The companies in this field, what each one claims, and what their evidence actually shows. Stated fairly — where a competitor’s evidence is genuinely good, we say so.
Including ourselves
We include ourselves in this comparison. Our own exosome line sits in the same evidence tier as most of the products below — no published in-vivo clinical efficacy study in dogs or cats. The difference we claim is disclosure and documentation, not proof.
Autologous adipose-derived stem cell processing service for dogs, cats and horses (the clinic ships fat, VetStem's Poway CA lab processes and returns cells), PrecisePRP Canine and Equine off-the-shelf pooled freeze-dried platelet-rich plasma, and autologous cell banking. StemStat Ortho, an off-the-shelf allogeneic canine osteoarthritis product, is in development.
Model
Clinic-direct service bureau plus veterinarian credentialing and a cell-banking subscription; holds exclusive licenses to over 70 patents by its own account.
What they sayVetStem states it has processed over 40,000 stem cell treatments as of April 2025, and describes PrecisePRP Canine as the first FDA-reviewed allogeneic off-the-shelf cell medicine product.
What the evidence showsVetStem has the best single canine dataset in this category and that deserves saying: a prospective, randomized, masked, placebo-controlled trial across nine US clinics, 74 dogs analysed, found 79.2% owner-assessed success versus 55.4% placebo (p=0.029). Three things travel with it honestly. That trial tested an allogeneic product, while the flagship commercial service is autologous. The placebo arm itself succeeded 55.4% of the time, so the absolute benefit was about 24 percentage points. And the authors explicitly did not address cartilage regeneration, so no cartilage-regrowth claim is supported by it. Separately, the PrecisePRP description is accurate as written: FDA made a risk-based safety and quality determination, not an efficacy approval, and shortening it to FDA-approved would be false.
Regulatory note: The autologous service is not FDA-approved and is marketed under the lower-enforcement-priority posture of FDA CVM guidance GFI #218. PrecisePRP Canine and Equine appear on FDA's public risk-reviewed ACTP list, which is a safety and quality determination with enforcement discretion, not an approval and not a finding that the product works. StemStat Ortho is neither approved nor conditionally approved and no peer-reviewed efficacy data for it was located.
Nothing commercially as of September 2026. Five investigational allogeneic off-the-shelf uterine-derived mesenchymal stem cell programs: sonruvetcel for refractory feline chronic gingivostomatitis (lead), intravenous canine osteoarthritis, feline osteoarthritis, feline chronic kidney disease and canine atopic dermatitis. The stem cell banking business it launched with in 2019 is no longer offered.
Model
Development-stage pharmaceutical company pursuing FDA new-animal-drug approval, including the expanded conditional approval pathway. San Diego; $18M Series B closed 2025 to fund manufacturing.
What they sayGallant reports that its feline gingivostomatitis program has a completed FDA technical section for safety, and that an 88-dog randomized, blinded, placebo-controlled pilot of intravenous stem cells for canine osteoarthritis showed statistically significant improvement in validated owner-reported outcomes at days 60 and 90. Its own release states the product is investigational and has not received FDA approval or conditional approval.
What the evidence showsGallant is doing the thing most of this category avoids: going through FDA's actual approval process with an investigational new animal drug file, and saying out loud on its own materials that the product is investigational. That is a genuine and citable contrast with sellers who assert an exemption. The limit is equally plain: the canine osteoarthritis pilot is a press release with no p-values, no effect sizes and no confidence intervals disclosed, and it is not peer-reviewed or published. Its strongest published evidence is not its own product but the two UC Davis co-authored uterine-cell trials in cats with severe mouth disease, which are the highest-quality feline cell-therapy papers in existence and were safety-led, not placebo-controlled. Gallant does not currently claim efficacy, and neither should anyone on its behalf.
Regulatory note: No Gallant product is FDA-approved or conditionally approved. FDA's hub page and its risk-reviewed ACTP list both still showed no approved or conditionally approved animal cell or tissue product at their most recent stated update dates, and neither mentions Gallant. Whether conditional approval for sonruvetcel has since been granted should be re-checked against FDA's own pages before any statement is published.
