Two little-known animal viruses are quietly climbing the watch list of global health experts. Influenza D virus and a canine coronavirus strain linked to human pneumonia have not yet sparked large outbreaks, but researchers say their genetic quirks and exposure patterns give them real potential to drive the next major health crisis. I see in their trajectory a familiar pattern from past pandemics: years of low-level warning signs, followed by a sudden shift that catches unprepared systems off guard.
Both pathogens circulate largely out of sight, in barns, feedlots and veterinary clinics rather than crowded city hospitals. That apparent distance from everyday life is exactly what worries scientists who study how infections jump from animals to people. The concern is not what these viruses are doing today, but what they could do if they adapt for efficient human-to-human spread in a world that has already shown how vulnerable it is to respiratory threats.
Why scientists are sounding the alarm now
The latest warnings about these two viruses come from a group of Scientists and Researchers who specialize in emerging infections and who are watching animal reservoirs as closely as human case counts. In their view, influenza D virus and a canine coronavirus known as HuPn-2018 have all the hallmarks of pathogens that could move from sporadic human infections to sustained transmission. Their assessment is grounded in field work, genetic sequencing and clinical investigations that trace unexplained respiratory illness back to livestock and companion animals, then forward again into households and workplaces through close contact with people.
In a detailed analysis of emerging pathogens, scientists describe how these viruses have already crossed the species barrier at least once, which is often the hardest evolutionary step. A companion report from public health and veterinary experts frames influenza D virus and canine coronavirus as “possible public health threats,” not because they are currently causing mass casualties, but because they are spreading widely in animals that live in close proximity to humans and have already produced documented human disease. I read that as a call to treat them as serious pre-pandemic candidates rather than obscure curiosities.
Influenza D: a cattle virus with human reach
Influenza D virus was first identified in cattle, where it contributes to respiratory disease that is costly but rarely headline-grabbing. In feedlots and dairy operations, this virus is now entrenched enough that it is considered part of the broader bovine respiratory disease complex. One assessment estimates that this syndrome, which includes influenza D among its contributors, costs the United States cattle industry upwards of $1 billion each year. That economic footprint is one reason veterinarians and virologists have been tracking the virus so closely, generating a body of data that now doubles as an early warning system for human health.
What moves influenza D into a different risk category is mounting evidence that it does not stop at cattle. Researchers have detected antibodies and viral genetic material in people who work closely with livestock, suggesting that the virus can infect humans and trigger respiratory symptoms. A technical report labeled as an Early Release in the journal Emerging Infectious Diseases, titled Emerging Respiratory Virus, places influenza D in Volume 32, Number 1 of that series and details how the virus binds to receptors in the human airway. I see that receptor compatibility as a key red flag, because it means the virus already has some of the molecular tools it would need to spread more efficiently among people if other mutations fall into place.
Canine coronavirus HuPn-2018: from kennels to hospital wards
The second virus drawing scrutiny is a canine coronavirus strain known as HuPn-2018, which has been linked to human respiratory illness in Southeast Asia. Researchers traced this virus to patients with pneumonia and then back to dogs, identifying a genetic signature that marks it as a canine-origin pathogen that has crossed into people. In coverage of these findings, By Jill Pease reports that Researchers documented this link in clinical samples from hospitalized patients, underscoring that the virus is not just a benign passenger but a plausible cause of serious disease. For me, the fact that it surfaced in a hospital setting, rather than only in mild community cases, raises the stakes.
Scientists say these two viruses may become the next public health threats, and canine coronavirus HuPn-2018 is central to that warning because it illustrates how close daily contact with pets can open a pathway for novel infections. In a summary aimed at health professionals, Scientists describe how HuPn-2018 was detected in multiple patients and emphasize that it carries genetic elements from different coronavirus lineages, a sign of past recombination events. That kind of genetic mixing is exactly what can produce new traits, including altered transmissibility or immune evasion, and it is one reason I see this virus as more than a niche veterinary concern.
The One Health lens: people, animals and shared air
What ties influenza D virus and canine coronavirus HuPn-2018 together is not just their animal origins, but the way they expose gaps in how we monitor diseases that move between species. Scientists led by Gregory Gray, M.D., who directs the One Health Research and Training Laboratory at the University of Texas Medic, have argued that respiratory viruses in livestock and companion animals need to be tracked with the same rigor as human influenza or SARS-related coronaviruses. Their work, highlighted in an analysis of One Health strategies, frames these viruses as test cases for whether global health systems can truly integrate veterinary and human surveillance.
From my perspective, the One Health approach is not an abstract slogan but a practical checklist: Are farm workers being routinely screened for influenza D exposure, and are veterinarians empowered to flag unusual respiratory clusters in dogs that might signal more HuPn-2018 activity? A feature on Two emerging pathogens with animal origins stresses that both viruses have so far been quietly circulating in animals with only sporadic human cases. That quiet phase is precisely when integrated surveillance can still change the trajectory, by catching early adaptation and guiding interventions before exponential spread begins.
How much risk, and what can be done now
It is important to be clear about what scientists are and are not saying. No one is claiming that influenza D virus or canine coronavirus HuPn-2018 is currently causing a global emergency. Instead, the message is that these viruses have already cleared several hurdles on the path from animal pathogen to human threat, and that ignoring them now would repeat mistakes made before COVID-19. A technical overview of influenza D and canine coronavirus HuPn-2018 in Volume 32 of Emerging Infectious Diseases notes that both have demonstrated the capacity to infect human airway cells, a prerequisite for efficient respiratory spread. That cellular foothold, combined with ongoing exposure in farms and homes, is what elevates their risk profile.
Experts quoted in a public health briefing from Jan warn that “If these viruses evolve the capacity to easily transmit person to person, they may be able to cause epidemics or pandemics since humans have little to no pre-existing immunity,” a line attributed to a scientist from UF’s Emerging Pathogens Institute and cited in a Jan update. A companion piece aimed at a broader audience repeats that warning and underscores that Jan is a pivotal moment to invest in better diagnostics and animal surveillance, before these viruses gain a stronger foothold. I read those statements as a push for preemptive action: targeted monitoring in high-risk occupations, research into candidate vaccines, and clear communication with veterinarians and physicians so that unusual respiratory cases are investigated rather than dismissed.
