavalcanti

Avaliação do ritmo cardíaco em cães da raça Boxer saudáveis pela eletrocardiografia contínua (Holter)

The cardiac rhythm in a 24-hour period of 12 dogs of the Boxer breed, clinically healthy, males and females, of different ages was evaluated. No differences between males and females in the minimum, medium and maximum cardiac rates were observed (P>0.05). The females showed larger number of ventricular premature complex than the males. The major disorder in the cardiac rhythm was the ventricular premature complex. Several dogs showed the R over T phenomenon. Episodes of ventricular bigeminy and trigeminy were also observed.

Avaliação ecodopplercardiográfica da função diastólica em cães da raça Boxer

Major diastolics indexes, including the mitral propagation velocity (Vp), were evaluated in 36 healthy Boxer dogs, 18 males and 18 females, aging from 1.5 to 6-years-old. The aortic root and left atrium ratio, measured in B mode, was 1.17±0.11. The peaks of velocity of waves of the left atrium filling were: systolic 31.41±6.87cm/s, diastolic 73.85±17.04cm/s and atrial reversal 28.90±8.33cm/s. The ratios of the waves of initial ventricular filling were 1.58±0.19 to mitral valve and 1.62±0.29 to tricuspid valve. From the evaluated indexes, the Vp was only weakly correlated (r=0.39) with E and A waves of mitral valve and with D, showing itself, relativity, as an independence index. Regarding to the Vp, no significant differences were seen between the gender of the animals and among the observers. The Vp decreased as the age increased, showing mean values of 99.73±16.06cm/s.

Endoscopic transcervical intrauterine artificial insemination in Labrador Retriever bitches

Besides post-thawing reduced semen quality, there are some difficulties in the execution of the endoscopic transcervical intrauterine artificial insemination (AI) with frozen-thawed semen in bitches. Therefore, the aims of the present study were to evaluate behavioral and reproductive parameters (i.e., vaginal cytology and serum progesterone level) to determine time of insemination and to investigate the particularities and difficulties of this technique in bitches using fresh semen. Ten Labrador Retriever bitches were submitted to three endoscopic transcervical intrauterine AIs (with 48 h intervals). Oestrus and ovulation period were established by behaviour evaluation, progesterone assays and vaginal cytology, enabling optimal timing for AI during oestrus. During AI, the following aspects were evaluated: cervical os catheterization difficulty, semen deposition resistance, occurrence of semen backflow, and time required to perform the AI. In this study, it was possible to catheterize the cervical os in all bitches, with different degrees of difficulty, by manipulating the equipment to allow cervical visualization and catheter introduction in the cervical canal. Serial serum progesterone assays enabled estimation of LH surge day, and thus of ovulation. The pregnancy rate was 90%, with a litter size of 5.0 ± 2.6 puppies per bitch. It was concluded that the difficulties in the execution of the endoscopic transcervical intrauterine AI technique in Labrador Retriever bitches were minimized by the equipment manipulation and practical experience.

Doença renal medular cística em uma cadela Yorkshire Terrier: relato de caso

A Yorkshire Terrier bitch presented hematemesis, abdominal distention, poliuria, and polidipsia. After clinical examination, it was established a clinical suspect of nephropathy. The complementary exams showed normochromic and normocytic anemia and serum concentrations of ureia (306mg/dl) and creatinine (3.6mg/dl) above the references values. At two-dimensional ultrasound hipoechoic and anechoic cystic areas were observed, as well as hiperechogenic renal pattern and corticomedullary ratio loss. At necropsy, the medullary region presented many small cysts in a fibrous connective tissue. Cortical tubulointesticial lesion was responsible to the resulting renal failure. It was established a tubulointersticial nephritis diagnosis.

