Editor’s Note
As we all know, parvovirus cases can be both very rewarding and extremely heartbreaking. While doing my routine literature review to prepare for this newsletter, I came across the new JAVMA study on fecal microbiota transplantation in parvo puppies — it's nice to see advancements being made outside of just IV fluids and antiemetics. I thought it would be nice to have a themed issue reviewing some of the more recent parvovirus literature.
What I like about this month's slate is the range. FMT and CPMA approach the same disease from completely different angles — one's a microbiome-directed adjunct, the other's a targeted antiviral — but both are genuinely new tools, not just refinements of supportive care we've been doing for decades. At a time when the cost of veterinary care keeps climbing and more owners are weighing hospitalization against their budget, having a broader spectrum of care to offer feels overdue. Neither is a silver bullet, and I've tried to be honest about the caveats in each write-up, but I'm glad to see the literature moving this direction. I thought the CPMA paper was worth a review— most of us are likely aware of the Elanco product, but how many of us actually read the paper?
As always — thanks for being here. I'd love to hear what's working for you, what isn't, or anything else on your mind — all feedback welcome.
Study Spotlight
A Single Enema, Two Weeks of Capsules: Fecal Microbiota Transplantation (FMT) Cuts Parvo Hospitalization by Two Days in recent JAVMA study
Winston JA, Jennings R, Randolph NK, et al. Fecal microbiota transplantation dosing regiment accelerates clinical resolution in canine parvovirus infection: a novel spectrum-of-care approach. J Am Vet Med Assoc. 2026. doi:10.2460/javma.25.11.0764
What They Did
Prospective, double-blinded, placebo-controlled trial (interim analysis) at Ohio State’s veterinary teaching hospital. Twenty-seven client-owned dogs with naturally occurring parvovirus were randomized to standard-of-care (IV fluids, antibiotics, antiemetics) plus either FMT— a single enema followed by 14 days of oral lyophilized capsules (n=19)— or placebo (saline enema plus placebo capsules: n=8). FMT products came from three sources (in-house fecal bank and two commercial AnimalBiome formulations), pooled for this interim analysis. Primary outcome was length of hospitalization.
What They Found
The placebo arm was halted early on ethical grounds after 37.5% of those dogs were withdrawn for worsening clinical status, versus 0% in the FMT group. FMT-treated dogs had significantly reduced maximum medications scores (P=.0310) and, among survivors, were discharged 2 days sooner than placebo dogs (median 4 vs. 6 days, P=0.0258). By Day 7, 72% of FMT dogs had resolved diarrhea versus 0% of placebo dogs. Mortality trended lower in the FMT group (15.8% vs 25%) but wasn’t statistically significant (P=.5192). Cost savings were real but likewise didn’t reach significance ($2,915 vs. $5,707 median hospitalization cost; P=0.0624). FMT did not reduce fecal viral shedding or provoke a measurable host immune response.
On The Floor
A single in-hospital enema plus a take-home capsule course is low-risk, feasible for inpatients or outpatients, and may meaningfully shorten hospitalization time. This adjunctive therapy gives us another tool to utilize as often we have to present spectrum-of-care options for owners weighing cost against treatment. FMT capsules are commercially available from animalbiome.com (product name: Gut Restore); note AnimalBiome did not provide financial support or donated materials for this study.
The Caveat
This is an interim analysis of a small trial (n=27, placebo n=8), and the placebo arm was stopped early— the full planned trial was never completed as designed. Three different FMT formulations were pooled together for this analysis, so we don’t yet know whether product source matters. The Animal Biome product is also quite expensive (~$225/60 capsules). The mechanism is also unclear: FMT accelerated clinical recovery without reducing viral shedding or triggering a detectable immune response. This was a single-center study with cost savings, while clinically real, weren’t statistically significant.
