IACUC Policy #5: Barbering in Rodents

  1. Personnel and Purpose
    1. This standard operating procedure is designed to be used by laboratory managers, animal caretakers, and researchers to manage and minimize barbering in laboratory mice.
  2. Explanation of Barbering
    1. Barbering is defined as abnormal whisker and fur plucking behavior commonly seen in mice. It has been thought to be associated with an expression of social dominance.
    2. The implications on the research results are still unknown, thus the overall consequences for the research and its validity are unknown. If barbering is widespread within a research group, consideration by the researcher as to the full effects on their results must be taken.
    3. Incidence and Risk Factors
      1. A female bias
      2. Onset during puberty
      3. Reproductive status and genetic background
        1. More likely in C57BL/6 and 129s derived strains
      4. Husbandry factors such as cage design, cage location, cage mate relationship, and the presence of other barbers
  3. Identification and Scoring Guidelines
    1. Common clinical signs:
      1. Hair loss around the whiskers, dorsal face (including the eyes), between the ears, the dorsal neck, back and rump.
      2. Self –barbering: Barbering to oneself which is commonly seen in mice housed separately. This tends to present as hair loss around the chest, genitals, and the inside and outside of the forearms.
      3. Infected wounds: Wounds can become infected if the biting damages the outer layers of the skin and allows bacteria to gain entry and form an infection. It is a potential cause of a condition called Ulcerative Dermatitis. See Policy #6: Managing Ulcerative Dermatitis in Rodents.
    2. Scoring Guidelines
      1. Mild -- the mice show some very mild hair loss around face and ears. It appears mainly as a thinner coat cover in these areas. The mouse shows normal behaviors in the cage. 
      2. Moderate – quite a lot of hair loss over head, neck, legs or thorax. In these patches, the skin is still intact and there is no evidence of infection.
      3. Severe- the hair loss has progressed, and the skin is broken through. The skin visible is red and shiny and may appear infected (moist with a discharge). The mouse may or may not be showing other signs of stress or discomfort such as anorexia, quiet behavior.
  4. Management
    1. Once barbering has been identified within a cage, a standard plan of action will be instigated by the researcher and animal caretakers.
      1. Identify the mouse that is performing the barbering. There is usually one unaffected mouse in the cage. Separate that mouse to a different cage.
      2. Closer monitoring – once daily inspection of wounds
      3. Increase the rotation of environmental stimulation
      4. If their condition deteriorates or are not viable for the project, they should be culled immediately.
      5. If the wounds begin to break through the skin and become infected, the affected mouse will be treated for its wounds. See Policy #6: Managing Ulcerative Dermatitis in Rodents.
  5. Documentation
    1. Cages with suspected barbering should be marked. Staff and the ACF Director should monitor the cage for any signs of Ulcerative Dermatitis (visit IACUC Policy #6: Managing Ulcerative Dermatitis in Rodents).
  6. Exceptions
    1. The Attending Veterinarian or designee may grant exceptions to this policy when it is deemed in the best interest of the animals.