Avaliação por eletrocardiografia contínua (holter) em cães da raça Pastor Alemão praticantes de atividade física regular

ABSTRACT The pattern for ambulatory electrocardiography was evaluated in 25 healthy German Shepherd dogs. The influences of gender, age, and physical activity in HR maximum, mean, and minimum (HRmx, HRme, and HRmin, respectively) were studied. The physically active dogs (PA) showed lower HRme than sedentary animals (S) (P=0.03), whereas HRmx and HRmin were not altered (P=0.06 and P=0.65, respectively). The HRme was 80.89 ± 13.85 for PA and 112.94 ± 35.71 for S. No effect of gender and age on HR was observed. It is possible to state that the physical activity can modulate the sinus node of the dogs. Keywords: dog, German Shepherd, ambulatory electrocardiography, physical activity REFERENCIAS BIBLIOGRAFICAS BILLMAN, G.E. Aerobic exercise conditioning: a nonpharmacological antiarrhythmic intervention. J. Appl. Physiol ., v.92, p.446-454, 2002. DIXON, E.M.; KAMATH, M.V.; MCCARTNEY, N. et al. Neural regulation of heart rate variability in endurance athletes and sedentary controls. Cardiovasc. Res

Efeitos colaterais da ranitidina aplicada em dose terapêutica em cães saudáveis

The purpose of this study was to verify if the ranitidine dosage of 2mg kg-1 by intravenous path causes emesis or hypotension in healthy dogs. They were selected 10 Labrador Retriever, 10 Beagles and 10 mongrel dogs, five animals of each sex. The animals were submitted to clinical examination and blood pressure evaluation before ranitidine administration and also 10 minutes and 4 hours after administration of it. After administration was observed that 13.3% of the animals presented normal; 6.7% of the dogs presented apathy; 50% of the animals presented salivation and 30% presented apathy, salivation, emesis mimic or emesis. There was no significative arterial blood pressure decrease after ranitidine administration. It was concluded that ranitidine useful in therapeutic dosage by intravenous path may provoke apathy, salivation, emesis mimic and emesis.

Fibrilação atrial em cão associada ao quimiodectoma infiltrativo atrial: relato de caso

This case reports a mongrel dog referred to a veterinarian due to tiredness and syncope episodes. Atrial fibrillation and ventricular premature complex were observed during electrocardiographic exam. The anti-arrhythmic treatment was not effective and the dog died from syncope. At necropsy, a mass invading the internal area of the left atrium was evidenced in the base of the heart. The occurrence of chemodectoma was histologically exhibited. Infiltrations in the atrial myocardium caused alterations in the miocites and produced reentrant circuits and/or atrial depolarization ectopic points.

Infarto agudo do miocárdio e injeção intramiocárdica experimental em cães: estudos clínico, enzimático, eletrocardiográfico e ecocardiográfico

Ischemic events in dogs are uncommon; however, this may be under-reported. The myocardial infarction was created by left anterior descending coronary ligation in healthy mongrel dogs in clinical and laboratorial exams. These dogs were evaluated clinically, electrocardiography (ECG), through ambulatory electrocardiography (AE), echocardiography (ECO), creatine kinase enzyme (CK), creatine kinase MB fraction enzyme (CK-MB) and histopathologically. Even in these animals we observed the occurrence of arrhythmia after intramyocardial injection by AE. The animals exhibited left ventricular chamber enlargement and increase in myocardial performance index at ECO. In ECG, there were deviations in ST segment in the precordial leads V1 and V2. CK and CK-MB showed high increase, CK and CK-MB peaks occurred six and 12 hours after infarction, respectively. Histopathology of the infarction in the inferior wall of the left ventricle and replacement of muscle tissue by fibrous tissue were seen. Furthermore, intramyocardial injection that may be used for therapeutic purposes was evaluated by AE, which demonstrated no increase in the ventricular arrhythmias. Therefore, myocardial infarction in dogs can be detected with the tests available and intramyocardial injection can be used as a therapeutic way.

Atrial septal defect in an elderly dog.

ASDs are most commonly seen in dogs (Guglielmini et al., 2002;Sanders et al., 2005 , MacDonald, 2006. Regardless of type, isolated )ASD usually result in a left-to-right shunting across the defect (Guglielmini et al., 2002). The clinical sings of congenital heart disease occur n ianimals younger than three-year-old and they are rarely seen in aged dogs Kittleson and Kienle, (1998; Guglielmini et al., 2002;Chetboul et al., 2006). Echocardiography is necessary to determine the diagnosis and severity of the shunt (Kittleson and Kienle, 1998). Treatment of small septal defects is not necessary. Medical treatment consists of systemic arterial vasodilation to reduce the severity of the shunt. Paliative medical therapy with diuretics and angiotensin converting enzyme inhibitors is used for treatment of congestive heart failure. Positive inotropic drugs may be needed if there is myocardial failure, often as a result of severe aortic insufficiency (Kittleson and Kienle, 1998).