Hematologic changes associated with the appearance of eccentrocytes after intragastric administration of garlic extract to dogs

Effect of Garlic Extract on the Erythrocyte as a Simple Model Cell

Garlic is known to have diverse effects on mammalian cells, being cytotoxic, especially to cancer cells, but also protect against oxidative stress. Mammalian erythrocyte is a simple cell devoid of intracellular organelles, protein synthesis ability, and most signaling pathways. Therefore, examination of the effects of garlic on erythrocytes allows for revealing primary events in the cellular action of garlic extract. In this study, human erythrocytes or erythrocyte membranes were exposed to garlic extract at various dilutions. Hemoglobin oxidation to methemoglobin, increased binding of hemoglobin to the membrane, and formation of Heinz bodies were observed. Garlic extract depleted acid-soluble thiols, especially glutathione, and induced a prooxidative shift in the cellular glutathione redox potential. The extract increased the osmotic fragility of erythrocytes, induced hemolysis, and inhibited hemolysis in isotonic ammonium chloride, indicative of decreased membrane permeability for Cl- and increased the membrane fluidity. Fluorescent probes indicated an increased level of reactive oxygen species and induction of lipid peroxidation, but these results should be interpreted with care since the extract alone induced oxidation of the probes (dichlorodihydrofluorescein diacetate and BODIPY C11). These results demonstrate that garlic extract induces oxidative changes in the erythrocyte, first of all, thiol and hemoglobin oxidation.

Therapeutic effect of aged garlic extract on gingivitis in dogs

Periodontal disease is one of the most common dental health problems in dogs. Clinical studies in humans have shown that aged garlic extract (AGE), which contains stable and water-soluble sulfur-containing bioactive compounds, improves the symptoms of periodontal diseases. Our previous study demonstrated that oral administration of AGE in healthy Beagle dogs at 90 mg/kg/day for 12 weeks had no adverse effects such as hemolytic anemia, which is well known to occur as a result of ingestion of Allium species, including onions and garlic, in dogs. However, the therapeutic potential of AGE in canine periodontal disease remains unclear. Accordingly, we investigated the therapeutic effects of AGE in Beagle dogs with mild gingivitis. Feeding 18 mg/kg/day of AGE for 8 weeks resulted in the improvement of gingival index score, level of volatile sulfur compounds in exhaled air, and enzyme activity of periodontal pathogens without any adverse effects on clinical signs and hematological and serum biochemical parameters. Moreover, AGE increased the concentration of salivary cathelicidin, an antimicrobial peptide that contributes to the oral innate immune response. These results suggest that AGE could be a potential therapeutic agent for canine gingivitis.

Case series: Heinz body formation in 13 multimorbid dogs following metamizole administration

Background

Heinz Body (HB) anemia is a result of oxidative damage and is an uncommon condition in dogs relative to cats. In this retrospective case series, clinical features, laboratory values, concurrent diseases, and outcomes of 13 multimorbid dogs that developed HBs after receiving metamizole are reported.

Case description

Of the 13 dogs in this case series that developed HBs, 10 were older and multimorbid, but the only feature that all the dogs had in common was receiving metamizole. HBs were detected in 7 out of 13 dogs within a few days (3-10 days) after starting metamizole treatment. The metamizole dose was 38-159 mg/kg/day. The highest percentage of HBs detected was 28-95% (mean, 46%). There was no correlation between the percentage of HBs and the daily dose of metamizole. All but 1 dog had mild-to-severe anemia at the time of the highest HB appearance. The number of HBs did not correlate with the hematocrit at that time. In 8/12 dogs, no stress leukogram was present. Approximately half of the dogs with HBs also had evidence of gastrointestinal hemorrhage, which could have masked additional oxidative damage.

Conclusion

In multimorbid dogs that develop regenerative anemia after receiving metamizole, hemolysis due to HB development caused by oxidative damage should be considered as an important differential diagnosis.

