Guideline position, pivotal evidence, effect sizes, negative findings — canine equine distal limb wounds

1. Summary

No veterinary clinical-practice guideline addressing negative pressure wound therapy (NPWT) or distal-limb wound management specifically was located for either species in this pass: a direct fetch of AAHA's own guideline index page failed, a repeat fetch of a 2026 BEVA equine wound-care commentary already cited in the domain dossier also failed, and a targeted PubMed search returned no guideline-type record for either species. Those three independent negative attempts are read together below as the state of the evidence rather than as separate coincidental failures. Beyond the guideline question, this pass surfaced one previously undocumented canine randomized trial that extends the comparative-effectiveness picture already in the domain dossier, two scoping reviews (one equine-general, one NPWT-specific) that both characterize the underlying evidence quality as weak, and a verbatim negative finding — already cited by number in the domain dossier but not previously quoted — describing a canister-free device's dressing failing to hold adhesion in an equine wound model. No registered NPWT trial for either species was found on ClinicalTrials.gov, which is the expected structural absence for a human-subjects registry.

2. What Changed

_Baseline (v1). No prior version; this establishes the starting point for future diffs._

3. Details

Guideline position — three independent negative attempts, not one

A direct fetch of AAHA's own clinical-guideline index page (https://www.aaha.org/for-veterinary-professionals/aaha-guidelines/) returned HTTP 403 on 2026-09-01 and was not retrieved, consistent with the intermittent bot mitigation this repo's other veterinary domain dossiers already record for aaha.org. A repeat fetch of the 2026 Equine Veterinary Education commentary the domain dossier already cites for its "no solid evidence on best practices" line also returned HTTP 403 on this pass; its content is not reproduced here because it was not independently re-retrieved this time [5]. A PubMed search across four guideline-oriented query strings — "AAHA wound management guidelines dog," "AAHA guideline surgical wound canine 2022," "veterinary wound management consensus guideline," "equine wound healing best practice review" — run via connectors literature on 2026-09-01 returned no ACVS-, AAHA-, or AAEP-authored guideline document for either species. A web search located no AAEP consensus statement on wound management either, only unrelated AAEP guideline documents (antimicrobial use, rescue-facility care). Read together, three independent channels — a professional-association site, a peer-reviewed commentary, and PubMed's own index — converge on the same absence: no accessible veterinary clinical-practice guideline sets a position on NPWT, or on distal-limb wound management generally, for dogs or horses.

Pivotal evidence and effect sizes — a previously undocumented canine randomized trial

PMID 29890536, "Comparison of Negative Pressure Wound Therapy and Silver-Coated Foam Dressings in Open Wound Treatment in Dogs: A Prospective Controlled Clinical Trial" (Veterinary and Comparative Orthopaedics and Traumatology, 2018) [1], is a prospective, randomized, matched-pairs design (n=26 dogs, 13 per arm: Group A received NPWT, Group B received silver-coated foam dressing) — distinct from, and not cited in, the domain dossier's retrospective sibling study of the same comparator pairing (PMID 25449799, 2015). Effect sizes, with n, population and date: total time to wound closure was significantly shorter with NPWT (mean 14.2 days) than with silver-coated foam dressing (mean 28.6 days), p=0.018, n=26 dogs, 2018 [1]; wound area on planimetry was significantly smaller in the NPWT arm at days 3, 6, and 9, p<0.05 at every time point, same n/population [1]; and local infection progressed significantly less in the NPWT arm, p=0.01, same n/population [1]. Verbatim: "Total time to closure was significantly (p = 0.018) shorter in Group A (14.2 days) compared with Group B (28.6 days) ... NPWT-treated wounds showed faster closure, improved macro-deformation and less local signs of infection." [1] [single-source]

This is the first randomized (as distinct from retrospective or matched-pair-only) canine comparative trial located across both this report and the domain dossier's own prior search. It only partly closes the domain dossier's stated gap — "no canine or equine randomized controlled trial of NPWT versus conventional bandaging was located" — because the comparator here is silver-coated foam, not conventional bandaging.

Negative and equivocal findings, equine — two reviews and a feasibility failure

PMID 38791717, "The Best Protocol to Treat Equine Skin Wounds by Second Intention Healing: A Scoping Review of the Literature" (Animals, published 2024-05-18) [2], extracted data from 81 manuscripts covering all equine wound-treatment types (not NPWT-specific), with the distal limb the most frequent wound location. Verbatim, with n and date: "All of the case reports, case series, and clinical studies reported positive outcomes with regard to the treatment used, while only 36% of the experimental studies found significant healing improvement in treated wounds compared to control groups" (n=59 experimental studies among 81 included manuscripts, 2024) [2]. This is a general equine wound-treatment mixed-evidence figure rather than an NPWT-specific one, reported here because it bears directly on this domain's evidence-quality question. [single-source]

PMID 37624295, "Negative-Pressure Wound Therapy (NPWT) in Horses: A Scoping Review" (Veterinary Sciences, published 2023-08-06) [3] — already listed in the domain dossier's source list but not previously quoted at abstract depth — screened 24 manuscripts to 15 meeting inclusion criteria. Verbatim: "The existing evidence for the effectiveness of NPWT remains uncertain in equine medicine ... randomized controlled trials should be performed to quantify the benefits and establish precise protocols in horses." [3] [single-source]

