An Outbreak of Feline Panleukopenia in a Northeastern US Animal Shelter Eloïse Cucui Basic Science Advisor: Dr. Elizabeth Berliner Clinical Science Advisor: Dr. Lena DeTar Senior Seminar paper Cornell University College of Veterinary Medicine February 22, 2017 Keywords: feline; panleukopenia; parvovirus; shelter; outbreak 1 Summary: An animal shelter housing 250 cats experienced an outbreak of sudden death, vomiting, and diarrhea in their feline population. Two weeks into the outbreak, feline panleukopenia was diagnosed in multiple cats. Over the course of one month, 40-45 animals either died or were euthanized due to illness. Field investigation determined that inadequate vaccination protocols, continued intake, overcrowding, prolonged length-of-stay (LOS), and inappropriate housing, including lack of isolation for sick animals, all contributed to the rapid spread of feline panleukopenia in this facility. Recommendations included consistently vaccinating all cats at time of intake, establishing designated isolation and quarantine areas, discouraging intake of new animals, reducing stress (by decreasing LOS and improving housing), and hiring full-time medical shelter staff. After these recommendations were implemented, no new cases of panleukopenia developed. Most of the remaining kittens survived, and even though the shelter admitted two panleukopenia positive kittens, they did not experience another outbreak. Introduction: Feline panleukopenia is caused by feline parvovirus (FPV), a non-enveloped DNA virus 1 which can persist in the environment for up to one year. The virus has high morbidity and mortality (50-90%), especially in naïve kittens, and can be transmitted fecal-orally directly 1,2 between animals, by fomites, or through environmental contamination. FPV is predominantly 1- shed in vomit and feces, but may also be found in most bodily fluids, including urine and blood. 3 The incubation period ranges from 2-14 days, though average is 5-7 days, and infected cats 1,3 may shed up to 2-3 days before displaying clinical signs. FPV replicates in rapidly dividing cells such as the intestinal crypt epithelium, lymphoid tissues, and bone marrow stem cells, 1,3 resulting in vomiting, diarrhea, and immunosuppression (from panleukopenia). 2 Although FPV is a highly vaccine-preventable disease rarely seen in privately-owned, adult pet cat populations, shelters inherently possess multiple factors which predispose them to 1,4 experiencing outbreaks of infectious diseases such as FPV. Shelters have a high population density of animals of different ages with varying immunological statuses, levels of susceptibility, 3,5 and unknown vaccination histories commingling in constant flux. Animals housed in shelters are regularly exposed to stressors such as strange smells and sounds, environmental changes, 5 new diets, unfamiliar handling or restraint, and irregular human contact. Some animals will be able to cope with short-term stressors by engaging in hiding, perching, socialization, and enrichment, but prolonged exposure to stressors negatively impacts the immune system and 5,6 decreases resistance to infection. Overcrowding not only contributes to stress, but also creates a higher disease burden and increases the contact rate between susceptible animals, thereby 5-7 increasing opportunities for disease introduction and transmission. All of these factors combined put shelter populations at increased risk of contracting infectious diseases. Because stress and overcrowding can perpetuate disease transmission, shelter outbreaks of FPV are not uncommon, and can rapidly have devastating consequences. Case history: The shelter in question is privately funded and has an open admissions policy. They have municipal contracts for canine animal control, but no feline animal control contracts. Humane investigations are a large part of the shelter’s operations. At the time of the outbreak, the shelter was housing approximately 250 cats, 150 dogs, and dozens of exotic pocket pets. The shelter was not euthanizing animals for space, and did not employ any full time medical staff. Spay/neuter was performed once weekly by two veterinarians and one licensed veterinary technician without any specialized training in shelter medicine. The shelter had also recently undergone some 3 organizational changes including hiring a new Executive Director, resulting in administrative and financial challenges. Three different areas within the shelter were designated for housing cats: “the ward” (used for intake), the adoption floor (comprising the lobby, cat adoptions rooms 1-5, and a communal housing room), and the medical center (used to recover cats after spay/neuter). The outbreak began in the ward, with cats and kittens experiencing sudden death, vomiting, and (+/- hemorrhagic) diarrhea accompanied by signs of systemic illness (i.e. dehydration, lethargy, and anorexia). Sick animals were initially moved into the medical center, but as new cases occurred in other areas of the shelter (adoptions room 5 and communal housing) and the medical center achieved capacity, sick cats were no longer removed from their rooms. Two weeks into the outbreak, a volunteer spay/neuter community veterinarian diagnosed FPV in multiple cats via canine parvovirus ELISA fecal antigen SNAP test. The shelter was unable to provide supportive treatment to symptomatic animals. One month into the outbreak, 40-45 cats had either died or been euthanized, and the shelter requested a consultation regarding outbreak management. The shelter had been inconsistently vaccinating incoming adult cats with a parenteral modified live virus (MLV) FVRCP