The dogs’ characteristics, working history and indication behaviours
| Dog name | Breed | Age | Sex | Alert response for positive sample | Working history |
| Silja | Labrador retriever | 6 | F | Pawing | Narcotics |
| Rele | Labrador retriever | 5 | M | Sits | Dangerous goods |
| Kosti | Labrador retriever | 8 | M | Sits | Dangerous goods |
| E.T. | White Shepherd | 4 | F | Nose freeze + one paw | Canine cancer |
E.T. was initially trained to discriminate SARS-CoV-2 infection using urine samples and later, skin swab samples, while the other three were directly trained by skin swabs from patients with COVID-19 in the acute stage of the disease.