Basic Pet Nutrition
[The following information applies primarily to dog and cat food - food formulations for ferrets and small mammals are less well researched, and there is a wide variation in recommendations from the top experts in their medical care - I would refer owners of Rabbits, Guinea Pigs, Ferrets, and other small mammals to Veterinary Partners for more information]
When it comes to pet food, there are about as many options as there are breeds of pets. Making an intelligent decision is not always easy. Here are our guidelines for selecting pet foods based on over 20 years of veterinary experience and numerous nutrition lectures and courses.
A) Life Stage Diets:
Feed a major name brand pet food that is based on your pet's age: Puppy/Growth formula for the first six to eighteen months, depending upon breed, eight to twelve months for miniature breeds, twelve to eighteen months for giant breeds and for pregnant and nursing females. Adult/Maintenance for normal weight adult pets. Light/Less Active for overweight pets or spayed/neutered strict house pets. Senior/Mature for pets over seven years old, or spayed/neutered strict house pets. The research and reputation behind Science Diet; Iams; Eukanuba; and the "Pro Plan", "Beneful", and "ONE" lines of Purina foods are the best [Royal Canin a relatively recent introduction to the United States, looks like it will also be a very reliable brand]. Several brands of "over the counter" pet foods are actually too rich for many pets.
B) Prescription Diets:
For pets with special medical problems, prescription diets may be best. Prescription diets are available from the larger pet food producers (Eukanuba, Science Diet, Purina, Royal Canin), but are sold only through veterinary offices. Each of these diets has been modified to provide the best balance of nutrients for a particular medical problem. Some of the particular chronic medical problems that prescription diets can help control include kidney or bladder stones, chronic kidney disease, heart disease, weight loss, diabetes, liver disease, brain/cognitive disorders, cancer, arthritis, and some allergic and skin diseases. The decision to use a prescription diet as part of the management for an ongoing illness must be made by both you and your veterinarian.
C) Pet Food Labels:
While comparing labels between brands of food is frequently done in an attempt to find a more economical copy of one of the major name brands, it tends to be a wasted effort. Pet food labels are frequently quite misleading. Companies are not required to indicate on the label anything regarding the QUALITY of the ingredients used. Companies also have a lot of freedom in how the ingredients are listed on the label, for example, while a reputable company will list the combination of ground chicken skin, bone, and meat pieces as "Chicken By-product meal," a less reputable company may simply call it chicken, and while this may sound disgusting to us today, 50 years ago, our parents and grandparents would have considered it normal (contrary to popular myth, feathers, hooves, and viscera are not usually included by the better companies, making "Chicken By-product meal" more like the base for a good "Chicken Stock"). Pet foods which are transported across state lines for sale and pet foods that are advertised in national media (television and magazines in particular) fall under an additional set of federal regulations established by the Federal Trade Commission (advertising) and the Commerce Commission (interstate transport). Pet foods which are sold within the state where they are manufactured and do not cross state lines are generally never inspected. The only legal requirement is that the name and address of the manufacturer be accurate.
"Store Brands", foods sold only in one chain of stores, usually with that store's name or brand line name are generally manufactured within the same state in which they are sold. The manufacturer for these foods is selected on a low bid basis. We therefore consider them to be "generic" and of questionable quality regardless of whether or not they are marketed as a "premium" or a "basic" food. In fact, many smaller pet food companies do not own their own mills either, and also select mills for their foods based upon the low-bid approach.
The reputation of the company is the single most important information you can have about a pet food. It is much more important than anything else printed on the label. We also feel that the companies we recommend (Iams, Hill's Science Diet Pet Foods, Royal Canin and the Purina Pro-Plan line) have proven themselves through their background, on going research, and track record. Many other brands exists, and most are generally adequate for the majority of pets, but these four companies have time and again proven their worth.
*** A recent lecture on Pet Nutrition helped explain some of the issues around the "Menu" pet food recall from 1997. While the major national manufacturers do tend to own their own feed mills for the production of their foods, they do not always have the expertise to make every type of food they wish to sell, particularly for some "Niche Markets", and will subcontract to a company (like "Menu Foods") that has a strong reputation for that particular product type. The problem came about when an unscrupulous supplier deliberately substituted a cheap tainted product that he knew would be able to pass the quality control testing that was in place at the time. The major manufacturers all had archived samples of their raw ingredients as well as their final product, so when the offending chemical became known, they were able to rapidly determine which specific batches of final product were affected.
D) AAFCO statement:
A common source of confusion when shopping for pet foods is the AAFCO statement. Traditionally, it was assumed that any food approved by the AAFCO (American Association of Feed Control Officials - the federal pet food regulators), had proven itself nutritionally adequate.
