How to Choose Pet Food: Reading Labels and 5 Perspectives for Identifying the Right Food for Your Dog or Cat

Pet shops and online stores are lined with countless varieties of pet food, and terms like "additive-free," "grain-free," and "premium" are everywhere. However, what you really need to check is not the marketing jargon, but the information on the package and the actual condition of your dog or cat.

In this article, based on documents from the Ministry of the Environment and the Ministry of Agriculture, Forestry and Fisheries, as well as the guidelines of veterinary organizations such as the World Small Animal Veterinary Association (WSAVA), we will organize the perspectives you need to stop feeling overwhelmed when choosing food.

First, Know the "Nutritional Differences Between Dogs and Cats"

As a prerequisite for choosing food, dogs and cats have different nutritional requirements.

Cats are carnivores and require more protein than dogs. Additionally, cats are unable to produce enough of a nutrient called taurine in their bodies, so they must obtain it from their diet. Documents from the Ministry of the Environment explain that a lack of taurine can lead to eye and heart diseases.

Why shouldn't you keep feeding cat food to dogs or dog food to cats? Because dog food is designed to meet the specific requirements of dogs, it may lack the protein or taurine that cats need. If you have multiple pets, try to set up feeding areas so that each pet can eat their own food.

Perspective 1: Check if it is a "Complete and Balanced" Food

Pet food has a defined "purpose" on the label.

Label Purpose	Meaning	Classification
Complete and Balanced	Food adjusted to provide all necessary nutrients for maintaining health when given with fresh water	Daily main meal
Snacks (Treats)	For communication or rewards	Limit quantity
Other purposes	Specific nutrient supplementation or to improve palatability (General food, side dishes, etc.)	Use in combination with a main meal

For daily main meals, the basic rule is to choose products labeled as "Complete and Balanced." Even if a canned food looks delicious, if it is labeled as "general food" or "side dish," it may not provide enough nutrients on its own.

Perspective 2: How to Read Package Labels

In Japan, the Pet Food Safety Act mandates that dog and cat food labels include the following five items:

• Name (clearly distinguishing whether it is for dogs or cats)
• List of ingredients
• Expiration date
• Name and address of the business
• Country of origin

Furthermore, industry voluntary rules (Fair Competition Code for Pet Food Labeling) also specify the inclusion of the purpose, net weight, feeding method, and nutritional components.

Ingredients are listed in "descending order"

In principle, ingredients are listed in descending order by weight. Checking the first few items tells you the main components of the food. However, you cannot judge quality by the list of ingredients alone. What is important is whether the combination of ingredients results in a balanced nutritional profile.

Nutritional components are "minimum" and "maximum" values

These are displayed as "Crude protein: X% or more," "Crude fat: X% or more," "Crude fiber: X% or less," and "Moisture: X% or less." The term "crude" indicates that the values are approximate due to the nature of the analytical method.

Why can't you simply compare the values of dry food and wet food? Because wet food has a high moisture content of around 70–80%, the protein percentage appears lower. To compare them correctly, consider the values on a dry matter basis (excluding moisture) or contact the manufacturer.

Feeding amounts are only a "guide"

The feeding amounts on the package are guidelines based on standard weight and activity levels. Since required calories vary depending on whether the pet is spayed/neutered, their activity level, and their age, you should use these as a reference while adjusting based on their physical condition.

Perspective 3: Match the Life Stage and Physical Condition

The required energy and nutritional balance differ between growth stages (puppies/kittens), adulthood, and senior stages. Check the label for terms like "All Life Stages," "Adult," or "7+ Years."

However, age is just one guide. Even at 10 years old, an active pet and a sedentary one have different requirements. Use the Body Condition Score (BCS), which evaluates physical condition based on weight changes and how easily you can feel the ribs or see a waistline, as a reference.

If you are using "therapeutic food" for an illness or chronic condition, this must be given under the diagnosis and guidance of a veterinarian. Do not start or stop these foods based on your own judgment; consult your veterinarian.

Dry Food or Wet Food: Which to Choose?

Both have their advantages; there is no single "right" answer.

