Shelter's November Panleukopenia Outbreak

The City of San Angelo Animal Shelter experienced a panleukopenia outbreak in the cat colony behind the shelter building in late 2023.  Shelter Chief Morgan Chegwidden wrote in an e-mail to Best Friends Animal Society on Tuesday, November 14th.  It stated:

I’ve got more feedback on our increased deaths of adult cats from our colony. I apologize I wasn’t prepared with the latest info. 

• San Angelo Animal Services hosts a colony onsite. 
• The population is largely mature cats born here, marketed for adoption, failed to get adopted for 4+ months, gently introduced to our barn, if not thriving retrieved back to shelter. 
• Additional cats wander up/dumped on property, catch, TNVR. 
• Early October, shelter supervisor Halie caught 10 of the new arrivals, sheltered them in community cat room awaiting surgery. 
• 8 appeared healthy, alert, well groomed.
• 2 didn’t seem 100% thriving, but not snotty, diarrhea; just a bit thin and lethargic, tested positive for panleukopenia within 24 hours of arrival (not contracted in shelter), PAWS determined too far gone for treatment, euthanized. 
  
• 4 more died in custody, their remains were thin, signs of diarrhea in litter box, no signs of URI.
• These kennels were evacuated, deep cleaned, disinfected with 409 and Rescue (on a rotation).
• At least* 8 more mature cats (not neonates, 6+ months) have been found deceased on the property.
• Their remains appeared to be thin, no signs of URI, not grooming themselves.
  
• One of these cats was TNVR’d to the property years ago, the rest are new arrivals with no vaccine history/unaltered.
  
• *the cats have 10+ acres to roam and natural areas to retreat to when sick/dying.

We’re considering rounding up the remaining cats (1) assess their health and administer vaccine boosters and (2) impound/set up a panleukopenia ward for any identified as sick for supportive care (pen G and fluids). What would you recommend? Is there a concern panleukopenia lives in the soil onsite for years?

Best Friends replied with recommendations on managing the disease and disinfection procedures for the shelter to utilize. One Best Friends e-mail summarized the shelter situation:

The old colony cats that were already sterilized and vaccinated haven't been impacted much. The cats have been wandering in since the early part of the year but weren't brought in to be fixed until October due to limited surgery capacity. It's once they started bringing them in for surgery that the disease outbreak started.  Other cats in the shelter haven't contracted whatever it is.

The owner of a problem cat colony received assistance from the shelter during this period.  The gentleman did not have funds for spay/neuter.  

The owner complained about his cats dying after they'd been spayed/neutered at the shelter.  Their symptoms were consistent with panleukopenia.  

A more in depth response from Best Friends' veterinarian included:

The biggest concern is exactly what you’ve identified – the virus can remain viable in the soil for months. In this situation, vaccination is going to be the only thing that prevents infection.

Best Friends advised the handling the remaining colony cats:

For current cats – yes, I would trap/catch and administer FVRCP (modified live, injectable), and assess for illness. Parvo snap doesn’t do a great job of picking up virus prior to the onset of clinical signs, but you could use it to screen – but a negative doesn’t completely rule out very early (pre-clinical) infection. And, if already infected, then the booster vaccine won’t change anything. However, it might help you catch some of the positives (we can see a pos test ~24 hours prior to signs).

At this point, the soil is already contaminated and so I don’t worry so much about additional contamination that would happen from releasing a cat that will then break with disease in a few days, but if you think you won’t be able to recatch cats if they break with signs after release, then you may elect to hold on to them under quarantine and monitoring for 10-14 days. I would NOT hold them in the same iso room with clinical cats – if they’re not infected, we don’t want them to become infected.

Treatment recommendations included:

For treatment of infected cats, I can share our protocol. It includes intensive care, but there is also the outpatient protocol (modeled after a successful protocol for outpatient treatment of parvo in puppies) – SCF, convenia (rather than pen G), Cerenia are the pillars of treatment.

Going forward Best Friends suggested:

Any time, for the foreseeable future (6-12 months, depending on climate, rainfall), that a new cat appears – it should high priority to catch and vaccinate that cat as soon as possible. These cats can be released fairly quickly if they are adults – they should respond rapidly to a single dose of MLV vaccine (3-5 days). Anything under ~4-5 months of age should be considered high risk and should not be released on site as vaccine response is unpredictable in cats less than 16 weeks of age.

Freezing pauses the clock, and lots of rainfall will help to wash it away – so if you’re in a dry place with little rainfall, I use 12 months as my guideline. Warmer, very wet places can expect elimination at ~6 months or so (but could say 12 to be safe).

I would use this opportunity to evaluate shelter biosecurity protocols – it’s now on your property in the soil, meaning it could be brought in by staff, depending on what the geography is like. This would be of particular concern if you have group housing rooms where staff might walk into the room and could track it in (less of a concern if all cats are single housed in kennels). I would consider a footwear change if there is opportunity for contamination in this manner, if staff are out in areas of the property that the cats have a lot of access to. If you don’t have a set cadence for deep cleaning floors in all areas of the shelter, I would implement this now (and use Rescue, as it is effective against panleuk). And, of course, monitor your shelter cats closely – if we start seeing an uptick in shelter cases, then we know we need to investigate further. 

How are you diluting the Rescue for deep cleaning? What does daily cleaning look like for cats in the shelter (vs. deep cleaning)?

Also – I recommend that you discontinue the use of 409 around cats. This is a quaternary ammonium compound and, in addition to be ineffective against panleukopenia and other hardy viruses (including parvo and calicivirus), it can be toxic to cats (causes tongue ulcers, fever, pneumonia, death). Rescue is effective and is the disinfectant of choice for
shelters.

As Best Friends noted prevention is the best method to reduce disease and unwanted outcomes. 

The public was not informed of the outbreak in November.  A disease outbreak can occur at any time, however once it has, citizens should know. Might that have prevented the distress experienced by the gentleman with unaltered cats that died after shelter spay/neuter?  Maybe, maybe not.