What can be the cause?

1. Use of additives in food:
- thickening agents
- hardening agents
- preservatives
- colouring agents, aromatic substances and flavourings

2. Use of high temperatures:
- unsaturated fats become saturated
- vitamins are neutralised
- enzymes are killed

3. Unsuitable ingredients or basic products:
- bone meal: may cause excessive intake of calcium
- melted fats: too many saturated and too few unsaturated fatty acids
- fish meal: has a disturbed amino-acids pattern (your dog is not a seadog)
- genetically modified corn
- soy: can be used, but only for 45% of proteins
- beet pulp: contains saponins.

Dogs don’t need these additives, but they are essential for preparing dry food.