Chapter 4: Quarantine and Removal of Exposed Cats

Risk Assessment

When one animal from a population is diagnosed with FPV, the question arises: what do you do about others in the environment? Are they all likely to get sick? Will widespread quarantine or depopulation be necessary? Or is it okay to simply carry on business as usual, or somewhere in between? The answers to these questions are dependent on several factors.

Not all exposed cats will become infected. Due to varying levels of maternal antibody, it is not even uncommon for only some members of a litter to develop disease. The risk of infection depends on the animal’s individual immune and vaccination status, the overall cleanliness of the environment and the level of proximity between the exposed and infected animal.

The most important factor in disease risk is vaccination: a “fully” vaccinated cat over 5 months old is at very low risk of infection (i.e. vaccinated at least 3 days prior to exposure, keeping in mind that shedding may occur up to 3 days before clinical signs become apparent). However, even incompletely vaccinated animals can survive an exposure if health is good and dose is low.

Risk due to environmental spread is reduced if:

• The shelter is not crowded.
• Cats are housed in double compartment units and handling during cleaning is minimized.
• A proven parvocidal disinfect (e.g. Accel/Rescue®, Trifectant®) is used daily to disinfect all animal housing areas, including transport vehicles, exam surfaces, and common rooms.
• Separate tools and equipment are used for each area of the shelter.
• Common rooms, exam surfaces, and carriers are cleaned and disinfected between each use.
• Cleaning staff have the time and ability to evaluate each cat before cleaning and use gloves between unthrifty and high risk individuals.

Risk due to cat immune status is reduced if:

• All cats are vaccinated immediately upon intake as described above.
• Risk is very low in cats four months and older that are either:
  • Vaccinated with an MLV SC FVRCP vaccine at least one week prior to exposure.
  • Have a documented history of vaccination at or after 18-20 weeks of age at least two weeks and within three years prior to exposure.
• Risk is greater in kittens under four months old even if vaccinated (due to maternal antibody interference).
• Risk is greater in cats vaccinated less than a week before exposure, or vaccinated with a killed or intranasal vaccine.
• Risk is greatest in closely exposed, unvaccinated cats.
• All ages should be considered at risk if unprotected by vaccines. FPV is regularly documented in adult cats in shelters, both strays and those surrendered by their owners.

Serology may be a useful tool to identify cats at low risk and limit the number of cats requiring quarantine. Serological tests for panleukopenia are available from several laboratories. Not all laboratories have been validated; consult with your local veterinary school. 

There is a panleukopenia titer kit (VacciCheck ImmunoCombTM  by Biogal) available for in-house use. One study found the sensitivity and specificity to be up to 89% (meaning that there is a ~ 1 in 10 risk of false positive results [calling a cat protected when really not]). Combined with rectal temperature and careful physical exam revealing no abnormalities, healthy adult cats with a protective IgG titer at the time of exposure can be considered at very low risk – moving these cats along as usual, with no quarantine, is a reasonable choice.

If a single case occurs in an area where all animals have been vaccinated and environmental spread risk is deemed low based on the above-listed factors, quarantine may not be necessary. If spread is observed or few of the above precautions are in place, the whole ward or even the whole shelter may need to be considered at risk/exposed. An intermediate response is to assess risk for immediately adjacent cages only – this is logical only if exposure is likely much lower in cats elsewhere in the ward.

Quarantine

Cats that are both meaningfully exposed and at-risk must be strictly quarantined to prevent continued spread of disease. If a full ward has been exposed and all cats are considered at risk, it may be most efficient to simply shut down that ward to new admissions for the quarantine period. If exposed/at-risk cats are scattered throughout the building, gather them together into an area of the shelter that can be easily cleaned, allows individual cat monitoring (one litter or cat per cage), and can be effectively segregated from the rest of the building.

If there is no separate place to quarantine cats within the shelter, consider closing the shelter to new intakes during the quarantine period and quarantining cats on site. It may be easier to set up an off-site location or short term agreement with a local veterinary facility to permit emergency admissions to continue during this time. Well-informed foster homes with the ability to adequately monitor and segregate cats may also be an option, especially when the risk of illness is considered relatively low.Any area where cats are quarantined must be able to be thoroughly cleaned and disinfected - no carpet, furniture, wood, grass, etc. Foster parents should be counseled carefully about the need to prevent contamination of their homes, as well as the grave prognosis should the cats become ill.

Precautions for quarantine:

• Minimize handling of cats during quarantine – ideally provide double compartment housing to limit handling and possibility of fomite transmission(to learn about making single cages into double compartment housing units – please see our Information sheet on Manufactured Portals.
• Wear appropriate personal protective equipment aka PPE (lab coats or smocks, boots or shoe covers, and gloves).
• Use shoe covers or dedicated boots. Foot baths are not effective.
• Use supplies (brooms, feeding carts, scrub brushes, etc.) dedicated to quarantine and used only in that room.
• Changes gloves or thoroughly wash hands between handling quarantine cats.
• Handle cats in quarantine after caring for healthy cats or have separate staff dedicated to care for the cats in quarantine.
• Quarantine precautions should be maintained for 14 days. Although most cases will become evident within the first 7-10 days, it is very sad to go through all the effort of a ten day quarantine, only to have a cat break with signs on day 11 and have to start all over again!

Serum for exposed/unvaccinated cats

For exposed cats and kittens that were not vaccinated prior to the time of exposure, vaccine schedules should be maintained as usual. There is no evidence vaccination after exposure will prevent development of clinical panleukopenia, but vaccination is important for other shelter-acquired diseases.

Infectious Diseases of the Dog and Cat 4 states that 2ml of serum from an immune cat given SC or intraperitoneal soon after exposure may provide some protection. There is currently no peer-reviewed evidence that the administration of serum provides any protection or reduction of clinical disease. See our FAQ addressing this question here: https://www.uwsheltermedicine.com/library/resources/efficacy-of-feline-serum-transfusion-for-prevention-or-reduction-of-disease-in-panleukopenia-exposed-kittens