I previously described the potential pitfalls for those using DNA tests to identify dogs leaving behind specimens (aka poop) in public areas.

As expected, more communities are using the “poop detector tests” to penalize residents who do not pick up after their dogs.  As described recently in the New York Times, a condominium in Brooklyn Heights is using mandatory DNA testing of resident dogs to fine those who fail to clean up after their canine companions.

The objections and concerns described in the article included residents fearful that their neighbors would frame them with “fecal evidence” or those who believed this type of scrutiny could evolve into breed ownership limitations.

A number of laboratories are now offering DNA testing, including for example:

  1. Veterinary Genetics Laboratory at the University of California, Davis (DogPile ID Database)
  2. PooPrints

The University of California describes why its testing is reliable:

Although feces is not an ideal source for DNA profiling, the Forensic Unit of the VGL has developed new tests that can overcome problems commonly encountered with feces testing to make sure that your results are accurate, reproducible, and can hold up in court. The DogPile ID test is the only dog DNA testing offered by an accredited crime laboratory that has been accepted by a court of law.

PooPrints describes the science behind its testing.

Our instruments (electronic pipettes, balances, reagent cold storage, etc.) must pass maintenance, yearly calibration, and certification from a third party provider. Considered the industry gold standard in medium to high throughput in genetic analysis, our ABI 3730 DNA Analyzer is also certified yearly by an ABI service engineer. Our technicians must complete training and evaluation in each category before moving on to analyze our customer samples. These standards allow BioPet Vet Lab to offer precise and reproducible DNA fragment analysis.

It also explains why its DNA tests are more reliable than DNA tests used to determine breed, which are known to be somewhat unreliable.

Canine breed identification lends itself to slight variations, because results are based on statistical clustering comparison with a specific database of genotypes of purebreds. This clustering analysis produces statistics based on the database it is compared against. Meaning the actual breed percentages are only as strong as the database it is compared against; too few breeds in the database and you could be less likely to capture all breeds present in a mix-breed sample. Too many breeds in the database, and you run the risk of oversaturating and resulting too many breeds all with lower percentages. So, while the method of extracting and producing the genotype may be very precise, the clustering analysis with a purebred database is the variant in resulting. In contrast to breed identification, PooPrints creates a profile specific to the individual dog, and we do not determine any information concerning the breed makeup.

PooPrints also explains how it can differentiate contaminated samples.

It is clear that DNA testing is a growing industry.  With increased interest and use, there will likely be additional opportunities for these laboratories to certify the validity of their techniques.

However, the mishandling of a sample when obtained and through shipment remains a concern, and could provide a defense for an owner accused of not scooping the poop.