Canine individual and breed identification

HealthLaw

Canine individual and breed identification

Dogs (Canis lupus familiaris) are described as being man’s best friend. In the past the close relationship influenced how dogs were bred, leading to trait differentiation to develop those characteristics for a particular function such as hunting or herding. Nowadays as close companions to humans, specific traits have developed, and many more breeds created. Being closely associated with human’s everyday life means that animals can be associated with criminal activity as silent witnesses, perpetrators, or assistants in a crime. Biological traces such as blood, saliva or hair specimens can be retrieved from crime scenes, left directly by the dog, or transferred to the scene of a crime by their human owner. Inference of the breed of the dog can help establish the circumstances of the case and provide useful intelligence to support a criminal investigation and aid the resolution of the crime.

The first part of this project devotes itself to the creation of databases for canine identification and haplogroup characterisation with the analysis of short tandem repeat markers and full mitochondrial genomes sequencing from over 1000 dogs, to provide breed identification and population frequency determination. A collection of between ten and fifty of the most representative dogs are being analysed and the data will also be used to compare the individualised sequences with breed-specific collections in mainland Europe. Moreover, a collection of samples from dangerous dogs (banned in the UK) is also being sought through collaborators in the US for the creation of a database to compare the specific traits between English Pitbull and American Pitbull with the aim of stopping end of life decisions in regards of wrongly accused dogs.

Aims

Database creation for the UK canine population using gold standard methods for short tandem repeat analysis and cutting edge massively parallel sequencing.
Investigation of the whole mitochondrial genomes of a representative selection of dogs with known pedigree.

Methods

Whole mitogenomes in up to 1200 dogs will characterise the main haplogroups found in the UK.
Individualisation and breed inference will be recovered from analysis of short tandem repeat canine-specific markers in the same set.

Summary of Findings

Over 800 dogs have been characterised for whole mitogenomes revealing the usefulness of using full mitochondrial data compared to control region data, with over 250 clades identified of which 27% of which have unique sequences. Structure analysis of the autosomes STRs has shown over 60 of 80 breeds investigated have a characteristic set of markers that could provide useful intelligence in a criminal investigation.