Immune Support for Dogs: The Science Behind Turkey Tail, Reishi, Curcumin & Fisetin

Published by the SciRouter Editorial Team for general educational purposes. Last updated June 2026. This article is informational only and is not veterinary advice — always consult your own veterinarian. · Estimated read time: ~16 minutes

What does the science actually say about mushroom and polyphenol immune support for dogs?

The honest, short answer: turkey tail polysaccharopeptide (PSP) has the deepest research base of the four — including one randomized canine trial in hemangiosarcoma and a larger human/Japanese oncology literature — while reishi now has a peer-reviewed canine immune study, curcumin has canine joint-comfort trials, and fisetin's evidence is mostly translational (mouse and human). None of these compounds treats or cures disease; the published work supports a structure/function role in baseline immune-cell function and inflammatory-pathway balance, and the canine-specific evidence is meaningfully thinner than the human literature. This guide walks through the mechanism, the landmark studies, the canine data, and — crucially — what the research does not say.

A note on framing. Everything below uses structure/function language. These are dietary supplement ingredients, not veterinary drugs. They have not been evaluated by the FDA or EMA to diagnose, treat, cure, or prevent any disease. Always talk to your veterinarian before starting a supplement, especially if your dog is on prescription medication, is pregnant, or has a diagnosed condition.

Key Takeaways

• Turkey tail PSP/PSK is the most-studied ingredient. A 2012 University of Pennsylvania double-blind randomized pilot trial found high-dose PSP delayed metastasis and produced among the longest reported survival times in canine splenic hemangiosarcoma [1]. A 2022 follow-up trial found PSP did not add survival benefit on top of doxorubicin [2] — an important, honest counterweight.
• Reishi now has direct canine immune data. A 2024 Journal of Animal Science study in healthy adult dogs found that 15 mg/kg/day Ganoderma lucidum increased phagocytic activity and rabies-vaccine-specific IgG, with no adverse health-marker effects [3].
• The connecting thread is natural killer (NK) cells — innate-immune lymphocytes that decline in number and function with age (immunosenescence) [4][5][6].
• Curcumin's strongest canine evidence is joint comfort, not immune endpoints. Bioavailable forms such as BCM-95 address curcumin's notoriously poor absorption [7][8][9][10].
• Fisetin is a senolytic with strong mouse data [11][12] but minimal dog-specific evidence; the closest canine signal is a 2024 senior-dog RCT of a senolytic + NAD? combination on cognition [13].
• "Immune support" is a baseline-support concept, not a disease treatment. These ingredients are studied as daily, multi-week interventions — not same-day fixes.
• Veterinary supplement science is thinner than human science. Where data is translational, this article says so explicitly.

Why the aging canine immune system needs support: NK cells and immunosenescence

A dog's immune system is architecturally similar to a human's. The innate arm — macrophages, dendritic cells, neutrophils, and natural killer (NK) cells — provides fast, non-specific first response. The adaptive arm — T cells and B cells — provides slower, antigen-specific, memory-forming responses. Both arms decline with age, a process called immunosenescence [5][6].

What is a natural killer (NK) cell? NK cells are innate-immune lymphocytes that patrol for stressed, virally infected, or transformed cells and kill them without needing prior sensitization. They recognize "missing self" (loss of normal MHC-I surface markers) and "induced self" (stress ligands such as those bound by the NKG2D receptor), then release cytotoxic granules (perforin and granzymes) and secrete interferon-gamma (IFN-?) to recruit the broader immune response [6]. A 2024 review provides a comprehensive map of NK-cell signaling and function [6].

Why NK cells are the connecting thread. With age, NK cells shift toward a more mature, less proliferative phenotype, and their per-cell cytotoxicity and cytokine output tend to fall — even when total NK counts hold steady [4]. Reviews of aging NK biology describe reduced killing capacity and blunted responsiveness as hallmarks of the aging innate system [4]. The four molecules in this article each touch this axis from a different angle: the mushroom polysaccharides engage pattern-recognition receptors that activate NK and macrophage function; curcumin modulates the inflammatory signaling milieu those cells operate in; and fisetin targets senescent cells, which secrete the chronic low-grade inflammatory factors ("inflammaging") that suppress immune performance.