Emerging Plant Intoxications in Domestic Animals: A European Perspective

Exposure to phytotoxins that are present in imported ornamental or native plants is an important cause of animal disease. Factors such as animal behaviors (especially indoor pets), climate change, and an increase in the global market for household and ornamental plants led to the appearance of new, previously unreported plant poisonings in Europe. This has resulted in an increase in the incidence of rarely reported intoxications. This review presents some of the emerging and well-established plant species that are responsible for poisoning episodes in companion animals and livestock in Europe. The main plant species are described, and the mechanism of action of the primary active agents and their clinical effects are presented. Data reflecting the real incidence of emerging poisoning cases from plant toxins are scarce to nonexistent in most European countries due to a lack of a centralized reporting/poison control system. The diversity of plant species and phytotoxins, as well as the emerging nature of certain plant poisonings, warrant a continuous update of knowledge by veterinarians and animal owners. The taxonomy and active agents present in these plants should be communicated to ensure awareness of the risks these toxins pose for domestic animals.

Anaemia in Ruminants Caused by Plant Consumption

Plant toxicology has affected animals throughout evolution. Plants have adapted themselves to the environment. This adaptation has led to the development of defensive strategies to avoid being consumed. Plants have several chemical compounds, which can cause deleterious effects on people or animals that consume them, causing a wide variety of clinical signs. Plants from various latitudes, both cultivated for human and animal feeding or decorative purpose and even wild growth plants are able to generate anaemia in ruminants. Coumarins or ptaquiloside predispose bleeding and haemorrhages, causing a haemorrhagic disease in affected animals. In this group, some important fodder plants, such sweet clover (Genus Melilotus spp.), or other weeds distributed worldwide, such as bracken fern (Pteridium aquilinum) of giant fennel (Ferula communis), are included. On the other hand, sulfur-containing chemicals (e.g., n-propyl disulfate and S-propyl cysteine sulfoxides (SMCOs)) may cause severe direct damage to the erythrocyte and their membrane, leading to their destruction and causing haemolytic anaemia in the animal. This review presents the most frequent intoxication by plants causing anaemia in ruminants. Toxic compounds, clinical signs, diagnosis and possible treatments are also presented.

The potential side effects of herbal preparations in domestic animals

A recent series of deaths in previously healthy dogs in Victoria, Australia associated with the ingestion of raw meat contaminated by indospicine derived from native Australian plants of the Indigofera species draws attention to the potential that exists for herbal toxicity in domestic animals. Although the efficacy of herbal remedies generally remains unproven in domestic animals, herbal preparations are being increasingly used as supplements and treatments. Issues with incorrect ingredients, inadequate processing, faulty, incomplete or inaccurate product labelling, contamination with toxins, adulteration with undeclared pharmaceutical agents and herb-herb interactions are well recognized as causes of adverse effects in humans. However, apart from of the effects of noxious weed species, the literature on herbal toxicity in domestic animals is sparse. Thus, the forensic evaluation of cases of suspected poisoning in domestic animals should also encompass an accurate description the type and dose of any herbal preparations that may have been recently administered.

Short report: Aqueous extract of chives (Allium schoenoprasum L.) plant impairs erythrocyte deformability in sickle cell patients

Sickle cell anemia (SCA) is a genetic disorder characterized by chronic hemolysis and the presence of erythrocytes with low deformability, which may trigger vaso-occlusive crises. We tested the in-vitro effects of aqueous extract of vhives (Allium schoenoprasum L.) on erythrocyte deformability of SCA patients. Blood samples from 6 apparently healthy volunteers and 5 SCA patients were collected into heparin coated tubes. Both apparently healthy and SCA patient blood samples were incubated with 80μg/mL chives plant aqueous extract at 37°C for 60 min and erythrocyte deformability was measured by ektacytometry (3 Pa and 30 Pa; 37°C). Results of incubation of apparently healthy blood samples with plant extract showed that incubation did not alter erythrocyte deformability significantly. However, for SCA blood samples, erythrocyte deformability decreased significantly with plant extract exposure at 3 Pa (p <  0.043) and 30 Pa (p <  0.043). In conclusion, although ex-vivo incubation with plant extract does not fully model gastrointestinal processing of onions, the decrease in SCA erythrocyte deformability following incubation with aqueous chives should stimulate further studies to test the in-vivo effects of this diet in sickle cell mice.