There are in fact, two allowed AAFCO statements, depending upon how the food was tested. 1) The food be been shown to be adequate by using it in feeding trials according to the guidelines of the AAFCO; and 2) The the company has tested the food chemically and show that it matches nutritional profiles established by the AAFCO. The first statement proves that the food is adequate under laboratory feeding conditions (not ideal, but currently the best available method). The guidelines used in the second statement, only show that the chemical analysis of the food suggest that it is adequate. The second method says nothing about whether the ingredients used are compatible (certain supplements have been shown to cancel out other supplements - certain forms of calcium bind irreversibly to trace minerals leading to trace mineral deficiencies), edible/palatable (will pets eat it?), or digestible (the ingredients used may not be able to be utilized by the body). While feeding trial test are not perfect, we do find that foods which have been tested by the AAFCO feeding trial guidelines are much more likely to keep pets healthy than diets tested by chemical analysis.
It is important that we go even further.
Does the company of record manufacture the food them self, or do they subcontract? (as stated above, many "well respected" companies do not own a feed mill and subcontract all their foods out, usually by "low bid")
If they subcontract, do they select a subcontractor feed mill based upon reputation or based upon low bid? (again, as stated above, most food companies will subcontract a specific "minor" product line to an independent feed mill with a strong reputation for processing a specific type of food - as was the case with canned foods that contained "gravy" before the melamine/Menu recall a few years back).
Do they, or their subcontractor, test each raw ingredient for quality, content, and contamination? (recent episodes of salmonella infection, mold (aflotoxin) contamination, and E. coli contamination show that some pet food companies do not consider this an important step, nor learn from their mistakes).
Do they, or their subcontractor, test the end product for quality, content, and contamination?
One thing every pet food label is required to have, is a telephone number for the manufacturer of the food. Call the number on your pet's food bag and start asking questions. Also determine how helpful the Customer Service representative is, how friendly, knowledgeable, cooperative. The way the Customer Service department handles customer calls is a good indicator of the company as a whole.
E) Holistic, Organic, Natural and Vegetarian Diets:
Several companies have started marketing "natural" diets for pets. The implication is that these diets, being "natural" and therefore lower in processed ingredients and preservatives, makes them better/healthier for our pets. The majority of these foods are from small companies and have little or no nutritional research behind them. These diets may or may not be tested for nutrient level at the time of processing, or again at the labeled expiration date (if they have an expiration date). Since the "natural" food preservatives (primarily vitamins E or C) deteriorate rapidly, these foods are more prone to triggering illness in pets than the more traditionally "preserved" pet foods from mold, bacterial growth, or nutritional deficiency due to the break down of key ingredients.
"Vegetarian Diets" fall into this same category. Pets (and especially cats), by their nature, are carnivores. Their bodies are designed specifically to process meat protein and animal fat most efficiently. They are much poorer at processing plant carbohydrates, plant proteins, or plant fats than more omnivorous animals such as man. Some pets (especially dogs) may do adequately on a vegetarian diet for years, but this is more a tribute to the tolerance of the body than the quality of the food.
Natural and Vegetarian Diets, more than anything else, are examples of the extremes that food processors will go to in an attempt to appeal to the human psyche and emotion in an attempt to get a small corner of the tremendous pet food sales market.
Regarding "Organic", there was a time when the USDA was certifying pet food processing plants as "USDA Certified Organic", a few years ago, they discontinued this certification. Only a handful of companies successfully qualified for the USDA Certified Organic label when it was available (one notable one being "Newman's Own"). Many of the organic pet foods that I have examined lack any certification seal (meaning that there is no evidence that the processing plant or the ingredients have been examined by an independent organic certification group), making "Organic" a meaningless marketing term.
F) Treats and table scraps:
The best treats to feed any pet are treats that resemble the pet's diet as closely as possible. We recommend buying the treats where you buy the pet's food, and from the same manufacturer. Most of these treats have guidelines printed on the bag that tells how many treats equal how much of the food. Remember, treats are treats, and even if "balanced and complete" will be higher in fat and therefore calories, so breaking them up (make one treat serve for two to four rewards) is best. If using human food, remember: NO BONES (splintering bones kill pets), only cooked meat or cooked or raw vegetables. Many dogs love carrots, green beans and other vegetables, and you can save a lot of calories by using these lower calorie/higher fiber treats. Since fruits are higher in sugar, and therefore more likely to trigger other problems (including diabetes), they should be avoided. Also keep it SMALL: for meat or fatty treats - a piece about the size of a raisin is enough for all dogs.