A few honest framings before the molecules:

• Most healthy adult dogs do not need an immune supplement. The strongest rationale for daily baseline support is in seniors (roughly 7+ for medium-large breeds, 9+ for small breeds), dogs recovering from illness, and owners pursuing proactive healthspan support.
• Supplements sit above the foundations, not in place of them. Appropriate calories, body condition, exercise, dental care, and a complete diet come first [14][15].
• Veterinary nutrition references for the immune-nutrition relationship are well-established: a 2006 small-animal-practice chapter on nutrition and immune function [14] and a 2011 review of immunonutrition in companion animals [15].

Turkey tail polysaccharopeptide (PSP/PSK): what is it, and what do the dog studies show?

What it is

Turkey tail (Trametes versicolor, formerly Coriolus versicolor) is a common polypore mushroom whose protein-bound polysaccharide fractions are among the most-studied immune-active natural products in the world. Two closely related fractions dominate the literature:

• PSK (polysaccharide-K, brand name Krestin) — isolated in Japan, where it has decades of oncology research as an adjuvant. The foundational description appeared in 1984 [16].
• PSP (polysaccharopeptide) — a closely related protein-bound ?-glucan fraction; I'm-Yunity is a quality-controlled commercial PSP used in veterinary research.

Mechanism

PSP/PSK are ?-glucans — branched polysaccharides that the innate immune system reads as a "fungal/pathogen" signature. They engage pattern-recognition receptors, notably dectin-1 and complement receptor 3, on macrophages, dendritic cells, and NK cells. Receptor engagement triggers cytokine release (IFN-?, IL-12, TNF-?) that primes downstream NK and T-cell activity. A 2002 review covers the PSK mechanism literature in depth [17], and a 2012 immunocompetent-mouse study showed PSK augmented docetaxel chemotherapy response in an immune-mediated, NK/T-cell-dependent fashion [18].

The canine evidence — the good and the null

This is where turkey tail stands apart from the other three molecules: it has an actual randomized canine clinical trial.

The landmark Penn Vet trial (Brown & Reetz, 2012) [1]. In a double-blind, randomized, multi-dose pilot study, 15 dogs with naturally occurring splenic hemangiosarcoma received PSP (I'm-Yunity) at 25, 50, or 100 mg/kg/day. Dogs on the highest dose had a median time to abdominal-metastasis progression of 112 days versus 30 days in the lowest-dose group, and the authors reported some of the longest survival times then published for this aggressive cancer. This is the study most frequently cited in popular "turkey tail for dogs" coverage.

The honest counterweight (Gedney et al., 2022) [2]. A larger follow-up in Veterinary and Comparative Oncology evaluated PSP (I'm-Yunity) alone or combined with doxorubicin after splenectomy in dogs with splenic hemangiosarcoma. The result: adding PSP to doxorubicin did not improve survival, and female dogs on PSP monotherapy did worse than females on doxorubicin-plus-placebo. This null/negative result matters. It tempers the 2012 pilot and is exactly why responsible framing avoids overclaiming: a small positive pilot does not equal a proven cancer therapy, and a daily immune-support product is not a cancer treatment.

The takeaway for a baseline immune-support context is mechanistic, not oncologic: PSP/PSK reliably engage innate-immune ?-glucan pathways across species, which is the structure/function rationale for including standardized turkey tail extract in a general immune formula — separate from any disease claim.

Dose context

Japanese PSK oncology protocols dose adult humans at ~3 g/day [17]. The canine hemangiosarcoma trials used 25–100 mg/kg/day of PSP [1][2]. For a general baseline-support context (not oncology), products typically dose turkey tail extract standardized to PSP content and body-weight-scaled — well below the high oncologic doses. Your veterinarian can advise on what is appropriate for your individual dog.

Limitations

Canine PSP dose-finding outside of hemangiosarcoma is sparse; many small canine immune-support reports appear in conference proceedings rather than peer-reviewed journals; and the 2022 null result shows the benefit signal is not robust in every setting [2].

Reishi (Ganoderma lucidum): does it actually do anything in dogs?

What it is

Reishi (Ganoderma lucidum, "Lingzhi") is a polypore mushroom with a long traditional-medicine history and a substantial modern mechanism literature. Its bioactives fall into two main classes: polysaccharides (?-glucans) — immunomodulatory, like turkey tail — and triterpenes (ganoderic acids) — associated with anti-inflammatory and antioxidant activity.