PMID 30841889, "Feasibility of a disposable canister-free negative-pressure wound therapy (NPWT) device for treating open wounds in horses" (BMC Veterinary Research, published 2019-03-06) [4] — also already in the domain dossier's source list but not previously quoted — reports an ex vivo experiment followed by a preliminary in vivo experiment on intact skin, intended to extend to an experimental open-wound model. Verbatim: "difficulties with adhesion and seal prevented the completion of the experimental wound study despite the use of many adjunctive adhesives ... The current PICO® dressing design is not suitable to be used as a dressing for open wounds in horses though the device is well tolerated by equine patients." [4] The wound-model portion of the study was not completed because of this failure — a stronger, verbatim statement of the same adhesive/seal problem the domain dossier's own §5 already names from a different, secondhand source. [single-source]

Trial-registry check — the expected structural absence

connectors trials was queried for condition="canine wound" AND intervention="negative pressure wound therapy" (0 records) and condition="equine wound" (16 records inspected, e.g. NCT04848714, NCT00935428, NCT06300255 — all human-subject studies: equine-assisted therapy for PTSD, an antivenin pharmacokinetic trial, a horse-related-injury survey, and similar — none an animal-patient wound trial) [6]. This is the expected structural absence rather than a finding of anything: ClinicalTrials.gov is a human-subjects registry and does not index veterinary trials, the same limitation the domain dossier already records for its epidemiology and reimbursement sections.

4. Sources

[1] Comparison of Negative Pressure Wound Therapy and Silver-Coated Foam Dressings in Open Wound Treatment in Dogs: A Prospective Controlled Clinical Trial — Veterinary and Comparative Orthopaedics and Traumatology (published 2018-07, day not given in the PubMed record; accessed 2026-09-01). PMID 29890536 — https://pubmed.ncbi.nlm.nih.gov/29890536/ [peer-reviewed] [2] The Best Protocol to Treat Equine Skin Wounds by Second Intention Healing: A Scoping Review of the Literature — Animals (MDPI) (published 2024-05-18; accessed 2026-09-01). PMID 38791717 — https://pubmed.ncbi.nlm.nih.gov/38791717/ [peer-reviewed] [3] Negative-Pressure Wound Therapy (NPWT) in Horses: A Scoping Review — Veterinary Sciences (published 2023-08-06; accessed 2026-09-01). PMID 37624295 — https://pubmed.ncbi.nlm.nih.gov/37624295/ [peer-reviewed] [4] Feasibility of a disposable canister-free negative-pressure wound therapy (NPWT) device for treating open wounds in horses — BMC Veterinary Research (published 2019-03-06; accessed 2026-09-01). PMID 30841889 — https://pubmed.ncbi.nlm.nih.gov/30841889/ [peer-reviewed] [5] Ribeiro et al., "Wound healing in horses: What went wrong?" — Equine Veterinary Education (published 2026, day/month not given in the record; re-attempted 2026-09-01, returned HTTP 403 — not retrieved this pass; independently retrieved by the domain dossier on 2026-08-27, not reproduced here). DOI 10.1111/eve.70089 — https://beva.onlinelibrary.wiley.com/doi/10.1111/eve.70089 [other] [6] ClinicalTrials.gov trials query via python3 -m connectors trials --condition "canine wound" --intervention "negative pressure wound therapy" (0 records) and --condition "equine wound" (16 records inspected, including NCT04848714, NCT00935428, NCT06300255 — none veterinary) — ClinicalTrials.gov (queried 2026-09-01; accessed 2026-09-01). https://clinicaltrials.gov/ [trial-registry]

5. Sourcing & Gaps

Well established: the guideline-position absence rests on three independent negative attempts converging on the same result — the AAHA index fetch, the BEVA commentary re-fetch [5], and the PubMed guideline-oriented search described in §3 — which is the closest thing to a corroborated absence this report can state without a directional marker on any single one of them. Nothing else in this report reaches two-source agreement on a positive finding.

Thin: the canine RCT effect sizes [1], the equine general-treatment scoping review's 36% figure [2], the NPWT-specific scoping review's uncertainty conclusion [3], and the PICO adhesion-failure finding [4] each rest on exactly one study and carry [single-source].

Rescoped from class 3: none. This report answers class-2 (published-finding) and class-1 (registry-absence) questions only; no stakeholder-future question was posed or answered here.

Out of scope: human NPWT clinical guidelines (e.g., wound-care-society consensus documents) were treated as out of this domain's declared species scope and not reviewed, consistent with the domain dossier's own treatment of human NPWT literature as market/regulatory backdrop rather than clinical-evidence content for this domain. CPT descriptors, veterinary datasets requiring a paid license, and any patent-landscape check remain out of scope for the same reasons the domain dossier already states.

Not searched vs. not found: the guideline question is found-and-negative — both a targeted fetch and a targeted PubMed search were run and returned nothing — not merely unsearched. The AAHA guideline index fetch is likewise found-and-negative (a 403 response, not an absence of attempt). The underlying Schnierer et al. equine case series the domain dossier's own §4 cites secondhand was not searched again this pass; it remains available only at second hand via a commentary this report could not re-retrieve (HTTP 403, [5]).

[inference] The canine RCT [1] and the domain dossier's retrospective study (PMID 25449799) share a comparator-arm design (NPWT vs. silver-coated foam) and a similar journal; this report does not assert they share authorship, institution, or patient population, since neither abstract states that and no full text was retrieved to check either way.

6. Claim Candidates