Skin Nutritional - Pathology

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General

• Often combined deficiency which improves when animal is fed a balnced diet
• Sometimes caused by change in demand (pregnancy, growth, cold weather) or due to disease

Zinc Deficiency

• Mainly in dogs and pigs, sometimes ruminants
• In pigs:
  • Grossly:circumscribed reddened papules and plaques, thick crusting and scaling, fissures along ventral abdomen and medial thighs, sometimes generalised
  • Microscopically: parakeratosis, acantosis, pseudoepitheliomatous hyperplasia, hypergranulosis
  • Commonly secondary bacterial dermatitis
• In dogs:
  • Siberian huskies and Alaskan malamutes:
    • Grossly: scales and crusts around mouthm chin, eyes, joints, prepuse, scrotum, vulva
    • Microscopically: diffuse hyperkeratosis extending to follicles, superficial perivascular dermatitis with eosinophils
  • Rapidly growing puppies:
    • Grossly: scaly plaques on skin, nasal planum and foot pads
• In ruminants:
  • Grossly: alopecia, crusts and scales on face, neck and distal extremities and mucocutaneous junctions
  • Microscopically: parakeratosis, sometimes hyperkeratosis

Copper Deficiency

• Hair or wool depigmentation
  • Black sheep develop bands of lighter colouring
  • Cattle develop spectacle pattern of depigmentation around eyes)
  • Coat colour may change from black to reddish brown

Vitamin A Deficiency

• In dogs
• Grossly: generalised scaling
• Microscopically: marked follicular hyperkeratosis

Vitamin E Deficiency

• Steatitis may develop in cats fed excess fatty acids or with vitamin E deficincy
• Grossly: firm, yellow or orange nodules in subcutaneous tissue
• Microscopically: nodular to diffuse granulomatous panniculitis, macrophages and giant cells, oedema, fat necrosis, neutrophils and ceroid pigment