Downloaded from http://veterinaryrecord.bmj.com/ on May 14, 2015 - Published by group.bmj.com
Short Communication
Short Communication Glyphosate-surfactant herbicide poisoning in domestic animals: an epidemiological survey C. Cortinovis, F. Davanzo, M. Rivolta, F. Caloni GLYPHOSATE (N-phosphonomethyl-glycine) is a non-selective systemic herbicide widely used by both professional and home gardeners (Bradberry and others 2004). Commercial glyphosatebased formulations generally consist of an aqueous mixture of glyphosate in the form of a salt, a surfactant and various minor components (Bradberry and others 2004). The toxic mechanisms of glyphosate formulations are unclear. Animal experiments suggest that the toxicity is due primarily to the surfactant, since it has an oral LD50 approximately four times lower than glyphosate (Bradberry and others 2004). Few data are available on glyphosate intoxication and prognosis in the veterinary literature. According to the Centre National d’Informations Toxicologiques Vétérinaires (CNITV) (Burgat and others 1998, Berny and others 2010), the Italian Veterinary Toxicologic Assistance Service (SATV) (Giuliano Albo and Nebbia 2004) and the human Poison Control Centre of Milan (Centro Antiveleni di Milano, CAV) (Caloni and others 2012), glyphosate is the herbicide most commonly involved in animal poisonings. Since its launch, the Veterinary Poisons Information Service (VPIS) in London has received 1323 enquiries about dogs (n=992) and cats (n=331) exposed to glyphosate-based products (Bates and Edwards 2013). In the present study, a retrospective analysis of all enquiries related to animal exposures to glyphosate-containing herbicides collected by the CAV from January 2006 to December 2012 was performed. For each enquiry, details of the exposure and the clinical history are recorded in the CAV database. Follow-up calls are made to obtain continuous updates of case reports, including the final outcome. The cases analysed involved various commercial products containing glyphosate identified by container label. The severity of clinical signs was classified as: ‘no signs’, mild, moderate, severe and death, according to the methodology used by Gwaltney-Brant (2007). CAV collected 38 cases of glyphosate-surfactant herbicide exposure involving domestic animals, which corresponds to 2.6 per cent of all animal poisoning cases recorded (1429) over the 2006–2012 period. During this period, glyphosate was the
Veterinary Record (2015) C. Cortinovis, DVM, PhD, F. Caloni, Prof DVM, PhD, Department of Health, Animal Science and Food Safety (VESPA), Università degli Studi di Milano, Via Celoria 10, Milan 20133, Italy F. Davanzo, MD, M. Rivolta,
herbicide with the highest number of calls (77.6 per cent of herbicide calls). In the last two years, CAV recorded a substantial increase in enquiries about glyphosate-related animal poisoning (Fig 1). Of these enquiries, 31 were from veterinarians and seven from animal owners. Dogs were the most commonly poisoned species (n=27), followed by cats (n=6). Enquiries related to other species were much fewer in comparison and involved horses (n=2), followed by goats and sheep (n=1 each). A case involving both horses and sheep after the ingestion of hay treated with a glyphosatesurfactant herbicide was also reported. Data showed that exposure to glyphosate-surfactant herbicides occurred by oral intake (n=36), by inhalation and by ocular contact (n=1 each). Of the animal exposures with known outcomes (n=24; 18 dogs, four cats, one horse, one sheep), three cases (two dogs and one horse) had no signs. Mild signs developed in six cases (five dogs and one cat), moderate signs developed in nine cases (six dogs, two cats and one sheep), severe signs developed in one case (one dog) and death occurred in five cases (four dogs and one cat). The clinical signs recorded for symptomatic dogs (n=21) are listed in Table 1. Of these dogs, 19 (90.5 per cent) had gastrointestinal signs, including hypersalivation, vomiting and diarrhoea, and six (28.6 per cent) developed increased muscular activity, such as tremors, muscle fasciculations or convulsions. Only one dog was reported to have no gastrointestinal signs, but still developed muscular effects. Fatal renal failure developed in two poisoning episodes. Glyphosate and the other formulation components with high molecular weights are non-volatile, thus making inhalation a minor route of exposure (Goldstein and others 2002). However, in one episode, inhalation of glyphosate-surfactant herbicide by a dog resulted in hypersalivation, tremors and hyperthermia followed by death. In cats, exposure to glyphosate-containing herbicides did not produce clinical signs in one episode. In symptomatic cats, vomiting, tremors, muscle fasciculations, drowsiness and mydriasis were observed. Renal failure occurred in two cases and led to death in one case. Conjunctivitis was reported once after ocular contact (Burgat and others 1998). No clinical signs developed in horses and goats after exposure to glyphosate-surfactant herbicides, whereas hypersalivation, tremors, swelling of the neck and dyspnoea were reported in a flock of sheep. No fatal outcomes were recorded for these species. Since its introduction, glyphosate has rapidly risen in popularity due to its effectiveness and relatively low toxicity in mammals (Williams and others 2012). Glyphosate was the herbicide which stimulated the highest number of calls to the CAV.
