Rethinking Parvovirus Protocols: A Low-Cost Oral Fecal Transplant Trial

Oral fecal microbiota transplant (FMT) capsules sound like the kind of elegant fix we all want for canine parvovirus: simple to give, easy to store, and built for high-volume shelter medicine. But when you put a microbiome therapy into a randomized controlled trial in a real outpatient protocol, the story gets more complicated and far more useful.

We sit down with manuscript authors Drs. Meghan Hoel and Amanda Gimenez to unpack their shelter-based study at Austin Pets Alive and why they designed it for the realities of accessible veterinary care. We dig into the key choices that make-or-break field research: why oral capsules were more feasible than rectal FMT, how they approached dosing without a known “right” answer, and how blinding and consistency can actually hold up over a two-year trial in a dynamic shelter environment. We also talk about what “recovery” should mean when survival is already high, and why time to normal stool and a negative SNAP parvo test matters for isolation space, staffing, and cost.

Then we get into the results and the nuance clinicians care about most. The oral FMT capsule regimens did not shorten recovery, did not reduce ICU transfers, and did not show a clear survival benefit. Even without definitive proof of harm, the overall trend pushes us to ask a harder question: should we assume FMT is benign when the intestinal barrier is severely damaged and immune defenses may be suppressed? We close with what better follow-up studies could look like, including timing later in recovery, comparing delivery routes, confirming microbial viability, and adding longitudinal microbiome sequencing.

If you care about evidence-based parvovirus treatment, the veterinary microbiome, and what actually works in shelter medicine, subscribe, share this conversation with a colleague, and leave us a rating and review. What would you test next?

JAVMA article: https://doi.org/10.2460/javma.26.01.0051

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Transcript

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Welcome And Study Overview

Lisa Fortier 0:32

Welcome to Epic Award-winning Veterinary Vertex, the Avium Made Journal's podcast, where we delve into behind-the-scenes looks with manuscript authors. I'm editor-in-chief Lisa Fortier, joined by associate editor Sarah Wright. Today we're discussing fecal microbiome transplant for parvavirus in the outpatient setting with our guests, Megan Ho and Amanda Jimenez. Thank you for joining us, Megan and Amanda.

SPEAKER_03 0:57

Thank you so much for having us. We're excited to talk about our study. It represents several years of work, and we're passionate about the accessible medicine space. So we're excited to get the opportunity to discuss our findings.

Lisa Fortier 1:12

Fantastic. Let's get going. Amanda,

Why Microbiome Matters In Parvo

Lisa Fortier 1:15

what made you think the gut microbiome was an important and under tested piece of parbavirus puzzle?

SPEAKER_05 1:21

Yeah, so because parvavirus causes a big disruption of the intestinal microbiome. And there had already been a landmark study showing that rectal FMT accelerated recovery in our hospitalized puppies. We really wanted to know whether there's a practical or commercially available option of FMT to then be able to be implemented and provide similar benefits in an outpatient setting where costs and ease of administration are really major considerations.

Why Shelters And Outpatient Care

Sarah Wright 1:48

I think this study is so cool. I think FMT is fascinating. So I was really excited to see this come out. So why study this in an outpatient shelter setting rather than like in a hospital ICU?

SPEAKER_03 1:59

Yeah, that was something that we talked about a lot when we were putting the study together. The decision to host it at Austin Pets Alive, also known as APA, uh, was partially logistic and partially scientific. Um, to do a successful randomized controlled trial well, we knew we needed to have a pretty high case volume. Um, Parvo, fortunately up in Wisconsin, is not as prevalent as it is in the southern states. Um, and APA also has a robust standardized outpatient protocol and the patient numbers to make this study possible. Um, we also thought the outpatient question was one that really needed answering. A lot of shelters successfully manage Parvo without a traditional ICU. So we wanted to know if adding FMT would improve outcomes in a real-world setting. And the goal was to generate evidence that could help shelters, but also clinics in the accessible care space, um, for especially for pet owners who can't afford the typical inpatient treatment for uh CPV. So there are some overlaps that we could capitalize on between protocols and goals of both shelter medicine and clinics that operate in accessible medicine spaces.

Why Oral Capsules And Dosing

Lisa Fortier 3:16

Megan, why did you choose oral capsules over other delivery routes? And how did you settle on testing these three dosing regimens? How do you determine the dose in the same trial?

SPEAKER_03 3:26

Yeah, so um when we were putting the study together and chatting with shelters, the um feasibility component of a um rectal like enema, FMT was was not necessarily something they felt they could easily accomplish. Um, with FMT enemas, we have to do donor screening, um, fresh feces, preparation, and then the administration. And so um shelter and accessible care spaces, we try to prioritize non-labor-intensive interventions. And so we were looking at what was commercially available. There were these FMT capsules, which are standardized, they already have the donor protocols figured out. They're easy to store, easy to administer, um, and therefore just a lot more feasible and um easier to get shelters on board with. And so if they had worked, they could be more easily integrated into a protocol.

unknown 4:24

Yeah.

