Bacteria from cats and dogs have become less resistant to antibiotics

Bacteria from cats and dogs have become less resistant to antibiotics in recent years, likely as a result of reduced antibiotic use. Despite this positive development, the proportion of antibiotic-resistant strains still remains high, and action must be taken to improve this, says the Laboratory of Clinical Microbiology at the Faculty of Veterinary Medicine, University of Helsinki. Follow-up data for a monitoring program has been collected during 2014 – 2017.

The proportion of MRSP bacteria decreased among canine staphylococci

For the first time, the proportion of methicillin-resistant staphylococci pseudintermedius (MRSP) dropped below 10 percent.

"The percentage of MRSP strains has never been this low during the follow-up period," says docent Merja Rantala, director of the Laboratory of Clinical Microbiology at the Faculty of Veterinary Medicine. The laboratory established at the University of Helsinki began MRSP monitoring in 2011.


Image: The proportion of methicillin-resistant Staphylococcus pseudintermedius strains in Finland during 2011-2017. Source: Faculty of Veterinary Medicine, University of Helsinki.

"Canine staphylococci have also exhibited reduced resistance to other antibiotics, but there is still work to do", says Rantala. For example, almost one-quarter of the bacterial strains remain resistant to macrolide antibiotics, she continues.

E. coli bacteria are also slightly less resistant than before

Resistance among canine Escherichia coli bacteria has largely remained unchanged, or declined slightly. E. coli is the most common cause of urinary tract infection in dogs.

The most significant reduction was seen in fluoroquinolone resistance – which dropped by 50 percent – from 15 to 7 percent.

"Fluoroquinolones are very important reserve antibiotics, so this development must be seen as positive," says Thomas Grönthal, Doctor of Veterinary Medicine at the University 

Feline pathogens are more susceptible to antibiotics than canine pathogens

The monitoring program was also able to provide novel insights into the antimicrobial resistance of feline pathogens. Previously, there were too few samples to explore this.

Across the board, staphylococci and E. colibacteria from cats were more susceptible to antibiotics than were those from dogs. Nevertheless, resistance levels dropped even among feline pathogens. For example, resistance to amoxicillin-clavulanic acid decreased significantly; in 2017, it was only 7 percent.

The proportion of ESBL and AmpC bacteria remained stable

ESBL and AmpC enzymes produced by bacteria can deactivate several penicillin and cephalosporin antibiotics. This makes treating infections significantly more difficult.

The proportion of canine E. coli bacteria that produced broad-spectrum beta-lactamases, or ESBL enzymes, has varied between 2 and 4 percent in earlier years. However, it was only 1.6 percent in 2017. A slightly higher percentage was seen in the proportion of canine AmpC-producing bacteria. In cats, the proportions of these bacteria were 0.6 – 2.4 percent. 

Carbapenemase-producing bacterial strains have not been detected since 2015.

What caused the positive development?

Evira and Fimea published a blog post (in Finnish) on 15 November 2018, stating that the sale of antibiotic tablets has decreased significantly. Even without species-specific data on antibiotic consumption, it is known that antibiotics are predominantly administered to cats and dogs in tablet form.

"Veterinarians have rolled up their sleeves and worked at full capacity to combat antibiotic resistance; instead of prescribing antibiotics, veterinarians are submitting bacteriological specimens for analysis far more often than before," Grönthal says with gratitude.

"Even though there is light at the end of the tunnel, additional work still lies ahead. We challenge veterinarians and pet owners to continue their efforts towards improving the resistance situation," Rantala states.

The European Antibiotic Awareness Day is celebrated annually on the 18 of November. The purpose of this day is to promote the prudent use of antibiotics and to increase awareness of antibiotic resistance. The FINRES-Vet report on the consumption of antibiotics and antibiotic resistance in animals will be published later this autumn.

Further information:

The European Antibiotic Awareness Day is celebrated annually on 18 November.

Frequently asked questions about MRSP

Frequently asked questions about ESBL

Frequently asked questions about NDM bacteria

The transmission of NDM-bacteria between dogs and humans has been established for the first time

Contact information:

Merja Rantala, Docent, Specialist in Veterinary Medicine (Infectious Animal Diseases), University of Helsinki, Faculty of Veterinary Medicine, t. 050 415 5482; 

Thomas Grönthal, Clinical Instructor, University of Helsinki, Faculty of Veterinary Medicine, t. 050 415 0590;

Antibiotic-resistant bacteria are not dangerous to healthy animals, but the infections they cause are difficult to treat, and recovery may be prolonged. In the worst case, an effective drug may not be available. This decreases the well-being of the animals. Resistant bacteria may also be transferred between animals and humans, thus negatively affecting public health.