doi: 10.1136/vr.102763 Centro Antiveleni di Milano, Ospedale Niguarda Cà Granda, Piazza Ospedale Maggiore 3, Milan 20162, Italy E-mail for correspondence: [email protected] Provenance: not commissioned; externally peer reviewed Accepted January 21, 2015
FIG 1: Frequency of animal species exposure (per cent) to glyphosate-surfactant herbicides reported to the Poison Control Centre of Milan from the beginning of 2006 to the end of 2012
April 18, 2015 | Veterinary Record
Downloaded from http://veterinaryrecord.bmj.com/ on May 14, 2015 - Published by group.bmj.com
Short Communication TABLE 1: Clinical signs reported in dogs following exposure to glyphosate-surfactant herbicides Clinical signs
Number of cases
Frequency (%)
9 8 7 5 3 2 2 1 1 1 1 1
33.3 29.6 25.9 18.5 11.1 7.4 7.4 3.7 3.7 3.7 3.7 3.7
Vomiting Hypersalivation Diarrhoea Tremors Muscle fasciculations Renal impairment Melena Convulsions Hyperthermia Dyspnoea Drowsiness Oral ulcerations
numbers of cats in the present study is too small to draw conclusions about differences between cats and dogs. The low number of cases and the lack of information on the amount of glyphosate-based herbicide ingested mean that the results cannot be generalised. However, the data collected could be used to increase awareness among animal owners and veterinarians about the potential for glyphosate-surfactant herbicide toxicosis, as a significant annual increase of these poisonings can be seen.
Acknowledgements The authors are very grateful to Francesca Assisi, Maurizio Bissoli, Rossana Borghini, Tiziana Della Puppa, Valeria Dimasi, Marcello Ferruzzi, Paola Angela Moro, Antonella Pirina, Ilaria Rebutti, Angelo Roberto Travaglia, Fabrizio Maria Sesana and Paolo Severgnini.
Poison Control Centre of Milan data 2006–2012
References Moreover, CAV data show a trend of increasing poisonings with glyphosate-surfactant herbicides, probably reflecting the increased use of this herbicide in recent years (Williams and others 2012). A reliance on glyphosate as the primary method of weed control has led to problems with weed resistance and to an overall increase in the number of glyphosate applications yearly (Annett and others 2014). As previously reported (Burgat and others 1998, Giuliano Albo and Nebbia 2004, Bates and Edwards 2013), dogs were the most frequently poisoned species and the most common clinical signs included vomiting, hypersalivation and diarrhoea due to gastrointestinal irritation. Gastrointestinal bleeding recorded as melena was also reported in some episodes. Signs of increased muscular activity were not uncommon in more severe cases. Renal impairment was reported both in dogs and in cats and led to death in three cases. Renal impairment usually reflects reduced organ perfusion, although a direct toxic effect of glyphosate or surfactant may also contribute (Bradberry and others 2004). The mortality rate based on cases with known outcome was relatively high (20.8 per cent), especially compared with other studies (Burgat and others 1998, Bates and Edwards 2013). No fatal outcome was recorded in a French survey (Burgat and others 1998) and of the 292 cases (229 dogs and 63 cats) recorded by the VPIS, only 18 (nine dogs and nine cats) were fatal (Bates and Edwards 2013). According to the VPIS (Bates and Edwards 2013), the mortality rate in cats (22 per cent) was more than four times higher than in dogs (5 per cent). Unfortunately, the
Veterinary Record | April 18, 2015
ANNETT, R., HABIBI, H. R. & HONTELA, A. (2014) Impact of glyphosate and glyphosate-based herbicides on the freshwater environment. Journal of Applied Toxicology 34, 458–479 BATES, N. & EDWARDS, N. (2013) Glyphosate toxicity in animals. Clinical Toxicology 51, 1243 BERNY, P., CALONI, F., CROUBELS, S., SACHANA, M., VANDENBROUCKE, V., DAVANZO, F. & GUITART, R. (2010) Animal poisoning in Europe. Part 2: companion animals. The Veterinary Journal 183, 255–259 BRADBERRY, S. M., PROUDFOOT, A. T. & VALE, J. A. (2004) Glyphosate poisoning. Toxicological Reviews 23, 159–167 BURGAT, V., KECK, G., GUERRE, P., BIGORRE, V. & PINEAU, X. (1998) Glyphosate toxicosis in domestic animals: a survey from the data of Centre National d’Informations Toxicologiques Vétérinaires. Veterinary and Human Toxicology 40, 363–367 CALONI, F., CORTINOVIS, C., RIVOLTA, M. & DAVANZO, F. (2012) Animal poisoning in Italy: 10 years of epidemiological data from