Mammary Cancer in Dogs

Mammary cancer in dogs and breast cancer in women have a remarkable amount in common, far more than most pet parents realize. Understanding these similarities can help you make more informed, less fear-driven decisions about your dog's health.

How Dog Mammary Cancer and Human Breast Cancer Are Alike

The parallels between these two diseases run deep, right down to the molecular level. Dogs carry versions of the same genes linked to breast cancer in women, including BRCA1 and BRCA2, the genes made famous by human genetic testing, and when these genes don't work properly, mammary cancer risk rises in both species just the same.¹ Many dog mammary tumors are also driven by the same molecular "on switches" found in human breast cancer, including a mutation called PIK3CA, one of the most common mutations identified in both species.²

Hormones play a similar role too. Just as in women, the hormone estrogen can fuel the growth of mammary tumors in dogs. Many canine mammary tumors carry estrogen receptors, the "docking stations" that allow estrogen to send its growth signals directly to cancer cells. Even under the microscope, the tumors look alike. Veterinary pathologists classify dog mammary tumors into subtypes that mirror the categories used in human breast cancer, including hormone-receptor-positive, HER2-positive, and triple-negative types.³ And in both species, tumors tend to follow the same progression pattern, starting benign and, in some cases, turning malignant over time, with the most aggressive tumors often losing their hormone receptors altogether, meaning hormones no longer control their growth.⁴

Because of these striking similarities, dogs are considered one of the best natural models we have for studying human breast cancer, and discoveries in one species often help the other.⁵

The Hormone Balancing Act

Hormones, especially estrogen, have a genuinely complicated relationship with mammary cancer in dogs, and I want to walk you through why. On one hand, estrogen and progesterone stimulate mammary cells to grow and divide. Over a dog's lifetime, this repeated stimulation raises the odds that something eventually goes wrong at the cellular level.

But hormones can also be protective. Research has shown that in some dogs with aggressive, hormone-receptor-negative tumors (tumors that no longer respond to estrogen at all), having higher estrogen levels was associated with slower spread of the cancer. Scientists believe this may be because estrogen helps the immune system fight cancer cells, even in tumors that no longer "listen" to estrogen directly.⁶

How the body breaks estrogen down matters just as much as how much estrogen is circulating. Estrogen is metabolized through multiple chemical pathways, and some produce breakdown products that are harmless or even protective, while others produce byproducts that can damage DNA and promote cancer. Dogs process estrogen through the same breakdown pathways we do, which means the balance between "good" and "bad" estrogen metabolites likely influences cancer risk in dogs just as it does in people.

What About Genetic Testing for Mammary Cancer in Dogs?

In humans, BRCA1 and BRCA2 genetic testing is a well-established tool that helps women understand their personal breast cancer risk and make proactive decisions. Naturally, you may wonder whether we can do the same for our dogs.

The short answer, unfortunately, is not yet. Scientists have confirmed that variants in BRCA1 and BRCA2, along with other genes like RAD51 and STK11, are linked to mammary cancer risk in certain dog breeds. ⁷ The trouble is that these findings are mostly breed-specific, meaning a genetic variation that raises risk in one breed may not matter at all in another. And unlike the high-risk BRCA mutations we test for in humans, the known canine gene variations have a comparatively modest effect on individual risk. They nudge the odds up, but they don't predict cancer with any real certainty for an individual dog.

There is currently no commercially validated, widely available genetic test your veterinarian can order to generate a meaningful mammary cancer risk score for your particular dog. This remains an active area of research, though, and I'm hopeful that reliable genetic testing for dogs will become available down the road.

The Spay Debate

For decades, early spaying was promoted as something close to preventive medicine, largely on the strength of a single 1969 study claiming that mammary cancer risk rose to 0.5%, 8%, and 26% depending on whether a dog was spayed before her first heat, second heat, or later.⁸ That figure has been repeated so often it's become veterinary gospel. But real scrutiny has changed this picture considerably.⁹ Using rigorous Cochrane review guidelines, Beauvis et al. examined studies on neutering and mammary tumors and found that nine carried a high risk of bias and four, a moderate risk. Their conclusion was blunt: the evidence that neutering reduces mammary cancer risk, and that the age at which a dog is neutered matters, is "weak and not a sound basis for firm recommendations." A 2024 scoping review examining neutering timing relative to puberty concluded that robust evidence "does not yet exist" and that the effect on tumor development "remains unclear."¹⁰

