Parvo-like illness in N Michigan

[Deb_and_Ed_M]

Weirdly, this seems contained (at the moment) to Otsego County in north/central Michigan - but several dogs have died from Parvo-like symptoms, yet tested negative for Parvo. I mention this mainly because that area is a popular tourist and camping destination.

It sounds like younger <2 yrs old, not-fully-vaccinated animals were most likely affected; and I assume most RVers traveling with dogs make sure they are properly vaccinated, so I'm "preaching to the choir"

Sick-dog outbreak

[Deb_and_Ed_M]

The latest news in a nutshell, is that it has spread to another northern MI county (Clare Co); and as the necropsy reports are coming in, the dogs DID have parvo. It just isn't consistent in showing up in initial live-animal testing?

And I think they said 80% of the dogs who died either weren't vaccinated; or were young dogs partially-vaccinated.

[toedtoes]

I think it may be that folks are too reliant on the test results and forget that false positives and negatives can and do happen. So if the test comes back negative, they automatically go to "mysterious illness" rather than "wait, could we have gotten a false negative".

[dturm]

When Parvo first started to show up in the early 80's, we had no tests and no vaccinations and really didn't know what we were dealing with. We learned to diagnose the way we used to do a lot, based on clinical presentation, physical exam and history. With the development of technical aids in medicine, I wonder if this skill is being lost to a degree. I do appreciate that many vets here diagnosed parvo despite negative tests.

Regarding parvo, we could diagnose pretty accurately by smell. There is a particular odor to the diarrhea, different than the "normal" diarrhea we see almost daily.

[BCSnob]

You saw this?

Update from State Veterinarian on ‘Parvo-like Illness’ in Northern Michigan Dogs

[Deb_and_Ed_M]

Thanks, Mark and Dr Doug - I was hoping you both would respond. Normally I'd say "nah" to blue-green algae that far north, but we HAVE had a very hot summer.

[dturm]

We see a high incidence of algae blooms this time of year. They can affect many dogs at the same time and often mimic other diseases. I'd be interested in lab results (other than parvo test) and necropsy results. It is a mystery.

[toedtoes]

Good point.

Also, the article indicates that about 20 dogs were reported to the animal shelter as getting sick, but only indicated one went to a vet. Were the others vaccinated at all? Is this an area where maybe folks don't generally get preventative health care for their animals? Were the affected dogs all adopted out of that shelter? Or is that shelter also animal control?

[BCSnob]

Perhaps viral evolution (mutation into new variants) and diagnostic tests not keeping pace with the viral evolution are the issues here.

Impact of emerging strains of canine parvovirus
Moore, Jennafer

Canine parvovirus 2 (CPV-2) is an extremely contagious virus that causes high morbidity and mortality in canines, especially pediatrics. The virus was first discovered in 1978, while it was in the midst of a global pandemic. Since this time, it has remained at the forefront of veterinary medicine. Canine parvovirus 2 causes acute hemorrhagic enteritis and myocarditis, both of which are very difficult for canines to recover from, making it one of the leading causes of death. Viral shedding occurs through the feces of infected animals that occurs during the incubation period, and it spreads through contact with individuals and fomites. Canine parvovirus 2 is a robust virus, having the ability to resist many disinfectants and survive in contaminated soil for up to 5 months or longer. Additionally, there are ongoing issues that include the failure of available vaccines in providing adequate protective immunity and the lack of some in-clinic diagnostic assays to positively identify the virus. New strains of the virus, such as CPV-2c, have evolved over the last 30 years, and they have also spread all over the world. All of these factors have led to the inability to contain the virus and its disease manifestation. The purpose of this report is to understand how strains of canine parvovirus have emerged over the years as well as to describe the impact of new strains on canine health.

and....

Comparison of different diagnostic methods in detection of canine parvovirus infection

Abstract
Aim: The study is to compare sensitivity and specificity rates of the enzyme-linked immunosorbent assay (ELISA), immunochromatographic assay (IC) and polymerase chain reaction (PCR) tests which are widely used to diagnose CPV-2 infections of dogs with severe gastroenteritis symptoms.

Materials and Methods: The stool samples were collected from 100 unvaccinated dogs with gastroenteritis symptoms. They were analyzed by ELISA and IC test kits for CPV-2. Also, the samples were investigated by PCR assay using the CPV-2 primer set amplify partial of VP2 gene to determine sensitivity and specificity of the tests.

Results: The sensitivity of IC was 36,6% and of ELISA was 24,2% compared to the PCR test. Also, both tests had 100% specificity. The IC test, and ELISA results were determined statistically different according to PCR (p <0.05).

Conclusion: The ELISA and IC assays had low sensitivity. Therefore, the tests can give false negative results in puppies with gastroenteritis symptoms and this situation can increase the spread of the disease. In conclusion, the negative determined samples by IC and ELISA methods should be verified by PCR and detailed studies should be
carried out to increase the sensitivity of these tests.

[toedtoes]

That's scary.

The article said that one person took their dog to the vet who tested for parvo and got negative results. I wonder if the others were actually tested or not, etc. If not, it could be parvo and the one dog had a faulty test.

Definitely a good reminder to make sure your pets are vaccinated and to not take your young, not fully vaccinated puppies out and about.

[Lwiddis]

Terrible news. Hope the authorities can get a handle on it.