As we discovered last time, there is no shortage of variety in pet foods. Store bought foods now come in all sorts of classes and although this can seem overwhelming, it’s actually great news since, with so many choices available, you can be sure you’ll find something to suit both your dog, your budget and your lifestyle.

In Part 1 we looked into the differences between complete and complementary foods but in this article we’ll go one step further and will start examining all of the different methods that are used to make store bought foods, how they can affect the food and their pros and cons for both you and your dog.

Dry foods

Dry foods are by a country mile the most popular category of dog foods all over the world. They generally offer good value for money and, crucially, they are about as convenient as it gets.

Extruded foods

The vast majority of dry dog foods are made by a process called extrusion. Extrusion basically involves the ingredients being ground, mixed and passed though what is essentially a giant steam cooker before being cut into biscuit shapes and dried with currents of hot air. It is quick, consistent, relatively easy and inexpensive so an obvious choice for manufacturers. It does however involve some pretty high temperatures and pressures which may result in the loss of some of the natural nutrients contained in the raw ingredients.

Baked foods

Baking typically involves the biscuits passing slowly through a long oven atop a conveyor belt.

It allows biscuits to be made using lower pressures than extrusion which may leave more of the natural nutrients intact but it also tends to require the inclusion of wheat gluten to bind the biscuits which might not agree with all dogs.

Cold-pressed foods

Cold-pressed complete pet foods are still fairly new on the scene but their popularity is growing rapidly. They present all of the advantages of more conventional dry food processing but without the potentially damaging high temperatures. Ingredients do, however, still have to be dried and ground before pressing and some, like grains, also have to be pre-cooked so cold-pressing still involves a certain level of processing.

Air-dried foods

Air drying takes things one step further as the ingredients usually start the process fresh rather than ground or pre-cooked. The food is exposed to a current of heated air, gently removing the water through evaporation which is thought to reduce the damage to nutrients compared to conventional cooking methods. Some air dried foods need to be rehydrated by adding water so, while the packs might seem small, the volume of food you get from them is considerably larger.

Freeze-dried foods

Freeze dried foods are created by first freezing and then gently heating the ingredients within a vacuum to remove any moisture. In this way, the nutrients undergo very little damage making it arguably the most 'natural' form of dry food available. Another pro is that they have an incredible shelf life without the need for any preservatives. Freeze-dried foods do, however, tend to be eye-wateringly expensive but since many require rehydration with water, the final volume is often a lot more than you might think.

Next time…

Dry food are great but they are just the start! In Part 3 we’ll be taking a look at the various alternatives including wet, fresh and, of course, raw foods so be sure to take a look.