None of this means the hormone connection isn't real; it clearly is, just as it is in women, and it's every bit as nuanced. A Japanese study of 7,802 cases found that neutered females had a lower overall mammary cancer risk, with a risk ratio of 0.57, even though overall prevalence was climbing regardless of neutering trends in the broader population.¹¹ A randomized controlled trial found that ovariohysterectomy performed at the same time as benign tumor removal cut the risk of new tumors by roughly 50%, though notably, it did not improve overall survival.¹²

Dr. Christine Zink, DVM, PhD, DACVP, DACVSMR, a veterinary pathologist and internationally recognized expert in canine sports medicine and rehabilitation, and Professor Emerita at the Johns Hopkins University School of Medicine, has spent years advancing comparative pathology and canine performance research. She points out that at the time many of the original spay-and-cancer studies were conducted, the overall incidence of mammary tumors in the population was approximately 199 per 100,000 female dogs, meaning the actual risk to any individual intact female was roughly 0.2%. Meanwhile, the combined risk of other, often far deadlier cancers climbs substantially in desexed dogs.

She notes that spayed female Golden Retrievers develop other cancers, including lymphosarcoma, hemangiosarcoma, and mast cell tumors, at three to four times the rate of intact females, and a large study of more than 150,000 dogs found that spayed females had significantly higher odds of lymphoma, mast cell tumors, and melanoma compared with intact females.¹³  Neutered dogs of both sexes carried a 3.2-fold increased risk of lymphoma, with spayed females showing an even steeper 4.4-fold increase. Low serum estrogen has also been associated with an increased risk of non-mammary tumors in dogs following surgery. Dr. Zink is careful to add important context here: while roughly 30% of mammary tumors are malignant, when they're caught and surgically removed early, the prognosis is generally quite favorable¹⁴, a sharp contrast to cancers like hemangiosarcoma, lymphosarcoma, and bladder cancer, which are usually fatal.

The Effects of Spaying

Spaying carries significant trade-offs that often go unmentioned.  Cancer risk itself rises in several categories: that same study of more than 150,000 dogs found spayed females had higher odds of lymphoma (odds ratio 1.43), mast cell tumors (odds ratio 1.92), and melanoma (odds ratio 1.63) compared with intact females. In Golden Retrievers specifically, neutering at any point up through eight years of age raised the rate of developing at least one cancer three to four times over intact females, whose baseline rate was just 3%. Gonadectomized dogs of both sexes show elevated lymphoma and hemangiosarcoma risk, a pattern researchers link to sustained, abnormally high luteinizing hormone activating LH receptors on tumor cells and driving their proliferation.

Orthopedic problems climb too. In Golden Retrievers, gonadectomy performed before six months of age raised the incidence of joint disorders four to five-fold. A prospective cohort study confirmed a fourfold orthopedic-injury risk in dogs neutered at six months or younger, and found gonadectomy at any age to be a risk factor for overweight and obesity.¹⁵Speaking of which, obesity risk climbs measurably as well; a study of 155,199 Banfield patients confirmed that gonadectomy raises overweight and obesity risk for most dogs, though the degree varies by breed size and sex.¹⁶

Then there's what I think of as the estrogen paradox. In dogs with spontaneous mammary carcinomas, estrogen behaves as a pro-carcinogen in estrogen-receptor-positive tumors, but appears genuinely protective in estrogen-receptor-negative tumors and against non-mammary cancers. Low serum estrogen was significantly linked to a higher rate of non-mammary tumors after surgery.¹⁷ This helps explain a pattern that initially seems counterintuitive: dogs spayed early, who lose their estrogen permanently, go on to develop more lymphoma, hemangiosarcoma, and other cancers. What all of this really teaches us is that mammary and breast cancer are every bit as complicated in dogs as they are in humans. There are no clean, one-size-fits-all rules here, and every path forward comes with its own trade-offs.

What Should Pet Parents Do?