Ardent Animal Health (the 2020 rebrand of MediVet Biologics)
ActiStem in-clinic adipose stem cell therapy kits, PRP therapy, spay and neuter cell banking, and ArdentOnco for oncology. Nicholasville, Kentucky.
Model
Sells kits, reagents, equipment and training so the veterinary practice processes the cells in-house and same-day, with a lab-processing fallback and cell banking. A product-and-consumable plus continuing-education model, structurally different from a central service bureau.
What they sayArdent reports over 20,000 treatments globally. Under the MediVet name the company issued a 2016 release saying a double-blind randomized placebo-controlled study scientifically proved significant improvement in pets with hip osteoarthritis.
What the evidence showsThe study behind that release was a 22-dog pilot, 10 treated and 12 placebo, at Kansas State University, giving stem cells and platelet-rich plasma together by two routes at once. A 22-dog pilot of a combination treatment cannot scientifically prove efficacy, and the citation itself could not be verified in PubMed during this research, so it should be checked directly at the journal before being cited at all. It is fair to note what FDA did next as a matter of public record: on 22 October 2024 FDA issued Ardent a warning letter (MARCS-CMS 662394) stating that ActiStem and PureVet PRP were unapproved new animal drugs, citing sections 301(a), 512(a) and 501(a)(5) of the Food, Drug and Cosmetic Act, and quoting the company's own marketing, including claims that the therapy rebuilds and regenerates cartilage. Those products were made from the patient animal's own cells, and FDA applied the unapproved-new-animal-drug charge anyway.
Regulatory note: Received an FDA warning letter dated 22 October 2024, MARCS-CMS 662394, for marketing unapproved new animal drugs. This is a matter of public record on FDA's own site. Separately, FDA guidance GFI #218 states that persons using in-clinic cell processing systems are themselves manufacturers subject to current good manufacturing practice, registration and drug listing, which means an in-clinic kit model transfers that regulatory exposure to the customer clinic.
The former name of the same Kentucky company, which relaunched as Ardent Animal Health in 2020. The MediVet brand still appears on affiliate and clinic pages marketing in-clinic adipose stem cell therapy for dogs and cats.
Model
Historic in-clinic processing kit and training model; identical to Ardent's, under the earlier brand. Not a separate company.
What they sayA figure circulating on MediVet-affiliated clinic pages states that in a recent randomized sampling of 155 canines suffering from osteoarthritis, over 95% showed improvements as reported by the treating veterinarians.
What the evidence showsThat 95% figure has no control group, no blinding, no published protocol and no publication, and the assessment was made by the treating veterinarian, who is neither blinded nor financially disinterested, on a company-selected sample. Set against the 55.4% placebo success rate measured in the one properly controlled canine osteoarthritis trial in this field, a 95% uncontrolled improvement rate carries no information about whether the treatment worked. It is worth knowing this brand and Ardent are the same company, because a reader comparing MediVet and Ardent may believe they are seeing two independent sources.
Regulatory note: MediVet Biologics and Ardent Animal Health are the same legal entity under different brand names; the October 2024 FDA warning letter (MARCS-CMS 662394) was issued to Ardent Animal Health, LLC. MediVet Biologics should not be confused with Aratana Therapeutics, a separate Kansas company acquired by Elanco in 2019 that had no regenerative-medicine product.
Spryng with OsteoCushion, an injectable collagen-elastin hydrogel microparticle product given into the joint for lameness and osteoarthritis in dogs, cats and horses. Launched to veterinarians in 2021; manufactured in an ISO 7 clean room in Minneapolis.
Model
Distributor-led veterinary device sales through Vedco and Clipper, reachable via MWI and Covetrus, plus direct-to-clinic sales and in-licensing of human device technology for pet use. Publicly traded, OTCQB: PETV.
What they sayPetVivo states that Spryng is classified as a veterinary medical device and that pre-market approval is not required by FDA, that more than 2,000 horses and dogs have been treated, and it announced a peer-reviewed clinical study of Spryng published in Veterinary Record in July 2026.
