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What about Garlic for dogs? Is it safe or not!

Updated: Feb 18, 2023

A Japanese study* proves that garlic toxicity is almost impossible to reach. Dose - 1/2 lb (equal to about 78 cloves) per 100 lbs body weight is the amount force-fed to study dogs each day for seven straight days. (3 1/2 lbs total equal to 546 raw cloves per 100 lbs bodyweight)

Result - Microscopic examination of subject dogs' blood showed oxidative damage to a small percentage of red blood cells. No dog was anemic. No dog was reported to show sickness, weakness, or other negative signs. Researchers guessed that continued feeding would eventually cause anemia. *Lee, K.W., Yamato, O., Tajima, M., Kuraoka, M., Omae, S., Meade,Y. "Hematologic changes associated with the appearance of eccentrocytes after intragastric administration of garlic extracts to dogs."American Journal of Veterinary Research. November 2000. Vol. 61, No. 11, 1446-1450. Toxicity is Dose Dependent A central concept of toxicology is that effects are dose-dependent; even water can lead to water intoxication when taken in large enough doses, whereas for even a very toxic substance such as snake venom there is a dose below which there is no detectable toxic effect.

Learn and understand the myth’s surrounding garlic and its supposed toxicity, and discover the many health benefits it offers dogs and cats.

When it comes to your patients’ health – preventatively or curatively – you need accurate information about safety and benefits. Garlic, long used as a beneficial herb, and listed by the FDA as approved for pet food, is still under attack in spite of a 2004 follow-up study recommending garlic for dogs by the majority of scientists involved in a 2000 study done by Japan. Even the ASPCA’s poison hotline information recently added garlic to its list of toxins, although they report no individual cases linked to garlic ingestion in 2014, as they do for most other toxins. While it is understandable that you may hesitate to use garlic, the facts below may shift your thinking. BENEFITS For centuries, humans have used herbs, and garlic has been a primary remedy for a large number of symptoms. As long as people have been using garlic, they have also been feeding it to their animal companions.

Garlic’s properties have proven far-reaching, easily assimilated, and safe. In the past 80 years, during holistic medicine’s rebirth in the United States, garlic has been in the forefront of both human care and animal husbandry. Every textbook I have researched on herbal medicine that also mentions pet care recommends it, especially for its incredible anti-parasitic, anti-carcinogenic, and antiseptic properties. In my own experience, garlic has also benefited animals with valley fever (Coccidioidomycosis), heartworm/fleas/ticks, IBS, diabetes, liver, heart and kidney disease, allergies, uncontrollable staph infections (that are non-responsive to all antibiotic protocols), and a host of other conditions. Garlic is also a staple in my preventative protocols.

Garlic has been widely and safely used by hundreds of thousands of pet parents for over 30 years, with no reported serious negative side effects

A multi-pronged approach

A veterinarian for over the last 35 years: Healthier animals rarely attract many pests, especially fleas and mosquitoes, and flies in horses. If and when they do get infected with an insect-transmitted illness, they recover rapidly with holistic approaches.

My goal, then, is to build health and have a multitude of gentle, safe options (for animals, humans and the planet) to offer clients, reserving the “chemical of the year” for unique circumstances. Clients feel confident buying their essential oils from me. Most alternative pest repellent products involve essential oils, flower essences, nutrition & herbs.

Separating fact from fiction

For the last few decades, primarily as a result of the onion’s reputation for triggering Heinz body hemolytic anemia because of its higher concentration of thiosulphate, garlic (the onion’s “kissing cousin”) was also said to be toxic. Garlic simply does not contain the same thiosulphate concentration as the onion does. In fact, it is barely traceable and readily excreted. “In the testing of onions and garlic on (the dog’s) blood cell oxidation, onions have about 15 times the ability of garlic to damage red blood cells,” states nutritionist Dr. Dave Summers on

Almost all the “evidence” against garlic for dogs comes from a 2000 study at Hokkaido University.2 Four dogs were each given 1.25 ml of garlic extract per kg of body weight for seven straight days. For example, if the dog weighed 50 pounds, he would be given approximately 25 large raw garlic cloves. None of the dogs showed any outward toxicity symptoms, but there was an effect on their red blood cells, even though at these highly-elevated doses none of the dogs developed anemia. “We believe that foods containing garlic should be avoided for use in dogs,” the researchers stated. However, a study published by Chang, et al in 2004 clearly showed that allicin is beneficial to mammals’ health, and there was no report of hemolytic anemia in spite of the high concentrations of garlic provided during the study. “In contrast, the maximal aggregation percentage returned to the control level at 1mM of all(en)yl thiosulfates in both canine and human platelets,” rather than remaining high enough to be a problem as originally thought. This encouraged the scientists to reverse their earlier 2000 recommendations against garlic for dogs and actually recommend garlic to promote immune functions and prevent cardiovascular diseases.

