Authors
H.E.Booij-Vrieling (DDS, DVM, PhD, Dipl EVDC. Dept Clinical Sciences, FVM-UU),
H.Fieten (DVM, PhD, Dipl ECVIM, MSc genetic epidemiology. Dept Clinical Sciences, FVM-UU),
H.Vernooij (MSc, Dept Population Health Sciences, FVM-UU).

Objective
The aim of the project was to investigate whether the shedding of the incisor teeth can be used as an evidence based tool to estimate the age of a puppy.

Animals
Owners of puppies with a known and reliable birthdate were asked to send twice a week a frontal viewed picture of their dogs teeth and measure weekly the weight.

Procedures
Data collection started at the age of 10 weeks until the dog has shed all 12 incisor teeth. Dogs were arranged according to the breed and assigned to a weight category.

Results
For the analysis complete data of 629 pups was used. More than one hundred different breeds participated. The shedding process follows a fixed pattern: starts with the mesial-, followed by the middle and ends with the lateral incisors. This is similar for the maxilla and the mandible. Dogs from breeds with higher weights (> 15 kg) start shedding at the mean age of 108 days (15.4 weeks). Dogs with very low weights (< 5kg) start about 4 weeks later, at a mean age of 137 days (19.6 weeks). Median time frames for shedding incisor teeth do not differ between smaller and larger breeds (21-25 days), but individual variation is more prevalent in the lower weight categories.

Conclusions
Starting points and time frames for shedding incisor teeth differ between weight categories.
The indicated time in most literature (12-15 weeks) needs to be reviewed. 

The current dataset can be used to predict the age of a puppy based on the shedded teeth and to compare the estimate with the age registered in the dog’s passport to detect inconsistencies.

Funding through; Expertisecentrum Genetica Diergeneeskunde, 2023.

No conflict of interest