The same bacteria that challenges hospitals is now hitting our pets, and the implications might just concern us all.
Imagine your dog shaking its head in discomfort, plagued by a persistent ear infection that just won't go away. The veterinarian identifies the culprit: Pseudomonas aeruginosa, a common bacterium. But there's a troubling twist—this particular strain produces IMP-45, a special enzyme that dismantles last-resort antibiotics 1 .
Antimicrobial resistance is one of the top 10 global public health threats facing humanity according to the World Health Organization.
This isn't merely a veterinary concern; it's a window into the broader challenge of antimicrobial resistance. The line between human and animal health is blurring, and the discovery of IMP-45 in dogs sounds a note of caution for the One Health ecosystem we all share.
The gene instructing bacteria to produce IMP-45 is not locked within the core chromosome. It resides on mobile genetic elements, tiny packets of DNA that can be easily shared between different bacteria, even across species 4 7 . This mobility transforms a single resistant bacterium into a potential factory for widespread resistance.
For years, multidrug-resistant Pseudomonas aeruginosa has been a notorious challenge in human hospitals. Genomics now reveals that the bacterial strains infecting our pets are often the same as those found in people.
A comprehensive genomic study published in 2025 analyzed Pseudomonas aeruginosa isolates from dogs with otitis (ear infections). The research found that all three major P. aeruginosa phylogroups (A–C) are represented in dogs, and there is no genetic element specific to either host species 2 . This indicates that similar strains freely infect both humans and dogs.
A real-world incident in 2023 starkly illustrated this connection. Two dogs treated at a specialty veterinary hospital in New Jersey were diagnosed with carbapenem-resistant Pseudomonas aeruginosa (CRPA) 4 7 .
Genomic sequencing revealed the canine isolates were separated by only 2 and 5 single-nucleotide polymorphisms from the human outbreak strain 7 .
To understand how scientists uncover these resistance patterns, let's examine a typical investigation, such as a 2023 study that analyzed P. aeruginosa from the ear canals of dogs in Japan 8 .
Swabs were taken from the ear canals of 29 dogs affected by otitis.
The study revealed a high frequency of resistance to several antimicrobial agents. All isolates were resistant to certain drugs like cefovecin and cefpodoxime, but thankfully, most remained susceptible to stronger antibiotics like cefepime and piperacillin/tazobactam 8 .
Pseudomonas aeruginosa's resilience is not accidental. It employs a sophisticated arsenal of defense mechanisms, many of which are shared among human and animal strains.
Some P. aeruginosa strains carry integrated viruses called prophages in their genomes. These prophages can encode proteins that benefit the host bacterium, such as toxin/antitoxin modules that promote persistence and may be linked to antibiotic tolerance 3 .
The discovery of IMP-45 and other complex resistance mechanisms in canine Pseudomonas is a call to action, not a cause for despair. Addressing this threat requires a unified One Health approach that integrates human, animal, and environmental health.
Veterinarians are encouraged to be proactive in diagnostics, requesting carbapenem susceptibility testing for Gram-negative bacteria that show resistance to broader-spectrum cephalosporins 7 .
Public awareness is also crucial; pet owners and veterinarians should stay informed about product recalls and outbreaks associated with items used across species, such as certain eye drops 4 .
The bond we share with our pets is one of life's great joys. Protecting that bond now means vigilantly guarding against invisible threats, fostering a future where antibiotics remain effective for all beings who depend on them.