Changes

*Sometimes caused by change in demand (pregnancy, growth, cold weather) or due to disease

*Sometimes caused by change in demand (pregnancy, growth, cold weather) or due to disease

===Zinc deficiency===

===[[Zinc Deficiency]]===

*Mainly in dogs and pigs, sometimes ruminants

*Mainly in dogs and pigs, sometimes ruminants

*'''In pigs''':

*'''In pigs''':

===Copper deficiency===

 

===[[Copper Deficiency]]===

*Hair or wool depigmentation

*Hair or wool depigmentation

**Black sheep develop bands of lighter colouring

**Black sheep develop bands of lighter colouring

**Coat colour may change from black to reddish brown

**Coat colour may change from black to reddish brown

===Vitamin A deficiency===

 

 

 

===[[Vitamin A Deficiency]]===

*In dogs

*In dogs

*Grossly: generalised scaling

*Grossly: generalised scaling

*Microscopically: marked follicular hyperkeratosis

*Microscopically: marked follicular hyperkeratosis

===Vitamin E deficiency===

 

 

 

===[[Vitamin E Deficiency]]===

*Steatitis may develop in cats fed excess fatty acids or with vitamin E deficincy

*Steatitis may develop in cats fed excess fatty acids or with vitamin E deficincy

*Grossly: firm, yellow or orange nodules in subcutaneous tissue

*Grossly: firm, yellow or orange nodules in subcutaneous tissue

*Microscopically: nodular to diffuse granulomatous panniculitis, macrophages and giant cells, oedema, fat necrosis, [[Neutrophils|neutrophils]] and ceroid pigment

*Microscopically: nodular to diffuse granulomatous panniculitis, macrophages and giant cells, oedema, fat necrosis, [[Neutrophils|neutrophils]] and ceroid pigment