Mechanism

Reishi ?-glucans engage the same family of innate pattern-recognition receptors as turkey tail (dectin-1, TLRs, complement receptors), stimulating macrophage, dendritic-cell, and NK-cell activity and shifting cytokine output. A 2019 review summarizes the immunomodulating mechanisms of Ganoderma [19]; a 2011 review focuses specifically on Ganoderma lucidum polysaccharides and their immunomodulation and potential anti-tumor activity [20]; and a 2024 review surveys the broader therapeutic-potential literature [21]. A 2018 human RCT found that yogurt enriched with reishi ?-glucans modulated immune markers [22]. On the triterpene side, a 2026 systematic review and meta-analysis of preclinical evidence concluded that Ganoderma lucidum triterpenes have measurable anti-inflammatory potential [23].

The canine evidence — newer and encouraging

Until recently, reishi's case in dogs was almost entirely translational. That changed with a 2024 Journal of Animal Science study (Kayser et al.) [3], which tested Ganoderma lucidum supplementation directly in healthy adult dogs. At the 15 mg/kg/day dose, dogs showed greater phagocytic activity (immune cells engulfing targets more actively) and higher rabies-vaccine-specific serum IgG after vaccination, with no adverse effects on standard health markers. This is a genuine, peer-reviewed, dog-specific immune-function signal — and it is exactly the kind of structure/function endpoint (immune-cell activity, vaccine response) that supports a baseline-support rationale without making a disease claim.

Why pair two mushrooms?

PSP and reishi ?-glucans engage overlapping but non-identical pattern-recognition pathways, and reishi adds the triterpene anti-inflammatory axis [23] that turkey tail lacks. Combining them broadens innate-immune engagement — a rationale grounded in the ?-glucan and triterpene immunology literature rather than head-to-head canine trials.

Dose context and limitations

The canine immune signal was seen at 15 mg/kg/day of a specific extract [3]; this is not a universal dose for all reishi products, since ?-glucan and triterpene content vary widely by extract and standardization. Most reishi efficacy data remains human, in vitro, or rodent; the single canine immune study, while encouraging, is one study.

Curcumin (BCM-95): why is a joint-comfort molecule in an immune formula?

What it is

Curcumin is the principal polyphenol pigment of turmeric (Curcuma longa). Its central problem is bioavailability: free curcumin is poorly water-soluble, unstable at intestinal pH, and rapidly metabolized, so plain dietary turmeric delivers very little curcumin to systemic circulation. BCM-95 (Biocurcumax) is a curcumin–essential-oil preparation shown in a 2008 human pilot cross-over study to have substantially higher oral bioavailability than standard curcumin [8]. Higher bioavailability means more compound reaches circulation per milligram dosed.

Mechanism

Curcumin is best characterized as an inflammatory-pathway modulator and antioxidant. It influences NF-?B signaling and downstream inflammatory mediators, which is the basis for its joint-comfort effects. It also interacts with immune cells — the human literature describes curcumin modulating macrophage, dendritic-cell, T-cell, and NK-cell activity — but these immune effects are less rigorously established than its anti-inflammatory action.

The canine evidence

The canine research base for curcumin is real but anchored in joint comfort, not immune endpoints:

• A 2017 randomized, double-blind, placebo-controlled study tested a curcuminoids-containing diet supplement (with hydrolyzed collagen and green tea extract) in owners' dogs with osteoarthritis and reported improvement on standard canine OA assessments [7].
• A 2022 study evaluated a green-lipped mussel + curcumin combination in dogs with osteoarthritis [9].
• A 2016 review surveyed canine osteoarthritis-supplement evidence from 2004–2014, including curcumin among studied ingredients [10].

Honest framing

The strongest canine-specific endpoint for curcumin is joint comfort, not immune function. Including curcumin in an immune-support formula extends the rationale to inflammatory-pathway balance — mechanistically adjacent to immune support, since chronic inflammation ("inflammaging") suppresses immune performance — but it is not the same as a demonstrated canine immune endpoint. We flag this distinction directly.

Dose context and limitations

BCM-95 has been studied in humans at roughly 500–1000 mg/day equivalents [8]. Canine dosing is body-weight-scaled. Curcumin can affect platelet function and may interact with anticoagulants and some chemotherapy agents — another reason to involve your veterinarian.

