Colistin resistance detected in shelter dogs imported from Russia

Rescue dogs imported from poor hygienic conditions should be handled as risk group patients at veterinary premises until more information is available about the occurrence of antimicrobial resistance in this population.

Colistin and multi-drug resistant ESBL Escherichia coli isolates have been observed in rescue shelter dogs imported from Russia to Finland. The bacterial isolates originated from the ESBL screening of specimens from two dogs arriving in Finland at the end of February. Both isolates carried a transferable mcr-1 gene that mediates colistin resistance. Colistin is the last resort antimicrobial agent for humans for the treatment of severe infections caused by multi-drug resistant bacteria when no other options are left. These bacteria may be transferrable from animals to humans and vice versa.

This marks the second time that mcr-1 mediated colistin resistance has been reported in Finland. In November last year, the Finnish Food Safety Authority Evira informed the general public that transferrable colistin resistance was detected in shelter dogs in Russia that awaited transportation to Finland.

Multi-drug–resistant bacteria frequent in imported shelter dogs

Researchers in the Faculty of Veterinary Medicine reported last autumn that nearly half of dogs rescued from Russia were found to be carriers of multi-drug–resistant ESBL bacteria. These bacteria and other multi-drug resistant pathogens, such as MRSA and MRSP, are also common in infections in these dogs.

“High animal density and pressure from infectious agents together with poor hygienic conditions and uncontrolled antimicrobial use facilitate the spread of antimicrobial resistance and infectious diseases in dog shelters,” says Docent Merja Rantala from the Faculty of Veterinary Medicine, University of Helsinki.

Rescue dogs imported from abroad are risk patients

Imported shelter dogs should be handled as a risk patient group at veterinary premises until more information is available on the occurrence of antimicrobial-resistant bacteria in these dogs. Enhanced precautionary measures should be followed when handling these patients. In addition, these dogs should be screened for the presence of ESBL, MRSA and MRSP. Specimens from infection sites should be sent for bacterial culture.

Other risk patient groups at veterinary clinics are patients suffering from chronic or intermittent skin or ear infections and other patients that have received multiple antimicrobial treatments.

The importation of rescue dogs should be reconsidered

Infections caused by multi-drug resistant organisms are difficult to treat due to the scarcity of therapeutic options. Multi-drug resistant bacteria can be transferred from animals to humans and can cause outbreaks in human and veterinary hospitals. If an animal is observed to be a carrier of ESBL, MRSA or MRSP, the owner should inform veterinarians about their pet’s status at the time the appointment is made.

In the case that the animal is ESBL or MRSA positive, and a human family member of the same family requires hospitalization, the hospital staff should be informed about the animal contact. Then the hospital can consider whether the family member should be screened for the presence of these bacteria.

Within the last few years, previously very rare or non-existent diseases have become more common in conjunction with the increasing number of imported dogs. Importing stray dogs from unknown conditions increases the risk of animal infectious diseases and antimicrobial resistance. The risk of rabies is also increasing. Rescue organizations should recognize the disease risks related to rescuing animals from poor conditions and take precautions to prevent disease from spreading.   

Merja Rantala discourages the practice of importing dogs from poor hygienic conditions.

“Shelter dogs can be supported and helped directly in their countries of origin.”

Lpecimens from rescue dogs were investigated at the Clinical Microbiology Laboratory of the Faculty of Veterinary Medicine, University of Helsinki. The presence of the mcr-1 gene was confirmed with the PCR method at Evira..