A campaign has been launched to boycott four leading medical charities accused of supporting "horrific" animal experiments.

Welfare group Animal Aid is urging members of the public to halt donations to Cancer Research UK, the British Heart Foundation, the Alzheimer's Society and Parkinson's UK.

The organisation has published a report, Victims of Charity, highlighting charity-funded tests that were said to cause "appalling suffering" to animals such as mice, monkeys, pigs and dogs. Examples included damaging the brains of monkeys with toxic chemicals, slowly destroying dogs' hearts, grafting cancer into animals and the use of diseased genetically engineered "mutants".

The campaign is backed by national newspaper adverts as well as postcards for members of the public to send to the charity chief executives with their comments. Animal Aid is calling on the public to withhold financial support from the four charities until they pledge to stop funding animal experiments.

Director Andrew Tyler said: "Animal Aid is under no illusions as to the pro-animal research lobby's significant financial and political clout. But the British public do not like the idea of animals enduring great suffering to no purpose, and Victims of Charity argues that this is precisely what is happening."

The report, written by a hospital doctor and a veterinary surgeon, is based on published accounts of experimental procedures and reviews in leading specialist journals. In total, 66 charities were identified that used public donations to fund animal research. However, the four named charities were singled out as organisations of "some standing and authority".

Dr David Scott, director of science funding at Cancer Research UK, responded: "In certain areas, research involving animals remains essential to understand, prevent and treat cancer. We do no research with monkeys, dogs or cats. We have strict ethical policies in relation to animals and follow rigorous Government guidelines to ensure that animals are only used where there's no alternative."

Jeremy Hughes, chief executive of the Alzheimer's Society, said: "The majority of our research programme does not involve animals and where there is no alternative we use maggots, fruit flies, mice and rats only. Our researchers are bound by animal welfare rules, which are the strictest in the world."

Peter Hollins, chief executive of the British Heart Foundation, said: "Our research has contributed to incredible medical advances over the decades. Many adults and children are only alive today thanks to pioneering treatments such as heart failure medicines, pacemakers and heart transplants which couldn't have been achieved without involving animals."

Dr Kieran Breen, director of research and development at Parkinson's UK, said: "Parkinson's UK invests around £4.6 million per year in a wide range of research projects looking at all aspects of Parkinson's because we are committed to finding better treatments and a cure. A small but vital part of our research involves animals and is rigorously controlled by UK legislation."