1. Examining The Dental Health of Declining
Muskox and Caribou Populations
Sanchit Chopra, Fabien Mavrot, and Susan Kutz
Jaws were collected during sport and subsistence hunts in
three different areas (Cambridge Bay and Kugluktuk -
Nunavut and Norman Wells - Northwest Territories) during
the years of 2015-2016. Samples were kept frozen until
they were shipped to the University of Calgary for post-
mortem examination.
INTRODUCTION
1. Stimmelmayr, R., Maier, J. A. K., Persons, K., Battig, J. 2006. Alces 42:65-
74.
2. Anne Gunn – Unpublished Work. INCISOR CRACKS AND BREAKAGE IN
VICTORIA ISLAND AND MAINLAND MUSKOXEN. Print.
3. Kutz, Susan et al. Integrative and Comparative Biology 44.2 (2004): 109-
118.
The sample size we investigated is small and
we will continue to monitor the dentition of
muskoxen and caribou in these populations
to further assess and understand the
situation.
Our data suggests muskoxen are more likely
to have dentition pathologies than caribou
and with more severe lesions. Abnormalities
were mostly situated on incisor teeth and
more specifically the two i1’s. Possible
reasons for the variance between muskox
and caribou dentition health could be
correlated with movement patterns resulting
in differences in vitamins and minerals
present in their diet. The occurrence of
incisor breakage have increased in
muskoxen from Cambridge Bay in the last 20
years. Possible reasons for the incisor
breakage include change in the vegetation
and thus changes in forces exerted on the
incisor arcade while feeding.
RESULTS CONCLUSION
FUTURE
We examined the dentition of nine mandibles and eight incisors bars for muskoxen and eleven mandibles
for caribou from 2015-2016. The proportion of individuals with at least one broken incisor was 13/17 for
muskoxen and 5/11 for caribou. In average, the proportion of broken incisors out of the total incisors
present in each jaw was 39.5% (range: 0-100) for muskoxen and 6.8% (range 0-25) for caribou. In addition,
nine muskoxen had rotated or displaced incisors. Mild gingivitis was found in four muskoxen and was
associated with food impaction in one case and with an encapsulated foreign body (tooth fragment or
stone) in another case. Incisor breakage in muskoxen seemed to affect mostly the central incisors (i1)
whereas no trend was detected for caribou (Fig. 2).
We would like to acknowledge Sara Skotarek
and Samuel Sharpe of the veterinary faculty,
Stephanie Behrens (affiliation), Mary Gamberg
(independantLisa-Marie Leclerc (Gv.NU), Tracy
Davison (Gv. NWT), the hunters and guides of
Cambridge Bay and Kugluktuk as well as the
sport hunters for providing us with the samples.
Ann Gunn (BC) for her help and guidance.
Muskox (Ovibos moschatus) and caribou (Rangifer
tarandus) are wild ruminants in the Arctic regions of
Canada. In the past decade, several North-American
muskox and caribou populations have declined1. Although
the reason for declines is unknown, several factors such as
global warming and the emergence of new diseases are
thought to be contributing factors.
In addition, there has been indications that jaw and
dentition problems may further impair the health of
Northern ungulates.2 In this study we aimed to:
1) Establish a standard examination protocol for long-term
monitoring of dental health
2) Examine and compare dental health of hunted
muskoxen and caribou
3) Compare our findings in muskoxen to previous data
collected during the 90’s 2
Figure 1: Standard mandible examination
protocol
Figure 2: Percentage of broken or missing incisors in muskoxen and caribou
Ecosystem and Public Health, Veterinary Medicine – University of Calgary
We identified key characteristics
relevant for caribou and muskox
dental examination for the protocol
we developed:
a) incisor breakage
b) molar wear pattern
c) enamel defect
In addition, we also recorded incisor
length, tooth cracks and misalignment
as well as soft tissue and bone
abnormalities (Fig. 1).
METHODS
ACKNOWLEDGEMENTS
REFERENCES
All muskoxen sampled in Cambridge
Bay (9/9) and 50% (2/4) of the
muskoxen from Kugluktuk had at
least one broken incisor. Prevalence
of incisor breakage in the same
muskox populations in the 90’s was
30% for Cambridge Bay and 60% for
Kugluktuk (Gunn et al., 2007) (Fig. 3).
Email: email@sanchitchopra.com
Phone: (403) 918 5633
Figure 3: Comparing percentage of incisor
breakage of muskoxen from 1990 and 2015-
2016 data
1. Standardized Protocol
2. Caribou and Muskox Dental Health
2. Comparing Breakage Data From 1990 – 2015/2016
* Significantly
different – Fishers
Test p<0.001
*
*
Healthy Incisor ArcadeBroken i1right Broken i1left