vaccine; vaccination of animals was only performed one day per week, with poor follow-up due to inadequate medical record-keeping. After the outbreak began, the shelter continued to admit new cats from investigations cases, but started to vaccinate these animals on intake. New intakes were housed in plastic dog carriers in the shelter’s garage as a temporary measure to separate incoming cats from the general population. Problem list: Vaccination: The shelter’s vaccination protocols were not in compliance with the guidelines for standards of care recommended by the Association of Shelter Veterinarians 4 (ASV); although they had been using a parenteral MLV vaccine, they had not been vaccinating animals on intake, nor had they been vaccinating ill or young animals. Furthermore, because of poor record-keeping, not all animals were receiving the appropriate booster vaccinations. Isolation/Quarantine: Sick and exposed animals were distributed throughout the shelter (in the ward, medical center, cat adoptions room 5, and communal housing room) in such a way that made it difficult to separate them from the population of healthy animals and prevent fomite transmission of FPV. Personal protective equipment (PPE) was only provided for the ward. Intake: Since animal cruelty investigations were an important part of the shelter’s mission, the shelter continued to admit new animals from cruelty cases, despite the risk that the new cats might contract FPV upon entering the shelter. The shelter also continued canine intake, which contributed to overcrowding, as well as increased costs and demands on staff time. LOS: Because the medical center was being used to house sick animals, the shelter’s spay/neuter operations could no longer function, and were put on hold, thus contributing to the increased LOS of intact animals which, according to shelter policy, could not be immediately adopted and thereby moved out of the shelter. LOS was also prolonged for adoptable animals, since many barriers to adoption were in place, such as requiring landlord approval, background checks, proof of current pets’ vaccination status, and adoption of bonded pairs. Housing: Feline housing provided inappropriate long-term living conditions. Because the shelter was overcrowded, plastic dog carriers and pop-up wire crates were being used to house multiple cats. These were not adequately spaced in the ward to prevent direct contact between cats. Small, stainless-steel cages designed for postoperative recovery in the medical center had been housing cats for weeks. Nursing mothers and kittens were housed in the same rooms as the general population, and the ward also housed dogs and cats of various ages together with exotic 5 prey species. None of the cages, carriers, or crates contained hide boxes or perches for the cats. The communal housing room contained dozens of difficult to disinfect materials and surfaces, such as carpeted cat trees and scratched plastic litter boxes. These litter boxes were washed by hand, as were the food and water bowls in all the feline housing areas. Staff: The shelter did not have any full-time medical staff. The veterinarians and technicians hired to perform spay/neuter surgeries once weekly had not received any specialized training in shelter medicine. The volunteer veterinarian who had diagnosed FPV had never had any experience with outbreak control or population management, and was unfamiliar with proper vaccination, isolation, quarantine, and sanitation/disinfection protocols appropriate to the shelter setting. Because the shelter did not partner with veterinarians knowledgeable about best practices in shelter medicine, they did not have any written standard operating procedures (SOPs). Recommendations: 1,4,5,8 Vaccination: Prevention of FPV is best achieved through vaccination. According to the ASV guidelines, all cats entering shelters should be vaccinated on intake with MLV FVRCP 4,5,9 1,4 vaccines. Parenteral vaccines mount a rapid and robust immune response within 1-2 days, 10 and full immunity may be achieved as early as one week post-vaccination. Because FPV is 10 highly immunogenic, a single vaccination confers strong, long-lasting immunity. Kittens may be vaccinated as young as four weeks old and revaccinated every two weeks until at least sixteen weeks of age to overcome the window of susceptibility created by maternally derived 1,4,11 antibodies. In the face of an outbreak, adult cats may also be revaccinated two weeks after 1,4,5 their initial vaccination; we recommended that the shelter booster their entire feline population. Ideally, cats about to enter the shelter would be vaccinated at least one week prior to 5 admission to maximize protection. If a shelter continues to admit cats during an outbreak, they 6 should vaccinate them on presentation and either send them to foster care or return them to their 6,7 owners for at least one week before placing them in the shelter. Even cats who are ill (e.g. with 1 respiratory signs) should be vaccinated, as the benefit of vaccination outweighs the risk, and 4 increasing the number of vaccinated cats improves herd immunity. Vaccinating a cat that 5,6 already has a current FPV infection will not prevent the development of disease. Isolation/Quarantine: Shelters should have a designated isolation area in which to house 1,6,7,9,12 infected animals apart from the general population. We recommended that the shelter use an office within the ward as an isolation room to transfer all sick animals from the medical center and other areas of the shelter. Animals that have been exposed to a contagious disease and who may become infectious should be