Preservatives range from safe, natural substances such as tocopherol (vitamin E) and ascorbic acid (vitamin C) to highly toxic chemicals such as ethoxyquin, butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA).
Food dyes and colorings like tartrazine, preservatives like benzoates, BHT and BHA, flavor enhancers like monosodium glutamate (MSG), and sweeteners like aspartame have also been suspected asthma triggers.
For example, tertiary butylhydroquinone (TBHQ), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) show evidence of carcinogenic activity in animal trials.
Avoid foods with the preservatives ethoxyquin, butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA), which are highly toxic.
BHA (Butylated hydroxyanisole) and BHT (Butylated hydroxytoluene), two other preservatives, aren't used in Timberwolf pet foods.