After hundreds of comments, hundreds more emails and untold discussions about GoodGuide's choice of Science Diet as its top brand, we turned back to GoodGuide to respond to the criticism. We've also reached out to Science Diet and -- based on the conversation started by our readers -- we will be doing our own story about what to look for when you going shopping for pet food.
The main issues leveled against Consumer Ally and its partner, GoodGuide.com, involve encouraging support for a product critics said is made primarily from grains and filler. And some suggested the food includes the rendered remains of pets and that veterinarians nationwide are complicit in an elaborate bribery plot that now involves GoodGuide and AOL.
"Your list of good dog foods is a crime. Science Diet is one of the worst dog foods available, as are the rest of the ones you listed as 'good,' one reader wrote. "I can guess who put you up to this ridiculous article. How do you sleep at night, (expletive deleted)?That was representative of many of the emails. Thankfully, most were not quite as hostile.
We've not yet heard back from the Science Diet folks, Colgate-Palmolive's Hill's Pet Nutrition. but will update this post if we do.
(Please click Refresh to check for updates.)
So, here is an FAQ assembled by the science team at GoodGuide and a link to a more detailed description of their methodology to evaluate pet food.
GoodGuide's Frequently Asked Questions about Pet Food Ratings
1) Some highly rated products contain ingredients that I believe are unhealthy for my pet. Why don't products that contain ingredients like grain or animal by-products receive lower scores?
While ingredient composition is a component of our pet food ratings, it is not the primary factor. Most veterinary nutritionists believe that product ingredient lists should not be the sole basis for rating the nutritional value of pet foods. This is because it is very difficult to reliably separate pet food ingredients into 'good' or 'bad' categories and because all pet foods are required to be formulated to meet basic nutritional requirements. Ingredients that sound unappetizing to humans (e.g., meals) or that are not part of a carnivore's historical diet (e.g., grains) can be nutritious for pets and desirable in a commercial pet food that has been designed to be an animal's sole source of food. Moreover, product ingredient lists do not provide enough ingredient detail or other information about the relative quantities of ingredients to make an accurate judgment about the overall nutritional value of a product.
Veterinary nutritionists consistently state that ingredient listings are neither the best nor sole indicator of the healthfulness of a pet food. As a result, ingredient composition contributes only about 10% of a product's health score in our rating system. Our ratings system assigns greater weight to three pet food characteristics that we believe are more important indicators of a product's overall nutritional quality:
- Nutritional Adequacy Test: AAFCO, the regulatory entity responsible for pet food, requires that pet food manufacturers confirm the nutritional adequacy of all products. The baseline approach is to do a chemical analysis of a product's formulation and compare the results with nutritional content standards. Alternatively, manufacturers test how a product peforms when fed over time to cats or dogs. Products that conduct feeding trials are preferred over formulations because they reflect real-world testing of a product's nutritional value. Nutritional adequacy statements, present on all pet food packages, reveal whether a product was formulated or assessed through a feeding trial.
- Caloric Content Disclosure: Even though human food requires calorie labels, pet foods aren't required to disclose caloric content. Since the obesity epidemic is hitting our canine and feline friends, it's more important than ever for pet owners to have the information they need to feed their pets appropriately. By stating caloric content on a pet food, manufacturers enable pet owners to feed their pets better AND demonstrate transparency. Therefore, products that disclose their caloric content receive a higher score than products that fail to provide calorie content.
- Life Stage: Research has shown that puppies and kittens have different nutritional requirements from adult cats and dogs. In general, growing pets require more nutrients per pound than adult pets. As a result, AAFCO has established two sets of profiles for cats and dogs: "growth and reproduction" and "maintenance." Pet foods must disclose which profile they meet. Many pet foods claim to meet both profiles (often with a statement like "suitable for all stages"). Usually this means that the product contains the highest level of nutrients needed to meet either profile. "All stages" products may contain excessive amounts of some nutrients, which can result in overfeeding. The preferred practice is to feed pets with food designed for a single life stage.
- For more on the methodology GoodGuide used to rate pet foods, see this recent blogpost or our detailed methodology page.
2) Dogs and cats are carnivores. How can grains be good for them?