SPEAKER_05 4:24

And at the time we designed the study, we really didn't know what the optimal dosing was going to be, especially in cases of parvavirus. So when we were testing, we tested those different durations of administration based on body weight and treatment length to see whether there might be some kind of dose response or duration response relationship. Um, based on that, we ultimately decided and found that there wasn't evidence that one regimen performed better than the other. So after kind of an interim analysis, we were able to kind of just pool the data and compare these two groups like that for the final analysis.

Blinding And Trial Logistics

Sarah Wright 5:00

It's a really impressive study. Amanda, how did you maintain blinding or masking in a busy shelter environment? And are you confident that it held?

SPEAKER_05 5:07

Yeah, so we are really confident in it. So the way that we did this all the way from Wisconsin to Texas was that the shelter staff who were administering treatments were following this randomized protocol we had in place. And we were over having having that be overseen by one of our co-authors who was at the actual practice. And so with Kevin being able to see things in real time, he wasn't blinded to the study and then able to not administer treatments, but ensure that it was being followed adequately by those who were administering the treatments. And then that selection process, we tried to make it as simple as possible. So for shelter staff, there was the pre-randomized stack. And the rule was when someone is enrolled, you take the top of the stack. And so for that, I also went by to visit uh to make sure that the study was going well in Texas. And I was also able to see then that like things were being followed really well. Shelter staff knew what they were doing, and so everything was going along as planned.

Lisa Fortier 6:04

Yeah, it's a really elegant study design and like really speaks to how you can make a simple study design robust as well.

Defining Recovery Beyond Survival

Lisa Fortier 6:12

Yeah. How did you guys define recovery?

SPEAKER_03 6:15

Yeah, so for recovery, this was integrated into APA's protocol. So they had it defined as a dog having two sequential solid stools and then also a negative SNAP parvo test. And as we all know, sometimes it may take a longer time for a patient to um get through diarrhea, longer than it will for vomiting, energy levels, improved appetite. So we did have the option to test patients sooner if they were starting to improve in those other areas of symptoms. Um, from the shelter perspective, um we felt that this was a useful um measure because the duration of recovery matters a lot because it affects housing, staffing, their isolation spaces, and costs. And then outside of shelter medicine in the accessible care space, we know clinicians care a lot about survival, right? But we also um we know that our the outpatient protocols do have a pretty good survival rate already. And so we wanted to shift our focus and um make sure that we were capturing symptom improvement and recovery time. Um, and this area is important for accessible care settings and shelters because the sooner we can get our patients feeling better, the more efficiently we can use our resources.

Results Show No Clear Benefit

Sarah Wright 7:37

Amanda, the survival gap, 94% control versus 82% fecal microbial transplant, doesn't reach significance after adjustment in your study. How do you interpret that?

SPEAKER_05 7:48

Yeah, so that's probably the question that we spent the most time thinking about. Statistically, we can't conclude that FMT caused worse outcomes. The confidence intervals were wide, and after adjusting for that age and weight, the differences weren't significant. But at the same time, the trend consistently moved in a direction that wasn't beneficial. So we didn't see improved recovery times or improved survival. There weren't fewer transfers into the intensive care. So while we can't claim hard harm definitively, we also don't have evidence to support a result that's, and that's really important uh to acknowledge that like benefit itself wasn't acknowledged either.

Lisa Fortier 8:28

Yeah, along those same trends, Megan, you guys flag possible negative effects rather than simply saying this is a null result. Sorry, this is a null result. What in the data pushed in your discussion toward that language?

SPEAKER_03 8:41

Yeah, we had to be very careful with our wording, especially with our p-value being 0.051. Um, we weren't necessarily saying that FMT was harmful and that we had proved that, but we also didn't want to ignore the fact that all of our measured outcomes either showed no benefit or trended away from benefit. And so from our perspective, if the treatment were truly helping, we would expect at least some positive measurable result. I felt like faster recovery, fewer ICU transfers, or better survival. And we just didn't see that. So we thought it was reasonable to raise the possibility in our discussion that introducing donor microbes into a severely damaged GI tract might not be entirely benign. And then we ultimately weren't able to statistically significantly conclude that it worsened survival. But we wanted to emphasize that we shouldn't assume that FMT is inherently benign and that further investigation should happen before we do a widespread adoption of FMT.

How FMT Could Cause Harm

Sarah Wright 9:48

Is there a biologically plausible mechanism by which fecal microbiome, sorry that again? Is there a biologically plausible mechanism by which FMT could actually cause harm in a dog whose gut epithelium is not actually destroyed?