Fisetin: a senolytic with great mouse data and a thin dog file

What it is

Fisetin is a flavonoid found in strawberries and other plants. It is studied as a senolytic / senotherapeutic — a compound that selectively clears or quiets senescent cells, which are aged, non-dividing cells that accumulate over time and secrete a pro-inflammatory cocktail (the senescence-associated secretory phenotype, or SASP) that drives chronic, low-grade "inflammaging."

Mechanism and the translational evidence

The foundational study (Yousefzadeh et al., 2018) characterized fisetin as a senotherapeutic that reduced senescent-cell burden and extended health- and lifespan in aged mice [11]. The senolytic field has continued to build: a 2021 Science paper reported that senolytics reduced coronavirus-related mortality in old mice, linking senescent-cell clearance to improved immune resilience in aged animals [12]. The mechanistic logic for an immune-support context: fewer senescent cells means less SASP-driven inflammation, which is associated with better-preserved immune-cell (including NK-cell) function.

The canine evidence — adjacent, not direct

Dog-specific fisetin data is minimal. The closest canine signal is a 2024 randomized, controlled trial in senior dogs (Simon et al., Scientific Reports) [13] testing a combined senolytic + NAD?-precursor product (not fisetin alone) in 70 dogs with mild-to-moderate cognitive impairment; the full-dose group showed significantly improved owner-assessed cognitive scores over three months, with hints of broader effects on frailty and activity. This is supportive of the senolytic concept in dogs but is not a trial of fisetin specifically, and cognition is not an immune endpoint.

Honest framing, dose context, and limitations

The case for fisetin in a canine immune formula is mechanistic and translational, not canine-RCT-validated. It is typically included at a modest, well-tolerated dose based on the mouse senolytic literature [11][12] and the general safety of dietary flavonoids — not on dog efficacy data. We want to be explicit: this is the thinnest dog-specific evidence base of the four molecules.

How do the four molecules compare?

Baseline immune support vs. cancer treatment: a critical distinction

This deserves its own section because it is where well-meaning content most often goes wrong.

Baseline immune support is a structure/function concept: supporting the normal function of immune cells and helping maintain inflammatory-pathway balance in a generally healthy animal, typically as a daily, multi-week regimen. That is the lane these four molecules occupy in a general supplement.

Cancer treatment is a disease-claim concept and a regulated medical act. The turkey tail oncology literature — the 1984 PSK description [16], the human/Japanese adjuvant studies [17], the 2012 canine pilot [1] — is genuinely interesting research, but it does not make a daily supplement a cancer therapy. The 2022 canine follow-up showing no survival benefit when PSP was added to doxorubicin [2] is the clearest reminder that promising mechanism and one positive pilot do not equal proven treatment.

If your dog has cancer or any diagnosed disease, the supplement question is one to raise with your veterinary oncologist as a possible complement to — never a replacement for — the medical plan. Some of these compounds (curcumin's platelet effects, ?-glucan immune modulation) can theoretically interact with chemotherapy, anticoagulants, or immunosuppressants, which is exactly why it is a veterinary conversation.

What the research does NOT say

• It does not say these ingredients treat, cure, or prevent canine cancer, autoimmune disease, or infection. The hemangiosarcoma studies are oncology research, including one null result [2]; they are not a basis for a treatment claim.
• It does not establish robust canine dose-response curves for PSP, reishi, or fisetin outside the specific studies cited. Much dosing is body-weight-scaled from human or rodent work.
• It does not show curcumin has a proven canine immune endpoint — the strong canine data is for joint comfort [7][9][10].
• It does not validate fisetin specifically in dogs; the canine senolytic signal comes from a combination product on a cognitive endpoint [13].
• It does not mean every reishi or turkey tail product is equivalent — ?-glucan/triterpene content varies enormously by species, extract method, and standardization.
• It does not replace foundational care: diet, body condition, exercise, and dental health remain the floor [14][15].

Frequently Asked Questions

Is turkey tail (PSP) safe for dogs?

Turkey tail polysaccharopeptide is widely used in canine immune-support supplements and was well-tolerated across the doses used in the canine hemangiosarcoma trials (25–100 mg/kg/day) [1][2]. It is generally considered well-tolerated, but "generally well-tolerated in studies" is not the same as "right for your dog." Consult your veterinarian first, especially if your dog is on prescription medication or has a diagnosed condition.

What dose of turkey tail PSP does the research support?

