Busting myths around stem cell therapy

When most veterinarians hear the term "stem cell therapy," their minds often go to autologous procedures – tissue harvested from the patient, processed by a company, and then injected back into the same patient days later. That was the old way of regenerative medicine. Now the field has advanced.

We are entering a new era defined by allogeneic therapies–stem cells derived from healthy donor tissue, manufactured in FDA-regulated facilities, and stored for use across multiple patients. Unlike autologous products, which have minimal regulatory oversight or published standards, allogeneic stem cell therapies are classified as drugs and must meet FDA requirements for safety, effectiveness, and manufacturing quality. These therapies are scalable, quality-controlled, and ready-to-use, representing a fundamentally new category in veterinary medicine.

This progress is exciting, and recent data shows that nearly half of veterinarians report high intent to adopt regenerative therapies in their practice.¹ Yet despite growing interest, misconceptions remain. Many of the concerns I hear day-to-day stem from outdated models or an incomplete understanding of how stem cells function in clinical care.

This article will walk through the most common misconceptions I encounter, alongside what the current science, regulation, and clinical data actually support.

Myth: Autologous and allogeneic stem cells are similar

Truth: Not all stem cells are the same

The quality and function of stem cells vary significantly depending on their source, consistency, and biological characteristics. Here’s how those differences play out in practice:

Stem cell quality: Stem cell yield, identity, viability, quality, and potency can vary widely depending on harvest site, processing methods, and patient health. This variability makes treatments from various sources inequivalent. Allogeneic or “ready-to-use” stem cells are pre-dosed and quality-controlled under stringent GMP-compliant manufacturing conditions, allowing for consistent and predictable administration.

Age: Multiple studies have shown that aging negatively affects MSC functionality.^2,3 Stem cells from older animals show reduced proliferation, impaired ability to form bone and cartilage, increased senescence, and decreased migratory capacity. This matters, as regenerative therapies can greatly impact how we treat age-related diseases, such as arthritis and chronic kidney disease, and using autologous cells from older patients may be less effective in these cases.²

Illness: MSCs harvested from sick or inflamed animals tend to have reduced potency. Research in humans with inflammatory conditions shows these cells can have impaired immunomodulatory effects compared to MSCs from healthy donors.² This limits the therapeutic potential of autologous options in diseased animals.

Most autologous therapies are sourced from adipose tissue, which contains a large volume of other cells. This total volume of cells is referred to as the stromal vascular fraction (SVF), and it is the SVF that is typically administered to the patient. Within the SVF, a small portion (~10%) are actually stem cells. Cells from SVF have different immunogenic potential compared to a pure MSC product, therefore, they cannot be viewed as equivalent stem cell therapies.^4,5

Accessibility: Allogeneic stem cells are ready-to-use and will be available on demand once FDA-approved. Harvested from FDA-qualified, healthy donors and manufactured in GMP-compliant labs, they are shipped frozen and can be thawed and administered as needed. These cells remain stable for 18+ months if stored under appropriate conditions.

Image created in BioRender

Myth: Stem cell therapy is the “wild west” with no oversight

Truth: There is a rigorous regulatory process

While this may have been true for earlier, loosely regulated options, today’s legitimate allogeneic stem cell therapies are progressing through formal FDA pathways. Just like any other veterinary drug, they are regulated by the FDA’s Center for Veterinary Medicine (CVM).

For serious conditions with limited alternatives, like refractory feline chronic gingivostomatitis (FCGS), the CVM offers a conditional approval pathway for minor conditions in a major species (MUMS). The conditional approval pathway allows therapies to reach patients quickly after meeting FDA requirements for safety, efficacy, and manufacturing standards. There are not yet any FDA-approved, ready-to-use allogeneic stem cell therapies in veterinary medicine.

Myth: Intravenous stem cells just get trapped in the lungs

Truth: The lungs help promote anti-inflammatory activity of IV stem cells AND MSCs still reach their target

This myth misrepresents the biodistribution and function of MSCs. Yes, many MSCs do initially localize in the lungs after IV administration. While there, they influence the pulmonary macrophages to shift toward an anti-inflammatory (M2) phenotype. These macrophages can then leave the lungs and exert anti-inflammatory effects elsewhere. After passing through the lungs, many viable MSCs migrate to peripheral organs, including the liver, spleen, heart, and even brain, guided by inflammatory signals.^6-9 Immediately after injection, MSCs exert paracrine effects – secreting cytokines and growth factors that influence immune cells in the bloodstream and tissues, allowing MSCs to modulate immune responses and promote restoration, even without long-term tissue engraftment.^10,11

Myth: Allogeneic stem cells are rejected by the immune system

Truth: Immune reactions are rare and short-lived

Allogeneic stem cells are generally well-tolerated, with a low risk of immune response or rejection.^12-14 MSCs are considered “immune-evasive” or “immune-privileged” because they lack MHC class II expression and display only low levels of MHC class I molecules. This limited expression helps them avoid detection by both the innate and adaptive immune systems.