SPEAKER_05 10:01

Yeah, so with FMT, we could potentially be harmful in dogs with parbovirus because the disease itself does cause severe intestinal damage and there is bone marrow suppression. So that together might increase our susceptibility to infection from the microbes that are introduced during the FMT process. In some papers in human medicine, adverse events uh related to FMT have been well documented and range from mild to severe. And then in a different study where we were looking at adult dogs evaluating uh fecal enemas, in adult dogs with chronic enteropathies, about 25% of those dogs did experience adverse events. So, considering like those papers' findings and the findings and a few others, further research should really be done to kind of investigate FMT's role in patients that have compromised intestinal epithelium. Ensuring, again, to echo Megan that we aren't providing treatments that we only think are benign.

Best Next Studies To Run

Lisa Fortier 11:00

Yeah, Amanda, you've just said that, you know, further studies, which is always the conclusion when we do a study, as it should be, you learn things and then you find out things to have more ideas. What would the ideal follow-up study look like? Different timing, route, population, or is it something entirely different?

SPEAKER_05 11:15

Yeah. So one question that I agree with is the timing part of that. So maybe introducing a microbiome therapy like later on in treatment would be something that we could see possible success with. So when we're thinking about this intestinal biome actually having time to heal, it may be worthwhile that FMT is used to repopulate the microbiome so that we're seeing things less like dysbiosis happening in that recovery period. Um, but with things where we are concerned that there's a like interruption, maybe that's not the timing for it. So, with that also, it would be valuable to incorporate sequencing of the data so we can actually understand whether donor microbes are successfully colonizing that gut and how the microbiome changes over time. And despite the pilot data, in addition to that, that we saw from animal microbiome that supported like the viability of the microbes that we were giving, uh, it could have been that things were reduced during shipping or that there was storage problems that reduced the efficacy of the FMT that we were providing these dogs. So it would also be good to kind of corroborate that the FMT that we were using was actually viable for our patients. Um, especially since manufacturers' claims are one thing, ensuring that that study and like the uh clinical outcomes match with what we're seeing, uh, that can actually help us answer some of those mechanistic questions that we still have.

Sarah Wright 12:39

You both have done a really great job of explaining the nuances of this study, and we really appreciate that. And this is definitely a very challenging study to run to, it sounds like the more we learn about it. What was the hardest part of running a two-year randomized controlled trial in a shelter? And what would you design differently?

SPEAKER_03 12:55

Yeah, I would say the biggest challenge was maintaining consistency over a two-year period in a very dynamic environment. And as we've discussed, an environment that's about a thousand miles away from us in Wisconsin. Um, as we know, shelters are busy, staff and volunteers change regularly, patient numbers fluctuate, and yet we need to make sure that protocols stay standardized for our data to be meaningful. And so, despite that being a challenge, I think we succeeded in maintaining a standardized protocol and obtaining meaningful results. And then just knowing uh that it's really valuable to have a simple study design in these types of environments. And then

Takeaways And Closing Notes

SPEAKER_03 13:39

the if we were to do it again, I think the one thing that would be really interesting that Amanda was talking about was incorporating longitudinal microbiome analyses. And then obviously that would be something that's resource intensive, but it would be really interesting to know kind of long term how these puppies would do.

Lisa Fortier 13:57

Tons of really great information in here, you guys. Uh, for our listeners, what is one take-home message you would like them to know about FMT in shelter medicine, whether it's capsules or other forms of FMT?

SPEAKER_03 14:09

Based on our study findings, I think that at this point in time, um, it would be worthwhile to continue researching FMT. As we know, this is a really growing area in veterinary medicine. It's shown a lot of promise in other settings and for other conditions. And so um, my takeaway is that at this point in time, I don't know that I would necessarily recommend doing FMT specifically for parvovirus treatment till we have further studies. Um, but that focusing on some of our interventions that have a bit more um a bit more robust uh backing and their efficacy at this point in time. Yeah.

SPEAKER_05 14:54

And I would just add that like I think it's important that all of us keep our ears open for the differences between like rectally administered FMT versus our oral FMTs, because like the differences in those might be profound depending on what we continue to find in our research about like the greater efficacy or one or both of those. Um, so that may be changing how we proceed in treating with FMT. And so just keeping our ears open for that with other studies or future studies that come out. Um and yeah, I think to echo Megan, I think just learning more about it and maybe not using it for our PARBO patients right now, um, but thinking ahead in the future as to ways that maybe we can bring this in in a more effective way.

Sarah Wright 15:33

Megan and Amanda, thank you so much for submitting your study to Javma and thank you for being here today. We've learned so much about FMT from you. Thank you so much for having us. Thank you, guys. For our listeners and viewers, you can read Megan and Amanda's article on JAVMA. I'm Sarah Wright with Lisa Fortier. Be sure to tune in next week for another episode of Veterinary Vertex. And don't forget to leave us a rating and review on FA Podcasts or wherever you listen.