VN July 2023

Vetnews | Julie 2023 37 to the owner before commencing any treatment  Conservative treatment may give some short-term success, but the problem often recurs.  Salpingohysterectomy often gives good long- term results, although some birds will continue to ovulate and develop yolk-related peritonitis (see below). These birds require environmental, nutritional and hormonal manipulation to minimise ovulation. • Yolk-peritonitis o Aetiology  retropulsion of yolk from oviduct into abdomen, possibly associated with metritis/salpingitis, oviductal cystic hyperplasia or oviductal impaction, or with exuberant reverse peristalsis  failure of the infundibulum to ‘capture’ ovulating yolk - fat, trauma or disease o Clinical signs  usually seen in high-producing hens, especially cockatiels  It is usually sterile. If septic, signs are consistent with severe septicaemia  clinical signs are related to a fluid-producing inflammatory reaction in the coelom: • dyspnoea • abdominal distension • weakness  may stop laying, or may lay malformed eggs (elongated)  Secondary diseases may develop as a result of yolk peritonitis:  neurological signs due to yolk emboli – ‘yolk stroke’  pancreatic disease, including diabetes mellitus o Diagnosis  marked leucocytosis  hypercalcaemia may be seen in reproductively active hens  Abdominal ultrasound confirms fluid distension of the abdomen, rather than organomegaly. Caseous material (inspissated yolks) may be detected.  Abdominocentesis reveals yellow-pink fluid. Cytology shows mesothelial cells, leucocytes and pink yolk globules o Treatment  short-term therapy • abdominal drainage • NSAID’s • Antibiotics • Hormonal manipulation to stop ovarian activity o GnRH Agonist - Deslorelin (Suprelorin 4.7mg implant) o Leuprolide acetate o HCG  longer-term therapy • most cases will require surgery to lavage abdomen and perform salpingohysterectomy • This is not always successful in preventing ovulation. Ovariectomy may be feasible, but fraught with danger due to nature of the blood supply. • Egg binding (dystocia) o Predisposing factors  Age – very young and very old birds are more frequently affected  Malnutrition and obesity, particularly seen on all- seed diets  Excessive egg production, especially in cockatiels, budgerigars and backyard poultry  Lack of physical fitness in caged birds o Aetiology  Oviductal muscle dysfunction  Calcium deficiency  Myositis due to excessive egg production  Concurrent salpingitis or metritis  Excessively sized or malformed eggs  Systemic problems • Concurrent illness • Hypothermia • Environmental stress o Clinical signs  excessive straining  ‘penguin-like’ posture  dyspnoea  collapse  abdominal distension o Diagnosis  history of egg-laying  clinical signs (see above)  abdominal palpation usually reveals an egg, but soft-shelled eggs can be difficult to detect  abdominal radiography  abdominal ultrasound Technical I Article >>> 38