When delivered intravenously, MSCs primarily act through paracrine signaling, influencing nearby cells rather than integrating long-term. Since they typically remain in the body for only a short time, the likelihood of delayed or lasting immune reactions is minimal.

Myth: Stem cells can form tumors

Truth: There is no evidence to date that MSCs cause tumors

This concern often comes from confusion around the different types of stem cells. They are classified into four main categories, based on their range of differentiation – from the most versatile to the most specialized:

• Totipotent: Can form all body and extraembryonic tissues (e.g., placenta); found only in the earliest embryonic stages.
• Pluripotent: Can become any cell in the body but not extraembryonic tissue; includes embryonic stem cells and induced pluripotent stem cells (iPSCs).
• Multipotent: Found in adult tissues; can become several cell types within a specific lineage. This includes MSCs, the type most commonly used in therapy.
• Unipotent: Found in adult tissues; can form only one cell type but can self-renew.

Totipotent and pluripotent stem cells (those with the ability to form all tissue types) do carry a low tumorigenic risk. However, the MSCs used in veterinary medicine are multipotent, meaning they can only differentiate into a few specific cell types (like bone, cartilage, or fat). Their role is to support repair, not regenerate entire organ systems, making tumor formation highly unlikely.

Myth: Stem cells should only be used when other treatments fail

Truth: Their ability to target disease at its root makes them a strong early option

MSCs work by reducing inflammation, modulating immune responses, and supporting tissue repair. They don’t just mask symptoms; they target underlying pathology.

That makes them ideal for early intervention, especially in conditions like osteoarthritis, chronic kidney disease, and several immune-mediated diseases. In human medicine, stem cells are increasingly used as part of a multimodal approach, not a last-ditch effort. Waiting until all else fails may actually limit the potential benefits of regenerative therapy.

Myth: All stem cell therapies come from embryos

Truth: Stem cells are sourced from adult tissues like fat and uterus in veterinary medicine

Stem cells used in clinical trials in support of FDA approval are derived from adult tissues, such as fat or uterus, and are collected from healthy donors. No embryonic tissue is used in these preparations.

For example, Gallant uses uterine-derived stem cells from FDA-qualified, pathogen-free donors. Uterine tissue offers several advantages as a stem cell source: it is abundantly available, collected non-invasively during routine procedures, and provides a consistent supply for manufacturing. By using tissue that would otherwise be discarded, this approach also aligns with principles of ethical sourcing and sustainability.

Myth: Stem cell therapy will be too expensive for most clients

Truth: Stem cell therapy is more affordable than it may seem

While regenerative medicine may sound high-cost at first mention, when you compare it to the long-term costs of chronic disease management, the picture shifts.

Take NSAIDs, which are often a first-line treatment for osteoarthritis and chronic inflammation. At a typical dose and weight range, they can cost $60 to $90 per month, not including the recommended bloodwork and regular check-ins needed to monitor for side effects.

Monoclonal antibodies offer a newer approach but require monthly injections and can cost $120 to $200 per dose, depending on the size of the animal.

Cyclosporine, used for a variety of immune-mediated diseases, can run between $80 to $150 per month, often indefinitely, especially when paired with additional supportive therapies.

Allogeneic stem cell therapy will be no higher in cost than these commonly used treatments, and in many cases, may cost less. It typically involves just 2 injections, spaced 2 weeks apart. That simplicity can lead to fewer follow-ups, reduced reliance on long-term medications, and lower overall expenses – not to mention greater peace of mind and a better quality of life for the pets we care for.

Myth: Administering stem cells requires complex tools or facilities

Truth: No special equipment required – it’s as easy as an IV injection

In truth, allogeneic stem cell therapies are delivered just like any slow IV injection. No specialized training or infusion pumps are needed.

At Gallant, for example, therapies arrive frozen, are thawed in-clinic, diluted in saline, and administered via a peripheral IV catheter. The process takes just a few minutes, with post-treatment monitoring for 1-2 hours.

