When looking at the Guaranteed Analysis on a bag of pet food, you may notice a category labeled “ash.” While it may sound like something leftover from a fire, in pet food, ash refers to the total amount of inorganic minerals present in the food after combustion in a laboratory test. These minerals include calcium, phosphorus, magnesium, potassium, sodium, and trace elements essential for a pet’s health.
Why Is Ash in Pet Food?
Ash is a natural byproduct of processing animal-based ingredients, particularly bones, organs, and connective tissues, which are rich in minerals. Since pets need these minerals for bone health, muscle function, and overall well-being, ash content is not a harmful additive but rather an indication of mineral presence.
- Higher Ash Content: Typically found in meat meals and fish-based diets, as bones contribute more minerals.
- Lower Ash Content: More common in plant-based or low-protein formulas.
Is Ash Bad for Pets?
Ash itself is not harmful, but excessive levels of certain minerals (like magnesium and phosphorus) can contribute to urinary issues, particularly in cats. This is why many cat foods designed for urinary health aim for controlled ash and magnesium levels.
- Dogs & Ash: Less of a concern, but balanced mineral intake is still important for bone health and kidney function.
- Cats & Ash: High ash, particularly high magnesium, has been linked to urinary problems like struvite crystals in some cats. Look for foods labeled as low magnesium or formulated for urinary health if this is a concern.
What’s a Normal Ash Level in Pet Food?
- Dry Kibble: Typically 5-10% ash
- Wet Food: Usually 1-3% ash
- Raw & Freeze-Dried: Varies, but can be higher due to bone content
The Bottom Line
Ash in pet food is simply a measure of essential minerals, not a harmful filler. However, if a pet has urinary issues, checking the mineral content (especially magnesium and phosphorus) may be important. Rather than focusing solely on ash levels, pet owners should look at overall nutrient balance and ingredient quality when choosing the best food for their pet.