Diet plays a fundamental role in your cat's health. A well-fed cat is a cat that feels good in its paws. But be careful, not all cat food is equal. Some can have consequences on the health of your whiskered one. Here are 5 reasons to change your cat's food.
1/ Your cat's dry food are too high in carbs
Risks for Cats: Overweight – Obesity – Diabetes
Did you know? Unlike many mammals, cats do not require carbohydrates. Our whiskered companions can synthesize glucose from amino acids provided by animal proteins. These amino acids are released during the digestion of proteins in their gastrointestinal tract. This process is known as gluconeogenesis.
Moreover, their bodies are not adapted to digest, absorb, and metabolize large quantities of carbohydrates. A food that is too high in carbohydrates may even harm their health. It has been suggested (2017 study) that a diet too rich in carbohydrates could increase insulin secretion demand, thus predisposing cats to the development of diabetes mellitus. It also promotes overweight and obesity in your cat.
Many kibble products, whether sold in supermarkets or specialized stores, unfortunately contain a lot of carbohydrates.
A carbohydrate-free kibble unfortunately doesn’t exist, since carbohydrates are naturally found in animal proteins and vegetables. More importantly, to produce kibble, starch is necessary — a carbohydrate stored by plants in granules which, when crushed, form a paste. This paste acts as a kind of glue that allows kibble to hold together and have a crispy and airy texture. To date, no manufacturer has found an alternative to eliminate starch.
What you should look for is kibble with the lowest possible carbohydrate content, especially if your cat is fed exclusively with dry food. If your whiskered friend eats a mixed diet (wet food and kibble) or mainly wet food, the carbohydrate content becomes less critical. At Ziggy, for example, our wet food contains less than 3% carbohydrates on a dry matter basis.
According to a study by Hewson-Hughes (2011), the maximum carbohydrate intake tolerated by cats is around 20 g/day, or 40% of the daily ration (estimated at about 50 g of kibble on average).
How can I find out the carbs content of my Dry Food?
Manufacturers are not required to indicate the carbohydrate content of their kibble. If it is not listed, you can calculate it yourself by adding up all the analytical constituents and subtracting the total from 100.
Example:
For kibble showing 37% crude protein, 13% crude fat, 7% crude ash, 4% crude fiber, and 10% moisture:
37 + 13 + 7 + 4 + 10 = 71
100 - 71 = 29
These kibbles contain about 29% carbohydrates, which is a bit too much. While this level is not alarming, for your cat's health, it is best to choose kibble with the lowest carbohydrate content possible, especially if your cat is fed exclusively dry food.
At Ziggy, all our kibble is low in carbohydrates:
Our adult sterilized cat food, chicken and salmon formulas, contain only 24% and 23% carbohydrates, respectively. Concerning our kitten food, it contains just 18% carbohydrates.
2/ His dry food contain too much phosphorus
The Risks of a Diet Too High in Phosphorus
Weakened kidneys
Phosphorus is a macromineral essential to your cat’s health. It plays a key role in growth, cellular differentiation, energy metabolism, fatty acid transport, and the synthesis of amino acids and proteins. As explained in our article on senior cat nutrition, phosphorus also works in synergy with another macromineral: calcium. Without phosphorus, calcium cannot be properly absorbed by your cat’s body.
Although essential, phosphorus should not be present in excessive amounts in your cat's diet. Several studies, including those by Böswald (2018) and Dobenecker (2018), have shown that foods too rich in digestible phosphorus can negatively affect kidney function in cats.
Just like urea, phosphorus is eliminated by the kidneys. The more phosphorus your cat consumes, the harder the kidneys must work to eliminate it.
Phosphorus is found in cereals and meat, but it is especially concentrated in bone and fish skeletons— ingredients often used in large quantities in low-quality kibble. We explain this further in our chapter dedicated to proteins.
How can you tell if your cat's dry food is too high in phosphorus?