The canine clinical trials used 25–100 mg/kg/day of standardized PSP (I'm-Yunity) in an oncology context [1][2]. General baseline-support products dose well below those oncologic levels, standardized to PSP content and body-weight-scaled. There is no single universal "correct" dose for healthy dogs — ask your veterinarian for guidance specific to your animal.

Does reishi actually do anything in dogs, or is it just human research?

There is now direct canine evidence: a 2024 Journal of Animal Science study found that 15 mg/kg/day Ganoderma lucidum increased phagocytic activity and rabies-vaccine-specific IgG in healthy adult dogs, with no adverse health-marker effects [3]. That is a real, dog-specific immune-function signal — though it is one study, and dosing depends heavily on the specific extract.

Why is curcumin in an immune supplement if its dog studies are about joints?

Curcumin's strongest canine evidence is indeed for joint comfort in osteoarthritis [7][9][10]. Its inclusion in an immune-support context rests on its role in inflammatory-pathway balance — chronic inflammation suppresses immune-cell function, so modulating it is mechanistically adjacent to immune support. We are explicit that the rigorous canine endpoint is joints, not immunity directly. Bioavailable forms like BCM-95 exist because plain curcumin is very poorly absorbed [8].

What is fisetin doing in a dog immune supplement?

Fisetin is a senolytic — it clears senescent cells that drive chronic "inflammaging" — with strong mouse data [11][12] and a 2024 senior-dog RCT showing cognitive benefit from a senolytic + NAD? combination [13]. Its inclusion is mechanistic and translational, at a modest, well-tolerated dose, not based on canine RCTs of fisetin alone. It is the thinnest dog-specific evidence base of the four.

Can I give these supplements alongside my dog's other medications or chemotherapy?

Only with veterinary guidance. Curcumin can affect platelet function and may interact with anticoagulants and some chemotherapy agents; ?-glucans modulate immune signaling and could theoretically interact with immunosuppressants or immunotherapy. Importantly, a 2022 canine trial found PSP did not improve survival when added to doxorubicin [2] — so do not assume "natural" means "helpful alongside chemo." This is a conversation for your veterinary oncologist.

How long before I'd expect to see effects?

Published immune-supplement studies typically run 4–12 weeks before measuring outcomes; the canine reishi study measured immune markers at day 28 [3]. The honest framing: these are daily-baseline-support ingredients, not same-day interventions.

Are these supplements a substitute for veterinary care?

No. They are dietary supplements that may support baseline immune-cell function and inflammatory-pathway balance. They are not drugs, have not been evaluated by the FDA or EMA, and do not diagnose, treat, cure, or prevent disease. They sit on top of — never in place of — proper diet, body-condition management, dental care, and veterinary medicine.