Raw meat-based diets for dogs: survey of owners' motivations, attitudes and practices

BACKGROUND

The popularity of raw meat-based diets (RMBDs) for pets has been increasing in recent years even if the reputed health benefits are mainly anecdotal. A web-based survey was developed to better understand the motivations and habits of owners who decided to feed their dogs RMBDs.

RESULTS

The questionnaire was completed by 218 dog owners, 62 of whom were living with people whose immune system was impaired or weakened. Internet was the preferred source of information for more than half of the respondents, and feeding dogs a more natural and healthier diet was the main reason behind owners' interest in RMBDs. About 80% of the participants completely abandoned commercial pet food and showed marked distrust especially towards the lack of clarity on the ingredients used (n = 169). The vast majority of owners interviewed (94%) believed RMBDs to be absolutely safe for dogs, and shinier coat, muscle mass gain, and cleaner teeth were the principal improvements seen on their pets. Controlling the composition and quality of the ingredients provided to their animals was the main advantage of RMBDs for 57% of the owners, while the main disadvantages were related to the purchase of some components (38%) and the time required (22%) for the preparation of the diet. Only 8% of the respondents relied on veterinarians for RMBD formulation, and a wide variety of feeding regimens and combinations of ingredients was observed.

CONCLUSIONS

As revealed by this study, most owners are unaware of the risks posed by the feeding of RMBDs for both animal and human health, and they often rely on questionable sources for advice on pet nutrition. Owners see RMBDs as a more natural and healthier alternative to commercial pet food even if the actual benefits remain unproven. Consulting veterinarians for proper information and board-certified nutritionists for the formulation of complete and balanced RMBDs should be promoted.

Safety and efficacy of aged garlic extract in dogs: upregulation of the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway and Nrf2-regulated phase II antioxidant enzymes

Background

Plants of Allium spp., including garlic (A. sativum) and onions (A. cepa), are known to be oxidatively toxic to canine erythrocytes resulting in Heinz body hemolytic anemia in dogs. In humans, these plants have been used as medicinal agents for multiple diseases since ancient times. Especially, fresh garlic extracted over a prolonged period produces less irritative and odorless aged garlic extract (AGE), containing unique and beneficial organosulfur compounds that can help prevent many kinds of diseases. In this study, the safety and efficacy of long-term oral administration of AGE is evaluated in dogs. The objectives are to confirm the safe dosage for long-term use and beneficial functions of AGE for dogs and to plan and design a canine health supplement or a preventive agent for multiple diseases based on the data of this study.

Results

Beagles were orally administered AGE (45 or 90 mg/kg body weight once a day) or an equivalent amount of water as control for 12 weeks. In AGE-treated groups, at 12 weeks post-administration at a dose of 90 mg/kg, there were no observable changes in the clinical signs, complete blood count, and serum biochemical parameters. Heinz bodies and eccentrocytes, the markers of oxidative damage in erythrocytes, did not appear in blood smear examination. In order to further evaluate the beneficial effects of AGE on health of dogs, the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) gene (NFE2L2) and Nrf2-regulated phase II antioxidant enzyme genes (NQO1, GCLM, HMOX1, and SOD2) were determined in whole blood between pre- and post-AGE administration. The expression of NFE2L2 gene was significantly upregulated in the AGE-treated groups [45 (p < 0.05) and 90 mg/kg (p < 0.01), 8 weeks] as compared to in the control group. Among the Nrf2-regulated enzymes examined, the expressions of NQO1 [45 (p < 0.05) and 90 mg/kg (p < 0.01), 8 weeks] and GCLM [45 (p < 0.05) and 90 mg/kg (p < 0.01), 12 weeks] genes were significantly upregulated.

Conclusion

The long-term oral administration of AGE at a dose of 90 mg/kg/day for 12 weeks did not show any adverse effects in dogs. Furthermore, the administration of AGE upregulated the gene expressions of canine Nrf2 and Nrf2-regulated phase II antioxidant enzymes. These results suggest that AGE might safely contribute to the health of dogs provided that the appropriate dosage is used.

Electronic supplementary material

The online version of this article (10.1186/s12917-018-1699-2) contains supplementary material, which is available to authorized users.

