This study evaluated the clinical, laboratory, ultrasonographic and pathological findings in 87 cows aged 2 to 10 years (4.5 ± 1.5 years) with type-4 abomasal ulcer.
The most common clinical findings were in decreasing order compromised health status accompanied by partial or complete anorexia (100%), abdominal guarding (81%), congested scleral vessels (77%), ruminal atony (73%), tachycardia (68%), tachypnoea (65%), positive foreign body tests (58%), decreased skin surface temperature (53%), fever (49%), reduction in negative intraabdominal pressure assessed transrectally (39%), poorly subdivided plant fragments in faeces (35%) and arched back (28%). The principal haematological abnormalities were hypokalaemia (72%), haemoconcentration (69%), azotaemia (56%), metabolic acidosis (49%), hyperfibrinogenaemia (45%), leukopenia (35%) and hypoproteinaemia (29%). Other abnormalities were aciduria (56%), haematuria (44%), increased chloride concentration in rumen fluid (34%) and abnormal peritoneal fluid (98%). Of 75 examined cows, 65 (87%) had ultrasonographic evidence of local or generalised peritonitis. On postmortem examination all cows had a type-4 abomasal ulcer and generalised peritonitis. In addition, 36 cows had type-1 ulcers, 6 had type-2 ulcers and one cow had a type-3 ulcer.
The clinical signs in cows with type-4 abomasal ulcer are associated with generalised peritonitis. An increased haematocrit, indicating shock-induced haemoconcentration is characteristic in contrast to cows with traumatic reticuloperitonitis. Ultrasonography is useful for visualising and assessing generalised peritonitis.
The diagnosis of type-4 abomasal ulcer based on clinical signs alone is difficult and therefore requires additional diagnostic procedures including the determination of the haematocrit and plasma protein concentration, abdominal ultrasonography and analysis of peritoneal fluid. In most cases, these steps lead to a correct diagnosis and allow timely euthanasia of the cow to prevent further suffering and unnecessary treatment costs.