When I lecture in shelters I always say a word about parvovirus infections, this deadly disease that is found in both canine and feline species (in felines we often hear the term “panleuk”, be aware this disease is in fact caused by a parvovirus – see our previous post here– ). Parvo is indeed part of those diseases that need to be on the shelter’ radars at all time: it is contagious and can easily spread in an at-risk population like a shelter’s one ; it persists in the environment for a long time ; because of that, there is the always-hard-to-control problem of fomite transmission ; when there is an outbreak, it has a huge impact on the adoption process, not to say the shelter’s budget. That’s why I try to keep my knowledge up to date on how to deal with this virus in a shelter setting, might come in handy in my everyday’s activities. I recently watched a webinar on the topic ( check it out here ). Great info was dispensed here and I really encourage you guys to do the same if time allows. If not (or if you just want a short summary of the key elements that were discussed), you can still read my notes below !
About the virus
Fact 1: Parvo is caused by a nude virus. There are different strains (CPV2a, 2b, 2c) for sure, but the good news is that this virus is what we refer to as “antigenically stable”. This simply means that, despite the strain variations, they do not mutate so much and if there is indeed a genetic difference between the strains, this difference is definitely not that huge. Why is that good news? Because this means that, whatever the strain we are dealing with, diagnosis/vaccination/treatment will still be efficient.
Fact 2: Concerning these different strains, while CPV-2b was the most commonly reported, CPV-2c has now become more prevalent. It seems that when dealing with this strain, the incubation period may be shortened and affected animals exhibit more severe clinical signs. Keep in mind there are no clinical studies to confirm this yet, but this is the actual clinical impression in the shelter community.
Fact 3: One of the most important step in order to protect the shelter is to be able to recognize the disease. Staff training and daily rounds are mandatory. Any abnormal GI sign, acute death in puppies or any dog that is “not doing well” should raise suspicion. Puppies are mainly affected but any non-vaccinated individual is at risk.
Fact 4: The incubation period is 3-14 days (in average 4-6) but shedding of the virus starts 2-3 days before occurrence of the clinical signs. Some dogs will shed up to a couple of weeks after they had recovered. This information is important in a shelter: it helps determine which individuals are at higher risk as soon as there is a clinical case reported. If a quarantine is ever needed, this one should therefore last at least 14 days.
Fact 5: There is no parvo-carrier state. If the dog is cured, the animal will certainly be protected for life.
Puppies are at high risk !
Fact 6: The current vaccines protect against CPV-2C : don’t abandon vaccination, it is still efficient and certainly the most essential tool in terms of medical prophylaxis.
Fact 7: One the reason puppies are more at-risk : the potential interference of the maternal antibodies on the vaccination. That’s why in shelters, it is often recommended to vaccinate them every 2 weeks until 18-20 weeks. It is however important to balance protection and socialization, whose key period is between 3-13 weeks. The solution is to make them move through the shelter system as quickly as possible. The sooner they are out, the better.
Fact 8: The virus is resistant in the environment and can survive up to 1 year in optimal conditions. As mentioned earlier, fomite transmission is therefore always an issue. Fur, feet, arms, hands, clothing, equipment, common walkways and play areas can indeed turn into fomites. Anytime it is possible, it is good to have separate equipments for each cage/housing area. Another good advice here to minimize the risk: use long gloves when manipulating individuals that are supposed to be at risk.
The importance of sanitation
Fact 9: When dealing with parvo, sanitation is key. Look at our previous posts to better understand 1/ the cleaning and disinfecting procedures and 2/ the disinfectants that are efficient to kill parvo . Keep in mind that chlorhexidine / alcohol-based / quaternary ammonium products will NOT be efficient for this purpose.
Fact 10: The animals’ coats can be heavily contaminated, so cleaning the animal is always a good idea, especially for puppies less than 5 months. A topical parvocidal (like Accelerated Hydrogen Peroxide – see our previous post) can be used. Don’t forget to wear protective clothing to prevent fomite transmission during bathing.
Fact 11: Very good news: the success rate of the treatment for parvo is now very hight : 75-90% success rate are reported with hospitalization.