There can be multiple causes for Heinz body hemolytic anemia. Wendy Wallner, DVM, reminds us that other substances such as acetaminophen (Tylenol) and benzocaine-containing topical preparations can also cause Heinz body hemolytic anemia in the dog. These preparations probably account for many cases since ingredients in creams are absorbed through the skin, allowing toxins to build up in the bloodstream. Source:

Garlic’s sulphur-inclusive compounds

Garlic contains multiple sulphur-inclusive compounds – alliin, a noted sulfoxide; and alliinase, an enzyme. When garlic is chopped, crushed, minced or chewed, the alliinase enzyme is activated, and combines with the alliin protein to produce allicin, the therapeutic component of garlic. Heat inactivates enzymes, so by waiting at least ten minutes after chopping so the enzyme has completed the reaction with the alliin, the therapeutic value is maximized. Allicin is heat stable. Source: Garlic – well-rounded and safe! | IVC Journal 1Summers D. “Understanding Garlic”. or fbid=643173565722197; October 10, 2013.

2Lee KW, Yamato O, Tajima M, Kuraoka M, Omae S, Maede Y. “Hematologic changes associated with the appearance of eccentrocytes after intragastric administration of garlic extract to dogs”. Am J Vet Res. 2000 Nov:61 (11): 1446-50.

3Chang HS, Yamato O, Sakai Y, Yamasaki M, Maede Y. “Acceleration of superoxide generation in polymorphonuclear leukocytes and inhibition of platelet aggregation by alk(en)yl thiosulfates derived from onion and garlic in dogs and humans”. Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, 060-0818 Sapporo, Japan, 2004.

4Riviere Jim E, Boothe Dawn M, Czarnecki-Maulden Gail L, Dzanis David A, Harris Patricia A, Hendriks Wouter H, Kirk Claudia A, Warren Lori K, Lewis Austin J, Arieti Ruth S. “Safety of Dietary Supplements for Horses, Dogs, and Cats”. Committee on Examining the Safety of Dietary Supplements for Horses, Dogs, and Cats, The National Academy of Sciences, 2008.

Our own Heaven Sent brand uses air-dried organic garlic in all our products for maximum health benefits.

Garlic Studies

Insecticidal and Repellent Effects Hills, L.D. (1972) Will garlic replace DDT? Org. Gard

en. Farm (Sept.) Banerji, A., Amonkar, S.V., and Bhabha Atomic Res. Ctr. (1978) Insecticidal properties of garlic. India. Patent 144 278. Chem. Abst. 92 (1980) 17 188. Bhuyan, M., Saxena, B.N., and Rao, K.M. (1974) Repellent properties of iol fraction of garlic. Allium sativum Linn. Indian J. Exp. Bio. 12:575-576. Sakai, I. (1992b) Allicin-containing pesticide for golf course greens. Japan. Patent 92 05 211. Chem. Abst. 116 (1992) 168 344. Weisler, R. (1989) Systemic insect repellent composition comprising vitamin B1 and allyl sulfide. U.S.A. Patent 4 876 090. Chem. Abst. 112 Population Studies - Low cancer

rates associated with regular garlic consumption. Dorant, E., van den Brandt. P.A., and Goldbohm, R.A. (1994b) A prospective cohort study on Allium vegetable consumption, garlic supplement use, and the risk of lung carcinoma in the Netherlands. Cancer Res. 54:6148-6153. Yang, C.S., Wang, Z.Y., and Hong, J.Y., (1994b) Inhibition of tumorigenesis by chemicals from garlic and tea. In: Advances in experimental medicine and biology: diet and cancer: markers, prevention, and treatment. M.M. Jacobs, ed. Plenum, New York, pp. 113-122. Chem. Abst. 122 (1995) 22 889. Caldwell, D.R. and Danzer, C.J. (1988) Effects of allyl sulfides on the growth of predominant gut anaerobes. Curr. Microbiol. 16:237-241. Chem. Abst. 108 (1988) 146 953. Abdullah, T.H., Kandil, O., Elkadi, A., and Carter, J. (1988) Garlic revisited: therapeutic for the major diseases of our times? J. Nat. Med. Assoc. 80:439-445. Chem. Abst. 109 (1988) 21 973. Int. Pharm. Abst. 26 (1989) 2286.