References

1. Brown DC, Reetz J. Single agent polysaccharopeptide delays metastases and improves survival in naturally occurring hemangiosarcoma. Evidence-Based Complementary and Alternative Medicine. 2012;2012:384301. PMID: 22988473. DOI: 10.1155/2012/384301. https://pubmed.ncbi.nlm.nih.gov/22988473/
2. Gedney A, Salah P, Mahoney JA, Krick E, Martins R, Scavello H, Lenz JA, Atherton MJ. Evaluation of the anti-tumour activity of Coriolus versicolor polysaccharopeptide (I'm-Yunity) alone or in combination with doxorubicin for canine splenic hemangiosarcoma. Veterinary and Comparative Oncology. 2022;20(3):688-696. PMID: 35442554. DOI: 10.1111/vco.12823. https://pubmed.ncbi.nlm.nih.gov/35442554/
3. Kayser E, Castaneda PL, Soto-Diaz K, Steelman AJ, Murphy A, Spindola M, He F, de Godoy MRC. Functional properties of Ganoderma lucidum supplementation in canine nutrition. Journal of Animal Science. 2024;102:skae051. PMID: 38417056. DOI: 10.1093/jas/skae051. https://pubmed.ncbi.nlm.nih.gov/38417056/
4. Brauning A, Rae M, Zhu G, Fulton E, Admasu TD, Stolzing A. Aging of the Immune System: Focus on Natural Killer Cells Phenotype and Functions. Cells. 2022;11(6):1017. PMID: 35326467. DOI: 10.3390/cells11061017. https://pubmed.ncbi.nlm.nih.gov/35326467/
5. Goyani P, Christodoulou R, Vassiliou E. Immunosenescence: Aging and Immune System Decline. Vaccines. 2024;12(12):1314. PMID: 39771976. DOI: 10.3390/vaccines12121314. https://pubmed.ncbi.nlm.nih.gov/39771976/
6. Chen S, Zhu H, Jounaidi Y. Comprehensive snapshots of natural killer cells functions, signaling, molecular mechanisms and clinical utilization. Signal Transduction and Targeted Therapy. 2024;9(1):302. PMID: 39511139. DOI: 10.1038/s41392-024-02005-w. https://pubmed.ncbi.nlm.nih.gov/39511139/
7. Comblain F, Barthelemy N, Lefebvre M, Schwartz C, Lesponne I, Serisier S, Feugier A, Balligand M, Henrotin Y. A randomized, double-blind, prospective, placebo-controlled study of the efficacy of a diet supplemented with curcuminoids extract, hydrolyzed collagen and green tea extract in owner's dogs with osteoarthritis. BMC Veterinary Research. 2017;13(1):395. PMID: 29262825. DOI: 10.1186/s12917-017-1317-8. https://pubmed.ncbi.nlm.nih.gov/29262825/
8. Antony B, Merina B, Iyer VS, Judy N, Lennertz K, Joyal S. A Pilot Cross-Over Study to Evaluate Human Oral Bioavailability of BCM-95CG (Biocurcumax), A Novel Bioenhanced Preparation of Curcumin. Indian Journal of Pharmaceutical Sciences. 2008;70(4):445-449. PMID: 20046768. DOI: 10.4103/0250-474X.44591. https://pubmed.ncbi.nlm.nih.gov/20046768/
9. Corbee RJ. The efficacy of a nutritional supplement containing green-lipped mussel, curcumin and blackcurrant leaf extract in dogs with osteoarthritis. Veterinary Medicine and Science. 2022;8(3):1025-1035. PMID: 35274496. DOI: 10.1002/vms3.779. https://pubmed.ncbi.nlm.nih.gov/35274496/
10. Comblain F, Serisier S, Barthelemy N, Balligand M, Henrotin Y. Review of dietary supplements for the management of osteoarthritis in dogs in studies from 2004 to 2014. Journal of Veterinary Pharmacology and Therapeutics. 2016;39(1):1-15. PMID: 26205697. DOI: 10.1111/jvp.12251. https://pubmed.ncbi.nlm.nih.gov/26205697/
11. Yousefzadeh MJ, Zhu Y, McGowan SJ, et al. Fisetin is a senotherapeutic that extends health and lifespan. EBioMedicine. 2018;36:18-28. PMID: 30279143. DOI: 10.1016/j.ebiom.2018.09.015. https://pubmed.ncbi.nlm.nih.gov/30279143/
12. Camell CD, Yousefzadeh MJ, Zhu Y, et al. Senolytics reduce coronavirus-related mortality in old mice. Science. 2021;373(6552):eabe4832. PMID: 34103349. DOI: 10.1126/science.abe4832. https://pubmed.ncbi.nlm.nih.gov/34103349/
13. Simon KE, Russell K, Mondino A, Yang CC, Case BC, Anderson Z, Whitley C, Griffith E, Gruen ME, Olby NJ. A randomized, controlled clinical trial demonstrates improved owner-assessed cognitive function in senior dogs receiving a senolytic and NAD+ precursor combination. Scientific Reports. 2024;14(1):12399. PMID: 38811634. DOI: 10.1038/s41598-024-63031-w. https://pubmed.ncbi.nlm.nih.gov/38811634/
14. Saker KE. Nutrition and immune function. Veterinary Clinics of North America: Small Animal Practice. 2006;36(6):1199-1224. PMID: 17085230. DOI: 10.1016/j.cvsm.2006.09.001. https://pubmed.ncbi.nlm.nih.gov/17085230/
15. Satyaraj E. Emerging paradigms in immunonutrition. Topics in Companion Animal Medicine. 2011;26(1):25-32. PMID: 21435623. DOI: 10.1053/j.tcam.2011.01.004. https://pubmed.ncbi.nlm.nih.gov/21435623/
16. Tsukagoshi S, Hashimoto Y, Fujii G, Kobayashi H, Nomoto K, Orita K. Krestin (PSK). Cancer Treatment Reviews. 1984;11(2):131-155. PMID: 6238674. DOI: 10.1016/0305-7372(84)90005-7. https://pubmed.ncbi.nlm.nih.gov/6238674/
17. Fisher M, Yang LX. Anticancer effects and mechanisms of polysaccharide-K (PSK): implications of cancer immunotherapy. Anticancer Research. 2002;22(3):1737-1754. PMID: 12168863. https://pubmed.ncbi.nlm.nih.gov/12168863/
18. Wenner CA, Martzen MR, Lu H, Verneris MR, Wang H, Slaton JW. Polysaccharide-K augments docetaxel-induced tumor suppression and antitumor immune response in an immunocompetent murine model. International Journal of Oncology. 2012;40(4):905-913. PMID: 22159900. DOI: 10.3892/ijo.2011.1292. https://pubmed.ncbi.nlm.nih.gov/22159900/
19. Wang X, Lin Z. Immunomodulating Effect of Ganoderma (Lingzhi) and Possible Mechanism. Advances in Experimental Medicine and Biology. 2019;1182:1-37. PMID: 31777013. DOI: 10.1007/978-981-32-9421-9_1. https://pubmed.ncbi.nlm.nih.gov/31777013/
20. Xu Z, Chen X, Zhong Z, Chen L, Wang Y. Ganoderma lucidum polysaccharides: immunomodulation and potential anti-tumor activities. The American Journal of Chinese Medicine. 2011;39(1):15-27. PMID: 21213395. DOI: 10.1142/S0192415X11008610. https://pubmed.ncbi.nlm.nih.gov/21213395/
21. Cancemi G, Caserta S, Gangemi S, Pioggia G, Allegra A. Exploring the Therapeutic Potential of Ganoderma lucidum in Cancer. Journal of Clinical Medicine. 2024;13(4):1153. PMID: 38398467. DOI: 10.3390/jcm13041153. https://pubmed.ncbi.nlm.nih.gov/38398467/
22. Henao SLD, Urrego SA, Cano AM, Higuita EA. Randomized Clinical Trial for the Evaluation of Immune Modulation by Yogurt Enriched with ?-Glucans from Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum. International Journal of Medicinal Mushrooms. 2018;20(8):705-716. PMID: 30317947. DOI: 10.1615/IntJMedMushrooms.2018026986. https://pubmed.ncbi.nlm.nih.gov/30317947/
23. Pozzobon RG, Rutckeviski R, de Lima LS, Oliveira CS, Smiderle FR. Anti-Inflammatory Potential of Ganoderma lucidum Triterpenes: A Systematic Review and Meta-Analysis of Preclinical Evidence. Pharmaceuticals (Basel). 2026;19(1):188. PMID: 41599785. DOI: 10.3390/ph19010188. https://pubmed.ncbi.nlm.nih.gov/41599785/

