RCSI Experiments Exposed

RCSI Experiments Exposed

Royal College of Surgeons Ireland evaded EU animal welfare rules with lethal experiments on chinchillas at American University



A Freedom of Information investigation by the Irish Anti-Vivisection Society (IAVS) has uncovered horrific chinchilla experiments on an estimated 23 chinchillas commissioned by the Royal College of Surgeons Ireland (RCSI). Our exposé has gained national media coverage in the Irish Mirror.

The vivisection project, which broke animal welfare rules on multiple occasions, was intended to test a potential new treatment for chronic ear drum perforation (Tympanic Membrane Perforation (TMP)). The procedures, which took place in the spring and summer of 2021, were performed in the USA at the Medical College of Wisconsin (MCW) in Milwaukee.

Unlike Ireland and the EU, the USA has no independent government regulation of animal experimentation so there are no legal limits on animal cruelty. The IAVS is calling on the government to investigate the conduct of the RCSI and to initiate the drafting of legislation prohibiting the offshoring of animal testing or research to countries with weaker regulations.


The documents obtained by the IAVS include:
  1. Observation records of the animals during the experiments  [1]
  2. MCW’s internal notification form detailing what was supposed to happen in the experiments, including measures to control pain and suffering [2] 
  3. The Request for Tender document issued by RCSI [3]
  4. MCW’s completed tender form approved by RCSI [4]
  5. The RCSI’s own guidance for animal experimentation [5]

Key findings:

  • Two female chinchillas, 1252F and 1264F, died during the initial ABR test, probably due to mistakes in anaesthesia.
  • In addition to the suffering caused by the ear drum perforation, many of the chinchillas suffered serious ear and eye infections due to the repeated surgeries, to the extent that the pain and distress caused head tilt in the animals. For example, on 30 June chinchilla 1259M was observed in a harrowing state: head tilt, right ear discharge, right eye closed with discharge, left ear whitish fluid; later that day he was noted to have an abscess in his right eye, expressing purulent material with moderate to severe ulceration, before being put down.
  • Most of the creatures endured severe and prolonged pain, with eight out of 15 experiments persisting beyond the point where the animal was supposed to have been euthanised. For example, a female called 1268F was even found dead with rigour mortis, in contravention of both the RCSI’s own guidelines, that claim that animals should have 24hr supervision, and MCW’s own application which claimed staff would be on hand to provide out-of-hours care. She was also one of several animals who were not put down as required when they had lost 20% of their original bodyweight. Despite having breached that limit on 26 May, there were no further observations for three days until she was found dead on 29 May.
  • The suffering repeatedly broke the internal rules set out by the MCW researchers. It also meant that the RCSI broke their own rules which say any animal research conducted outside the EU should still meet the requirements of Ireland/EU, which legally require animals to be euthanised once their suffering reaches a pre-determined level (known as a ‘humane endpoint’).
  • The Tender specifically required the laboratory to be experienced in this particular type of experiment. However, the documents reveal that MCW sacrificed an additional six chinchillas not specified in the tender in order to train in the surgical techniques that they were already supposed to be proficient in. [6] Indeed, MCW own internal approval form reveals that they saw part of the purpose of the project as to develop the model of chronic TMP, further undermining their claims to have pre-existing expertise.
  • The predicted failure rate for the surgery was a very high 30%, indicating the severity and difficulty of the vivisection procedures. Therefore the tender initially required 15 animals to achieve 10 results. It is unlikely that such a set of experiments would be permitted in Ireland or the EU with such a high failure rate.
  • The reality was significantly worse: MCW killed a minimum of 17 chinchillas in the actual experiments, two more than the tender’s estimate of 15, but only achieved a maximum of seven completed tests. In other words, the failure rate was actually 59%, double the predicted rate. In total, 23 animals had pain and suffering inflicted upon them for the sake of a failed study.
  • The RCSI had claimed in a response to the IAVS FoI request: ‘Therefore, the study was performed in an international centre of excellence which has extensive experience in refining this model over many years and ensuring that the minimum number of animals are used.’ [7]
  • One recent scientific review of animal models of ear drum perforation [8] states: ‘recent reviews of the literature still call for a reliable, clinically relevant model’, implying that that the chinchilla model is unreliable and not clinically-relevant. One basic problem is that artificially-induced perforations in animals are not the same as those occurring spontaneously in humans, thus they tend to heal up with the size of the perforation variable at 8 weeks which is the point at which experimental treatments are supposed to be tested.
  • One of the animals, 1251M, was given the experimental treatment just 5 weeks and 2 days after they had been inflicted with the ear drum perforation, in clear breach of the project protocol which required an 8 week wait.

