HEART DISEASE AND LEGUMES
The FDA is studying possible links between dogs foods and the heart disease dilated cardiomyopathy. Diets high in legumes have been linked with most cases reported to the agency.
Research is continuing in the study of whether dogs eating diets that are high in legumes or free from grain have an increased risk of heart disease.
Currently the reason why some diets may be associated with the development of DCM in some dogs has not be established. What should be done in the meantime, before making any diet changes, dog owners should work directly with their veterinarians, who can consult with a board-certified veterinary nutritionist, to determine the most appropriate diet for their dogs specific needs.
With DCM, the chambers of the heart progressively dilate and become less able to pump blood through the vascular system. Signs include lethargy and weakness, resulting from decreased delivery of oxygenated blood to the tissues, and coughing, high respiratory rate, and abdominal distention, secondary to increased pressure in the veins that carry blood to the heart and congestive heart failure.
Dogs that are large, giant-breed dogs and Cocker Spaniels seem to have the most genetic risk of developing DCM, according to the FDA. Even more alarming is that the FDA are receiving reports of DCM in breeds that don’t typically have this disease, such as Shetland Sheepdogs, Bost Terriers, and French Bulldogs.
According to Dr. Lee Anne Palmer, who leads the Adverse Event Review Team in the FDA Center for Veterinary Medicine Division of Veterinary Product Safety, 93% of the dog foods identified in DCM reports listed peas, lentils, or both among the first 10 ingredients on labels, and about 91% were grain free.
FDA data published in June, 2019 indicate at least 16 brands had 10 or more DCM reports connected to their products. Dr. Jennifer Jones, a veterinary medical officer in the FDA CVM Veterinary Laboratory Investigation and Response Network program, said that the FDA analyzed dog foods from homes and stores and conducted comprehensive nutritional screenings, including analysis of free and total amino acids, and all but two products came back normal.
The FDA has also found that 9% of dogs had hypothyroidism, which can contribute to DCM, which can contribute to DCM, and 8% had a history of tick-borne disease. Lyme disease-associated myocarditis can contribute to the disease. Researchers have asked about exposures to contaminants such as heavy metals and narcotics and have collected DNA samples in case a potential genetic link is discovered.
Some dogs have improved with changes in diet, and the FDA has provided examples in updates posted in February and June, 2019. Agency officials are studying follow-up echocardiograms to see which dogs improve in response to a diet change.
Blood taurine concentrations were found not to be predictors of DCM, as dozens of dogs with DCM had normal or high taurine concentrations.
Research has found that some dog breeds may have genetic predispositions to taurine deficiency and DCM and with certain diets that my be associated with taurine deficiency
The potential connection between diet and DCM could be associated with low bioavailability of taurine or the precursor amino acids dogs use in synthesizing taurine or with increased loss of taurine during digestion or decreased ability to synthesize taurine.
The number of reports to the FDA is likely underestimated to the actual number of dogs affected, because there are veterinarians that don’t report cases to the FDA.
Finally the FDA is also studying a spectrum of cardiac disease in animals without DCM to better understand whether the damage could be related to DCM development or is associated with diet