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in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

Objective

To determine heart rate (HR) and heart rate variability (HRV) after IV administration of 3 doses of atropine to clinically normal, large-breed adult dogs.

Animals

6 mixed-breed dogs, weighing between 23 and 50 kg.

Procedure

Continuous ECG were recorded prior to and following IV administration of saline (0.9% NaCl) solution and 0.02, 0.04, and 0.06 mg of atropine/kg of body weight. Heart rate and HRV within sympathetic and parasympathetic domains were determined, using customized software, and responses to treatments were compared. Each dog received all treatments with ≥ 2 days between treatments.

Results

HR increased and HRV within the parasympathetic domain decreased after all atropine treatments, compared with pretreatment values. Heart rate was significantly higher after administration of 0.06 mg of atropine/kg than after 0.02 mg/kg but was not different from HR after administration of 0.04 mg/kg. Five of 6 dogs given the 0.04 or 0.06 mg/kg dose attained HR > 135 beats/min, but only 1 of 6 dogs given the 0.02 mg/kg dose attained a HR > 135 beats/min. Heart rate variability within the parasympathetic domain decreased significantly from pretreatment values after all atropine treatments. Atropine doses of 0.04 and 0.06 mg/kg induced significantly lower HRV than did the 0.02 mg/kg dose, but HRV after the higher doses were not different from each other. HRV within the sympathetic domain after any treatment did not change from pretreatment values.

Conclusions and Clinical Relevance

IV administration of 0.04 or 0.06 mg of atropine/kg increased HR and induced complete parasympathetic blockade in clinically normal, large-breed adult dogs. (Am J Vet Res 1999;60:1000-1003)

Free access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Summary

Between October 1986 and September 1988, 37 cats with moderate to severe idiopathic myocardial failure (dilated cardiomyopathy) were evaluated prospectively. Low plasma taurine concentration and diet history including foods that can cause taurine deficiency were documented in most of the cats. Comparison with a retrospectively studied population of 33 cats with dilated cardiomyopathy diagnosed between 1980 and 1986 demonstrated that the clinical and historical findings in the 33 retrospectively studied cats were similar to those in the 37 cats studied prospectively. Clinical findings in the 2 groups were also similar to findings previously reported in the literature. Because clinical findings and diet history were similar in the prospective and retrospective groups, we believe that many cats in the latter group had diet-induced taurine deficiency. These findings support the conclusion that most cases of dilated cardiomyopathy in cats have a common etiopathogenesis related to diet and as such are preventable.

Free access
in Journal of the American Veterinary Medical Association

Summary

Between October 1986 and September 1988, 37 cats with moderate to severe idiopathic myocardial failure (dilated cardiomyopathy) were evaluated. Clinical management of these cats was similar to that described in the literature, except that it also included administration of 500 or 1,000 mg of the sulfur amino acid, taurine per day.

Early death (death within the first 30 days of treatment) occurred in 14 (38%) cats. One cat was lost to follow-up evaluation. Twenty-two cats (59%) had marked clinical and echocardiographic improvement and survived longer than 240 days. In all but 1 cat, the observed improvement in echocardiographic measurements persisted. Hypothermia and thromboembolism were positively associated with an increased risk of early death. Administration of digoxin did not significantly affect survival.

All 22 cats that survived > 30 days remained clinically stable despite withdrawal of all medications except taurine. Administration of taurine was eventually discontinued in 20 of the 22 cats and adequate taurine intake was thereafter provided for in the food.

The clinical response and 1-year survival rate of 58% (21 of 36 cats with a known outcome) in the taurine-treated group represents a marked improvement, compared with a 1-year survival rate of 13% (4 of 31 cats with a known outcome) in a retrospectively evaluated population of 33 cats with dilated cardiomyopathy.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objectives—To evaluate clinical, laboratory, and necropsy findings in dogs with infective endocarditis (IE).

Design—Retrospective case series.

Animals—71 dogs with possible or definite IE.

Procedures—Medical records were reviewed for signalment, clinical features, and results of clinicopathologic testing and diagnostic imaging. Yearly incidence and the effect of variables on survival were determined by use of survival curve analysis.

Results—The overall incidence of IE was 0.05%. Most affected dogs were of large breeds, and > 75% were older than 5 years. The aortic valve was affected in 36 of the 71 (51%) dogs, and the mitral valve was affected in 59%. Lameness caused by immune-mediated polyarthritis, septic arthritis, or peripheral arterial thromboembolism was observed in 53% of the dogs. Neurologic complications were diagnosed in 17 of 71 (24%) dogs. Thromboembolic disease was suspected in 31 of 71 (44%) of dogs. The mortality rate associated with IE was 56%, and median survival time was 54 days. Factors negatively associated with survival included thrombocytopenia, high serum creatinine concentration, renal complications, and thromboembolic complications.

Conclusions and Clinical Relevance—A diagnosis of IE should be suspected in dogs with fever, systolic or diastolic murmur, and locomotor problems. Dogs with thrombocytopenia, high serum creatinine concentration, thromboembolism, or renal complications may have a shorter survival time.

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in Journal of the American Veterinary Medical Association