The fact that dogs are able to sniff out corona infections is well known and is already being used. Amazingly, this is still possible if the PCR test is already negative again after a corona infection.
Corona detection dogs can not only identify samples from infected people, but also from long-Covid patients. This is reported by a research team led by the University of Veterinary Medicine Hannover (TIHO) in the journal "Frontiers in Medicine". "It is known that infectious respiratory diseases can release specific volatile organic compounds," said Holger Volk, head of TIHO's small animal clinic.
The results of the study supported the hypothesis that these connections are present in long-Covid patients in the long term after the initial infection. As early as summer 2020, the TiHo researchers published an initial study on sniffer dogs that had been trained to detect corona infections. They were able to identify infected people using saliva and respiratory secretion samples. As a follow-up study showed, sweat and urine are also suitable sample material. There have also been practical tests at concerts.
Now the samples came from long-Covid patients who were treated at the Hannover Medical School (MHH). The virus was no longer detectable in them using a PCR test. According to the TIHO virologist Claudia Schulz, the sniffer dogs can identify long-Covid diseases themselves, even if antibody tests can no longer make any statements about the cause of a disease.
The exceptional diagnostic ability of the dogs enables an optimized treatment of those affected. In various test scenarios, the scientists in the new study confronted nine corona detection dogs with samples from Sars-Cov-2-infected people, with long-Covid samples and with negative samples. If the dogs were presented with samples from long-Covid patients and those from healthy people for comparison, they recognized the patient samples in over 90 percent of the tests.
According to the research team, dogs are increasingly being used to detect smells in medicine. They are able to detect, for example, various types of cancer, malaria and some bacterial and viral infections.