A number of cattle have died this year as a result of poisoning from ingesting ragwort, Regional Veterinary Laboratories (RVLs) has confirmed.
Athlone RVL diagnosed “several cases of poisoning in cattle caused by ragwort”, with multiple deaths reported in affected herds.
This particular case was highlighted in the RVL’s report published in the Veterinary Ireland Journal.
One such case occurred in May, when a two-year-old heifer that presented with a history of being sick and agitated for two to three days, became “depressed-looking and developed tenesmus” (trying to force passing of faeces without needing to).
There was marked ascites, bowel oedema (a build-up of fluid in the body which causes the affected tissue to become swollen) and oedema of abomasal folds.
The carcase was pale, and the liver was pale and “difficult to cut”.
The damaged liver findings are consistent with pyrrolizidine alkaloid toxicity caused by ingestion of plants, such as ragwort, the RVL contended.
Poisoning due to ragwort consumption
In February, an 11-month-old Hereford weanling was submitted to Limerick from a dairy and calf-to-beef enterprise.
In total, 95 animals were in the affected group which was housed and fed on baled silage.
This was the fourth animal to die over a four-week period. The clinical signs reported were weakness, blindness, frothing from the mouth, and tenesmus.
On post-mortem examination, there was widespread oedema throughout the body with particularly severe oedema of the abomasal mucosa.
The liver was firm, pale, and shrunken.
No significant bacterial pathogens were isolated on culture. Histopathology (the diagnosis and study of diseases of the tissues) revealed lesions of diffuse fibrosis, bile duct proliferation and megalocytosis.
The findings were consistent with a chronic toxic hepatopathy, and pyrrolizidine alkaloid poisoning due to ragwort consumption was suspected to be the cause, the RVL detailed.
A review and change of the silage diet was recommended.