On the shelf, there are three products side by side that look similar: they are all dry, all have a long shelf life, and all claim a high meat content. What sets them apart is the dehydration method, which determines how much of the original raw material actually remains.
Below you will find a comparison of three technologies, practical differences in serving and storage, and what to look out for so you don't buy marketing instead of ingredients.
Three methods of preserving pet food: what determines nutritional value?
All technologies serve the same purpose: removing water, because it is what allows microorganisms to grow. The difference lies in how aggressively this is done.
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Freeze-drying freezes the raw material and then removes water from it in a vacuum, bypassing the liquid state. The entire dehydration stage takes place at a low temperature, so the material is not subjected to heat.
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Drying evaporates water with warm air at a moderate temperature, with some of the heat reaching the inside of the raw material pieces.
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Extrusion processes ingredients at temperatures reaching up to 150 to 200 degrees Celsius under high pressure and forms them into granules.
The higher the temperature and the longer it acts, the greater the loss of vitamins, heat-sensitive amino acids, and natural flavor compounds. This is the only sensible axis for comparing these three groups of products.
What is freeze-drying of pet food?
Freeze-drying, also called sublimation drying, takes place in three steps. First, the raw material is frozen, causing the water to turn into ice. Then the pressure is lowered, and the ice sublimates, meaning it turns directly into water vapor, bypassing the liquid phase. Finally, the remaining bound moisture is removed.
The result is a product that retains the original cellular structure, natural taste and aroma, and the shape of the raw material. Freeze-drying removes water but does not break down the tissue, which is why a piece of meat after dehydration still looks like meat, not like a compressed cube.
However, it is worth cooling down one of the most frequently repeated slogans here. Claims about retaining 98 or nearly 100 percent of nutritional value are a marketing simplification. Losses are clearly smaller than with drying and extrusion, but not zero: some oxygen-sensitive vitamins oxidize despite the lack of heat, and long storage in an unsealed package exacerbates this process.
Dried fruit and freeze-dried fruit: the simplest example of the difference
The easiest way to understand the difference is with an example known from your own kitchen. Dried fruits are dark, wrinkled, sticky, and clearly sweeter than fresh ones because the evaporation of water has concentrated the sugars, and the heat has changed the color and structure.
Freeze-dried fruits look completely different: they retain their color, shape, and volume, are light and crispy, and dissolve in the mouth, releasing a taste similar to fresh fruit. The same principle applies to vegetables and meat. A piece subjected to traditional drying is hard and shrunken, while a freeze-dried one retains its original form and, after being soaked in water, returns to a consistency similar to the original.
The pet food drying process: air drying and baking
The process of drying dog food is carried out in two ways today, and the course of the drying process determines how much of the raw material remains. Air drying with warm air takes place at a lower temperature than extrusion, so the food retains more nutrients and has a soft, dense consistency. Baking takes place at a higher temperature, providing crunchiness and intensifying the taste, but at the cost of greater losses.
Dried foods are a reasonable compromise between price and quality and are often the best choice for many owners. However, the quality of the ingredients is determined by the raw material, not the technology itself. They do not match freeze-dried products in terms of retaining natural nutrients, but they perform better than typical granules, especially when they have a high proportion of animal raw material.
Dry extruded food: how many nutrients does it lose at high temperatures?
Extrusion is the cheapest and most efficient method, which is why most foods available on the market are made this way. High pressure and temperature gelatinize starch, which increases its digestibility, but at the same time degrades B vitamins and lowers the availability of some amino acids, primarily lysine.
For this reason, vitamins and minerals in extruded foods are added after the process in the form of premixes. This is not a flaw in itself, because complete food must meet the animal's needs regardless of technological losses. However, it is worth knowing that the label declaration describes the product after supplementation, not the natural content of the raw material.
There are also reports of acrylamide formation in high-carbohydrate products subjected to high temperatures. It has been detected in some of the tested foods, but the scale of the phenomenon has not been clearly established. Substances formed at high temperatures are the subject of research, but their clinical significance for dogs remains unconfirmed, so this should not be treated as a certainty.
