Dehorning leads to chronic pain in calves

A study by the Vetsuisse Faculty of the University of Bern investigated the development of acute and chronic pain following dehorning in calves.

The now-published study shows that despite optimal anaesthesia and pain management, both acute and chronic pain and hypersensitivity can develop in calves.

Dehorning is an invasive procedure applied worldwide to newborn calves up to eight weeks of age. The horn buds are cauterised using a so-called thermocautery device. In humans, such wounds can cause long-term sensory deficits and chronic pain.

«Several studies have already shown that dehorning triggers behavioural and hormonal changes in calves that indicate acute pain,» explains study lead Claudia Spadavecchia.

The Methodology

The study was conducted on 34 male calves. On the day of dehorning, all calves were sedated and analgesics were administered both locally and systemically. Only a portion of the calves were actually dehorned; the remainder underwent sham dehorning in order to distinguish the effect of dehorning itself from the handling and pain treatment.

Chronic hypersensitivity in 38% of dehorned calves

38% of the dehorned calves developed chronic trigeminal hypersensitivity. Pain scores were significantly higher in the dehorned calves compared to the sham-dehorned calves throughout the entire study period up to the age of 105 days.

«We conclude from this that the consequences of dehorning can extend far beyond the acute phase. Individual animals may be affected by chronic trigeminal pain regardless of age and pain management», says Spadavecchia. More on animal rights.