quarantined until the maximum incubation period of the 1,6,7 disease passes without any new cases; if a new case develops, the animal should be moved to 6,7 isolation, and the quarantine period should be restarted. At the time of field investigation, 14 days (one FPV incubation period) had passed since the last deaths in adoptions room 5 and the communal housing room, so we recommended that quarantine be lifted from those rooms, the cats housed there be made available for adoption, and the ward become the new quarantine area for all other exposed cats. To prevent repeatedly restarting the quarantine period, we discussed the option of euthanizing remaining kittens in litters where FPV had been recently confirmed. Incoming animals should be protected from the exposed population by creating a “clean break” between the two and keeping them separated; these areas should be clearly identified with 6 visual and physical barriers. The ward (quarantine) and the office (isolation) should be considered “dirty” areas, and the adoption floor should be considered a “clean” area for newly admitted cats. Separate staff should be assigned to work in isolation, quarantine, and the rest of the shelter; if this is not feasible, staff should work in “clean” areas before progressing to “dirty” 7 6,7,12 areas. Appropriate PPE and sanitation/disinfection protocols should be used in “dirty” areas, 6,7 and members of the public should not be allowed to visit animals housed there. Intake: Since overcrowding of susceptible animals propagates disease, shelters 7 experiencing outbreaks should close or significantly limit all animal intake. This includes ceasing intake from neglect and hoarding cases, as the shelter was not legally obligated to admit owned animals involved in humane investigations. Any cats entering the shelter at the time of the outbreak would be at risk of contracting FPV and either dying or being euthanized, and the shelter did not have adequate space to house more animals. We recommended that the shelter close dog intake, as well, since canine housing was also overcrowded, and admitting more dogs would decrease staffing resources needed to manage the FPV outbreak and increase the number of animals needing spay/neuter surgeries. LOS: Decreasing LOS increases capacity and decreases overcrowding, stress, and spread 13 of disease, thereby also decreasing costs. The shelter is not an appropriate environment for nursing mothers and kittens; these should be fostered to minimize stress, maximize socialization, 1,5,9,12 and decrease pathogen encounters. Because lack of spay/neuter is a major roadblock to 5,13 adoption, we recommended that the shelter reach out to local veterinarians for assistance with surgeries; promote healthy, altered animals for adoption; and remove barriers to adoption. 9 Although the ASV advises against adopting out intact animals, the risk of doing so is outweighed by the benefits of removing intact animals from the FPV shelter environment; we stressed that if the shelter were to adopt out intact animals, they either implement a foster-to- adopt program until animals could be altered, or provide spay/neuter vouchers with aggressive follow-up to ensure that all intact adopted animals would be altered. 8 Housing: A shelter’s physical capacity is defined by the number of appropriate housing 13 units, not by the physical number of cages it contains. To minimize stress, ideal feline housing 9 has 2 feet of triangulated space between the cat’s resting area, food, and litterbox. Because this configuration was not possible in the plastic dog carriers and pop-up wire crates, we recommended that these be discarded. Any cages still in use should be spaced at least 3 feet apart 9 to prevent direct contact and droplet transmission between cats. Retrofitting small banked cages 13 with portholes increases space and helps to achieve the desirable 2 foot triangulation. Hide boxes should be placed in every cage to provide both an area of privacy and vertical perching 5,9 space for the cats to promote comfort and reduce stress. Stressful environments with poor air 5,9,12 quality, lighting, temperature, and noise control should be avoided, so we recommended that the shelter discontinue using the garage for intake and move all animals housed there to the adoption floor. To further reduce stress and prevent disease transmission, animals should be 5,9,12 segregated in separate rooms by age and species. Sanitation/Disinfection: Litter boxes and food or water bowls should not be washed by hand; either disposable items should be used, or reusable items sanitized and disinfected using a 14 dishwasher. Items that cannot be disinfected such as scratched litterboxes or carpeted surfaces 6 should be discarded. Complete, disposable PPE (gloves, gowns, and booties) should be worn in 14 all “dirty” areas and changed and disposed of appropriately between kennels. The shelter had been using an appropriate accelerated hydrogen peroxide product for disinfection; we advised that they follow manufacturer recommendations and first use the product to mechanically remove any organic debris before reapplying the product and allowing 5 minutes of contact time. Hypochlorites are also effective against non-enveloped viruses when freshly made at a 1:32 14 dilution every 24 hours and protected from light. However, they require 10 minutes of contact 9 time and cannot be used in the presence of organic matter, so surfaces must first be sanitized 14 with detergent and then thoroughly rinsed before application. Accelerated hydrogen peroxide and sodium hypochlorite should not be used together, since mixing the two will cause a