Acute renal failure as the cause of death in chickens following intravenous inoculation with avian influenza virus A/chicken/Alabama/7395/75 (H4N8).

One-day-old and 5-week-old commercial leghorn, specific-pathogen-free leghorn, and broiler chickens were inoculated intravenously with either avian influenza virus isolate A/chicken/Alabama/7395/75 (H4N8) (Ck/AL) or sterile diluent. Ck/AL infection resulted in a 44% mortality rate, reduced weight gains, and necrosis of proximal renal tubules and/or tubulointerstitial nephritis. The renal tubule necrosis was more severe and widespread in chickens that died than in chickens that were euthanatized. Hyperuricemia, hypercalcemia, and hyperphosphatemia were present in 5-week-old chickens at day 5 postinfection. Influenza virus isolate Ck/AL was nephropathogenic, and death was associated with acute severe renal damage and failure. Some data suggested that the pathogenicity of Ck/AL may be more severe in leghorns than broilers.