Given everything above, Dr. Zink suggests owners strongly consider an ovary-sparing spay, essentially a hysterectomy, rather than a traditional ovariohysterectomy. This approach eliminates the risk of pyometra while preserving the dog's protective hormones, and she argues that the veterinary profession should develop routine mammary screening programs, including imaging, for intact females, much as we've done for women for decades now.

Beyond the spay decision itself, there's a great deal within your control. Keeping your dog lean from puppyhood is one of the single strongest modifiable risk factors we know of; dogs who are lean between 9 and 12 months of age carry dramatically reduced risk later in life.¹⁸ Feeding a minimally processed, species-appropriate diet matters too. The evidence linking ultra-processed food to worse health outcomes is substantial in both dogs and people, and fresh, lightly cooked, or well-formulated raw diets consistently show healthier metabolic profiles, richer gut microbiomes, and lower inflammation than extruded kibble.¹⁹ I'd also urge you to avoid exogenous progestagens used for estrus suppression, since they raise tumor risk and tend to produce tumors that are overwhelmingly malignant when they do occur.²⁰

If your female dog remains intact, commit to regular mammary exams. Routine palpation and imaging catch tumors early, when roughly 70% are still benign, and removal is curative. And finally, do what you can to limit her exposure to endocrine-disrupting chemicals, which brings me to a topic I think doesn't get nearly enough attention.

Endocrine-Disrupting Chemicals (EDCs) and Mammary Cancer Risk

Beyond a dog's own hormonal biology, the environment she lives in day to day may meaningfully influence her mammary cancer risk too, largely through exposure to endocrine-disrupting chemicals, or EDCs. These are artificial substances that interfere with the body's normal hormone signaling, and they're everywhere in modern life: plastics, food packaging, pesticides, herbicides, cosmetics, personal care products, and contaminated food and water all carry them.²¹ Many of these chemicals are what's known as xenoestrogens, meaning their chemical structures closely resemble natural estrogen, allowing them to latch onto the same estrogen receptors and mimic estrogen's effects, effectively adding to the total estrogen-like signal a body accumulates over a lifetime.²²

The research linking EDC exposure to increased breast and mammary cancer risk is substantial. A systematic review of 131 human epidemiological studies concluded that certain EDCs, including the pesticides DDT and DDE, bisphenol A (BPA), phthalates, PCBs, and parabens, can potentially elevate breast cancer risk, with the danger especially pronounced when exposure happens early in life.²³ Other systematic reviews and meta-analyses have reached strikingly similar conclusions, with the strongest and most consistent associations found for organochlorine pesticides and specific PCB compounds.²⁴Because the vast majority of breast cancers have no inherited cause, environmental and lifestyle factors like these are drawing increasing concern from researchers.²⁵

Mechanistically, estrogenic EDCs such as BPA promote the proliferation, migration, and survival of mammary cells by hijacking the very same estrogen receptor pathways that natural estrogen relies on, and they can even switch on estrogen-target genes and promote cancer stem cell characteristics.²⁶ Because these chemicals are highly persistent in the environment and accumulate in body fat, exposure can be long-lasting, and, troublingly, can even span generations. The mammary gland is considered especially vulnerable to this kind of disruption²⁷, often described as a "sentinel organ," with the developing gland during pregnancy, nursing, and early life representing a particularly sensitive window of exposure.

I want to be clear that this isn't only a human concern. Dogs share our homes, our yards, our water, and because they're lower to the ground and groom themselves constantly, they may well encounter these environmental chemicals just as much as we do, if not more, making them genuinely valuable sentinels for shared environmental cancer risk.

A study of 1,764 dogs found that those living in areas with very high cadmium, a heavy-metal environmental pollutant, had a markedly higher proportion of mammary gland tumors, directly linking environmental pollution to mammary tumor development in pet dogs.²⁸ Laboratory and animal studies further confirm that agricultural pesticides and chemicals like BPA can disrupt mammary gland development and promote tumor formation across multiple species.²⁹

I'll let Dr. Zink close this section in her own words, from her website³⁰, where her full citations are also available:

"The risk of dogs developing mammary cancer is classically listed as 0.5%, 8%, and 26% higher depending on whether ovariohysterectomy is performed before the first, second or any estrus thereafter, respectively. However, a meta-study that examined peer-reviewed journal articles addressing the subject of whether there was evidence of an effect of neutering or age of neutering on the risk of mammary tumors concluded that the evidence that neutering reduces the risk of mammary cancer is weak and does not constitute a sound basis for firm recommendations.