The Calcium-to-Phosphorus Ratio: A Key Indicator
While the phosphorus level is important, what you really need to look at on your bag of kibble is the calcium-to-phosphorus ratio, expressed as Ca/P. For a healthy cat with no kidney issues, the ideal ratio should be between 1 and 2. For cats with kidney disease, the recommended ratio is between 2 and 3.
If the ratio is not listed, you can calculate it yourself by dividing the calcium content by the phosphorus content.
And if the phosphorus content is not disclosed at all, here’s a tip: walk away. If the manufacturer hides this information, it’s probably because they have something to hide. And when something is hidden, there’s usually a good reason to be concerned…
3/ Its kibble contains poor quality proteins
Risks for Cats: Weakened kidneys, Nutritional deficiencies, Flatulence, Diarrhea, Dull coat, Bad breath
Many manufacturers use reconstituted meat (a blend of animal and plant proteins), meat meal, or mechanically separated meat (MSM) to produce food for our cats.
In case you didn’t know, MSM is a product “obtained by mechanically removing meat from bones or poultry carcasses.” After deboning, it may still contain bone fragments, cartilage, or marrow. Hardly a meal to purr about.
Like starch, MSM is nearly unavoidable in kibble production, but not all MSM is of equal quality. In premium kibble, you’ll find a higher proportion of animal proteins, while low-end kibble contains more bone residues, especially minerals. And as we’ve seen earlier, too many minerals—particularly phosphorus—can harm your cat’s kidneys and may lead to chronic kidney disease in the long term.
Carcass-based ingredients also contribute to collagen intake, a protein rich in hydroxyproline. This amino acid can increase urinary oxalate excretion.
These proteins are also poorly digestible. When they reach the large intestine, they undergo putrefaction and may cause gas or diarrhea. If your cat is passing a lot of gas, it’s likely due to low-quality food. The same goes for bad breath—difficult digestion can lead to inflammation of the stomach and intestines.
Lastly, proteins are crucial for the health of your cat’s skin and coat. They supply essential amino acids such as methionine and isoleucine. A deficiency in methionine can lead to hair loss, slower growth, and a dull coat. This sulfur-containing amino acid is found in eggs, fish, and meat. Isoleucine is abundant in animal tissues, especially muscle (beef, lamb, and poultry)—sources often lacking in low-quality kibble!
To reduce production costs, many manufacturers also use plant proteins, mainly from grains and legume seeds like peas and soy. Unlike animal proteins, plant proteins do not provide all essential amino acids, particularly taurine and arginine. They fail to meet your cat’s nutritional needs and may lead to deficiencies.
How can I check the quality of the proteins used in kibbles?
Useful Indicators on Your Cat Food Label:
- The Protein-to-Phosphorus Ratio (PPR)
A high-quality protein is one that effectively provides essential amino acids. In feline nutrition, the Protein-to-Phosphorus Ratio (PPR) helps evaluate the quality of the protein sources used in the food.
High-value proteins—those with a high biological value (i.e., the percentage of protein retained by the body)—have a high PPR, generally above 35. These include fish, meat, eggs, and organ meats.
Low-Quality Protein Sources and Other Key Indicators
On the other hand, low-quality protein sources (with low biological value) have a low Protein-to-Phosphorus Ratio (PPR)—below 25. This is the case for grains, carcasses, and bones. Since phosphorus is a mineral primarily found in bones, a low PPR suggests that a significant amount of bone or carcass material has been added to the kibble.
To calculate it, simply divide the crude protein percentage by the phosphorus percentage.
- Phosphorus content:
On its own, this value lets you know whether the kibble contains bone residues or fish bones.
- Crude ash content:
This is an indirect quality indicator. It represents the total amount of minerals in your cat’s kibble after complete combustion.
A high ash content often indicates that carcass material has been added.
⚠️ Note: A diet rich in ash can lead to white, hard stools, and even constipation in cats!
To learn more, feel free to read our detailed article on proteins in feline nutrition—we explain everything!
4/ Dry food doesn't cover his protein needs
Risks for Cats: Lack of energy, Constant hunger, Weight loss or weight gain
For a cat to stay healthy, it must consume a sufficient amount of animal protein.