Veterinary and regulatory disclaimer

This article is for educational purposes only and describes the published research on individual dietary-supplement ingredients. The ingredients discussed — turkey tail (Trametes versicolor) polysaccharopeptide, reishi (Ganoderma lucidum) extract, bioavailable curcumin (BCM-95), and fisetin — are dietary supplement ingredients, not veterinary drugs. They have not been evaluated by the U.S. Food and Drug Administration (FDA) or the European Medicines Agency (EMA) and are not intended to diagnose, treat, cure, or prevent any disease in dogs or any other animal. All statements here are structure/function statements about supporting normal immune-cell function and inflammatory-pathway balance. Nothing in this article is veterinary medical advice. Individual dogs vary widely by breed, age, size, and health status. Always consult your veterinarian before starting any supplement, particularly if your dog is pregnant or nursing, is on prescription medication (including anticoagulants, immunosuppressants, or chemotherapy), or has a diagnosed health condition. If your dog has a serious illness such as cancer, supplements should be discussed with your veterinary oncologist as a possible complement to — never a replacement for — the medical care plan.

This ingredient-science deep dive informs the formulation of NK9, SciRouter's daily canine immune-support powder built around turkey tail PSP, reishi extract, BCM-95 curcumin, and fisetin. NK9 is a dietary supplement for general baseline immune support and is not a treatment for any disease — see the NK9 product page for ingredient amounts and manufacturing details.

Related reading: Immune Support for Cats · Cancer in Dogs and Cats: A Complete Guide.