“Should I feed wet or dry food, doc?”
That’s one of the most common questions I get from cat owners. I usually reply, “If possible, both.” I base my recommendation on the fact that cats tend to form early and strong opinions regarding what they will and will not eat, and that by offering both, owners can keep all their options open.
It turns out that my recommendation is essentially right, but for more important reasons than I’ve been citing. Research published in the Journal of Comparative Physiology B illustrates why. Here are a few of the highlights. The paper is open access (yeah!), so take a look at the whole thing for all the details.
In order to meet its nutrient requirements, an animal is faced with the seemingly simple task of eating food. But foods are not simply parcels of nutriment; they are complex mixtures of nutrients, water and other chemical components … [A]nimals in their natural environment may be faced with a number of food sources which differ in quality (i.e. nutritional and non-nutritional content) as well as quantity (availability) leaving the animal with the problem of deciding ‘what’ and ‘how much’ to eat.
Domestic cats are often fed manufactured pet foods which are produced in two main formats, dry (i.e. kibbles/biscuits; ~7–10% moisture) and wet (i.e. in cans or pouches; ~75–85% moisture). We previously investigated the ability of cats to regulate macronutrient intake when provided with a choice of dry foods or wet foods and demonstrated that cats have a ‘target’ intake of approximately 52% of total energy as protein, 36% as fat and 12% as carbohydrate (Hewson-Hughes et al. 2011)
This series of experiments examined the ability of cats to regulate macronutrient intake when provided with foods that not only differed in macronutrient composition, but also in moisture content and consequently in texture and energy density … [I]t can be seen that self-selecting cats in all three experiments achieved remarkably similar diet compositions in terms of the proportions of protein, fat and carbohydrate selected when offered very different combinations of wet and dry foods. Whilst not identical, these profiles accord well with the target composition reported previously …. [A]chieving this regulatory outcome involved cats eating different amounts and proportions of foods according to nutrient content, not whether wet or dry. This conclusion is supported by simulations which indicated that had the cats eaten a fixed amount from each bowl of food offered, the macronutrient composition of the resulting diet would have been significantly different to the actual compositions selected and the target macronutrient profile.
Interestingly, the macronutrient profile of the diets composed by domestic cats in the present experiments and previously (Hewson-Hughes et al., 2011) are similar to that reported for free-ranging feral cats (52/46/2; Plantinga et al., 2011), indicating that domestic cats have retained the capacity to regulate macronutrient intake to closely match the ‘natural’ diet of their wild ancestors, even though the manufactured foods provided to domestic cats bear little resemblance to the natural foods (e.g. small vertebrate prey).
So it looks like our cats can handle most of the decision making with regards to what they should eat on their own. From now on, I’m going to recommend that owners feed their cats high quality wet and dry foods at each meal at least twice daily (removing the food in between meals to prevent overeating).
Do any of you feed your cats in this way? What’s your experience?
Dr. Jennifer Coates
Consistent proportional macronutrient intake selected by adult domestic cats (Felis catus) despite variations in macronutrient and moisture content of foods offered. Hewson-Hughes AK, Hewson-Hughes VL, Colyer A, Miller AT, Hall SR, Raubenheimer D, Simpson SJ. J Comp Physiol B. 2012 Dec 12.