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In my role as senior director of shelter medicine at the ASPCA, I consult with shelters from across the country during widespread or severe infectious disease outbreaks. Most are facilities housing dogs and cats, although equine and farm animal shelters in the United States are increasingly seeking medical advice.
The phrase “herd health” is often used to refer to medical care for animals in a shelter. This term originates from livestock production sytems, where it is defined as a combination of regularly scheduled veterinary activities and good herd management designed to optimize animal health and productivity. Prevention and disease surveillance are key parts of any herd health program, because in any herd, just as in any shelter, consequences of disease can be significant. Outbreaks can be consequential to any population’s overall health and have emotional and economic impact on a facility and its staff. For example, canine parvovirus or panleukopenia can result in serious illness, loss of lives and damage to the public perception of the shelter. Salmonellosis or Streptococcus equi (“strangles”) can create a similar situation in a horse facility. There are some fundamental similarities and differences in the way outbreaks of serious infectious disease are managed in large and small animal “herds” that are worth reflecting on.
Certainly, core measures that optimize animals’ resistance to disease, such as vaccination, parasite control and stress reduction are much the same in any population of animals. The main modes by which disease transmits (direct contact, indirect/fomite contact, droplet, aerosol and vector) are also similar (see “How Disease Spreads,” below). Although specific pathogens may differ between species and require targeted therapy, basic strategies to interrupt disease transmission and decrease animals’ exposure do not.
A key difference can be noted in the strategies commonly employed to combat outbreaks. In large animal settings, when officials identify a serious or spreading disease, they often quickly close facilities to new admissions and prevent animals from exiting as an initial step in containing an outbreak. Halting animal movement and creating a primary perimeter around sick animals (isolation) and secondarily around the exposed population (quarantine) can prevent spread to animals who have not been previously exposed or out into the community while you determine the extent of the problem and develop a diagnosis and management plan.
This sort of prompt cessation of animal movement is much less common in small animal shelters, where closing due to infectious disease concerns is often considered extreme or even impossible. Instead, shelters often try to do business as usual while simultaneously implementing outbreak control measures. Certainly, this can often be successful, but managing small animal “herds” through short periods of shutting to the public could help shelters break disease cycles more effectively.
Many shelters fear that publicly closing may create a negative perception of the health of the animals or the shelter as a whole. Shelters reflect community issues; if you’re receiving animals in a variety of conditions from multiple sources, most likely you’ll occasionally have to deal with significant illness. If handled well, being transparent from the time an unusual disease situation arises can build trust with the community
How Disease Spreads
1. Direct Contact – involves direct body surface to body surface, from one animal to another.
2. Indirect Contact or Fomite – contact between susceptible animal and a contaminated inanimate object (equipment, clothing, surfaces); often the result of poorly washed hands
.3. Droplet – small infectious droplets travel a short distance through the air and deposit on host’s mucosal surfaces. Droplets can also land in the environment and lead to indirect contact transmission.
4. Airborne – infectious residue from dried droplets or dust remains suspended and able to travel distances through the air; remains infectious for long periods of time.
6. Vector – disease transmission occurs through another animal capable of transmitting disease to a host; potential carriers include rodents, flies and mosquitoes.
Dr. Nilufer Wilkins is Pasco County Animal Services’ staff veterinarian in Land O’ Lakes, Fla. Last year, her municipal shelter, the only public animal shelter in the county, with an annual canine intake of approximately 3,000 dogs, opted to close its canine areas when canine parvovirus occurred in its wards.
Wilkins says the shelter made the difficult decision because “we felt it was important to prevent exposure to incoming dogs. Even though the virus was in the community, as that is how it came into the shelter, we did not want to send out dogs that might be incubating the virus. We felt that we could better manage the outbreak by having more control of our on-site population.”
She recommends a proactive approach, reaching out for expert advice sooner rather than later, and letting local residents know you’re consulting with experts to give them confidence that the shelter is doing everything possible for the animals.
