Changes

Puppies fed a phenylalanine deficient diet experience decreased food intake and weight loss<ref name ="Milner"/>. Adults dogs fed inadequate phelylalanine and tyrosine levels in the diet develop a reddening of the haircoat<ref name="Biourge"/>.  

Puppies fed a phenylalanine deficient diet experience decreased food intake and weight loss<ref name ="Milner"/>. Adults dogs fed inadequate phelylalanine and tyrosine levels in the diet develop a reddening of the haircoat<ref name="Biourge"/>.  

====Cats:====  

====Cats:====  

Feeding a phenylalanine deficient diet to kittens results in weight loss, while no change in weight gain is seen when tyrosine is deficient but adequate phenylalanine levels are present.10 Kittens fed adequate phenylalanine for growth, but suboptimal amounts for melanin production develop reddening of the haircoat<ref name="Yu"/>, which can progress to ataxia, vocalizing, ptylism, hyperactivity, and abnormal tail posture (tail held bent forward) if continued for more than 6 months<ref name="Anderson"/>.

Feeding a phenylalanine deficient diet to kittens results in weight loss, while no change in weight gain is seen when tyrosine is deficient but adequate phenylalanine levels are present<ref>Rogers QR and Morris JG. Essentiality of amino acids for the growing kitten. J Nutr 1979;109:718-723.</ref>. Kittens fed adequate phenylalanine for growth, but suboptimal amounts for melanin production develop reddening of the haircoat<ref name="Yu"/>, which can progress to ataxia, vocalizing, ptylism, hyperactivity, and abnormal tail posture (tail held bent forward) if continued for more than 6 months<ref name="Anderson"/>.

==5. Toxicity==

==5. Toxicity==