What the evidence showsThe Veterinary Record paper is real peer-reviewed work and that should be credited. Read its design, though: 40 client-owned dogs, proof-of-concept, no control group, blinding not specified, company-funded, and 55% of dogs reached at least a 25% improvement on the pain score at 84 days. The authors' own word for what they showed was feasibility. Because the one properly controlled canine osteoarthritis trial in this field measured a 55.4% placebo response, an uncontrolled 55% response rate cannot be separated from placebo. PetVivo also discloses in its federal filing that the foundational safety and efficacy study for Spryng was done in rabbits in 2007, and states candidly that later university studies exist largely because distributors require a third-party study before catalog listing.
Regulatory note: Marketed on a veterinary medical device pathway, which is why no FDA pre-market approval was required and why no regulator has assessed whether it works. Health Canada issued an acknowledgement of Spryng as a veterinary medical device in January 2026, which is an acknowledgement and not an approval. PetVivo's FY2026 10-K carries an auditor's going-concern paragraph, reporting $1,141,607 revenue against a $10,473,672 net loss.
Librela (bedinvetmab), a monthly injected anti-nerve-growth-factor monoclonal antibody for osteoarthritis pain in dogs; Solensia (frunevetmab), the feline equivalent; Cytopoint (lokivetmab) for canine atopic dermatitis; plus Lenivia and Portela, three-month-interval anti-NGF antibodies approved in Canada and the EU during 2025.
Model
Full pharmaceutical model: FDA-approved new animal drugs sold through veterinary distribution, supported by direct-to-owner advertising. FY2025 revenue $9.5B with a $6.587B companion animal segment.
What they sayZoetis markets these as approved treatments for osteoarthritis pain, supported by peer-reviewed pivotal placebo-controlled trials, and has published its own global pharmacovigilance analysis reporting 9.48 adverse events per 10,000 doses across 18.1 million doses sold, concluding that the most reported events are rare or very rare.
What the evidence showsThese are the only genuinely FDA-approved products in the canine osteoarthritis injectable space, and the efficacy is real but more modest than the marketing implies. In the US registration trial, day-28 success was 47.4% on the drug versus 36.6% on placebo, p=0.0410, with a number-needed-to-treat of about 9. Objective force-plate gait analysis found the injection non-inferior to a daily oral tablet, not superior. On safety the honest position is that the evidence is conflicting: FDA issued a Dear Veterinarian Letter in December 2024, the US label gained a post-approval experience section in February 2025, independent specialists have published a nine-fold reporting asymmetry and a mechanistic argument about rapidly progressive osteoarthritis, Zoetis has published a rebuttal, and a separate methodological critique has been published too. Disproportionality analysis shows a reporting difference and cannot establish cause in either direction. For cats, the approved product's measured effect sizes were 0.18 to 0.3, and skin disorders were significantly more frequent in treated cats in the pivotal trial.
Regulatory note: Fully FDA-approved new animal drugs. Librela is NADA 141-562, approved 5 May 2023. FDA CVM guidance GFI #218 does not apply, because monoclonal antibodies are excluded from it and went through the full new-animal-drug approval route. FDA issued a Dear Veterinarian Letter on Librela adverse events dated 16 December 2024 and the US label was updated in February 2025.
ArthramidVet, a 2.5% cross-linked injectable polyacrylamide hydrogel at 25 mg/mL given into the joint. A biomaterial, not a biologic. Equine-first, extending into dogs and cats.
Model
Prescription veterinary product sold clinic-direct and through distribution; registered as a prescription product for horses in Australia and New Zealand since 2020.
What they sayContura's marketing says 2.5% polyacrylamide hydrogel changes the osteoarthritis landscape in multiple species, and its published canine paper reports that 82% of owners rated their dog somewhat better or much better, that 44% of dogs on pain medication reduced or stopped it, and that 90% of owners would consider repeating the injection.
