Grade C
Procedures which cause marked anxiety, fear, pain or distress where any suffering caused is ended by euthanasia or by therapeutic or other interventions before it becomes excessive or where the suffering is short-lived and complete recovery can occur. Experiments which cause moderate anxiety, fear, pain or distress for long periods.

For instance: recovery from major surgery done under general anaesthetic but without the use of pain killer after the operation (e.g. reference animals used in studies to test how well particular pain killers work after surgery done under anaesthetic); marked social or environmental deprivation; capture, handling, restraint or housing, without the use of tranquillisers, of wild or semi-domesticated animals that exhibit marked flight responses.

Severe suffering or noxiousness. Procedures require strong justification.