Pharmaco-Toxicological Aspects of Herbal Drugs Used in Domestic Animals

Herbal drugs are more and more used both in human and veterinary medicine to mitigate and prevent minor diseases and to support conventional medicine using allopathic drugs. Nevertheless, ‘natural product’ does not mean lack of adverse effects, and many people and veterinarians do not know enough about the adverse reactions that can occur following the administration of such drugs in domestic animals. Moreover, herbal products can interact with each other when administered concomitantly or can agonize or antagonize the effects of synthetic drugs administered as primary therapy. The use of non-conventional medicines (NCM) should be considered as a veterinary practise. In this paper, the herbal drugs most utilized in domestic animals, both pets and large animals, are reviewed, as their use is increasing, despite the prejudices of the academic world and some of the adverse effects and interactions that can occur in domestic animals.

Some food toxic for pets

According to world statistics, dogs and cats are the species that owners most frequently seek assistance with potential poisonings, accounting 95-98% of all reported animal cases. Exposures occur more commonly in the summer and in December that is associated with the holiday season. The majority (>90%) of animal poisonings are accidental and acute in nature and occur near or at the animal owner's home. Feeding human foodstuff to pets may also prove dangerous for their health.The aim of this review was to present common food items that should not be fed (intentionally or unintentionally) to dogs, i.e. chocolate, caffeine, and other methylxanthines, grapes, raisins, onion, garlic, avocado, alcohol, nuts, xylitol contained in chewing gum and candies, etc. Onion and avocado are toxic for cats, too. The clinical effects of individual toxicants and possible therapy are also mentioned. Knowing what human food has the potential to be involved in serious toxicoses should allow veterinarians to better educate their clients on means of preventing pet poisonings.It can be concluded that the best advice must surely be to give animal fodder or treats specifically developed for their diets.

Proteinaceous cytotoxic component of Allium sativum induces apoptosis of INT-407 intestinal cells

Garlic has long been known for its wide array of therapeutic effects, including hypolipidemic, antihypertensive, antimicrobial, and possibly anticancer effects; conversely, some adverse effects of garlic, such as acute pain and neurogenic inflammation, have also been reported. However, information detailing the toxicological significance of garlic is scarce. In this study, the cytotoxicities of fresh garlic extract (FGE) and boiled garlic extract (BGE) and their underlying toxic mechanisms were investigated using INT-407 intestinal epithelial cells. A brief exposure (20 minutes) to FGE induced a concentration-dependent increase in cell death (37 +/- 2% at 300 microg/mL), but no cytotoxic effects were induced after exposure to BGE. For FGE, only the high-molecular-mass (>10-kDa) proteins were associated with cytotoxic effects. FGE-treated cells showed morphological changes such as increased cell rounding and fragmentation, suggesting programmed cell death (apoptosis). Apoptosis of FGE-treated cells was evaluated by observing the fragmented multinuclei stained with Hoechst 33342. From the cell cycle analysis, the increase in hypodiploidic cells and in the G2/M phase cell population suggested not only apoptosis but also cell cycle arrest of FGE-treated cells. Pretreatment with N-acetyl-l-cysteine almost completely prevented FGE-induced cell death, suggesting that reactive oxygen species (ROS) may play a key role in FGE-associated cytotoxicity. Consumption of fresh garlic may be linked to potential cytotoxicity of intestinal cells when ROS scavengers are not present.

The molecular mechanisms of diallyl disulfide and diallyl sulfide induced hepatocyte cytotoxicity

Diallyl disulfide (DADS) and diallyl sulfide (DAS) are the major metabolites found in garlic oil and have been reported to lower cholesterol and prevent cancer. The molecular cytotoxic mechanisms of DADS and DAS have not been determined. The cytotoxic effectiveness of hydrogen versus allyl sulfides towards hepatocytes was found to be as follows: NaHS>DADS>DAS. Hepatocyte mitochondrial membrane potential was decreased and reactive oxygen species (ROS) and TBARS formation was increased by all three allyl sulfides. (1) DADS induced cytotoxicity was prevented by the H(2)S scavenger hydroxocobalamin, which also prevented cytochrome oxidase dependent mitochondrial respiration suggesting that H(2)S inhibition of cytochrome oxidase contributed to DADS hepatocyte cytotoxicity. (2) DAS cytotoxicity on the other hand was prevented by hydralazine, an acrolein trap. Hydralazine also prevented DAS induced GSH depletion, decreased mitochondrial membrane potential and increased ROS and TBARS formation. Chloral hydrate, the aldehyde dehydrogenase 2 inhibitor, however had the opposite effects, which could suggest that acrolein contributed to DAS hepatocyte cytotoxicity.