the Poison Control Centre of Milan. Veterinary Record 170, 415 GIULIANO ALBO, A. & NEBBIA, C. (2004) Incidence of poisonings in domestic carnivores in Italy. Veterinary Research Communications 28(Suppl 1), 83–88 GOLDSTEIN, D. A., ACQUAVELLA, J. F., MANNION, R. M. & FARMER, D. R. (2002) An analysis of glyphosate data from the California Environmental Protection Agency Pesticide Illness Surveillance Program. Journal of Toxicology – Clinical Toxicology 40, 885–892 GWALTNEY-BRANT, S. M. (2007) Epidemiology of animal poisoning. In Veterinary Toxicology: Basic and Clinical Principles. Ed R. C. GUPTA. Elsevier Inc., pp 67–73 WILLIAMS, A. L., WATSON, R. E. & DESESSO, J. M. (2012) Developmental and reproductive outcomes in humans and animals after glyphosate exposure: a critical analysis. Journal of Toxicology and Environmental Health Part B: Critical Reviews 15, 39–96
Downloaded from http://veterinaryrecord.bmj.com/ on May 14, 2015 - Published by group.bmj.com
Glyphosate-surfactant herbicide poisoning in domestic animals: an epidemiological survey C. Cortinovis, F. Davanzo, M. Rivolta and F. Caloni Veterinary Record 2015 176: 413 originally published online February 11, 2015
doi: 10.1136/vr.102763 Updated information and services can be found at: http://veterinaryrecord.bmj.com/content/176/16/413.1
These include:
References Email alerting service
This article cites 9 articles, 1 of which you can access for free at: http://veterinaryrecord.bmj.com/content/176/16/413.1#BIBL Receive free email alerts when new articles cite this article. Sign up in the box at the top right corner of the online article.
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Short Communication
Short Communication Glyphosate-surfactant herbicide poisoning in domestic animals: an epidemiological survey C. Cortinovis, F. Davanzo, M. Rivolta, F. Caloni GLYPHOSATE (N-phosphonomethyl-glycine) is a non-selective systemic herbicide widely used by both professional and home gardeners (Bradberry and others 2004). Commercial glyphosatebased formulations generally consist of an aqueous mixture of glyphosate in the form of a salt, a surfactant and various minor components (Bradberry and others 2004). The toxic mechanisms of glyphosate formulations are unclear. Animal experiments suggest that the toxicity is due primarily to the surfactant, since it has an oral LD50 approximately four times lower than glyphosate (Bradberry and others 2004). Few data are available on glyphosate intoxication and prognosis in the veterinary literature. According to the Centre National d’Informations Toxicologiques Vétérinaires (CNITV) (Burgat and others 1998, Berny and others 2010), the Italian Veterinary Toxicologic Assistance Service (SATV) (Giuliano Albo and Nebbia 2004) and the human Poison Control Centre of Milan (Centro Antiveleni di Milano, CAV) (Caloni and others 2012), glyphosate is the herbicide most commonly involved in animal poisonings. Since its launch, the Veterinary Poisons Information Service (VPIS) in London has received 1323 enquiries about dogs (n=992) and cats (n=331) exposed to glyphosate-based products (Bates and Edwards 2013). In the present study, a retrospective analysis of all enquiries related to animal exposures to glyphosate-containing herbicides collected by the CAV from January 2006 to December 2012 was performed. For each enquiry, details of the exposure and the clinical history are recorded in the CAV database. Follow-up calls are made to obtain continuous updates of case reports, including the final outcome. The cases analysed involved various commercial products containing glyphosate identified by container label. The severity of clinical signs was classified as: ‘no signs’, mild, moderate, severe and death, according to the methodology used by Gwaltney-Brant (2007). CAV collected 38 cases of glyphosate-surfactant herbicide exposure involving domestic animals, which corresponds to 2.6 per cent of all animal poisoning cases recorded (1429) over the 2006–2012 period. During this period, glyphosate was the
Veterinary Record (2015) C. Cortinovis, DVM, PhD, F. Caloni, Prof DVM, PhD, Department of Health, Animal Science and Food Safety (VESPA), Università degli Studi di Milano, Via Celoria 10, Milan 20133, Italy F. Davanzo, MD, M. Rivolta,
