Humane endpoints

A broad definition of Humane endpoint is a concept for continuous refinement of animal studies (Hendriksen et al., 2010).

This broad definition is aligned with the 3R principles (Balls et al., 1995, Russell and Burch, 1959).

Continuous improvements or refinement is embedded in the directive 2010/63 (European Commission, 2010)

• Article 4.3 Member States shall ensure refinement of breeding, accommodation and care, and of methods used in procedures, eliminating or reducing to the minimum any possible pain, suffering, distress or lasting harm to the animals.

Refinement of study specific endpoints and alternatives to death/moribund as endpoint

	Focus of the Study	Proposed Endpoint	Reference
INFECTIONS, IMMUNE SYSTEM	Infectious diseases	Acute phase responses	Olfert, E.D. and D.L. Godson, Humane endpoints for infectious disease animal models. ILAR J, 2000. 41(2): p. 99-104.
		Body Temperature	Olfert, E.D. and D.L. Godson, Humane endpoints for infectious disease animal models. ILAR J, 2000. 41(2): p. 99-104.
		Weight loss	Olfert, E.D. and D.L. Godson, Humane endpoints for infectious disease animal models. ILAR J, 2000. 41(2): p. 99-104.
	Shock by cecal ligations and puncture (CLP)	Observation of Loss of ability to ambulate. Body weight and temperature	Nemzek, J. A., Xiao, H. Y., Minard, A. E., BOLGOS, G. L. & REMICK, D. G. 2004. Humane endpoints in shock research. Shock, 21, 17-25.
	Rheumatoid arthritis in rodents	Swollen digits, knuckle, midfoot and ancle/wrist scoring, Ulceration, gait and posture analysis	Hawkins, P., et al., Applying refinement to the use of mice and rats in rheumatoid arthritis research. Inflammopharmacology, 2015. 23(4): p. 131-50.
CANCER
	Early Cancer detection	Ultrasound	Wang, L. V. (2003). Ultrasound-mediated biophotonic imaging: a review of acousto-optical tomography and photo-acoustic tomography. Disease Markers, 19(2-3), 123–138. https://doi.org/10.1155/2004/478079
	Intracranial Glioma in rat	Body weight algorithm	Helgers, S.O.A., et al., Body weight algorithm predicts humane endpoint in an intracranial rat glioma model. Sci Rep, 2020. 10(1): p. 9020.
	Severe irradiations studies in NHP	Rapid decrease of body temperature for 3 consecutive days combined with general behaviour score	Bertho, J.M., et al., Humane endpoints in severe irradiation experiments using non-human primates: a retrospective analysis. Scandinavian Journal of Laboratory Animal Science, 2020. 46(1): p. 1-15
	Total-Body Irradiation in Mouse	Body weight, temperature by telemetry	Koch, A., et al., Establishment of Early Endpoints in Mouse Total-Body Irradiation Model. PLoS One, 2016. 11(8): p. e0161079.
	Colon cancer in rats	black feces or presence of fresh blood	Kobaek-Larsen, Morten, Fenger, Claus, & Ritskes-Hoitinga, Jelmera. (2004). Secondary effects induced by the colon carcinogen azoxymethane in BDIX rats. APMIS : Acta Pathologica, Microbiologica et Immunologica Scandinavica, 112(6), 319–329. https://doi.org/10.1111/j.1600-0463.2004.apm1120601.x
	Experimental liver metastases	Laparoscopy	Kobaek-Larsen, M., et al., Laparoscopy of rats with experimental liver metastases: a method to assess new humane endpoints. Lab Anim, 2004. 38(2): p. 162-8.
CNS
	Amyotrophic Lateral Sclerosis (ALS)	Decline in motoric Function	Mead, R.J., et al., Optimised and rapid pre-clinical screening in the SOD1(G93A) transgenic mouse model of amyotrophic lateral sclerosis (ALS). PLoS One, 2011. 6(8): p. e23244.
		Home cage running wheel	Bennett, E.J., et al., Early detection of motor dysfunction in the SOD1G93A mouse model of Amyotrophic Lateral Sclerosis (ALS) using home cage running wheels. PLoS One, 2014. 9(9): p. e107918.
TOX testing
	Alternatives to LD 50	Hypotermiadose50 (HD50) replaces LD50	Soothill, J. S., Morton, D. B. & Ahmad, A. 1992. The HID50 (hypothermia-inducing dose 50): an alternative to the LD50 for measurement of bacterial virulence. Int J Exp Pathol, 73, 95-8.
SURGERY
	Post laparotomy	Telemetric recording of heart rate	Arras, M., et al., Assessment of post-laparotomy pain in laboratory mice by telemetric recording of heart rate and heart rate variability. BMC Vet Res, 2007. 3: p. 16.
Other organ systems
	Murine model for cholestasis	Burrowing activity	Zhang, X., et al., A rational approach of early humane endpoint determination in a murine model for cholestasis. ALTEX, 2020. 37(2): p. 197-207.
	Anti-urolithiasis activity of test compounds by zinc disc implantation	Imaging (X-ray radiographs) of the bladder deposits	Singh, P.K., et al., Zinc disc implantation model of urinary bladder calculi and humane endpoints. Lab Anim, 2010. 44(3): p. 226-30.