“Also, be sure to keep staff and volunteers informed during the outbreak,” Wilkins says. “This promotes confidence and unity throughout the shelter and helps prevent miscommunication to the public. We had a great response from the community, veterinarians and rescue groups on how we handled the outbreak. [They were] pleased [that] we were not hiding the outbreak, that we kept them informed throughout and that we did not perform mass euthanasia to control the outbreak.”
Dr. Jeff Fankhauser, chief veterinarian at the Dumb Friends League in Denver, adds that communicating openly with individuals and organizations in the animal welfare field is helpful. His organization briefly suspended canine intake and adoption at one of its facilities last spring when a sudden increase in severe respiratory illness occurred in dogs.
“Early in the process, we were able to involve our local veterinary associations to help get the word out to veterinarians in the community and in turn to pet owners,” he says. “We quickly received countless messages of support and offers of help from other veterinarians across the country. Through this, we were able to access expert advice and assistance in diagnosing and managing our event.”
For Fankhauser, one of the most difficult aspects of managing an outbreak is not knowing the cause and scope of the problem early in the process. Defined as an occurrence of disease that is greater than would be expected in a particular time or place, the first indication of a shelter outbreak may be animals dying, not responding to typical therapies or showing new or unusual signs of clinical illness. Performing rapid and sensitive diagnostics, and consulting early with a shelter veterinarian, will best inform your patient-management strategy as well as overall outbreak control.
If animals are dying, necropsy should always be performed. Consulting with a shelter veterinarian can provide valuable diagnostic oversight and facilitate the tracking of epidemiological data. If your shelter does not have a staff veterinarian, reach out to a consultant; several programs around the country, including those at the University of Florida, the UC Davis Koret Shelter Medicine Program and Cornell University may be able to help (Fankhauser notes that consultation with experts, such as Dr. Lemac Morris of Boehringer-Ingelheim, was critical to controlling the event at the Dumb Friends League).
Minimally, basic information about affected animals should be logged, including age, breed, sex, vaccine status, entry date, clinical signs, date signs develop, testing performed and results, movement in facility and community origin, if known. It’s important to assess this information to identify the cause and determine the success of your control measures. All of this can be much simpler to interpret in a population of animals that is stable for a short period of time.
In most cases, obtaining an initial diagnosis will take at least one or two days. When test results are not immediately available, a worst-case scenario should be presumed; initiate contagion-control measures that best minimize disease spread. Measures may be very different in respiratory disease events (where airborne transmission is a major concern and the entire population must be considered exposed) than in gastrointestinal diseases like the parvo outbreak in Pasco County. In airborne events, generally a much larger group of animals must be considered exposed; this may mean an entire facility needs to close, instead of just a ward or room.
Control strategies further depend on the physical shelter facility and number of animals affected. In any outbreak, isolating clinically ill animals from apparently healthy animals should be a first step. The clinically ill animals are potentially infectious and should be housed physically away from other animals and handled in a biosecure manner (handled either by dedicated staff or after the handling of healthy animals, with use of preventive measures) until they can be confirmed to no longer be a contagious threat. By doing so, you limit the spread of disease.
Not every facility will have a dedicated isolation space with capacity for sick animals in an outbreak. During some outbreaks, shelters may need to consider using off-site housing or temporarily changing where animals are housed within the facility. It is wrong to assume that animals exhibiting only mild signs, or even those with no signs, pose no risk to others. There are many infectious diseases, such as canine influenza virus and distemper, that are readily transmitted by animals with few to no obvious signs.
This is why a second step in contagion control is determining the extent of exposure and quarantining those animals at risk of developing disease. Animals should remain in the quarantine area until they show clinical signs—thus requiring a move to isolation—or until they can be proven noninfectious or at low risk of becoming infected.
