Salt / Sodium
Salt, a mineral that many dog and cat owners would rather not see in their furry companions’ food. But is this justified? FEDIAF (European Pet Food Industry Federation) has established a minimum required amount of salt for both dogs (0.1 g) and cats (0.08 g). Although these amounts are very low, this shows that dogs and cats need salt.
Dogs and cats need salt to maintain the osmotic value of the extracellular fluid in their cells. Sodium is also needed to transmit impulses to nerve cells and for muscle contraction. In addition, sodium is needed to regulate the permeability of cell membranes. However, large amounts of salt can have negative consequences for dogs and cats. Excess salt could result in hypertension—high blood pressure.
The assumption that high levels of salt cause dogs and cats to develop elevated blood pressure has, however, been disproven. Research has shown that this is not true. Dogs were given different levels of salt for a certain period, but their blood pressure remained the same. This shows that increased salt intake does not affect the animals’ blood pressure.
Another function of sodium is to contribute to the absorption of certain nutrients, sugars, and amino acids in the small intestine. Sodium can also affect calcium absorption and influences the absorption of water-soluble vitamins.
Most sodium absorption takes place in the small intestine. The mineral is excreted mainly through the urine; small amounts are excreted in the feces or through perspiration. Because dogs and cats can essentially sweat only through their paw pads, perspiration-related loss in these animals is small. When sodium intake is low, the body is able to keep urinary loss of the mineral to a minimum.
Certain hormones in the body, aldosterone and antidiuretic hormone, ensure that the ratio of sodium to potassium in the body remains constant. The need for sodium increases during reproduction, lactation, heat stress, and rapid growth.
Misconception: It is often thought that salt is added to dog and cat food to make it more appealing to the animals. However, adding salt serves no purpose. But why is that? Research has shown that dogs are relatively insensitive to salt in their food; they do not show a preference for food that contains a lot of salt. This is because the taste buds of dogs and cats differ from those of humans. The animals simply do not prefer food containing large amounts of salt.