Modern pets have evolved in association with humans to be omnivores and do well on the foods humans typically consume. Just as with human diets, there are many different ways to meet nutritional needs. As has been well-documented in What Pets Eat, a consumer guide to pet nutrition by experts Marion Nestle and Malden Nesheim, the pet food industry uses the materials that remain after production of many human foods, among them sugar, alcohol, beer, and flour as well as cattle, pigs and chickens. Many of these materials contribute nutrients-vitamins, minerals, protein-or energy that dogs and cats can use. Veterinary nutritionists like Joseph Wakshlag are generally skeptical of assertions that vegetable products like corn, soy or rice are "bad" ingredients that have no place in pet food. AAFCO's nutritional standards for dogs and cats specify a mix of protein, carbohydrates and fats, but do not advise or require that these nutrients only be provided from animal-based products.
3) I have used a product you rate and it definitely did not work for my dog.
Just like people, pets can be perfectly healthy from a variety of diets -- there isn't one correct diet or formulation. Your pet's happiness and vitality is the best indication of a healthy diet. It's important to remember that not all diets work for every pet. The number of comments we have received approving or criticizing the same pet food product reflect this fact. When looking solely at health, many products score similarly, so its possible to choose from many well-scoring products. Keep in mind that for most pets, this one product is the sole source of nutrition. This way of feeding is very different from the way we eat, and from the way we approach food.
4) I believe that a home-cooked diet or raw meat is the best diet for pets. Your ratings are focused on commercial pet foods but should instead be educating people how to prepare healthier food for their pets.
Our ratings can only be used to compare commercially available products. We are not able to compare commercial products to a home-made diet, because there is so much variability in what people could feed their pets. It is important to remember that cats and dogs have nutritional needs that differ from humans, so we recommend consulting a professional before attempting to feed a pet a home-made diet. Unless you are following expert guidance, animals are more likely to get the nutrients they need, in the right amounts, from a commercial product. See, for example, the advice of nutrition experts Marion Nestle and Malden Nesheim on this issue.
5) Are feeding tests cruel to animals? I do not support animal testing.
Feeding trials are considered the gold standard for confirming that a pet food provides the necessary nourishment for an animal. The goal of feeding trials is to determine whether eating an actual product for a prolonged period of time results in a healthy animal. The alternative, laboratory testing of formulations, only verifies that nutrient levels in a product meet requisite analytical standards. Feeding trials should not be confused with the animal testing that is done to assess the safety of chemical ingredients in other consumer products.
6) Why are issues other than the nutritional health of my pet included in your pet food ratings?
The nutritional value of a pet food constitutes one-third of the summary rating we assign to a pet food. An additional one-third of the score is based on a pet food manufacturer's environmental performance. This component of the rating addresses issues like the environmental impacts of pet food production (i.e., what are the manufacturer's policies and performance in regard to acquiring raw materials, using energy and water resources, etc.). The final one-third of the score is based on a manufacturer's social performance. This component of the rating addresses issues like a manufacturer's treatment of its employees and the communities it operates in, as well as its reputation among consumers for customer satisfaction, its history of product recalls, etc.
7) Are these ratings biased? Why does Science Diet get the highest product scores?
Science Diet has top-rated products in our pet food categories because our scoring system rewards products with a high Health score that are made by a company with high Environmental and Social scores. Other dog food products such as Purina Pro Plan Natural Chicken & Brown Rice Formula and Purina Pro Plan Natural Beef & Barley Formula and Eukanuba Large Breed Puppy also get top scores in health, but their manufacturers have lower environmental and/or social scores, which brings down their overall rating. Some manufacturers score higher than Science Diet on environmental or social impacts, but lower product-level health ratings bring down their overall score. For example, products from brands such as Acana and Newman's Own Organics receive top scores on Social criteria. Products from brands such as Evo, and Newman's Own Organics receive top scores on Environmental criteria.
Note that if a user wants to select pet food products based on their Health ratings only, or pet food manufacturers based on Environment or Social ratings only, that can be done at http://www.goodguide.com/products/?filter=dog+food.
8) Who developed these ratings? Were they funded by a pet food manufacturer? Why should I trust them?
Consumer Ally's pet food ratings were developed by its partner GoodGuide.com. GoodGuide is the leading online resource for obtaining science-based ratings of the health, environmental and social impacts of products and companies. For more on GoodGuide, see http://www.goodguide.com/about.
The pet food ratings were not funded by any pet food manufacturer, nor did any manufacturer participate in the development of the pet food rating methodology. GoodGuide is committed to generating ratings using the best science available. To develop its pet food ratings, GoodGuide worked with a consulting veterinary nutritionist (a Diplomate of the American College of Veterinary Nutrition) and solicited feedback on its overall approach from members of the ACVN.