Hematology without the numbers: in-clinic blood film evaluation

Technical advances have made it possible for many private veterinary practices to purchase reasonably priced automated hematology instruments to perform in-clinic blood analyses. Although these instruments can quickly provide "numbers" to the clinician, evaluation of a well-made blood film can often provide information critical to the interpretation of those numbers. Blood film review is essential to identify important abnormalities such as neutrophilic left shifts and toxic change, neoplastic cells, hemoparasites, and erythrocyte morphologic changes that may suggest the cause of an anemia. Additionally, the blood film provides an important quality control measure for the automated hematology results. This article outlines a simple method of blood film evaluation, highlights the most common clinically important abnormalities, and reinforces the importance of blood film evaluation as a quality control measure.

Effect of diallyl trisulfide-rich garlic oil on blood coagulation and plasma activity of anticoagulation factors in rats

Diallyl trisulfide (DAT)-rich garlic oil was fed to Sprague-Dawley rats and the effects of this DAT-rich garlic oil on bleeding time, clotting time and anticoagulation factors were examined. Garlic oil supplement at 5 or 50mg garlic oil/kg bodyweight significantly prolonged bleeding time and thrombin time, and enhanced anticoagulation factor activity, such as antithrombin III and protein C (P<0.05). These results suggested that the anticoagulant action of DAT-rich garlic oil was due to inhibition and/or inactivation of thrombin. In addition, DAT-rich garlic oil benefits blood anticoagulation factors, which might further prevent the development of thrombus formation. However, the intake of garlic oil at high dose significantly increased plasma fibrinogen concentration (P<0.05), and affected the levels of several hematological parameters such as erythrocyte count, hemoglobin and platelets (P<0.05). The adverse effect of high doses of garlic oil might further influence the hemostatic balance. Therefore, the concentration of DAT-rich garlic oil should be carefully considered in its application. Supplementation of garlic oil at 5mg/kg bodyweight has anticoagulation effect in this animal study.

Nutritional and Herbal Therapies in the Treatment of Heart Disease in Cats and Dogs

Nutritional supplements such as L-carnitine and taurine have been found to be beneficial in dogs and cats with certain cardiac diseases. However, not all animals with cardiac disease respond to nutritional supplementation, which means that further work must be done to identify causes of cardiac disease. Herbal therapies have been used in dogs and cats based on information available from their use in humans. This paper reviews the possible benefits and side effects of L-carnitine, taurine, and herbal supplements.

Growth inhibitory effect of alk(en)yl thiosulfates derived from onion and garlic in human immortalized and tumor cell lines

Two alk(en)yl thiosulfates, sodium n-propyl thiosulfate (NPTS) and sodium 2-propenyl thiosulfate (2PTS), are natural constituents of onion and garlic, respectively, which were identified originally as causative agents of onion- and garlic-induced hemolytic anemia in dogs. As a continuation of our studies on the beneficial functions of NPTS and 2PTS, in the present study, we investigated the antitumor effects of these compounds. They were shown to inhibit the in vitro proliferation of three human tumorigenic cell lines, WiDr, 293 and HL-60, in a dose-dependent manner. Overall, NPTS seemed to have weak activity for inhibiting cell growth compared with 2PTS, though not in WiDr cells, which were sensitive to both compounds. NPTS and 2PTS caused oxidative damage to HL-60 cells and induced apoptosis. The extent of apoptosis was approximately proportional to that of the oxidative damage and also to that of the cytotoxicity caused by these compounds. These results suggest that the alk(en)yl thiosulfates have an antitumor effect through the induction of apoptosis initiated by oxidative stress.

