Poultry Gout

Poultry Gout

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  GOUT Dr. Jeny KJohn Asst. Professor (Clinical Pathology) Sardar Vallabhbhai Patel University of Agriculture and technology, Meerut
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  Definition • It isa disorder of uric acid metabolism characterized by deposition of urate crystals in tissues • Due to increase in the concentration of uric acid in blood (hyperuricaemia) and body fluids • Mainly a disease of humans and birds
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  Types • Primary :basic cause is unknown or when the cause is an inborn metabolic abnormality • Secondary : Cause is known
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  Gout in poultry •Uric acid is produced in the liver and is the end product of nitrogen metabolism in birds • Therefore birds can develop gout following abnormal accumulation of urates • Its not a disease entity, but a clinical sign of renal dysfunction that causes hyperuricaemia
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  Manifestations of Goutin poultry • Visceral Gout: Deposition of urates in viscera • Articular Gout: Deposition of urates around joints
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  Pathogenesis • Birds areprone to gout because they are uricotelic (protein metabolism product is uric acid) • They lack the enzyme uricase, which convert uric acid into allantoin. • Uric acid is water insoluble. • Therefore any injury to kidneys interfere with elimination of uric acid and which then accumulates in blood and leads to visceral gout
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  Visceral Gout • Characterizedby precipitation of urates in the kidneys and on serous surfaces of the heart, liver, mesentery, airsacs or peritoneum • Synovial sheaths of tendons and joints and surface of muscles get involved and precipitation can occur within the liver, spleen and other organs- in severe case
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  Gross appearance • Depositionon serous membrane appears as white chalky coating
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  Microscopic appearance • Clustersof urate crystal appears as pale, elongated, needle shaped structures in tissue sections • Crystals are surrounded by an inflammatory reaction of macrophages, lymphocytes, fibroblasts and foreign body giant cells • Crystals not visible in paraffin sections only clefts in which urate was present can been seen
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  Causes • Dehydration dueto water deprivation • Vit A deficiency • Mycotoxins such as oosporein • Secondary to urolithiasis • Treatment with sodium bicarbonate • Visceral gout is only noticed in birds at the time of necropsy
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  Articular gout • Sporadicproblem of not much economic importance • Clinically characterized by leg shifting, lameness and inability to bend the toes • It is characterized by tophi • These are deposits of urates around joints particularly those of the feet • Joints are enlarged and feet appear deformed • White semi-fluid deposits of urates may be found within the joints Chronic cases: urate precipitates can be observed in the comb, wattles and trachea