At a Glance
01- A Monoclonal Antibody The Prevented Death in a Parvo Challenge Trial
Larson L, Miller L, Margiasso M, et al. Early administration of canine parvovirus monoclonal antibody prevented mortality after experimental challenge. J Am Vet Med Assoc. 2024;262(4):506-512. doi:10.2460/javma.23.09.0541
Pivotal, randomized, blinded, placebo-controlled challenge trial run to support USDA licensure of canine parvovirus monoclonal antibody (CPMA). Twenty-eight purpose-bred 8-week-old Beagle puppies were intranasally challenged with virulent CPV-2b; once fecal shedding confirmed infection (Day 4), dogs received a single IV dose of CPMA (n=21) or saline placebo (n=7), with no other treatment given to either group— a regulatory requirement to isolate the drug’s effect. Every CPMA-treated dog survived; 4 of 7 controls (57%) died or were euthanized by Day 7-8 (P=.0017). CPMA dogs also had significantly less fever, faster resolution of vomiting and lethargy, better appetite return, and reduced fecal viral shedding— without any blunting of their own adaptive immune response (IgM levels were equivalent between groups).
On the floor: This is the pivotal trial behind CPMA’s USDA conditional approval— the first targeted antiviral for parvovirus, meant to complement rather than replace standard supportive care. While I have already started utilizing this in my practice and subjectively feel it helps cases when instituted early in the course of the clinical disease, it is worth watching for data in naturally occurring disease treated alongside fluids and antiemetics, since this trial tested CPMA alone by regulatory design. A retrospective shelter study (Welton et al., 2025 ABVP Abstracts) has since reported shorter hospitalization with CPMA added to standard of care in naturally occurring infection, though as a conference abstract it hasn’t yet gone through full peer review. Note, this product is manufactured by Elanco under the new name “Trutect” and received full USDA approval in December of 2025.
02- Rethinking Parvo Prognosis: Three Values That Outperform Leukopenia
Chalifoux NV, Parker SE, Cosford KL. Prognostic indicators at presentation for canine parvovirus enteritis: 322 cases (2001-2018). J Vet Emerg Crit Care. 2021;31(3):402-413. doi:10.111/vec.13052
A retrospective review of 322 hospitalized parvovirus dogs at a university teaching hospital (2001-2018) put historical “gut feel” prognostic indicators to a multivariable test— and reshuffled the hierarchy. Overall survival was 91%, but three admission values independently predicted outcome: low glucose, high total magnesium, and low hematocrit. Each 1 mmol/L drop in glucose cut survival odds nearly in half (OR 1.85 lower odds, 95% CI 1.03-3.33); each 0.1 mol/L rise in total magnesium roughly halved odds again (OR 2.50, 95% CI 1.24-5.06); and a low HCT at presentation was the single biggest red flag, with almost 11-fold lower odds of survival (OR 10.69, 95% CI 1.24-94.71). Notably, leukopenia— long treated as a key severity marker— did not hold up as an independent predictor once the other variables were controlled for.
On the floor: Hematocrit and glucose— both part of routine baseline bloodwork— deserve more weight in your triage conversation than leukopenia alone. Given its strength as a predictor here, total magnesium may be worth adding to your baseline panel when a case looks borderline.
Protocol Note
As a Reminder: Standard Disinfectants Won’t Cut It for Parvovirus
CPV is a nonenveloped virus, which makes it resistant to disinfectants that work fine against enveloped pathogens. Per AAHA’s infection control guidelines, quaternary ammonium compounds— a staple in most practices’ everyday cleaning rotation— have limited efficacy against nonenveloped viruses like CPV, even with their full 10-30 minute contact time. Bleach (1:10-1:50 dilution) and accelerated hydrogen peroxide products are both effective against CPV and actually require less contact time— 1-5 minutes and 1-10 respectively—provided organic debris is removed from the surface first.
Stull JW, Bjorvik E, Bub J, Dvorak G, Petersen C, Troyer H. 2018 AAHA Infection Control, Prevention, and Biosecurity Guidelines. J Am Anim Hospital Assoc. 2018;54(6):297-326. doi:10.5346/JAAHA-MS-6903