Comparison of three technologies in terms of nutritional value and digestibility
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Criterion |
Freeze-dried food |
Dried food |
Dry extruded food |
|---|---|---|---|
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Process temperature |
No high temperature |
Moderate |
Very high |
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Water content in the product |
Below 5 percent |
About 10 to 14 percent |
Maximum 14 percent |
|
Vitamin losses |
Lowest |
Moderate |
Highest, supplemented with premix |
|
Retention of raw material structure |
Full |
Partial |
None, formed granules |
|
Natural taste and aroma |
Retained |
Partially retained |
Requires flavor enhancement |
|
Share of animal ingredients |
Usually very high |
Varied |
Varied, often low |
|
Cost of a daily portion |
Highest |
Medium |
Lowest |
The digestibility of freeze-dried foods and good dried foods is usually higher than that of granules, but this is primarily due to the meat content and the lack of cheap fillers, not the technology itself.
Do enzymes in food support a dog's digestive system?
This claim appears in descriptions of raw and freeze-dried foods very often and requires correction. Enzymes present in the raw material will not survive the acidic environment of a dog's stomach, and those that do survive are digested like any other protein. There is no evidence that natural enzymes from food support an animal's digestion.
The real advantages of freeze-dried products lie elsewhere: in the high proportion of animal raw material, the lack of high-temperature processing, and the fact that the ingredients can be read in their entirety. These are sufficient arguments, and they do not need to be supported by a mechanism that does not work.
What is the best food for a dog?
There is no single food that is best for all animals because they differ in their needs, tolerance, and health situation. Several things count at once when choosing food.
Age, activity level, and health status of the dog
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A puppy needs food with high caloric density and controlled levels of calcium and phosphorus, and puppy food differs from recipes for adult dogs.
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An adult dog primarily needs a portion adjusted to its lifestyle, because it is the activity level that determines energy requirements.
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Older dogs usually require lower caloric density while maintaining a supply of easily digestible protein.
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Dogs with food allergies need a short ingredient list and a single source of protein.
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Dogs with sensitive digestion tolerate products with a simple recipe and lower carbohydrate content better.
Protein is a condition for proper muscle function and supports the immune system, and its minimum content for an adult dog is, according to FEDIAF guidelines, about 18 percent in dry matter. This is the lower limit, not a goal: high-meat foods exceed it many times over.
When choosing food: what to look for on the label?
Regardless of the technology, pay attention to the same things: a named source of meat at the beginning of the ingredient list, no artificial colors or flavor enhancers, natural antioxidants instead of chemical preservatives, and clear information on whether the food is complete and forms the basis of a balanced dog diet. Fresh meat in a declaration refers to the weight before dehydration, so the percentage from the label should always be read together with the water content in the finished product. Entries about wholeprey proportions, in turn, mean a recipe that replicates the share of meat, offal, and bones in the body of prey.
When to choose dry food and when to choose wet food?
The question of choosing between dry and wet food comes up more often than the question about technology because it concerns daily practice.
The advantages of dry food are the convenience of dosing, long storage life, and lower cost per daily portion. At the same time, it is repeated that dry food takes care of oral hygiene. The effect exists, but it is limited: typical granules crumble upon first contact with the tooth, and real prevention remains brushing. Dental health therefore depends on hygiene procedures, not on the form of food in the bowl.
Advantages of wet food and its limitations
Wet food contains 70 to 85 percent water, while in dry food the water content usually does not exceed 14 percent. This difference translates into hydration, which is important for dogs that drink little, and into the volume of the portion: to provide the same energy, a dog must eat several times more wet food.
Limitations are the short shelf life after opening and the need for cold storage. Serving a larger amount of wet food also requires recalculating the portion. Wet food can be combined with dry food, provided that both are complete and the total caloric content fits within the daily requirement. For some dogs, it works better to serve them in separate meals because the transit time of both forms can be different.