The length of quarantine is determined by the diagnosis and generally lasts at least as long as the incubation period of a disease. For example, quarantine time for canine parvovirus or feline panleukopenia is two weeks. Two weeks is also sufficient for most cases of infectious canine respiratory disease, excluding distemper. Every time an animal develops clinical signs in a quarantined population, the quarantine time begins again. Quarantines can be much simpler to manage—and thus shorter—when a shelter is not simultaneously admitting new or naïve animals into the population or into wards that are adjacent to those housing potentially contagious animals.
During the Pasco County shelter’s outbreak, in addition to isolation and quarantine, ensuring and reinforcing environmental sanitation was a critical aspect of contagion control. Although parvovirus can be physically contained more easily than respiratory disease, it is a nonenveloped virus and can persist in the shelter for long periods without proper cleaning and disinfection. While shelters should ideally always have sanitation regimens in place that are effective against common pathogens, during an outbreak it is critical to review these protocols and choose and properly apply a disinfectant that’s effective against the problem pathogen. A brief closure can allow time to review sanitation procedures, dedicate staff time to deep cleaning and ensure sanitation of areas that might not regularly receive it.
A recent outbreak of Streptococcus equi zooepidemicus at a municipal shelter that preferred its identity to remain undisclosed highlighted the difficult choices shelters need to make as they balance herd health and public safety.
“Because of the volume of animals we take in and the number of people we have visiting our shelter daily, there was no way we would be able to properly sanitize the shelter without closing,” says the shelter veterinarian who managed the outbreak. “Since we had cases of sick dogs in several areas of our shelter, we had no way to safely quarantine incoming animals to prevent exposure. And we needed our staff to be focused on cleaning and the care of the animals we had. If we had not closed, their attention would have been divided between caring for the animals, cleaning and caring for our customers.”
A shelter vet’s responsibilities when an outbreak occurs include protecting the shelter’s animals as well as those in the community by minimizing their exposure to the disease. “In addition, we must be cognizant of the potential for zoonotic diseases and limit public contact with infected and exposed animals until we know what we’re dealing with,” she says. “Public health and the health of the pets in our community should always be a top priority. First and foremost, in my opinion, is containing the disease to a specific locale, be that one room of the shelter, or the entire shelter.”
While closing to the public for any period of time is not a decision any shelter can make lightly, as the field of shelter medicine evolves, continuing to explore this and other models for rapid containment of disease may benefit all creatures—large and small.
Tips for Public and Media Communications in the Event of a Temporary Closure Due to Disease
Before the crisis
- Establish contacts with the local media so that, if a crisis does occur, you won’t be calling a stranger, and they won’t be hearing from one.
During the crisis
- Ensure that your entire staff/volunteers/leadership/board understand the issue and have been given written talking points for consistent messaging.
- Have a face-to-face meeting with the staff who are directly involved/impacted so that, in addition to written talking points, they have a chance to ask questions. (In large agencies, this isn’t always possible, but in smaller agencies, a quick staff huddle can really help.)
- Communicate to all partner and neighboring agencies in advance of your announcement, so they are ready for media contacting them and for any additional animal intake that may come their way.
- Post temporary signs inside and outside the building. Make sure they’re nicely formatted and message-consistent.
- Select a representative with a good understanding of the issue and have that person serve as the media’s primary contact throughout the incident.
- Inform the public and the media accurately, transparently and in a timely manner. Include basic information about the outbreak. Be clear about what you know and what you do not. State the facts; don’t withhold information or leave room for speculation.
- Provide information about actual and potential health risks, including what people can do to prevent disease and control the spread of the infection.
- If mistakes were made, admit to them, and make clear what’s being done to correct the situation and to prevent them in the future.
- Remember, less is more, and plain language is best. Don’t treat the situation lightly, and be truthful. When appropriate, the use of relatable analogies—such as how quickly a cold can spread among kids at day care—can help put things in perspective, stave off fears and bring back normalcy. Aim for messaging that emphasizes that the shelter is taking care of the animals in its facility and in the community through the actions it’s taking. Thank people for their help and understanding, and as soon as possible, make clear when the shelter will reopen for adoptions.
Read more information on isolation protocols.