Introduction
Some coronaviruses involved in this condition are considered to be bovine coronaviruses (or closely related thereto); others are avian coronaviruses closely related to infectious bronchitis virus. The infection is seen in turkeys and sometimes pheasants. Morbidity is close to 100% and mortality is 5-100%. Transmission is lateral with birds and faeces, with rapid spread. The course of the disease is about 2 weeks and birds then remain carriers for months. The viruses survive in frozen faeces for months.
Signs
- Anorexia.
- Depression.
- Frothy diarrhoea.
- Subnormal body temperature.
- Darkening of the head.
- Loss of weight.
- Huddling.
Post-mortem lesions
- Dehydration.
- Emaciation.
- Enteritis with petechial haemorrhages.
- Froth ingesta.
- Sometimes casts.
- Pancreas chalky.
- Urates in kidneys/ureters.
Diagnosis
Reproduction with filtered contents, isolation in turkey eggs, electron microscopy, immuno-fluorescence, Elisa. Commercial M4I IB Elisa will detect some infections.
Treatment
Warmth and good management, antibiotics, milk replacer, potassium chloride. Disinfect and rest houses for 3-4 weeks.
Prevention
All-in/all-out production, good hygiene and biosecurity, good management.