Endpoints for Animal Research Projects That Have the Potential
To Cause Severe or Chronic Pain or Distress

In addition to monitoring animals for signs of overall health and presence of pain, consideration must be given to when animals should be euthanized. Criteria for euthanasia of moribund (near-death) animals should be established in advance of the study. Identification of moribund animals in especially imporant in long-term studies in which neoplasia may be a common finding.

Animals should be euthanized before tumors reach a size that would cause undue pain or distress. This practice helps eliminate death as an end point in the experiment, minimizes pain and distress, and ensures that tissues collected for pathologic assessment are not autolytic and are free of the secondary complications of tissue stress or shock.

Moribund animals and animals scheduled for interim or final necroprsies should be euthanized by personnel trained in methods and techniques established by the American Veterinary Medical Association Panel on Euthanasia. Signs that indicate a moribund condition are listed below.

Selected Criteria for Euthansia of Moribund Animals:

  • Rapid Weight Loss (15-20% within a few days
  • Extended period of weight loss (progessing to emaciated state)
  • Spreading areas of alopecia caused by disease
  • Rough coat, hunched posture, distended abdomen, or lethargy, especially if debilitating or prolonged (3 days)
  • Diarrhea, especially if debilitating or prolonged (3 days)
  • Coughing, rales, wheezing and nasal discharge
  • Distinct icterus and/or anemia
  • Rapid growth of mass or masses or clinical signs of neoplasia
  • Central nervous sytem signs such as head tilt, tremors, spasticity, seizures, circling, or paralysis or paresis, especially if associated with anorexia
  • Frank bleeding from any orifice
  • Persistent self-induced trauma
  • Lesions interfering with eating or drinking
  • Clinical signs of suspected infectious disease requiring necropsy for diagnosis

Updated May 31, 2007 by SAK