What the evidence showsThe equine evidence is genuinely good, and a published review describes 82.5% of horses free of lameness at two-year follow-up while the author also notes most of those studies had limitations. The canine evidence is a different matter and the authors say so themselves. It is an anonymous owner survey of 100 respondents from 191 contacted, a 52% response rate, retrospective, with no control group, no blinding and a manufacturer co-author. Their own closing sentence is that controlled, prospective studies are needed to confirm its clinical efficacy. The fair criticism is not of the paper, which is honest, but of importing equine trial-grade evidence into dogs and cats where the evidence is one survey.
Regulatory note: Registered as a prescription (S4) product for intra-articular treatment of non-infectious lameness in horses in Australia and New Zealand since 2020. No canine registration was located; canine and feline use in the US and UK is off-label extension of an equine product. As a biomaterial device rather than a cell product it sits outside the animal cell and tissue product framework, which is why no regulator has assessed canine efficacy.
Synovetin OA, a tin-117m radioactive colloid microparticle suspension injected into the elbow joint, 2 to 4 mCi per mL in single patient-dose vials. Buford, Georgia.
Model
Licensed-clinic model: the practice must hold a radioactive-materials licence to administer it, which slows rollout and creates a moat. Its 100th licensed veterinary hospital was announced in November 2025.
What they sayExubrion markets tin-117m as having shown evidence of powerful disease-modifying properties and clinical outcomes that strongly support a positive disease-modifying mechanism, alongside a year-long pain relief message.
What the evidence showsThe year-long pain relief message is the better-supported half: the open-label data run out to 270 to 365 days, and in a 14-dog study over 70% of owners reported treatment success at all time points. The disease-modifying claim is not supported by any controlled canine trial. Not one canine efficacy study has a placebo or control arm; the efficacy studies are 9, 14 and 23 dogs, the largest study overall is a 44-dog dose-finding study, and the company's own pilot authors wrote that future studies with larger numbers and with a placebo group are needed. The single study that looked directly at structural progression found no significant difference in osteoarthritis progression between elbows given one injection and elbows given two, which is a null result on exactly the question a disease-modifying claim rests on.
Regulatory note: Marketed as a tin-117m microparticle suspension veterinary device, again a device pathway with no FDA efficacy approval located. Radiopharmaceutical handling is separately regulated by the Nuclear Regulatory Commission or an Agreement State, which is why only licensed hospitals can administer it.
DogStem, a suspension for injection containing 6.5 to 9 million equine umbilical cord mesenchymal stem cells, given into the hip or elbow of dogs with osteoarthritis. Horse cells injected into dogs. EquiCord SL, Madrid; UK distribution via TVM.
Model
Licensed pharmaceutical sold as a prescription-only veterinary medicine through veterinary distribution in the EU and UK. The real pharma model in pet cell therapy.
What they sayDogStem is marketed as delivering improvement in function and reduction of pain and lameness in mild to severe hip and elbow osteoarthritis, with three to more than twelve months of efficacy following a single dose.
What the evidence showsThis is the strongest regulatory position in pet cell therapy anywhere and it should be stated plainly: the European Commission granted a marketing authorisation on 17 June 2022, and the pivotal trial was a multicentric, double-blinded, randomized, placebo-controlled study of 80 client-owned dogs with force-platform gait analysis. At week 8, 63% improved on gait analysis, 77% on orthopaedic examination and 65% of owners judged quality of life improved. Two honest cautions travel with it. The published headline figures are within-group response rates rather than treatment-versus-placebo differences, and in a field where placebo response on owner-reported measures runs 28% to 55%, the delta is the number that matters and it is not in the abstract. And the duration claim rests on 59% of owners recalling more than six months of effect in an 18-month owner-recall follow-up, which is the weakest part of the dataset. EMA saw the full data and authorised the product, which is real validation.
Regulatory note: Holds a European Commission marketing authorisation dated 17 June 2022, procedure EMEA/V/C/005829, and is also authorised in the UK as a prescription-only veterinary medicine. It is not FDA-approved and is not available in the United States. Any claim that there is no licensed stem cell treatment for dogs needs a jurisdiction attached, because in the EU and UK there is one.
Arti-cell Forte, chondrogenic-induced equine allogeneic peripheral blood-derived mesenchymal stem cells given as a single injection into the joint, for mild to moderate recurrent lameness from non-septic joint inflammation in horses. Horses only, with no dog or cat indication.