At the time when many of the studies of gonadectomy and mammary tumor risk were conducted (late 1960s), incidence rates for all malignant neoplasms were 453.4/100,000 female dogs. Mammary tumors accounted for half of these tumors, or 198.8/100,000. Thus, the actual overall risk at that time of any bitch getting a mammary tumor was only 0.2%. These figures for increased risk of mammary cancer must be compared with the 200 to 400% increased risk of other cancers in spayed females.

 While about 30% of mammary cancers are malignant, as in humans, when caught and surgically removed early, the prognosis is very good. This is in comparison to the other cancers listed, such as hemangiosarcoma, lymphosarcoma, and bladder cancer, which are usually fatal. Given the balance of cancer risks listed above, owners of bitches should strongly consider having a hysterectomy (ovary-sparing spay) performed rather than an ovariohysterectomy, thus precluding the possibility of pyometra while retaining the benefits of the female hormones. In addition, the veterinary field should be developing programs for regular mammary examinations, including imaging, to facilitate early diagnosis of mammary cancer in all intact female dogs, as has been performed in women for decades."

Canine mammary cancer, much like human breast cancer, demands a nuanced, breed-specific, multifactorial approach rather than a rulebook. Whether and when to spay, or whether to pursue a hormone-sparing sterilization instead, should be an individual decision, one that weighs your dog's breed-specific cancer risks, her lifestyle and environmental exposures, and your own ability to monitor her closely over time. One-size-fits-all recommendations have no place in modern, evidence-based veterinary medicine.

Can Supplements Help Reduce a Dog's Mammary Cancer Risk?

You may have heard about supplements that could help lower cancer risk, particularly ones derived from vegetables like broccoli and cauliflower. Here's an honest look at what the research shows, and what I think pet parents should keep in mind.

DIM: The Most-Studied Option

DIM, short for diindolylmethane, is a natural compound your body and your dog's body produce when digesting cruciferous vegetables like broccoli, cauliflower, cabbage, and Brussels sprouts. It works by changing how the body processes estrogen, nudging estrogen breakdown toward a "safer" pathway and steering it away from the pathway capable of damaging cells and promoting cancer growth. In human studies, women who took DIM supplements showed a measurable shift toward that safer estrogen pathway. DIM has also been shown in laboratory studies to help cancer cells die off naturally, slow down tumor growth signals, and reduce inflammation, all of which work against cancer development.³¹

Other Supplements That Show Promise

Sulforaphane, found in broccoli sprouts, has demonstrated genuine anti-cancer effects in both lab and animal studies, supporting the body's natural detoxification systems while slowing cancer cell growth.³²

DHA and EPA, the omega-3 fatty acids found in marine oils, have shown some of the most promising cancer-fighting properties in the research I've reviewed. Animals fed omega-3-rich diets developed fewer tumors, experienced slower tumor growth, and even showed less cancer spread to other organs.³³,³⁴  In large human studies, people who regularly consumed fish oil had a lower risk of both breast and colorectal cancers, suggesting these healthy fats may offer real protection against cancer development over time.³⁵ Many veterinarians, myself included, already recommend fish oil for its anti-inflammatory benefits, which can support cancer prevention as a welcome side effect.³⁶ If you're supplementing, look for phospholipid forms packaged in glass rather than plastic.

Decaf Green Tea, and specifically its active compound EGCG, deserves a mention too. A 2025 meta-analysis of 43 human studies found that green tea consumption reduced overall cancer risk by 9%, while EGCG supplementation specifically reduced it by 28%.³⁷ In animal models, EGCG has consistently prevented chemically induced tumors across multiple organ sites, including the lung, colon, skin, and mammary glands, inhibiting tumor formation by 37% to 47% in intestinal cancer models and suppressing lung tumor development in carcinogen-treated mice.

