CVMA | Collecting Physical Evidence

Collecting Physical Evidence

  1. Prioritize collection of evidence. Items of evidence most likely to be destroyed by time, other people, or environmental conditions should be collected first.
  2. Avoid contaminating the evidence by wearing a cap, gown, mask, gloves, etc., as necessary.
  3. Assess and record the mental status and behaviour of the animal.
  4. Take photographs and/or video before and during the examination.
  5. Properly identify the animal(s) on the medical record and avoid guessing the animal’s breed or age if uncertain. See Medical Records
  6. Perform a complete physical examination, including body scoring
    • Do not simply focus on the chief complaint or obvious abnormalities.
    • Consider using standard forms to ensure that the physical examination is completely recorded.
    • Carefully examine the coat, mouth, and paws for evidence of chemicals, fiber, or other materials.
      • These areas may contain DNA from the perpetrator.
      • Look for evidence on the animal. For example, dirt from the paws or bits of leaves that cling to the fur may harbour traces of grease, oil, turpentine or other chemicals. These samples can yield critical information about the sheltering of the animal or home remedies the owner may have tried, or supportive evidence that an animal was deliberately set on fire.
      • Bits of paint on the animal's fur that match the paint of a car that allegedly hit the animal may be a critical piece of information.
    • Look for any evidence on the animal that may explain the condition or injury. For a detailed discussion, see The Veterinarian's Role in Handling Animal Abuse Cases : Veterinary Forensics : Making the Case - Proving Cruelty Through Forensics
    • Forensic entomology can assist in establishing the time of death or the age of injuries that contain maggots.
    • In the case of deceased animals, every attempt should be made to determine the exact cause of death during the post mortem.
  7. Perform CBC, chemistry panel, fecal, and urinalysis.
    • Neglected animals have a higher incidence of parasitism, anemia and hypoproteinemia.
  8. Take whole body radiographs.
    • Look for fractures in different stages of healing. In the attached slide, the two top and left bottom photos show old healed fractures (evident callus formation), while the bottom right photo shows recent fractures.
    • Key areas to examine are the head, ribs and extremities.
  9. Record the initial weight and subsequent weights on a regular or weekly basis. See weight change form and take photographs to document weight gain.
  10. Record daily updates even if there are no changes in the animal's condition. Any changes should be carefully described no matter how minor they may appear.
  11. Properly label and record evidence.
    • The animal and everything associated with the animal is evidence and must be saved, documented, tagged and secured, including the leash and collar.
    • Marking evidence means recording the following information. An evidence log is helpful.
      • Time seized
      • From whom
      • Detailed description of property
      • Manner packaged
      • Time tagged and deposited
      • Location deposited
    • Label the exhibit (or the package within which the exhibit has been placed) with the investigator’s initials, employee number (if applicable), and the date of the seizure.
      • Use a stylus to mark metallic objects. Place the mark in a discreet place.
      • Use a pen to mark absorbent articles, such as clothing or documents.
      • If an item is too small to be marked directly on its surface, place the item in a container (pill box or plastic vial), then seal and mark the container.
      • Never mark an item where evidentiary traces may exist.
      • For a set of similar objects, place the identification mark in the same general area on each object.
      • If the item has removable parts, mark each major part.
  12. Ensure that all evidence collected is accounted for at all times. See Chain of Custody and evidence log form.

For more information, see