Association of maximum voluntary dietary intake of freeze-dried garlic with Heinz body anemia in horses

OBJECTIVE

To characterize hematologic and clinical consequences of chronic dietary consumption of freeze-dried garlic at maximum voluntary intake in horses.

ANIMALS

4 healthy sex- and age-matched horses.

PROCEDURE

An initial garlic dose (0.05 g/kg, twice daily) was fed to 2 horses in a molasses carrier as part of their normal ration and was gradually increased to maximum voluntary intake (0.25 g/kg, twice daily) over 41 days. Dietary supplementation then continued for a total of 71 days. Two control horses were fed molasses with no garlic with their ration. Blood samples were collected weekly and analyzed for hematologic and biochemical changes, including the presence of Heinz bodies. Recovery of affected blood values was followed for 5 weeks after termination of dietary supplementation with garlic.

RESULTS

At a daily dose of > 0.2 g/kg, horses fed garlic developed hematologic and biochemical indications of Heinz body anemia, as characterized by increases in Heinz body score (HBS), mean corpuscular volume (MCV), mean corpuscular hemoglobin, platelet count, and serum unconjugated and total bilirubin concentrations and decreases in RBC count, blood hemoglobin concentration, mean corpuscular hemoglobin concentration, and serum haptoglobin concentration. Recovery from anemia was largely complete within 5 weeks after termination of dietary supplementation with garlic. Heinz body score and MCV remained high at the end of the 5-week recovery period.

CONCLUSIONS AND CLINICAL RELEVANCE

Horses will voluntarily consume sufficient quantities of garlic to cause Heinz body anemia. The potential for garlic toxicosis exists when horses are chronically fed garlic. Further study is required to determine the safe dietary dose of garlic in horses.

An overview of the antifungal properties of allicin and its breakdown products - the possibility of a safe and effective antifungal prophylactic

Reports about the safe and successful intravenous (i.v.) use of garlic derivatives in China against invasive fungal infections have been made, but little has been done to seriously investigate the in vivo use of these derivatives in the West. Laboratories have demonstrated impressive in vitro MICs using allitridium, one of these derivatives, against a range of medically important fungi. In addition, it has been demonstrated that allitridium shows in vitro synergy with amphotericin B, one of the main i.v. antifungal agents. Some of the breakdown products of allicin, the main parent antifungal compound in garlic, have been investigated for their general antimicrobial, anticancer and anticholesterol properties, and it appears that there is a common mode of action that underlies these activities. It appears that these small molecules have the ability to cross cell membranes and combine with sulfur-containing molecular groups in amino acids and proteins, thus interfering with cell metabolism. It has been suggested that the reason human cells are not poisoned by allicin derivatives is that they contain glutathione, a sulfur-containing amino acid that combines with the allicin derivative, thus preventing cell damage. In addition to their biochemical mechanism, these derivatives appear to stimulate cellular immunity, an important ability lacking in conventional antifungal chemotherapy. These derivatives appear to be safe, cheap, wide-spectrum and immunostimulatory, as well as possibly synergistic with conventional antifungal therapy, making them ideal candidates for investigation into their use as prophylactic antifungal agents.

Heinz Body Hemolytic Anemia With Eccentrocytosis From Ingestion of Chinese Chive (Allium tuberosum) and Garlic (Allium sativum) in a Dog

A 4-year-old, intact male miniature schnauzer was presented with anorexia. The dog had ingested some Chinese steamed dumplings 2 days before, which contained Chinese chive (Allium tuberosum) and garlic (Allium sativum). Hematological examinations revealed severe Heinz body hemolytic anemia with eccentrocytosis and an increased concentration of methemoglobin, which was thought to result from oxidative damage to erythrocytes by constituents in these Allium plants. In this case, eccentrocytosis was a hallmark finding and could be detected easily, suggesting that this hematological abnormality is useful in diagnosing Allium plant-induced hemolysis.

