A 10 lb, 9-month-old intact male Shih Tzu puppy with a heart murmur presented for vomiting and lethargy following dietary indiscretion.
A 9-month-old intact male Mastiff mixed breed with history of being underweight presented at a referral facility for echocardiogram due to heart murmur.
Initial Evaluation: The patient presented for examination due to coughing more recently. Was at swim therapy after MPL surgery and therapist heard new heart murmur. PE grade 2/6 heart murmur, harsh lung sounds, moderate effort. The patient is on a grain free lamb and lentil diet. Current Medications: Lasix 20mg PO BID-TID (3-5mg/kg/day), Pimobendan 5mg in AM and 2.5mg in PM.
Ultrasound findings and recommendations from initial echocardiogram are as follows: Chronic degenerative valve disease causing moderate mitral and mild tricuspid regurgitation. Moderate LA dilation is noted, which is concerning for progression in the future. In this small breed with CVD, the systolic dysfunction is striking and unusual. Possible causes include secondary to grain free diet (taurine deficiency), infarct to the myocardial wall, or simply primary dysfunction. Given the recent information on grain free diets, first step is either submit a taurine level and/or change the diet and supplement taurine. Taurine-deficiency is the sole cause of treatable dysfunction, although this patient will still have underlying CVD. Certainly continuing Pimobendan is also recommended, for cardiac support. With moderate LA dilation, there is some risk for CHF, however it is unclear if the Lasix initiated was necessary at this phase. Use of an ACE-I is recommended for long term anti-fibrotic benefit. Further investigation into the cough is recommended through screening chest radiographs, as potentially simple cough suppression may benefit QOL. Finally, a cardiac tumor associated with the aortic root is also identified. The most likely tumor type given this location and the history is a chemodectoma, however other differentials cannot be ruled out. Chemodectomas are often incidental findings, only causing clinical signs if blood flow is obstructed, pericardial effusion occurs, or a metastatic lesion causing systemic issues. The prognosis with cardiac chemodectomas is fair, with a MST of 1-2 years. The limiting factor is often hemorrhage into the pericardium. Other sequelae include impingement of cardiac blood flow secondary to tumor growth, or metastasis to the thorax or abdomen. At this time this is considered an incidental finding, and is unlikely to be causing an clinical issues due to it’s small size.
Plan: Consider screening chest radiographs as discussed. Consider hydrocodone if needed. If no h/o CHF or current concern, consider wean to lower dose: Give 15mg PO q12h. Continue Pimobendan as prescribed. Institute Benazepril 5mg PO q12h. Consider submit taurine levels and/or supplement taurine twice daily. Change to commercial non-grain free diet.
Patient presented 8 months later for lethargy. Current medications: Benazapril 5mgs twice daily, Pimobendan 5mgs a.m. and 2.5mgs p.m., Lasix 10mgs p.m. Blood pressure was 160mmHg. A recheck echocardiogram was performed.
A 2-year-old intact male Golden Retriever was presented for a detailed cardiology workup due to a loud systolic murmur detected on routine physical exam. The dog did not show any clinical symptoms at this time, amazingly, he was in very good condition: alert, loved to play with other dogs, and had a good appetite. He did not receive any medication. Clinically, he had a grade 4/6 systolic heart murmur with a PMI on the left side at the level of his heart base as well as a soft diastolic murmur at the same site. His heart rate and respiratory rate were normal, his mucous membranes were pink. Thoracic radiographs showed a generalized cardiomegaly (Vertebral Heart Score 12.5) and a prominent aortic segment. Moreover, on VD-views, the pulmonary vessels were prominent. The lung field displayed a mildly vascular pattern, but no evidence of left sided congestive heart failure.