Beginning in the early 2000s, the number of dogs with taurine deficiency and DCM subjectively appeared to decrease. Recently, however, we have heard from veterinary cardiologists who had an impression that they were diagnosing DCM in Golden Retrievers at higher rates than expected and in dogs of breeds

Pimobendan appeared to be well tolerated in cats with heart failure characterized by ventricular systolic dysfunction of various etiologies. Cats with systolic anterior motion of the mitral valve may develop systemic hypotension when treated with pimobendan. Additional studies are needed to establish dosages for pimobendan and its effects before it can be recommended for treatment of cats with CHF.

Background Angiotensin‐converting enzyme 2 (ACE2) is a homologue of angiotensin‐converting enzyme (ACE) and produces angiotensin peptides (APs), such as angiotensin 1‐9 and 1‐7 that are vasodilatory and natriuretic, and act to counterbalance angiotensin II. Hypothesis Evidence of ACE2 can be found in tissues and plasma of dogs. Equilibrium concentrations of renin angiotensin aldosterone system (RAAS) APs differ in dogs with heart disease compared to healthy dogs and recombinant human ACE2 (rhACE2) alters relative concentrations of APs. Animals Forty‐nine dogs with and 34 dogs without heart disease. Methods Immunohistochemistry and assays for tissue and plasma ACE2 activity and equilibrium concentrations of plasma RAAS APs were performed. Results Immunolabeling for ACE2 was present in kidney and myocardial tissue. Median plasma ACE2 activity was significantly increased in dogs with congestive heart failure (CHF; 6.9 mU/mg; interquartile range [IQR], 5.1‐12.1) as compared to control (2.2 mU/mg; IQR, 1.8‐3.0; P = .0003). Plasma equilibrium analysis of RAAS APs identified significant increases in the median concentrations of beneficial APs, such as angiotensin 1‐7, in dogs with CHF (486.7 pg/mL; IQR, 214.2‐1168) as compared to those with preclinical disease (41.0 pg/mL; IQR, 27.4‐45.1; P < .0001) or control (11.4 pg/mL; IQR, 7.1‐25.3; P = .01). Incubation of plasma samples from dogs with CHF with rhACE2 increased beneficial APs, such as angiotensin 1‐9 (preincubation, 10.3 pg/mL; IQR, 4.4‐37.2; postincubation, 2431 pg/mL; IQR, 1355‐3037; P = .02), while simultaneously decreasing maladaptive APs, such as angiotensin II (preincubation, 53.4 pg/mL; IQR, 28.6‐226.4; postincubation, 2.4 pg/mL; IQR, 0.50‐5.8; P = .02). Conclusions and Clinical Importance Recognition of the ACE2 system expands the conventional view of the RAAS in the dog and represents an important potential therapeutic target.

Objective To develop a perceived exertion scale for dogs exercising on a treadmill and to assess intra‐ and inter‐observer variability. Materials and Methods Fifteen healthy client‐owned dogs participated in paired exercise trials. Measurements of lactate, glucose, heart rate, temperature, respiratory rate and regional tissue oximetry were obtained before, during and after exercise. Perceived exertion scale scores were recorded during exercise and using video recordings to evaluate inter‐observer variability. Correlations were evaluated using the Spearman's non‐parametric method. Results Thirteen dogs completed both trials. Dogs walked or trotted on the treadmill with an average perceived exertion score of 2 in both trials. Holter heart rate was positively correlated with perceived exertion scale scores from all observers for both trials. In trial 1, plasma glucose decreased in association with increase in perceived exertion and, in trial 2, cutaneous oximetry decreased, respiratory rate increased and temperature increased with increases on the perceived exertion scale. Inter‐observer perceived exertion scale scores were positively correlated in both trials. There was no intra‐observer variability between trials. Clinical Significance The perceived exertion scale correlated with the measured physiologic parameters in dogs exercising at mild to moderate intensity. The perceived exertion scale was consistent and repeatable but larger study numbers and further validation are needed before it can be widely applied.

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