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

We recently identified sodium n-propyl thiosulfate (NPTS) and sodium 2-propenyl thiosulfate (2PTS) from boiled onion and garlic, respectively, as causative agents of hemolytic anemia in dogs. We present here data concerning the effects of these alk(en)yl thiosulfates on superoxide (O(2)(-)) generation in peripheral polymorphonuclear leukocytes (PMNs) and on adenosine 5'-diphosphate (ADP)-induced platelet aggregation in dogs and humans in vitro. Both NPTS and 2PTS increased O(2)(-) generation significantly (P<0.05 at 1mM NPTS, P<0.005 at 0.1 and 1mM 2PTS) and reduced its reaction time significantly (P<0.05 between 0.01 and 1mM NPTS and at 1mM 2PTS) in canine PMNs stimulated by phorbol 12-myristate 13-acetate, compared with the control without alk(en)yl thiosulfates. However, a tendency to return to the control level was observed at 10mM of the alk(en)yl thiosulfates in both O(2)(-) generation and its reaction time. Although NPTS and 2PTS did not exert any significant effect on the O(2)(-) generation in human PMNs, 2PTS reduced its reaction time significantly (P<0.05) at 1 and 10mM compared with the control, showing that 2PTS accelerated O(2)(-) generation in human PMNs. The difference in effects on O(2)(-) generation may be due to that in susceptibility to alk(en)yl thiosulfates between canine and human PMNs. On the other hand, NPTS and 2PTS were shown to significantly inhibit ADP-induced platelet aggregation at 0.01mM (P<0.01) in canine platelets and at 0.001-0.1mM (P<0.05) in human platelets. In contrast, the maximal aggregation percentage returned to the control level at 1mM of alk(en)yl thiosulfates in both canine and human platelets. From these results, we conclude that NPTS and 2PTS have the potential to promote immune functions and prevent cardiovascular diseases.

The use of nutraceuticals in cancer therapy

The high prevalence of nutraceutical use among human patients with cancer suggests that the use of nutraceuticals in pet animals with cancer is probably common. Dogs with a wide variety of malignant diseases have significant alterations in carbohydrate, protein, and fat metabolism. These metabolic alterations may be ameliorated by using functional foods relatively low in soluble carbohydrate, moderate amounts of protein that includes sources of arginine, and moderate amounts of fat supplemented with omega-3 long-chain polyunsaturated fatty acids. Well-controlled clinical studies in a variety of species with cancer, including rodents, people, and dogs, have documented that increased dietary and serum levels of omega-3 fatty acids are associated with a number of health benefits, including improved disease-free interval, survival time, and quality of life. Other nutraceuticals of interest in patients with cancer include antioxidant vitamins, trace minerals, glutamine, protease inhibitors, garlic, tea polyphenols, vitamin A, and shark cartilage.

Selected herbal hazards

One of the most important considerations in treating herbal ingestions is product quality assurance. Although most herbal companies are reputable, there are numerous reports of adulterated products (addition of substances not noted on the label). This has been particularly true of Chinese herbal products, which frequently contain pharmaceutical agents. Plant identification errors occur, and entire batches of product have been mixed using the wrong herb. In some cases, labels are written in a foreign language or only contain directions for mixing, making interpretation difficult. In cases where a known ingestion produces unexpected clinical signs, the potential for adulteration or other errors should be considered. When a product is not standardized, a consumer cannot be sure what dose of active constituents has been used or how bioavailable the product may be. Standardization also provides assurance that the actual herb is in the product [26]. Clients who use herbal products should be advised to treat them as a medication and to keep them away from pets. Specifically, ask clients if they take or use any natural or herbal products. Many people do not consider these substances drugs or assume, "If natural, it is harmless." Clients should be encouraged to learn about the herbal and neutraceutical products they are taking or giving their pets. Owners need to discuss the proper use of herbal products in pets with their veterinarian. Clients can be encouraged to discuss alternative therapies by discussing a pet's diagnosis and suggested treatments thoroughly. Discuss the client's expectations and opinions of alternative and conventional medicine. Issues of safety and efficacy must be fully explained to clients. Clients should be encouraged to report potential adverse reactions or to discuss different routes of therapy if a pet's medical condition is not improving. Clients who want to use alternative medical treatments should obtain a thorough medical workup so as to make a correct diagnosis and be referred to a veterinarian trained in alternative medicine. In choosing an alternative medicine practitioner, the same criteria would be used as for any other specialist: education, training, and professionalism [14].