Curcumin rounds out my list of favorites for cancer prevention. In animal models, dietary curcumin reduced chemically induced colon tumors by 51% to 66%, regardless of whether it was administered before, during, or after carcinogen exposure, and it also prevented duodenal and mammary tumors. Notably, curcumin has also been shown to significantly reduce the incidence of invasive carcinoma in mouse models.³⁸

Lion’s Mane Mushroom (Hericium erinaceus) is the newest addition I'm watching closely. A 2026 laboratory study³⁹ tested lion's mane extract directly against canine mammary cancer cells for the first time and found that it slowed cancer cell growth, triggered apoptosis  (the body’s natural way to remove damaged or abnormal cells)  by raising BAX and lowering BCL-2, cut the cells' ability to migrate roughly in half at higher doses, and reversed key markers of epithelial-to-mesenchymal transition, the process that lets cancer cells break away and spread, all while showing markedly less toxicity toward healthy canine kidney cells than toward the cancer cells themselves.  All of this suggests Lion’s Mane is far more toxic to cancer cells than normal canine cells, and by attacking cancer cells directly, they help prevent the spread of cancer, not just shrink tumors.

None of these supplements are a substitute for the fundamentals: keeping your dog lean, feeding a fresh and minimally processed diet, limiting her exposure to endocrine-disrupting chemicals, and staying diligent about regular exams. But as part of a comprehensive, thoughtful approach, they represent some of the most promising, evidence-backed tools we currently have.

Sources and References:

• ¹ Rivera P, Melin M, Biagi T, et al. Mammary tumor development in dogs is associated with BRCA1 and BRCA2. Cancer Research. 2009;69(22):8770–8774. doi:10.1158/0008-5472.CAN-09-1725.
• ²  Arendt ML, Sakthikumar S, Melin M, et al. PIK3CA is recurrently mutated in canine mammary tumors, similarly to in human mammary neoplasia. Scientific Reports. 2023;13(1):632. doi:10.1038/s41598-023-27664-7
• ³ Kim TM, Yang IS, Seung BJ, et al. Cross-species oncogenic signatures of breast cancer in canine mammary tumors. Nature Communications. 2020;11(1):3616. doi:10.1038/s41467-020-17458-0.
• ⁴ Gautam S, Gupta K, Rajendran VO, et al. ERα, HER-2, Pan-Ras, P53, and aromatase expression in spontaneous malignant canine mammary tumors: prognostic relevance and association with clinicohistological parameters. Research in Veterinary Science. 2025;183:105515. doi:10.1016/j.rvsc.2024.105515
• ⁵  Kim TM, Yang IS, Seung BJ, et al. Cross-species oncogenic signatures of breast cancer in canine mammary tumors. Nature Communications. 2020;11(1):3616. doi:10.1038/s41467-020-17458-0.
• ⁶  Sorenmo KU, Durham AC, Radaelli E, et al. The estrogen effect; clinical and histopathological evidence of dichotomous influences in dogs with spontaneous mammary carcinomas. PLoS One. 2019;14(10):e0224504. doi:10.1371/journal.pone.0224504
• ⁷  Canadas A, Santos M, Nogueira A, et al. Canine mammary tumor risk is associated with polymorphisms in RAD51 and STK11 genes. Journal of Veterinary Diagnostic Investigation. 2018;30(5):733–738. doi:10.1177/1040638718789231
• ⁸ Robert Schneider, C. Richard Dorn, D. O. N. Taylor, Factors Influencing Canine Mammary Cancer Development and Postsurgical Survival, JNCI: Journal of the National Cancer Institute, Volume 43, Issue 6, December 1969, Pages 1249–1261 https://doi.org/10.1093/jnci/43.6.1249
• ⁹ Beauvais, W., Cardwell, J.M. and Brodbelt, D.C. (2012), The effect of neutering on the risk of mammary tumours in dogs – a systematic review. Journal of Small Animal Practice, 53: 314-322. https://doi.org/10.1111/j.1748-5827.2011.01220.x
• ¹⁰ Moxon R, England GCW, Payne R, Corr SA, Freeman SL (2024) Effect of neutering timing in relation to puberty on health in the female dog–a scoping review. PLOS ONE 19(10): e0311779. https://doi.org/10.1371/journal.pone.0311779
• ¹¹ Shinji Hirano, Tatsuro Jifumi, Noriaki Miyoshi, Epidemiological analysis of mammary tumros in female dogs in Japan: A study based on Kyushu-Okinawa region, The Veterinary Journal vol 210, April 2025
• ¹² Kristiansen VM, Nødtvedt A, Breen AM, Langeland M, Teige J, Goldschmidt M, Jonasdottir TJ, Grotmol T, Sørenmo K. Effect of ovariohysterectomy at the time of tumor removal in dogs with benign mammary tumors and hyperplastic lesions: a randomized controlled clinical trial. J Vet Intern Med. 2013 Jul-Aug;27(4):935-42. doi: 10.1111/jvim.12110. Epub 2013 May 22. PMID: 23701181.K
• ¹³ The Veterinary Journal, Vol 317, June 2026
• ¹⁴ Zheng, Jing, Jiawang Feng, Hongyan Jin, Plos One Nov 22, 2024
• ¹⁵ Melissa Simpson, et al, Age at gonadectomy and risk of overweight/obesity and orthopedic injury in a cohort of Golden Retrievers, July 17, 2019 https://doi.org/10.1371/journal.pone.0209131
• ¹⁶ J Am Vet Med Assoc 2023 May 19
• ¹⁷ Science Daily, Univ of Penn, Estrogen’s opposing effects on mammary tumors in dogs, Nov 1 2019
• ¹⁸ Sonnenschein EG, Glickman LT, Goldschmidt MH, McKee LJ. Body conformation, diet, and risk of breast cancer in pet dogs: a case-control study. American Journal of Epidemiology. 1991;133(7):694–703. doi:10.1093/oxfordjournals.aje.a115944.
• ¹⁹ V.Holm S, Baarman E, Anturaniemi J, et al. The effect of a kibble diet versus a raw meat-based diet on energy metabolism biomarkers in dogs. Veterinary Journal. 2025;314:106462. doi:10.1016/j.tvjl.2025.106462
• ²⁰ Salas Y, Márquez A, Diaz D, Romero L. Epidemiological study of mammary tumors in female dogs diagnosed during the period 2002–2012: a growing animal health problem. PLoS One. 2015;10(5):e0127381. doi:10.1371/journal.pone.0127381
• ²¹ Wan MLY, Co VA, El-Nezami H. Endocrine disrupting chemicals and breast cancer: a systematic review of epidemiological studies. Crit Rev Food Sci Nutr. 2022;62(24):6549-6576. doi: 10.1080/10408398.2021.1903382. Epub 2021 Apr 5. PMID: 33819127.
• ²² Calaf GM, Ponce-Cusi R, Aguayo F, Muñoz JP, Bleak TC. Endocrine disruptors from the environment affecting breast cancer. Oncology Letters. 2020;20(1):19–32. doi:10.3892/ol.2020.11566