Regarding other treats: NO HOOVES, avoid products sold from open bins in pet stores (other pets have probably slobbered on the treats/chews). For rawhides: select products manufactured within the USA, shipments from Taiwan, Mexico and China have been found to be contaminated with the chemical formaldehyde (a very toxic leather preservative), Salmonella, and endotoxic E. coli bacteria. With all rawhides, greenies, nylabones (which have been known to crack teeth), and similar chews, monitor your pet and take the item away if they start working very aggressively with it or if you must leave. Choking can be a major risk for most of these types of chews.
Pets that are fed a quality, name brand pet food appropriate for their age and size rarely need supplements.
While there are a lot of supplements on the market, both for pets, and for people, many have the potential to do more harm than good, for while supplements may be natural, even "holistic", they can still have pharmacological properties which affect the body, and may affect how other medications or supplements work. Still, there are a few that are worth special note, and may be worth considering. With all supplements, there is an aspect of "Buyer Beware" as there is little government regulation.
Omega 3 Fatty Acids (Fish Oils). Omega 3 fatty acids have weak anti-inflammatory properties which can be very helpful in dealing with chronic inflammatory diseases like arthritis, allergies (skin and sinus irritation), and some vascular diseases. Especially for large breed dogs, supplementing fish oil may help slow or delay arthritic changes.
Glucosamine, Chondroitin sulfate, MSM, Avocado and Soy extracts. This groups of supplements are all reported to slow arthritic changes and aid in the management of chronic arthritis. We have had good luck with the combination product Dasuquin.
SAMe and Milk Thistle. These two supplements work as anti-oxidants and may work to help improve the livers ability to handle toxins. A combination product, Denamarin, has also been found to help some pets with senile mental changes.
Duralactin. Another product that is reported to help minimize arthritic inflammation of the joints.
H) Raw food diets and home made diets:
There are literally hundreds of variations on homemade diets circulating around. A few seem to be ok, most are deficient in many vitamins, minerals, or micronutrients (we are quite fortunate that the body is such a resilient structure and has been designed well enough that most creatures (including people for that matter) can thrive on less than ideal nutrition. We should remember though that other individuals may have their body taxed in ways that are not obvious (genetics, parasites, "minor, internal" birth defects, etc), and the extra insult of a nutritional deficiency will be too much.) For this reason, even though some individuals seem to do well, even raise successful litters, eating these foods, we do not consider it worth the risk and can not recommend it. Balancing a diet for any animal is very complicated, doing it consistently is near impossible. If you can not be discouraged from feeding a home made diet, there are veterinary nutritionists who can look at the recipe, analyze the ingredient list and let you know where deficiencies are likely to occur. There is a fee for this analysis. In general, any homemade diet should have at least six separate ingredients, including a starch source (carbohydrate - potato, grains, flour, oats, corn, etc.), fiber source (oats, vegetables), a couple of different protein sources (meat, egg white, legumes - beans, peas, etc.), and a fat source (especially important if lean meat or game meat - venison, wild rabbit - is used for a protein source). A good multivitamin/mineral supplement must also be given.
Raw meat and egg based diets are very high risk. This variation on the home made pet food diet has been gaining support in the past few years based primarily upon the argument that it is more "natural" and closer to the diet of wild canines than our current commercial, processed pet food. While wild cats, dogs and wolves have survived for millions of years on "natural" diets, the life span of pets increased dramatically from the 1960's to present day as commercial pet foods have replaced most of the older feeding methods (which traditionally have included more "raw" products). Veterinarians across the country have also documented several illnesses in animals fed raw foods, including salmonellosis, tularemia, E.coli endotoxemia, intestinal blockages and tears from bones, chipped teeth and dental diseases, deaths have occurred. A high percentage of pets on these diets have become chronic carriers and shedders of these same infectious agents. Having a pet in the household that chronically sheds Salmonella, endotoxic E. coli, Leptospirosis, or Listeria increases the likelihood of other family members being exposed and becoming sick. There is also the risk of infection from handling the large quantities of raw meat and eggs while preparing the diets.
A few years ago a study was published in which veterinary nutritionist analyzed home made raw food diets over the course of a year (B.A.R.F. diets - Bones And Raw Food). These diets had been prepared by several of the leading proponents of this feeding method. Despite the bone content of these diets, when analyzed, none of the recipes showed an adequate calcium level and all were also deficient in many other minerals as well as vitamins (especially the B vitamin group).
If you would like further research into why to avoid raw food diets, consult the following: