(Image via everydayhealth.com)

Staff Writer: Maya Arruda

Email: marruda7@umassd.edu

The 2020 coronavirus pandemic made people painfully familiar with respiratory illnesses. Many people lost loved ones to the novel SARS-CoV-2 virus. Thankfully, vaccines against this deadly coronavirus have reduced mortalities and allowed people to return to their everyday lives.

However, while humans have become safe from our novel respiratory pathogen, dogs are now in danger.

In the summer of 2022, dogs in New Hampshire began exhibiting troubling symptoms. The common symptoms were sneezing, coughing, and eye discharge, but unlike typical sicknesses, these symptoms were resistant to most treatments and lasted for weeks. Current antibiotics are ineffective. 

Since then, the sickness has spread throughout the country, infecting multiple breeds of dogs. Cases have been confirmed in:

• Oregon
• Colorado
• New Hampshire
• Rhode Island
• Massachusetts
• California
• Indiana
• Illinois
• Washington
• Idaho
• Georgia
• Florida

Considering how far away some of those states are from each other, this illness has likely spread to other states within the country. Hundreds of dogs have already been affected. 

Like with COVID-19, some dogs are more susceptible to this illness than others. Sick dogs are more vulnerable to this illness and can develop acute and severe pneumonia, meaning the berry-shaped air sacs in the lungs (called alveoli) fill up with fluid and pus. This makes breathing extremely difficult and can restrict oxygen circulation in severe cases. Once the infection reaches this stage, the dogs can die. 

This sickness is believed to be caused by a new (novel) bacterial pathogen. This bacterium is hypothesized to originate from the dog microbiome, the sum of bacteria species living on/within a larger organism. The bacteria is microscopic and hard to detect. Worst of all, it is not culturable. 

Usually, the microbiome is benign, if not outright beneficial, to the bigger organism. In this case, the dog. Usually, bacteria within the microbiome defend against pathogenic (harmful) bacteria by taking up food and living space, preventing the bacterial pathogen from growing and making the dog sick. 

Many species of bacteria are unknown. Most species of bacteria are still undiscovered. It is not surprising that a bacterial pathogen species has not been previously discovered, though this knowledge deficit is now detrimental to our dog’s well-being. 

Pathogen is the scientific word for anything that can make someone sick, including bacteria, fungi, and viruses. In the case of bacteria, pathogenicity (the ability to make someone sick) can be spread between different species through a process called horizontal gene transfer. 

Through horizontal gene transfer, once benign bacteria can become converted to cause horrible sickness. It is possible that a typical microbiome bacteria species became pathogenic through this method, though currently, this is not confirmed nor ruled out. 

Quite frankly, much about this dog bacterial pathogen is unknown, partly because it was recently discovered and partly because it cannot be cultured. 

For those who have never taken a microbiology class (which I imagine is the bulk of the population), culturing has been the primary method for studying bacteria since ye olde days (mid to late 1800s). Even in 2023, culturing is still the primary method of testing bacteria for antibiotic resistance to see what antibiotics would effectively treat an infection. The easiest still-utilized method for antibiotics susceptibility testing is the Kirby-Bauer Test, which requires culturable bacteria. 

Of which this new dog pathogen is not. Do you see where the problem is?

Because this bacteria cannot be cultured, scientists cannot determine which antibiotics would work against it. This means vets are shooting in the dark with their antibiotic regimens since they can’t know if they’ll work.

And, of course, since the bearer of good news hasn’t been seen since 2018, this is a terrible tactic for all dogs, both the sick and the uninfected. Using antibiotics repeatedly, especially if they are ineffective against the target pathogen, is dangerous because it causes antibiotic-resistant bacteria to emerge through selection. 

Because antibiotics kill all normal bacteria, antibiotic-resistant bacteria are the only ones alive to replicate, creating new populations of antibiotic-resistant bacteria. Antibiotic resistance develops in the target species, and other bacteria remain in the environment. This resistance makes it harder to treat infections with antibiotics in the future. 

It gets worse. Remember, antibiotics affect not only the pathogenic bacteria but all the bacteria in the microbiome, including the good ones. This paves the way for opportunistic bacteria (ordinarily harmless bacteria that can become bad if the good bacteria aren’t around to keep them in check) to cause problems and double-team the dog with the pathogen that hasn’t died yet. 

If you have a dog, the best advice is to keep it far away from other dogs (doggy quarantine, if you will) to prevent the spread of infection. 

If your dog shows respiratory symptoms, do not assume it’s just an ordinary dog cold. Take your pet to the vet as soon as possible. 

Keep your dog’s vaccinations up to date to prevent infection double-teaming if your dog gets sick, especially for other respiratory infections. 

Pet owners must be vigilant in managing this illness because vets do not know how to fully treat it.