• ²³ Wan MLY, Co VA, El-Nezami H. Endocrine disrupting chemicals and breast cancer: a systematic review of epidemiological studies. Critical Reviews in Food Science and Nutrition. 2022;62(24):6549–6576. doi:10.1080/10408398.2021.1903382.
• ²⁴ Rocha PRS, Oliveira VD, Vasques CI, Dos Reis PED, Amato AA. Exposure to endocrine disruptors and risk of breast cancer: a systematic review. Critical Reviews in Oncology/Hematology. 2021;161:103330. doi:10.1016/j.critrevonc.2021.103330
• ²⁵ Tiburcio D, Parsell M, Shapiro H, Adolphe S, Naranjo O, George S, Toborek M. Endocrine disruption to metastasis: How phthalates promote breast carcinogenesis. Ecotoxicol Environ Saf. 2025 Sep 15;303:118874. doi: 10.1016/j.ecoenv.2025.118874. Epub 2025 Aug 14. PMID: 40816212; PMCID: PMC12466654.
• ²⁶ Sánchez-Ocaña M, de Porras VR. Environmental endocrine disruptors and breast cancer: the role of bisphenols, polychlorinated biphenyls, parabens, and dioxins. Environmental Toxicology and Pharmacology. 2025;104834. doi:10.1016/j.etap.2025.104834.
• ²⁷  Rudel RA, Fenton SE, Ackerman JM, Euling SY, Makris SL. Environmental exposures and mammary gland development: state of the science, public health implications, and research recommendations. Environmental Health Perspectives. 2011;119(8):1053–1061. doi:10.1289/ehp.1002864.
• ²⁸  Dell’Anno F, Giugliano R, De Paolis L, Crescio I, Razzuoli E. Cadmium and cancer: a study on canine tumours and environmental bioindicators (Sus scrofa). Ecotoxicology and Environmental Safety. 2025;303:119005. doi:10.1016/j.ecoenv.2025.119005.
• ²⁹ Kass L, Gomez AL, Altamirano GA. Relationship between agrochemical compounds and mammary gland development and breast cancer. Molecular and Cellular Endocrinology. 2020;508:110789. doi:10.1016/j.mce.2020.110789.
• ³⁰ CanineSports.com
• ³¹ Küpeli Akkol E, Bardakci H, Barak TH, Aschner M, Şeker Karatoprak G, Khan H, Hussain Y. Herbal Ingredients in the Prevention of Breast Cancer: Comprehensive Review of Potential Molecular Targets and Role of Natural Products. Oxid Med Cell Longev. 2022 Aug 16;2022:6044640. doi: 10.1155/2022/6044640. PMID: 36017236; PMCID: PMC9398845.
• ³² A. Pogorzelska, M. Switalska, J. Wietrzyk, M. Mazur, K. Medynska, K.Witorska, Antitumor and antimetastatic effects of dietary sulforaphane in a triple-negative breast cancer models, Nature, 11 July 2024
• ³³ Rose DP, Connolly JM, Rayburn J, Coleman M. Influence of diets containing eicosapentaenoic or docosahexaenoic acid on growth and metastasis of breast cancer cells in nude mice. Journal of the National Cancer Institute. 1995;87(8):587–592. doi:10.1093/jnci/87.8.587.
• ³⁴ Khadge S, Thiele GM, Sharp JG, et al. Long-chain omega-3 polyunsaturated fatty acids decrease mammary tumor growth, multiorgan metastasis and enhance survival. Clinical & Experimental Metastasis. 2018;35(8):797–818. doi:10.1007/s10585-018-9941-7
• ³⁵ Zheng JS, Hu XJ, Zhao YM, Yang J, Li D. Intake of fish and marine n-3 polyunsaturated fatty acids and risk of breast cancer: meta-analysis of data from 21 independent prospective cohort studies. BMJ. 2013;346:f3706. doi:10.1136/bmj.f3706
• ³⁶ Zheng JS, Hu XJ, Zhao YM, Yang J, Li D. Intake of fish and marine n-3 polyunsaturated fatty acids and risk of breast cancer: meta-analysis of data from 21 independent prospective cohort studies. BMJ. 2013;346:f3706. doi:10.1136/bmj.f3706.
• ³⁷ Yang Zhang, Qiong Xu, Jiepin Hu, Feng Zhang, Youjie Yu, and Longying Ma,Green Tea and Epigallocatechin Gallate (EGCG) for Cancer Prevention: A Systematic Review and Meta-Analysis, The American Journal of Chinese MedicineVol. 53, No. 06, pp. 1755-1784 (2025),https://doi.org/10.1142/S0192415X2550065X
• ³⁸ Current Nanomaterials, Curcumin-based Nanoformulations to Target Breast Cancer, Badran, Mesmar, Wehbe, El Kurdi, Patra, Baydoun, Vol 8, Issue 1, 2023, DOI: 10.2174/2405461506666210831145230
• ³⁹ Jermnak U, Saengtienchai A, Jaroensong T, Kunakornsawat S, Soontararak S, Supsavhad W, Siripattarapravat K, Khieokhajonkhet A, Yohannes YB. Synergistic apoptotic and epithelial–mesenchymal transition-inhibitory effects of Hericium erinaceus extract in canine mammary cancer cell lines. Veterinary World. 2026;19(6):2318–2338. doi:10.14202/vetworld.2026.2318-2338.

About Karen Shaw Becker, DVM, CVH, CVA, CCRT

Veterinarian Dr. Karen Shaw Becker believes biologically appropriate food and an animal's immediate environment are essential in determining health, vitality, and lifespan. She has spent her career as a wildlife and exotic animal veterinarian and small animal clinician, empowering animal guardians to make intentional lifestyle decisions to enhance the well-being of their animals.