|(1)||Anorexia - due to the disease itself but also commonly associated with some therapeutic agents|
|(2)||Malabsorption - due to compromised gastrointestinal function.|
|(3)||Peripheral tissue deterioration due to underperfusion.|
|(4)||Hypermetabolism of respiratory and cardiac tissues.|
|(5)||Generalised hypermetabolism due to fever, sepsis or stress. The chronic sympathetic stimulation which is a normal compensatory mechanism in response to falling cardiac output will induce a catabolic state in the patient and may lead to peripheral insulin resistance.|
Cardiac patients have high energy requirements and need an increased energy intake. Fat provides 2.25 times as much energy per gram as either protein or carbohydrate, hence a high-fat diet is indicated. A high fat diet is also beneficial because the amount of food that an animal with heart disease needs to consume to meet its requirements is reduced, and fat in a ration increases its palatability. Clinical diseases associated with excessive fat consumption that are common in man (e.g. severe coronary artery disease and atherosclerosis) are fortunately rare in old cats and dogs.
For debilitated cases special feeding techniques may need to be employed including force feeding or tube feeding.