This makes regenerative therapy far more practical and scalable than earlier autologous protocols, which often required anesthesia, tissue collection, and lab harvesting.

A new category in veterinary medicine

Stem cell therapy is not futuristic or experimental anymore. It’s here – and it’s being held to the same standards as any other veterinary drug. With continued research and FDA-reviewed pathways, regenerative medicine is moving from promise to practice. As a profession, this opens the door to something deeper than symptom management. It’s a chance to address the underlying disease process – to help pets not just feel better, but get better.

References

1. Gallant Staff. Veterinarians Agree: Current Treatments Manage Symptoms; Anticipate Regenerative Options – Gallant Study. Gallant. Published June 30, 2025. Accessed July 30, 2025. https://www.gallant.com/blog/veterinarians-agree-current-treatments-manage-symptoms-anticipate-regenerative-options-gallant-study/
2. Durand N, Zubair AC. Autologous versus allogeneic mesenchymal stem cell therapy: The pros and cons. Surgery. 2022;171(5):1440-1442. doi:10.1016/j.surg.2021.10.057
3. Taguchi T, Borjesson DL, Osmond C, Griffon DJ. Influence of Donor’s Age on Immunomodulatory Properties of Canine Adipose Tissue-Derived Mesenchymal Stem Cells. Stem Cells Dev. 2019;28(23):1562-1571. doi:10.1089/scd.2019.0118
4. Tran TDX, Pham VQ, Tran NN, et al. Stromal Vascular Fraction and Mesenchymal Stem Cells from Human Adipose Tissue: A Comparison of Immune Modulation and Angiogenic Potential. Adv Exp Med Biol. Published online April 8, 2022. doi:10.1007/5584_2022_708
5. Maslennikov, Serhii & Golovakha, Maksym. (2023). The most commonly used cell surface markers for determining mesenchymal stromal cells in stromal vascular fraction and bone marrow autologous concentrate: a systematic review. Journal of Biotech Research. 14. 85-94
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7. Barbash IM, Chouraqui P, Baron J, et al. Systemic Delivery of Bone Marrow–Derived Mesenchymal Stem Cells to the Infarcted Myocardium: Feasibility, Cell Migration, and Body Distribution. Circulation. 2003;108(7):863-868. doi:10.1161/01.CIR.0000084828.50310.6A
8. Fukumura S, Sasaki M, Kataoka-Sasaki Y, et al. Intravenous infusion of mesenchymal stem cells reduces epileptogenesis in a rat model of status epilepticus. Epilepsy Res. 2018;141:56-63. doi:10.1016/j.eplepsyres.2018.02.008
9. Kahts M, Mellet J, Durandt C, et al. A proof-of-concept study to investigate the radiolabelling of human mesenchymal and hematopoietic stem cells with [89Zr]Zr-Df-Bz-NCS. EJNMMI Radiopharm Chem. 2024;9(1):82. doi:10.1186/s41181-024-00311-w
10. Lu D, Jiao X, Jiang W, et al. Mesenchymal stem cells influence monocyte/macrophage phenotype: Regulatory mode and potential clinical applications. Biomed Pharmacother. 2023;165:115042. doi:10.1016/j.biopha.2023.115042
11. Abumaree MH, Al Jumah MA, Kalionis B, et al. Human Placental Mesenchymal Stem Cells (pMSCs) Play a Role as Immune Suppressive Cells by Shifting Macrophage Differentiation from Inflammatory M1 to Anti-inflammatory M2 Macrophages. Stem Cell Rev Rep. 2013;9(5):620-641. doi:10.1007/s12015-013-9455-2
12. Williams ZJ, Pezzanite LM, Chow L, Rockow M, Dow SW. Evaluation of stem-cell therapies in companion animal disease models: a concise review (2015-2023). Stem Cells. 2024;42(8):677-705. doi:10.1093/stmcls/sxae034
13. Baranovskii DS, Klabukov ID, Arguchinskaya NV, et al. Adverse events, side effects and complications in mesenchymal stromal cell-based therapies. Stem Cell Investig. 2022;9:7-7. doi:10.21037/sci-2022-025
14. Thompson M, Mei SHJ, Wolfe D, et al. Cell therapy with intravascular administration of mesenchymal stromal cells continues to appear safe: An updated systematic review and meta-analysis. EClinicalMedicine. 2020;19:100249. doi:10.1016/j.eclinm.2019.100249