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Summary of what happened to the animals

Chinchilla 1250M was allowed to deteriorate until he was noted to be ‘very lethargic, anorexic, left eye infected (purulent discharge)’. He should have been put down when he had lost 20% of his original bodyweight, i.e. 516g. But he was not euthanised until he reached just 468g – the failure to adhere to the specified endpoint would be considered a serious illegal breach of licence in Ireland.

1254M also had to be put down before the end of the experiment. He appears to have suffered infection as the notes state ‘Necropsy performed… Will recommend antibiotics for all animals on study’. This comment indicates that the study did not adhere to the initial protocol which required ‘All are given antibiotic via drinking water to prevent infection.’ He had also exhibited head tilt and was observed: ‘The animal was depressed, with a hunched appearance. Increased respiratory depth/rate were noted. The animal’s body condition was decreased.’ The necropsy revealed necrosis of tissues in the liver and kidneys.

1255M also died prematurely, mostly likely due to an overall deterioration in health shown by severe weight loss. The particular technician responsible for him does not bother going into much detail and no notes were made for four days before his killing despite his poor health as evidence by the administration of fluids.

1256M was another failed experiment that continued for at least 4 or 5 days after he should have been put out his misery. 1257M and 1258M both suffered ear infections: 1257M was observed with head tilt and ‘spinning around cage’, while 1258M had ‘ongoing white discharge from right ear’.

1259M was one of those who suffered most. The vivisection procedures caused him to suffer head tilt, discharge from the his squinting right eye and right ear infection. On 23 June 2021 his weight had already dropped to 545g, considerably below the 20% weight loss that should have triggered euthanasia. By 30 June his symptoms were harrowing: head tilt, right ear discharge, right eye closed with discharge, left ear whitish fluid; later that day he was noted to have a abscess in his right eye, expressing purulent material with moderate to severe ulceration, before being put down. Certainly he was one animal to have suffered particularly severely because of the failure of the lab to stick to the prescribed endpoint.

1260M was another chinchilla to endure infection and discharge in his left eye and ear, as well as head tilt and a temporarily reduced appetite. 1261M also suffered left ear infection with fluid and ‘red-inflamed middle ear membrane’. 1263F experienced rapid weight loss and only made it to the end because the researchers ignored the endpoint again when she had lost more than 20% of her original bodyweight.

1265F started to lose weight immediately she arrived at the lab, plummeting from 595g on 6 May down to 537g by the 15 May. Despite being clearly ill, she was still subjected to the ear drum perforation and damaging interferences. By the 6 August her weight had dropped to just 388g, indicating she had probably gone at least a week since passing the supposed endpoint of 20% weight loss (i.e. 476g). the notes here are from the same technician as for 1255M, with very little in the way of clinical observations, indicating a degree of indifference to her pain and distress.

1266F was another chinchilla to suffer ear infection with pus needing to be sucked out of her left ear. Later in the experiment she was observed to be lethargic with reduced water and food consumption leading to dehydration and anorexia. Her weight on arrival was 742g so she should have been euthanised once she and decreased beyond 593g. However by the time she was given her final auditory brain stem response test and killed on 26 August she was just 551g, yet another breach of the welfare endpoint.

1267F went through rapid weight loss, arriving at 684g and already down to 646g on the day of ear drum perforation on 15 May. By 2 June she was already at 505g, below the 20% endpoint requiring euthanasia. Yet she was made to continue on; on 30 June she was squinting in both eyes, circling movements due to an infected inner ear lesion caused by the surgeries, with a possible eye infection.




[1] See ‘Animal Records…’ document
[2] See ‘Animal Welfare Procedures…’ document
[3] See ‘Service Request_Chinchilla Study_Tympanic Membrane’ document
[4] See Documents ‘FINAL – Appendix I – REDACTED’, ‘FINAL – Appendix 2’, ‘FINAL – Appendix 3’ and ‘FINAL – Appendix 4 REDACTED
[5] See ‘RCSI Guidance for Pre-clinical Research’ document
[6] MCW claimed: ‘our laboratory has significant experience in using this animal model and has pioneered many of the techniques and tools that have improved the suitability of this animal model’ ‘Animal Welfare Procedures’ document, Section E, 2.0)
[7] See Letter from RCSI to IAVS dated 27/01/23
[8] Langstom et al. (2020), ‘Animal Model of Chronic Tympanic Membrane Perforation’, The Anatomical Record: 303: 619-625
[9] See point 3 in document ‘Response to FOI Internal Review March 23