Two federal commissions have called for tighter regulations on primate experimentation, including a total ban on tests involving great apes.
But the Federal Institute of Technology in Zurich, where testing on small marmoset monkeys triggered off the commissions' report, rejected the findings as subjective.
The Swiss Ethics Committee on Non-human Biotechnology and the Swiss Committee on Animal Experiments this week published a report calling for "extreme caution" when approving experiments on primates owing to their "special" cognitive faculties.
These include being able to plan ahead, to act strategically, to mourn and to possess self-awareness.
The report recommended a total ban on experiments involving great apes (gorillas, chimpanzees, bonobos, orang-utans and humans) and said tests on other primates should proceed "only if justified by an adequate evaluation of interests".
Thousands of primates – all species related to monkeys, apes and lemurs – are used in scientific experiments around the world every year because of their psychological and physiological similarity to humans.
Under the current Swiss law on animal protection, whether experiments on animals are permissible must be decided by cantonal authorities on a case-by-case basis using an "evaluation of interests" – the estimated medical benefits versus the interest of animals in remaining stress free.
In the experiment that sparked the committees' report, scientists in Zurich separated baby marmosets, small New World monkeys, from their mothers randomly during their first month. The babies duly got "extremely stressed" during every intervention.
The aim of the project, which ended in February 2006, was to gain a better understanding of the causes and mechanisms of depression, which affects 340 million people, according to the World Health Organization.
The majority of both committees agreed that this deprivation and its consequences were "very severe" and that, no matter what human interests were involved, such experiments were ethically unacceptable.
All members (apart from four abstentions) questioned the relevance of the marmoset model to provide any meaningful findings for research into depression, a highly complex condition.
A majority of both committees regarded any evaluation of interests as ethically non-permissible for experiments involving great apes but permissible for other primates, subject to an interdisciplinary review.
A minority took the view that an evaluation of interests should not be allowed for all primates.
"I'm not satisfied at all," Norma Schenkel, a zoologist and member of the Committee on Animal Experiments, told swissinfo. "It's no use banning testing on great apes if there are no trials [involving them]."
Currently there are no experiments on great apes in Switzerland.
"It would make much more sense if [the committees] had been braver and banned clinical research on [all] primates when [serious] suffering is involved," she added.
In addition, the report recommended that a study be conducted to see whether the cantonal authorities responsible for handing out licences for tests possessed the required expertise.
It also said no institutions involved in funding research – such as the Swiss National Science Foundation – should authorise any primate experiments without requesting an ethical evaluation.
The Federal Institute of Technology in Zurich rejected the report, however.
Hans Sigg, animal welfare representative at the institute and Zurich University, warned of the dangers of relying on an "improperly conducted" ethical evaluation based on one experiment.
"The committees didn't use the input of a single primatologist," he told the institute's online newspaper. "What's more, not a single committee member saw the separation experiment for themselves."
"Because the committees opted not to use correct procedures for acquiring the basics, the entire assessment must be rejected as subjective," he concluded.
swissinfo, Thomas Stephens
The Swiss Committee on Animal Experiments is appointed by the government to advise the Federal Veterinary Office on anything to do with animal experiments.
It also advises cantons on animal-testing principles and intervenes in disputes.
The Swiss Ethics Committee on Non-human Biotechnology advises the government and authorities on legislation and enforcement from an ethical point of view.
It can also independently address topics of ethical relevance and submit recommendations on future legislation to the government.
According to the Federal Veterinary Office, in 2004 424 primates were used for experiments in Switzerland.
In 2004 497,786 animals were used in tests (up 4.7 per cent on 2003) – 440,000 of them were rats and mice.
There is no animal testing for cosmetic products in Switzerland.
The Swiss National Science Foundation has a budget of around SFr400 million ($330 million) and is currently financing 11 experiments with apes in Switzerland, amounting to SFr1.04 million.
Public spending on research and development in Switzerland totals around SFr3 billion.