herbicide with the highest number of calls (77.6 per cent of herbicide calls). In the last two years, CAV recorded a substantial increase in enquiries about glyphosate-related animal poisoning (Fig 1). Of these enquiries, 31 were from veterinarians and seven from animal owners. Dogs were the most commonly poisoned species (n=27), followed by cats (n=6). Enquiries related to other species were much fewer in comparison and involved horses (n=2), followed by goats and sheep (n=1 each). A case involving both horses and sheep after the ingestion of hay treated with a glyphosatesurfactant herbicide was also reported. Data showed that exposure to glyphosate-surfactant herbicides occurred by oral intake (n=36), by inhalation and by ocular contact (n=1 each). Of the animal exposures with known outcomes (n=24; 18 dogs, four cats, one horse, one sheep), three cases (two dogs and one horse) had no signs. Mild signs developed in six cases (five dogs and one cat), moderate signs developed in nine cases (six dogs, two cats and one sheep), severe signs developed in one case (one dog) and death occurred in five cases (four dogs and one cat). The clinical signs recorded for symptomatic dogs (n=21) are listed in Table 1. Of these dogs, 19 (90.5 per cent) had gastrointestinal signs, including hypersalivation, vomiting and diarrhoea, and six (28.6 per cent) developed increased muscular activity, such as tremors, muscle fasciculations or convulsions. Only one dog was reported to have no gastrointestinal signs, but still developed muscular effects. Fatal renal failure developed in two poisoning episodes. Glyphosate and the other formulation components with high molecular weights are non-volatile, thus making inhalation a minor route of exposure (Goldstein and others 2002). However, in one episode, inhalation of glyphosate-surfactant herbicide by a dog resulted in hypersalivation, tremors and hyperthermia followed by death. In cats, exposure to glyphosate-containing herbicides did not produce clinical signs in one episode. In symptomatic cats, vomiting, tremors, muscle fasciculations, drowsiness and mydriasis were observed. Renal failure occurred in two cases and led to death in one case. Conjunctivitis was reported once after ocular contact (Burgat and others 1998). No clinical signs developed in horses and goats after exposure to glyphosate-surfactant herbicides, whereas hypersalivation, tremors, swelling of the neck and dyspnoea were reported in a flock of sheep. No fatal outcomes were recorded for these species. Since its introduction, glyphosate has rapidly risen in popularity due to its effectiveness and relatively low toxicity in mammals (Williams and others 2012). Glyphosate was the herbicide which stimulated the highest number of calls to the CAV.
doi: 10.1136/vr.102763 Centro Antiveleni di Milano, Ospedale Niguarda Cà Granda, Piazza Ospedale Maggiore 3, Milan 20162, Italy E-mail for correspondence: [email protected] Provenance: not commissioned; externally peer reviewed Accepted January 21, 2015
FIG 1: Frequency of animal species exposure (per cent) to glyphosate-surfactant herbicides reported to the Poison Control Centre of Milan from the beginning of 2006 to the end of 2012
April 18, 2015 | Veterinary Record
Downloaded from http://veterinaryrecord.bmj.com/ on May 14, 2015 - Published by group.bmj.com
Short Communication TABLE 1: Clinical signs reported in dogs following exposure to glyphosate-surfactant herbicides Clinical signs
Number of cases
Frequency (%)
9 8 7 5 3 2 2 1 1 1 1 1
33.3 29.6 25.9 18.5 11.1 7.4 7.4 3.7 3.7 3.7 3.7 3.7
Vomiting Hypersalivation Diarrhoea Tremors Muscle fasciculations Renal impairment Melena Convulsions Hyperthermia Dyspnoea Drowsiness Oral ulcerations
numbers of cats in the present study is too small to draw conclusions about differences between cats and dogs. The low number of cases and the lack of information on the amount of glyphosate-based herbicide ingested mean that the results cannot be generalised. However, the data collected could be used to increase awareness among animal owners and veterinarians about the potential for glyphosate-surfactant herbicide toxicosis, as a significant annual increase of these poisonings can be seen.
Acknowledgements The authors are very grateful to Francesca Assisi, Maurizio Bissoli, Rossana Borghini, Tiziana Della Puppa, Valeria Dimasi, Marcello Ferruzzi, Paola Angela Moro, Antonella Pirina, Ilaria Rebutti, Angelo Roberto Travaglia, Fabrizio Maria Sesana and Paolo Severgnini.