Type	Moisture	Main Characteristics
Dry	Approx. 10% or less	Easy to store and measure. More cost-effective
Wet	Approx. 70–80%	Allows intake of moisture with food. Often more aromatic and palatable

Why is wet food sometimes recommended for cats? Because cats are believed to have ancestors from arid regions and tend not to drink much water, so getting moisture from food is beneficial. Using dry food as a staple and adding wet food is also a good option depending on your lifestyle. In such cases, adjust the amounts of each so the total calorie intake is not too high.

Perspective 4: Don't Be Swayed by Trendy Terms

"Grain-Free"

There is no sufficient scientific evidence that avoiding grains is superior for all dogs and cats. The U.S. Food and Drug Administration (FDA) investigated the link between grain-free diets high in legumes and canine dilated cardiomyopathy (a type of heart disease), and as of 2022, while it stated that a causal relationship has not been confirmed, it noted that it is a complex issue involving multiple factors. If a food allergy is suspected, it is important to identify the specific causative ingredient, so please consult your veterinarian.

"Additive-free" and "Human-grade"

What "additive-free" means varies by manufacturer—it depends on what is not added. Additives like antioxidants also play a role in maintaining food quality. Do not just look at the term; check what it specifically refers to.

Raw Food (Raw Diet)

The American Veterinary Medical Association (AVMA) does not recommend diets that include raw, uncooked meat, as they pose a risk of infection from bacteria such as Salmonella to both the pet and the family. If you choose to use one, we recommend consulting your veterinarian regarding hygiene management.

Perspective 5: Check Manufacturer Transparency

WSAVA lists the following points to check with a manufacturer when choosing food:

• Does an expert in animal nutrition play a role in designing the food?
• Who designs the nutritional profile and based on what criteria (e.g., are feeding trials conducted)?
• What are their quality control methods?
• Can they provide detailed information on nutrients and calories?

Manufacturers who provide specific answers to these questions on their official websites or through customer service are likely proactive in disclosing information.

Tips for Switching Food

Changing food abruptly can put a strain on the digestive system, such as causing loose stools. In general, it is common to take about a week to 10 days to gradually increase the ratio of the new food while mixing it with the old.

During the transition, observe the following:

• Palatability and speed of eating
• Condition and frequency of stools
• Whether vomiting occurs
• Condition of skin and coat (changes may take several weeks)

If vomiting or diarrhea persists, or the pet seems lethargic, stop the transition and consult a veterinary clinic.

Storage is Part of "How You Choose"

Once opened, dry food begins to oxidize and degrade due to air, moisture, and high temperatures.

• After opening, seal the bag tightly and store in an airtight container
• Avoid direct sunlight and hot, humid places
• Choose a size that can be consumed within about a month

Even if a large bag is more economical, if it takes a long time to finish, smaller bags or pre-portioned packs make it easier to maintain quality.

Summary: Food Choice Requires Both "Labels" and "Observation"

• Choose a "Complete and Balanced" food as your main meal
• Distinguish between dog and cat food and match the life stage
• Ingredients are listed in descending order; nutrients are listed as minimum/maximum values
• Focus on nutritional balance and manufacturer transparency rather than trendy words
• Switch foods gradually over 1 to 2 weeks, checking weight and stool

There is no single "perfect food." Confirm the basics on the label and find what works for your pet by observing their body condition, stool, coat luster, and energy levels. When you are lost or worried about their condition, the best path is to consult your regular veterinarian.

Frequently Asked Questions

Q. Is more expensive food better? A. Price is determined by various factors like ingredients, manufacturing methods, and branding, so you cannot judge the nutritional quality by price alone. It is realistic to check the "Complete and Balanced" label, the life stage, and manufacturer transparency, then choose from within a price range you can sustain.

Q. Is it okay to raise my pet on only homemade food? A. It is difficult to balance nutrients in homemade food, and it is prone to deficiencies like calcium. If you want to use it as a main meal, it is safe to have the recipe checked by a veterinarian or pet nutrition expert.

Q. Will they get bored if they keep eating the same food? A. If it is a "Complete and Balanced" food, there are generally no nutritional problems with continuing the same diet. If they seem to stop eating it, check to see if there is any hidden change in their health condition.