PS   The most likely reason for sniffer dogs doing a false positive would presumably be some other medical condition(s) that caused some of the same metabolic imbalances/products as COVID-19.     Since most medical conditions make one more vulnerable to COVID-19, the apparently high rate of false positives would make it highly important to keep those the tests identify as positive isolated FROM EACH OTHER, at least until a more accurate test (with a low rate of false positives) was done.

IMHO the haphazard manner in which measures have been implemented in many places (most especially in the United States) and the lack of understanding or outright denial of many government officials, makes it imperative that those distributing sniffer dogs, if this is done widely, make it very clear that it is critical to keep people the dogs identify as positive isolated from each other until a more accurate test is done.