twice per week. The temperature of the
animal housing room was set at 85˚
± 4˚ F with a humidity of at least 50%.
The light cycle was a 12-hour light/dark
cycle. Reverse osmosis water was used to
mist the cages twice daily to maintain
A novel caging system was created
using plastic feed bins ( 24”x16” 15”)
with a filter paper cover (Figure 1).
These bins provided depth and a solid
wall to prevent escape.
Enrichment devices such as huts, tunnels, and tubes were provided as components of the tunnel system and special
chambers (Figure 2). Food items, such as
corn with husk, provided another source
of enrichment. NMRs were observed
removing the husk and incorporating it
into their tunnels and chamber areas.
The NMRs were fed a low calcium diet
primarily consisting of sweet potatoes.
Fruits and vegetables were also provided to supplement this diet. Their daily
water intake was fulfilled from components of the diet.
Food was prepared and soaked in
water each morning at least five hours
prior to feeding. Animals were fed
once in the afternoon and any uneaten
food was discarded the following day.
A medium sized plastic container was
modified to serve as the food chamber.
It was hand washed daily and dried
prior to giving fresh food. Feed bins
and enrichment items were processed
through the tunnel washer to be disinfected before being used.
Aspen bedding was initially used as
the primary substrate with brown crinkle
paper added on to the cage. Roughly 3-4
inches of bedding was provided, this
depth allowed for burrowing. The crinkle paper was removed subsequent to
dermatological clinical changes and the
aspen bedding was ultimately replaced
with paper bedding.
Clinical issues requiring medical and
surgical intervention included an acute
onset of dermal inflammation and
scabbed lesions on the plantar surface
of the paws of the hind limbs in three
NMRs (Figure 3).
Differential diagnoses included trauma
secondary to fighting and/or abrasions
from the substrate material. The crinkle
paper substrate was removed and triple
antibiotic ointment (TAO) was applied to
Bone exposure of the distal aspect of
the tail was observed in a single NMR.
The animal was anesthetized with isoflu-rane for surgical intervention. Additional
trauma was observed on the 3rd and 4th
digits on the left hind paw with bone
exposure present on the 4th digit. The
animal was prepared for surgery and a
surgical plane of anesthesia was confirmed prior to surgical removal of the
exposed bone. Doses of buprenorphine
(0.03 mg) were administered subcutaneously for analgesia during the post-operative period. This animal was separated
to a smaller cage for post-operative
All animals were weighed at least
once weekly and weight loss was
observed in a single NMR. The NMR
was separated from the colony for close
monitoring of the appetite. Poor appetite
was observed following separation ultimately leading to the decision to eutha-nize via carbon dioxide asphyxiation.
M. pulmonis, P. pneumotropica-Heyl, P.
Ps. Aeruginosa, Salmonella Genus, S.
aureus, S. moniliformis, S. pneumonia,
Cryptosporidium, Entamoeba, Giardia,
Mite, P. mirabilis, Pinworm, and
Spironucleus muris, C. coli, and C. jejuni.
A per diem rate and standard operating procedure (SOP) for housing and
husbandry were created because this was
a new animal model for our facility. The
daily per diem rate was set at $2.20/cage
which is consistent with conventionally
housed rat cages at our facility.
Cages were changed biweekly with
the toilet area being spot changed Figure 3: Dermal Abrasions and Wounds
Figure 1: Modiified Feed Bin
Figure 2: Enclosure with Paper Substrate