Model
Large pharmaceutical company product, developed by Global Stem cell Technology, which Boehringer Ingelheim acquired.
What they sayBoehringer Ingelheim describes Arti-cell Forte as the first ever registered stem cell based veterinary medicine.
What the evidence showsThat claim is accurate as a matter of regulatory record: the European Commission granted the marketing authorisation on 9 April 2019, and it was the first stem cell based product authorised in animal health anywhere. It matters here for one reason and it is an honest one, which is that it proves a stem cell product can pass a real regulator when a properly powered placebo-controlled trial is done. It also matters that it is for horses only. Nothing about this authorisation says anything about what stem cells do for a dog or a cat, and a seller who invokes it while selling a dog product is borrowing credibility across a species line.
Regulatory note: European Commission marketing authorisation dated 9 April 2019, equine only. Not FDA-approved and no canine or feline indication exists. It is the counterexample to the claim that no stem cell product can be licensed, and it is also a reminder that the licence is species-specific and indication-specific.
ePEP-01, described by the company as a cell-free, shelf-stable platelet-derived biologic. Note that it is platelet-derived rather than stem-cell-derived. Lead program is equine musculoskeletal disease, with a stated pipeline in canine musculoskeletal, skin, wound healing, eye, respiratory and heart conditions.
Model
Development-stage animal health company spun out of RION, built on Mayo Clinic research, with exclusive global veterinary rights to RION's platform. Series A funded.
What they sayRION Vet states that its lead program is under the purview of FDA's Center for Veterinary Medicine and that ePEP-01 has been evaluated in over 50 horses for more than four years, showing improvement in lameness with favourable safety.
What the evidence showsThis is the most legitimate regulatory posture among companies selling into the exosome and cell-free space, because it names a sponsor pursuing an actual FDA pathway rather than asserting an exemption, and that is worth crediting. The evidence is still a press-release claim: no peer-reviewed publication of the 50-horse experience was located in PubMed. One detail is worth noticing. The launch release was reissued with the headline changed from first-in-class exosome biologics to first-in-class biologic therapeutic, a deliberate softening of the word exosome that tells you how carefully this term is now being handled.
Regulatory note: No approved product. The company states it is pursuing an FDA Center for Veterinary Medicine pathway for the equine lead program. Nothing on FDA's risk-reviewed animal cell and tissue product list corresponds to this product, and FDA states that no such products are FDA-approved.
Off-the-shelf, room-temperature biologics described as containing exosomes and growth factors, sourced from tissues collected during the natural birth of healthy foals. Marketed for equine soft-tissue injuries and for companion animal use.
Model
Direct product sales to veterinary practices, supported by named practitioner testimonials including sport-horse team veterinarians.
What they sayHilltop Bio states that exosomes and growth factors are naturally occurring components involved in intercellular communication, that veterinary products are regulated differently from human drugs and not all require FDA approval, and that it is actively engaging with FDA's Center for Veterinary Medicine. It also states openly that not all of its data is published in peer-reviewed journals.
What the evidence showsCredit the transparency: the company says on its own site that not all its findings are peer-reviewed, which is more than many sellers do. No peer-reviewed trial of Regenaflex was located. The regulatory sentence needs care. It is true in the abstract that some veterinary products do not require approval, but FDA's own page states that no animal cell, tissue and cell- or tissue-based product is FDA-approved and that marketing an unapproved one is illegal, and the four products on FDA's risk-reviewed list are all plasma or platelet products with no exosome product among them. A cell-derived product making structure or function claims is not one of the categories that sentence covers.
Regulatory note: No approved product and none on FDA's risk-reviewed list. FDA's own December 2019 public notification specifically named the pattern of claiming that a product falls outside FDA regulatory authority, so this framing should not be copied. Products derived from cells or tissues fall inside FDA's animal cell and tissue product definition, which explicitly covers articles derived from cells.
A point-of-care veterinary system for horses, described as based on exosomal activation of the horse's own adipose tissue, marketed for tendon and ligament injuries, joint and cartilage degeneration, post-surgical and post-trauma support, and skin and chronic inflammatory conditions. Equine only.
