"It's all the same, pet food isn't it?"
This is something that we frequently hear in the consulting room, but I'm afraid we have to contradict. Pet foods are not all the same. At a time when we are becoming concerned about what is found unexpectedly in human food, we should have similar concerns about pet food. If a human food which claims to be beef, actually contains horse, then what is in pet food?
One of the best ways to guarantee a good quality pet food is to go for a food which is made to a "fixed formula" rather than an "open formula." Buying a fixed formula food means that the food will contain exactly what it says on the bag or tin and will not change this from batch to batch.
Open formula food will have the same approximate nutritional value, but will change the ingredients from batch to batch depending on what is cheaper. This is why, when you look at many pet foods, their ingredient label will say "meat and meat derivatives." This could be venison one week and lamb the next. Many dogs and cats with food allergies or insensitivities will suddenly develop problems, even though the owner has not changed anything at home. Well, they may not have changed the food, but the food could have changed despite being sold in the same bag.
Many of the good quality pet foods often use only ingredients which are fit for human consumption, meaning that we could safely eat them too. Cheaper foods use cheaper ingredients, which may not be as good for your pet.
Cost per bag can be deceptive. The good quality foods may be more expensive per bag, but because they are made of good quality ingredients and have a high nutrient density, you need to feed less food per daily. This means they that they may work out the same price, or are only slightly more expensive per day than the cheaper, poorer quality foods.
Food for thought?
There's a great blog about food on another veterinary site at http://303animalclinic.com/tag/fixed-formula/