Poison Control Centre of Milan data 2006–2012
References Moreover, CAV data show a trend of increasing poisonings with glyphosate-surfactant herbicides, probably reflecting the increased use of this herbicide in recent years (Williams and others 2012). A reliance on glyphosate as the primary method of weed control has led to problems with weed resistance and to an overall increase in the number of glyphosate applications yearly (Annett and others 2014). As previously reported (Burgat and others 1998, Giuliano Albo and Nebbia 2004, Bates and Edwards 2013), dogs were the most frequently poisoned species and the most common clinical signs included vomiting, hypersalivation and diarrhoea due to gastrointestinal irritation. Gastrointestinal bleeding recorded as melena was also reported in some episodes. Signs of increased muscular activity were not uncommon in more severe cases. Renal impairment was reported both in dogs and in cats and led to death in three cases. Renal impairment usually reflects reduced organ perfusion, although a direct toxic effect of glyphosate or surfactant may also contribute (Bradberry and others 2004). The mortality rate based on cases with known outcome was relatively high (20.8 per cent), especially compared with other studies (Burgat and others 1998, Bates and Edwards 2013). No fatal outcome was recorded in a French survey (Burgat and others 1998) and of the 292 cases (229 dogs and 63 cats) recorded by the VPIS, only 18 (nine dogs and nine cats) were fatal (Bates and Edwards 2013). According to the VPIS (Bates and Edwards 2013), the mortality rate in cats (22 per cent) was more than four times higher than in dogs (5 per cent). Unfortunately, the
Veterinary Record | April 18, 2015
ANNETT, R., HABIBI, H. R. & HONTELA, A. (2014) Impact of glyphosate and glyphosate-based herbicides on the freshwater environment. Journal of Applied Toxicology 34, 458–479 BATES, N. & EDWARDS, N. (2013) Glyphosate toxicity in animals. Clinical Toxicology 51, 1243 BERNY, P., CALONI, F., CROUBELS, S., SACHANA, M., VANDENBROUCKE, V., DAVANZO, F. & GUITART, R. (2010) Animal poisoning in Europe. Part 2: companion animals. The Veterinary Journal 183, 255–259 BRADBERRY, S. M., PROUDFOOT, A. T. & VALE, J. A. (2004) Glyphosate poisoning. Toxicological Reviews 23, 159–167 BURGAT, V., KECK, G., GUERRE, P., BIGORRE, V. & PINEAU, X. (1998) Glyphosate toxicosis in domestic animals: a survey from the data of Centre National d’Informations Toxicologiques Vétérinaires. Veterinary and Human Toxicology 40, 363–367 CALONI, F., CORTINOVIS, C., RIVOLTA, M. & DAVANZO, F. (2012) Animal poisoning in Italy: 10 years of epidemiological data from the Poison Control Centre of Milan. Veterinary Record 170, 415 GIULIANO ALBO, A. & NEBBIA, C. (2004) Incidence of poisonings in domestic carnivores in Italy. Veterinary Research Communications 28(Suppl 1), 83–88 GOLDSTEIN, D. A., ACQUAVELLA, J. F., MANNION, R. M. & FARMER, D. R. (2002) An analysis of glyphosate data from the California Environmental Protection Agency Pesticide Illness Surveillance Program. Journal of Toxicology – Clinical Toxicology 40, 885–892 GWALTNEY-BRANT, S. M. (2007) Epidemiology of animal poisoning. In Veterinary Toxicology: Basic and Clinical Principles. Ed R. C. GUPTA. Elsevier Inc., pp 67–73 WILLIAMS, A. L., WATSON, R. E. & DESESSO, J. M. (2012) Developmental and reproductive outcomes in humans and animals after glyphosate exposure: a critical analysis. Journal of Toxicology and Environmental Health Part B: Critical Reviews 15, 39–96
Downloaded from http://veterinaryrecord.bmj.com/ on May 14, 2015 - Published by group.bmj.com
Glyphosate-surfactant herbicide poisoning in domestic animals: an epidemiological survey C. Cortinovis, F. Davanzo, M. Rivolta and F. Caloni Veterinary Record 2015 176: 413 originally published online February 11, 2015
doi: 10.1136/vr.102763 Updated information and services can be found at: http://veterinaryrecord.bmj.com/content/176/16/413.1
These include:
References Email alerting service
This article cites 9 articles, 1 of which you can access for free at: http://veterinaryrecord.bmj.com/content/176/16/413.1#BIBL Receive free email alerts when new articles cite this article. Sign up in the box at the top right corner of the online article.
Notes
To request permissions go to: http://group.bmj.com/group/rights-licensing/permissions To order reprints go to: http://journals.bmj.com/cgi/reprintform To subscribe to BMJ go to: http://group.bmj.com/subscribe/