Model
Point-of-care autologous processing system sold to equine practices, so the clinic performs the processing itself.
What they sayMilligraft advertises that the system delivers billions of mesenchymal stem cells and autologous exosomes, and cites a general scientific bibliography and peer-reviewed publications.
What the evidence showsThe four claimed indications are four different disease mechanisms, and no located trial supports any of them for this specific product. The dose claim is the clearest problem: billions is not a product specification, because it gives no particle count method, no protein content and no purity measure. International guidance on extracellular vesicle reporting, MISEV2023, discourages using exosome as a generic label at all, and FDA has stated there are no quality control standards for manufacturing extracellular vesicles that would let a commercial product be validated. There is also a structural point worth knowing: FDA guidance states that persons using in-clinic cell processing systems are themselves manufacturers, which means a point-of-care kit moves that regulatory obligation onto the clinic that buys it.
Regulatory note: No regulatory status claim is made on the product page and none was located. Equine only. Under FDA guidance GFI #218 a point-of-care autologous processing system makes the administering clinic a manufacturer subject to current good manufacturing practice, registration and drug listing requirements.
The stem cell procedure itself rather than a product, through what it describes as the UK's only dedicated stem cell clinic focused solely on treating joint conditions in dogs and cats.
Model
Direct-to-owner dedicated clinic. Consultation £250, and it states that stem cell therapy for hip joints plus complementary regenerative therapies will cost an average of £7,950, which it says is usually covered by pet insurance.
What they sayStem Cell Vet states that the treatment can reduce pain and increase mobility, may restore cartilage and lessen painful movement, that benefits can often last the dog's lifetime, and that in the majority of cases a dog will only ever need one treatment.
What the evidence showsNo citations are given on that page for any of those statements. Two of them run against the published record. The best canine stem cell trial in existence explicitly states that cartilage regeneration was not addressed, and no canine study located demonstrates cartilage restoration. On duration, the longest follow-up in any canine cell therapy trial located is 18 months, in which 59% of owners recalled more than six months of effect, so a lifetime-of-benefit claim has no dataset behind it. The page also offers professional registrations in place of evidence, and professional registration is not efficacy data. This is the most aggressive claim set located in this landscape, and at roughly £8,000 per treatment the gap between the claim and the evidence matters a great deal to the owner paying it.
Regulatory note: Described in independent UK sources as an unlicensed stem cell treatment, in contrast to DogStem, which is licensed in the UK. A culture-expanded autologous equivalent offered in the United States would fall into FDA's Autologous Type I category under GFI #218, which requires an approval and has no lower-enforcement-priority carve-out.
Formerly XoGlo, XoGlo Pro and Amnio2X, human perinatal exosome products. No veterinary product line was located and the company's veterinary web path returns a 404.
Model
Human-market exosome manufacturer. Any product from these names appearing in a veterinary clinic reached that clinic outside an authorised veterinary channel.
What they sayKimera has represented to FDA that it ceased manufacturing and distribution of XoGlo, XoGlo Pro and Amnio2X, and FDA closed out its warning letter on 12 June 2026 after a follow-up inspection found no evidence of continued manufacturing or distribution.
What the evidence showsThis entry exists because Kimera exosomes are still named in pet-market conversation, and an owner deserves the actual facts. FDA issued the company a warning letter dated 1 September 2023 over those three products; the company told FDA it had stopped making and distributing them; FDA closed the letter out in June 2026 on that basis. No authorised veterinary channel was located, so any pet exosome product traced to these names is diverted from a human product line that the manufacturer has told FDA it no longer makes. There is no veterinary efficacy evidence to assess, because there is no veterinary product to assess.
Regulatory note: FDA warning letter dated 1 September 2023 (MARCS-CMS 649343), closed out 12 June 2026 after the company represented it had ceased manufacturing and distribution. FDA maintains a standing public safety notification that there are no FDA-approved exosome products for any species and that exosomes intended to treat disease are regulated as drugs or biologics requiring pre-market approval.