Immune Stimulant Effects of Garlic: Animal and In Vitro Studies Nakata, T. (1973) Effects of fresh garlic extract on tumor growth. Nippon Eiseigaku Zasshi (Jap. J. Hyg.) 27:538-543. Chem. Abst. 79 (1973) 111 680 (Japanese). Nakata, T., and Fujiwara, M. (1975) Adjuvent action of garlic sugar solu-tion in animals immunized with Ehrlich ascites tumor cells attenuated with allicin. Gann 66:417-419. Weisberger, A.S., and Pensky, J. (1957) Tumor-inhibiting effects derived from an active principle of garlic (Allium sativum). Science 126:1112-1114. Effect of garlic on tumors in mice and rats Kametani, T., Fukumoto, K., and Umezawa, O. (1959) Studies on anticancer agents. I. Synthesis of various alkyl thiosulfinates and tumor-inhibiting effect. Yakugaku Kenkyu (Jap. J. Pharm. Chem.) 31:60-74. Chem. Abst. 54 (1960) 11 018 (Japanese). Hirsch, A.F., Piantadosi, C., and Irvin, J.L. (1965) Potential anticancer agents. II. The synthesis of some nitrogen mustard con

taining sulfones and thiosulfinates. J. Med. Chem. 8:10-14. Chem. Abst. 62 (1965) 5215. Zhou, J., Qi, R., and Zhang, M. (1988) Growth suppression of human leukemic cells in vitro by garlicin (ethyl ethanethiosulfinate). Shandong Yike Daxue Xuebao 26:43-47. Chem. Abst. 110 (1989) Cheng, H.H. and Tung, T.C. (1981) Effect of allithiamine on sarcoma-180 tumor growth in mice. Taiwan I Hsuch Hui Tsa Chih 80:385-393. Chem. Abst. 95 (1981) 197 366 (Chinese). Di Paolo, J.A. and Carruthers, C. (1960) The effect of allicin from garlic on tumor growth. Cancer Res. 20:431-434. Chem. Abst. 55 (1961) 3844. Kimura, Y. and Yamamoto, K. (1964) Cytological effect of chemicals on tumors: influence of crude extracts from garlic and some related species on MTK-sarcoma III. Gann 55:325-329. Chem. Abst. 63 (1965) 1089. Fujiwara, M. and Na

tata, T. (1967) Induction of tumor immunity with tumor cells treated with extract of garlic (Allium sativum). Nature 216:83-84. Aboul-Enein, A.M. (1986) Inhibition of tumor growth with possible immunity by Egyptian garlic extracts. Nahrung 30:161-169 Lau, B.H.S., Woolley, J.L., Marsh, C.L., Barker, G.R., Koobs, D.H., and Torrey, R.R. (1986a) Superiority of intralesional immunotherapy with Corynebacterium parvum and Allium sativum in control of murine transitional cell carcinoma. J. Urol. 136:701-705. Antioxidant Effects Jacob, R., Isensee, H., Rietz, B., Makdessi, S., and Sweiden, H. (1993a) Cardioprotection by dietary interventions in animal experiments: effect of garlic and various dietary oils under the conditions of experimental infarction. Pharm. Pharmacol. Lett. 3:124-127. Chem. Abst. 123. (1994) 162 425. Torok, B., Belagyi, J., Rietz, B., and Jacob, R. (1994) Effectiveness of garlic on the radical activity in radical generating systems. Antidote for Heavy Metal Poisoning and Other Toxins Hanafy, M.S.M

., Shalaby, S.M., El Fouly, M.A.A., El Aziz, M.I.A., and Soliman, F.A. (1994) Effect of garlic on lead contents in chicken tissues. Dtsch. Tieraeztl. Wochenschr. 101:157-158. Cha, C.W. (1987) A study on the effect of garlic to the heavy metal poisoning of rats. J. Korean Med. Sci. 2:213-223. Chem. Abst. 109 (1988) 18 322.

OTC & Conventional Vet Prescribed Flea & Tick Poisons 75,000 Adverse Reactions Reported (Millions Probably Unreported) National Pet Poison Hotline Report Incidents at 800-858-7378 How to tell if your pet has been poisoned Symptoms of poisoning by flea/tick treatments may include salivating, dilated pupils, tremors, vomiting, hiding, shivering, convulsions, and skin irritation. What to do if your pet has been poisoned If you suspect your pet may have suffered negative health effects as a result of a flea product, consult with your veterinarian immediately. Be sure to report all such incidents to the EPA's National Pesticide Telecommunications Network at 800-858-7378. "Spot-On" Flea & Tick Products Alleged to Cause Serious Harm to Dogs and Cats -- Pet Pharmaceutical Industry Under Fire in Multiple New Jersey Class Action Lawsuits -- NEWARK, N.J., Dec. 8, 2011 /PRNewswire via COMTEX/ — There is a growing sense of moral outrage and alarming statistics from consumers and pet advocates alike after over 75,000 complaints about the products have been reported to the EPA and nothing has been done to change the advertising, marketing or labeling of the products to alert pet owners of the possible serious side-effects. What's chilling is that those numbers only reflect what has been reported, the actual number of incidents may be much, much higher. /flea_tick_OTC_pet_products.html

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