harmful chemical reaction. Kennels must be thoroughly sanitized and disinfected between occupants, but on a daily basis, spot-cleaning is preferred, as it reduces stress by minimizing animal 9,14 handling. Staff: Finally, we recommended that the shelter hire full-time medical staff familiar with shelter medicine to train current shelter staff, conduct daily walk-around rounds, write SOPs, and oversee proper medical recordkeeping. Daily rounds allow for the recognition, diagnosis, and 9 subsequent treatment of ill animals. Shelters should have written SOPs for intakes (including vaccination and deworming protocols by age and species), treatment of common illnesses (such as upper respiratory infections and gastrointestinal disease), emergencies, euthanasia, and 5,9 disinfection/sanitation. Accurate medical records must be kept for each individual animal; these must contain patient identification number, pertinent behavioral or medical history, and any 9 diagnostics, treatments (including immunizations), or procedures performed. Outcome: The shelter continued to intake animals from cruelty investigations despite our recommendations, but immediately began vaccinating all animals on intake, no longer placed incoming animals in the garage, and moved all animals housed in the garage to the adoption floor. They elected not to euthanize exposed kittens, and instead converted the office within the ward into an isolation room and moved all nursing mothers and kittens from the medical center into the office, thereby allowing spay/neuter operations to resume in the medical center. They established the ward as their quarantine area and kept all exposed cats in quarantine until 14 days 10 had passed without any new cases. At this point, they moved all adoptable cats to the adoption floor and marked their cage cards with orange dots to indicate to potential adopters that these cats had been involved in the outbreak. The shelter reached out to local veterinary practices and received spay/neuter assistance to help them manage their backlog of intact animals. Two kittens died in the medical center shortly after the field investigation and before the shelter had established their new isolation and quarantine areas. Apart from these deaths, no other outbreak-related deaths occurred, and the outbreak was considered over after two 6,7 incubation periods (28 days) had passed without any new cases. A few weeks after declaring the outbreak over, the shelter inadvertently admitted two ill kittens and had placed them on the adoption floor with their population of healthy cats. After one kitten was found dead, both kittens were tested with canine parvovirus ELISA fecal antigen SNAP test and found to be positive for FPV. The surviving kitten was moved from the adoption floor to isolation and successfully treated. None of the other cats on the adoption floor that had been exposed to these kittens developed FPV because those cats had already been appropriately vaccinated, and a repeat outbreak scenario was avoided. By implementing our recommendations, the shelter was able to increase its capacity for care. Limiting animal intake, addressing the spay/neuter bottleneck, and relocating cats to appropriate housing areas all contributed to decreased LOS and reduced stress levels, which in turn promoted a healthier shelter environment for the animals. Proper population management and flow-through-planning are also key in preventing the spread of infectious diseases in animal shelters. Because of the role stress plays in propagating disease, ensuring appropriate behavioral and environmental wellbeing is just as important as providing adequate medical care in the shelter setting. 11 References: 1. Tuzio H. Feline Panleukopenia. In: Miller L, Hurley K, eds. Infectious Disease Management In Animal Shelters. Ames, Iowa: Wiley-Blackwell; 2009: Chapter 12. 2. Kruse BD, Unterer S, Horlacher K, Sauter‐Louis C, Hartmann K. Prognostic factors in cats with feline panleukopenia. Journal of Veterinary Internal Medicine. 2010;24:1271-1276. 3. Litster A, Benjanirut C. 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Feline panleukopenia virus, feline herpesvirus-1, and feline calicivirus antibody responses in seronegative specific pathogen-free cats after a single administration of two different modified live FVRCP vaccines. Journal of Feline Medicine and Surgery. 2009;11:159-162. 12 9. Newbury S et al. Guidelines for standards of care in animal shelters. Association of Shelter Veterinarians. http://www.sheltervet.org/assets/docs/shelter-standards-oct2011-wforward.pdf. Published 2010. Accessed September 11, 2016. 10. Jas D, Aeberlé C, Lacombe V, Guiot AL, Poulet H. Onset of immunity in kittens after vaccination with a non-adjuvanted vaccine against feline panleucopenia, feline calicivirus and feline herpesvirus. The Veterinary Journal. 2009;182:86-93. 11. Jakel V, Cussler K, Hanschmann K, et al. Vaccination against feline panleukopenia: implications from a field study in kittens. BMC Veterinary Research. 2012;8:62-62. 12. Möstl K, Egberink HF, Addie D, et al. Prevention of infectious diseases in cat shelters: ABCD guidelines. Journal of feline medicine and surgery. 2013;15:546-554. 13. Berliner E. In one door and out the other: practical flow through planning for shelters. Webcast presented online at Maddie’s Institute; March, 2012; http://www.maddiesfund.org/ Maddies_ Institute/Webcasts/In_One_Door_and_Out_the_Other.html. Accessed September 10, 2016. 14. Dvorak D, Petersen C. Sanitation and Disinfection. In: Miller L, Hurley K, eds. Infectious Disease Management In Animal Shelters. Ames, Iowa: Wiley-Blackwell; 2009: Chapter 4.