Dog food that combines both forms: freeze-dried food after rehydration
Freeze-dried food escapes this division. In the package, it is a dry, light, and durable product, and after being soaked in warm water, it becomes a moist, aromatic meal. Both freeze-drying and subsequent rehydration leave the composition unchanged, and the owner decides on the consistency.
For your dog, this means one thing: moist food without a can and without a refrigerator, regardless of the time of year. Rehydration increases the amount of water taken in with food and strengthens the smell, which can be decisive for picky eaters and older dogs with a weakened sense of smell. A meal served in this way is easier to offer to a pet that has lost interest in dry food.
Dr Malou freeze-dried foods are created using this very technology, and the base food contains over 90 percent human-grade meat and offal. It is worth mentioning an issue that is sometimes overlooked with freeze-dried products: sublimation itself is not a sterilization method. Microbiological safety is ensured here by a combination of a vacuum process with computer-controlled thermal processing and two-stage veterinary control of each batch.
Storage and serving: how to ensure a long storage period?
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Freeze-dried and dried food keep in a tightly closed package, in a dry and cool place, without access to light, because moisture from the air is the most dangerous for them.
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Extruded food store in the original bag placed in a container to limit fat oxidation.
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Serve freeze-dried food dry or after soaking in warm, but not hot, water, having waited a few minutes.
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Introduce new food over 7 to 10 days, mixing it with the previous one so that the digestive system has time to adapt.
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Daily requirement determine according to the dosage table, because dehydrated products have a completely different energy density than wet ones.
It is also worth calculating the cost differently than the price of the package suggests. The measure is the cost of a daily portion, and concentrated products are served in smaller quantities than granules with a high proportion of carbohydrates.
How to recognize that food is not serving the dog's health?
The best test is the dog itself, observed for several weeks after changing the diet. Signals that should catch your attention:
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Digestive problems: loose or very voluminous stools, gas, recurring diarrhea.
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Skin symptoms: itching, redness, dandruff, excessive hair loss.
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Deterioration of the coat: dull coat instead of a shiny coat, brittle claws.
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Drop in energy: apathy and reluctance to engage in activities that were not there before.
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Recurring infections: especially of the ears, which often go hand in hand with food intolerance.
Symptoms lasting longer than a few weeks require consultation because they may have a basis other than nutritional.
Feeding a dog with freeze-dried, dried, and dry food: frequently asked questions
How does freeze-drying differ from traditional drying?
Freeze-drying removes water from frozen raw material in a vacuum, without the use of high temperature, and drying evaporates it with warm air. The first process preserves the structure, color, and aroma of the raw material, the second changes them significantly and causes greater vitamin losses.
Is every type of freeze-dried food complete?
It depends on the product. Freeze-drying is a preservation method, not a recipe, so both complete foods and treats that constitute complementary food are created using this technology. Information about this is on the package, and that is what you need to check before buying.
Does freeze-dried food need to be soaked?
It does not have to be, but it is worth it. Served dry, it is a crunchy meal, and after rehydration, it provides additional water and smells stronger. When serving dry, the dog must have constant access to fresh water.
Is dried food the same as a freeze-dried product?
No. Both are dry and both have a long shelf life, but they differ in process temperature and the degree of raw material preservation. The names are sometimes used interchangeably in commercial descriptions, so it is worth checking which method the manufacturer states directly.
For which dogs is freeze-dried food a good solution?
It works well for picky dogs, for animals with food allergies requiring a short ingredient list, for active dogs needing concentrated energy, and when traveling, where weight and the lack of need for refrigeration count.
Can freeze-dried food be combined with extruded food in the diet of pets?
It can, and it is a popular solution: freeze-dried food then acts as an additive that increases the taste qualities and nutritional value of the meal. However, you must subtract its caloric content from the portion of the base food so as not to exceed the daily requirement of your four-legged friend.