Taking into account various factors like neutering and age, the daily protein requirement for an adult cat is estimated at 5.2 to 6 grams of protein per kilogram of optimal body weight, in order to maintain lean body mass (Dr. Laflamme, 2013).
However, your cat’s kibble may not meet these needs. On the label, look for the Protein-to-Calorie Ratio (PCR). This indicates how concentrated the kibble is in protein relative to its calorie content.
For adult cats, the ideal PCR should be:
- Over 75 g/mCal for an active, intact cat
- Over 87 g/mCal for a neutered or sedentary cat
- Over 100 g/mCal for a neutered and sedentary cat
If it’s not listed on the packaging, you can calculate it as follows:
% of crude protein / Metabolizable Energy (ME) x 1000
Example (Ziggy salmon kibble):
Crude protein: 44%
Metabolizable Energy (ME): 377 kcal/100 g
Calculation:
44 / 377 x 1000 = 116.7 g/mCal
So pay close attention to the PCR of your cat’s kibble. But keep in mind: a high PCR does not guarantee the quality of the protein.
5/ Its dry food are low in essential fatty acids
Consequences for Cats: Dull, thin coat – Excessive hair loss
Essential fatty acids, such as Omega-3 and Omega-6, are crucial for your cat. They play a key role in maintaining healthy skin and a shiny coat.
As we explain in our article on feline fur, there are two main types of Omega-6 fatty acids: linoleic acid and arachidonic acid.
- Linoleic acid is part of the composition of ceramides, which are naturally occurring skin lipids. These ceramides help maintain skin hydration by forming a protective barrier that prevents water loss. If there's a deficiency, linoleic acid is replaced by oleic acid (found in olive oil), which is less effective. The result: your cat’s fur loses its shine and becomes rough.
- Arachidonic acid supports the production of prostaglandin E3, a compound that stimulates epidermal cell renewal. Without arachidonic acid, the skin thins and becomes fragile. Your cat may start to shed excessively, and their coat becomes very fine and sparse.
If your cat’s coat is dull or patchy, their kibble might lack sufficient essential fatty acids (Omega-3 and 6), or it may only contain oleic acid, which is not enough.
Which oils are best?
Canola (rapeseed) oil and soybean oil are among the best options, as they contain a high and well-balanced content of Omega-6 and Omega-3 fatty acids.
In Summary: What are the best kibbles for your cat?
To keep your feline friend healthy, choose kibble that is:
- Rich in high-quality animal protein
- Low in carbohydrates
- High in essential fatty acids
- Low in phosphorus
And for kittens? Visit our blog to discover 4 essential criteria for choosing the best kitten food.
5 reasons to choose Ziggy Dry Food for your cat
Here, at Ziggy, our priority is to make every cat happy and we feed them with the very best for their health.
Our Dry Food for adult sterilized cats and kittens is:
- Low in carbohydrates
Our adult sterilized cat kibble with chicken and salmon contains only 24% and 23% carbohydrates, respectively. Our kitten kibble contains just 18% carbohydrates.
- Low in phosphorus
Our chicken kibble for sterilized adult cats has a Protein-to-Phosphorus Ratio (PPR) of 57, the salmon version scores 58, and the kitten formula reaches a PPR of 50.
- Rich in high-quality animal protein
Our kibble contains 44% quality protein with excellent digestibility—meaning smooth digestion, fresh breath, silky fur, healthy kidneys, and top physical condition.
- Adapted to your cat’s energy needs
Our salmon and chicken formulas have a Protein-to-Calorie Ratio (PCR) of 116.7 g/mCal and 114.97 g/mCal, respectively—perfect for maintaining your cat’s lean mass.
- Full of good fatty acids for a healthy coat
Our kibble is rich in Omega-3 and Omega-6 fatty acids, helping your cat maintain a shiny, healthy coat all year round.
A guide to choose the right Dry Food for your cat
Want to learn more about your whiskered friend’s food?
We’ve put together a complete guide to help you read and understand cat food packaging.
We explain everything you need to know so you can choose the best kibble and/or wet food for your cat. (Translated in French only)
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