VMD 513: Pet animal Breeding, Management, Nutrition and Health Care (1+1)

RICKETS, OSTEOMALACIA AND GOITER

Rickets and Osteomalacia

• Rickets is a disease characterized by a failure of mineralization of osteoid matrix in young rowing birds. This disease is frequently seen in long legged birds.
• Etiology: deficiency of dietary calcium, deficiency of vitamin D and a severely unbalanced calcium and phosphorus ratio.
• Clinical signs: softening of the vertebrae, claws, and sternum which may develop as S shape.
• Ribs can curve inward and spinal column deformities can also be seen.
• Affected birds reluctant to perch, walk or move their wings.
• Birds frequently rest on their hocks and appear to be waiting for death.

Osteomalacia

• Osteomalacia is a disease of adult birds where as rickets is a disease of young, growing birds.
• The causes of Osteomalacia are the same as those of rickets.
• The disease is frequently associated with prolonged egg laying with an insufficient calcium supply in the diet. Another cause is the lack of grit in the food.
• Clinical signs: the bones become thin, soft, painful and fragile and can break spontaneously when a bird is handled.
• Affected bird may appear drowsy, feather picked and reluctant to perch, mover or fly. The female lay brittle eggs or egg production may cease.
• Treatment: treatment is possible if the bird is not severely affected.
• Treatment includes calcium and vitamin D supplements.
• For vitamin D – cod-liver oil can be placed on seed, addition of vitamin D added daily to drinking water or subcutaneous injection of 500 IU vitamin D / 30 g body weight.
• For calcium, calcium gluconate or lactate can be give orally.
• Treatment must be completed by improvement of the diet by adding oyster shell grit, fish and cooked vegetables.

Goiter

• Goiter: a deficiency of iodine in the diet can result in result in decreased secretion of hormone thyroxin.
• The affected birds are lethargic, inactive and exhibit poor condition like dry skin, regged plumage.
• They are unable to maintain body temperature when exposed to environmental change, their body cholesterol increases and body weight tends to increased due to the deposition of excess fat.
• Another major clinical signs are labored respiration with squeaking noise.
• Goiter can be treated successfully using either iodine or levothyroxine. Iodine can be given by injection to obtain rapid improvement or orally for mild cases.