Figure 1: Bite wound to the scrotum of an 11.5-month-old male rat
Case history and photos
Three male rats (presumed brothers) named Widget, Cricket and Snip
were living in the same cage. One of the rats, Widget, repeatedly
harassed the other two. Widget had bitten Snip twice in the past: at
age 4.5 months he had bitten Snip on the rump, and at age 7 months he
had bitten Snip on the side of the belly. Both wounds had healed
When the rats were 11.5 months old they got into a fight (I heard
sounds of shrieks and crashes). Upon inspection, one of the rats,
Cricket, had a one inch long gaping gash running nearly the length of
his scrotum on the right side. The edges of the wound were straight
and there was little bleeding.
I cleaned the wound and separated Cricket from the others, placing
him alone in an aquarium lined with clean paper towels for the night,
and took him to the vet the next day.
The vet said that the bite had sliced through several layers of skin
but had not gone down to the testicle. The healing process had
already started: the lips of the wound were stuck to the layers
beneath in a semi-gaping position, and new skin cells were already
making their way across the exposed layers of tissue.
The vet said there were two options: stitch the wound shut, or leave
it alone and let it heal as it was.
If the wound were sewed shut, the vet would have to disrupt the
healing process that had already started. The vet would unstick the
skin from the layers below, and trim the lips of the wound to give
them a clean, fresh edge so they could heal together.
If there wound were left alone, the healing process would continue
undisrupted. Cricket would be left with a smooth, hairless scar.
The vet advised against the stitches, because the wound was already
healing nicely. Also, the vet said that scrotal skin is so sensitive
that Cricket might pick at stitches, making the wound worse. The vet
recommended leaving the wound alone, keeping Cricket in a clean cage
for the duration of the healing process on bedding that would not
contaminate the wound (such as paper towels), and putting him on
I took the vet’s advice. Cricket was kept in a 10 gallon aquarium for
two weeks on paper towels, changed several times a day. He received
0.2mL of Trimeth/Sulpha liquid suspension twice per day, orally, for
The vet also recommended separating and possibly neutering the rat
who had inflicted the bite.
Cricket’s wound healed uneventfully. There was no infection and
Cricket did not worry the wound. New skin covered the wound, leaving
an oval-shaped, smooth, hairless scar. Cricket was returned to the
main cage without incident.
While Cricket was healing in the aquarium, Widget bit Snip on the
knee, and in self-defense Snip bit Widget on the face, a shallow bite
just below the eye. After this incident I permanently removed Widget
from the main cage and housed him separately. Both bites healed
There have been no more bite wounds from the time of Widget’s separation.
Photo 1: Bite wound to scrotum on day 3.
Photo 2: Bite wound to scrotum on day 18 shows healing.
Case history and photos courtesy of
Anne Hanson, M.S., Ph.D. Animal Behavior
Posted on June 21, 2004, 16:03,
Last updated on April 8, 2010, 17:34