J. Kupper

Acute plant poisoning: Analysis of clinical features and circumstances of exposure

Introduction. Human contact with potentially toxic plants, which may occur through abuse or by accident or attempted suicide, is frequent and sometimes results in clinically significant toxicity. Objective. The aim of the present study was to identify which plants may lead to severe poisoning, and to define the clinical relevance of plant toxicity for humans in Switzerland. Methods. We analyzed 42 193 cases of human plant exposure and 255 acute moderate, severe, and lethal poisonings, which were reported to the Swiss Toxicological Information Centre between January 1995 and December 2009. Results. Plant contact was rarely responsible for serious poisonings. Lethal intoxications were extremely rare and were caused by plants with cardiotoxic (Taxus baccata) or mitosis-inhibiting (Colchicum autumnale) properties. Conclusions. Most often, plant contact was accidental and patients remained asymptomatic or developed mild symptoms, which fully resolved within a short time.

A fatal case of autumn crocus (Colchicum autumnale) poisoning in a heifer: confirmation by mass-spectrometric colchicine detection.

A heifer developed severe signs of acute gastrointestinal irritation 48 hr after ingesting fresh leaves of Colchicum autumnale growing on a damp meadow. Confirmation of the suspected toxicosis was obtained by detecting colchicine in serum and urine using liquid chromatography coupled with tandem mass spectrometry using atmospheric pressure chemical ionization. Although the serum colchicine concentration had declined to an apparently nontoxic level of 2.4 ng/ml, a more prominent concentration (640 ng/ml) indicative of colchicine poisoning was detected in the urine. This finding is consistent with the known toxicokinetic properties of colchicine, whereby a large volume of distribution results in low circulating blood concentrations and prolonged urinary excretion.

Excessive lead burden among golden eagles in the Swiss Alps

Fragments from lead ammunition pose a poisoning risk for predators like golden eagles that scavenge on non-retrieved carcasses or offal left behind by hunters. Three golden eagles were found in the Swiss Alps with an acute lead poisoning. To investigate whether the few cases of lead-poisoned golden eagles are exceptional events or whether a substantial proportion of the Alpine golden eagle population is affected by lead at sublethal levels, we measured body burdens in golden eagles from Switzerland in comparison to eagle owls from the same area and to their respective prey. These two raptor species differ in their food as eagle owls feed on live-caught prey. Lead levels in soft tissues were significantly higher in golden eagles (median 1.14 μg g−1 dry weight in liver, 0.99 μg g−1 in kidney) than in eagle owls (0.14 and 0.23 μg g−1). Bones of golden eagles contained 10 times more lead (median of 12.45 μg g−1 dry weight) than owl bones (1.28 μg g−1), which represent substantially higher levels than previously reported for golden eagles. Bones of prey of both golden eagles and eagle owls had low lead concentrations. In order to investigate whether the sublethal lead of golden eagles originates from ammunition or from generic environmental contamination, we examined lead isotope ratios. Lead isotope signatures of golden eagle bones were very similar to those of ammunition, but differed from the signatures of bones of their prey, eagle owls and soil. Isotope signatures did not change with increasing bone lead concentration in golden eagles or any other group examined. These findings indicate that in the Alps, most golden eagles take up lead from spent ammunition in carcasses or their offal in sublethal quantities throughout their life and a few in lethal quantities leading to acute lead poisoning.

Treatment of Ivermectin Overdose in a Miniature Shetland Pony Using Intravenous Administration of a Lipid Emulsion

An 11-month-old miniature Shetland Pony colt weighing 26 kg was presented to the University of Zurich Equine Hospital for evaluation of acute onset of generalized seizures, followed by unconsciousness and recumbency, 34 hours after a massive (>25-fold) overdose of deworming paste (140 mg ivermectin and 1.05 g praziquantel). Instead of the labeled quantities of 0.2 mg ivermectin/kg and 1.5 mg praziquantel/kg, the foal had received the entire tube, equivalent to 5.4 mg ivermectin/kg and 40.4 mg praziquantel/kg. At presentation, the colt was in a stuporous condition but responded to pain stimuli including jugular venous catheter placement. Heart rate was 26/min, respiratory rate was 20/min, and rectal temperature was 34.5°C (94.1°F). The peripheral pulses were very weak and not detectable by palpation at all superficial arteries. Both jugular veins were poorly filled and capillary refill time was prolonged at approximately 3 seconds. The distal limbs and ears were cold to the touch. Palpebral and pupillary reflexes as well as menace responses were absent. In contrast, the corneal reflex was preserved and both eyes showed spontaneous horizontal nystagmus. Muscular tone of the tongue was decreased, whereas the anal reflex appeared normal. The clinical signs were most consistent with ivermectin intoxication. Ivermectin overdoses trigger severe neurologic signs by opening c-aminobutyric acid (GABA)-gated chloride channels, which in turn causes membrane hyperpolarization and blockade of neuronal impulses. In adult horses, no signs of intoxication are observed up to an ivermectin dosage of 1.8 mg/kg, whereas ingestion of 2 mg/kg has been shown to cause lethargy, ataxia, and visual impairment. The praziquantel overdose was considered less relevant in this foal, because praziquantel has a wide margin of safety, and the present exposure would result in only mild neurological and gastrointestinal signs. Analyses of blood samples at admission identified a low blood glucose concentration (3.4 mmol/L; normal, 3.6–6.1 mmol/L), normal plasma protein concentration (70 g/L; normal, 57–80 g/L) with low albumin (11 g/L; normal, 22–37 g/L) and increased globulin concentrations (59 g/L; normal, 27–50 g/L), a total bilirubin concentration of 9 lmol/L (normal, 9 –39 lmol/L), increased c-glutamyl transferase activity (GGT, 53 IU/L; normal, 5–24 IU/L), and low total calcium concentration (2.40 mmol/L; normal, 2.88– 3.55 mmol/L). Blood urea nitrogen and creatinine concentrations, as well as plasma sodium, potassium, and chloride concentrations, were within reference ranges. The blood lactate concentration was 2.3 mmol/ L (normal, <3 mmol/L). A CBC disclosed normocytic, normochromic anemia (hematocrit, 19.3%; normal, 30–42%; hemoglobin concentration, 7.0 g/dL; normal, 10.8–14.9 g/dL) with increased white blood cell count (WBC, 11.2 9 10/lL; normal, 4.7–8.2 9 10/lL). Treatment was initiated with warmed lactated Ringer’s solution (LRS) supplemented with glucose to a concentration of 2.5%, administered through a jugular venous catheter at a rate of 60 mL/kg/h. After 10 minutes, the blood glucose concentration had reached 8.3 mmol/L and treatment was continued with LRS without glucose at the same rate. After 1 hour, the fluid was changed to a maintenance crystalloid solution containing 1.5% glucose and the infusion rate was decreased to 4 mL/kg/h. By that time, peripheral pulse quality, jugular vein filling, and capillary refill time had improved, and the patient urinated. The colt was placed under a heat lamp, on a forced-air heating From the Equine Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland (Bruenisholz, Schwarzwald); the Institute of Pharmacology and Toxicology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland (Kupper, Muentener, Naegeli); and the Institute of Forensic Medicine, Faculty of Medicine, University of Zurich, Zurich, Switzerland (Dally, Kraemer). The analytical methods described herein were previously presented as a research abstract. Dally AM, Kupper JR, Bruenisholz H, et al. Determination of ivermectin in plasma of a mini Shetland Pony after poisoning using LC-MS/MS – effectiveness of intravenous lipid therapy. 12th International Congress of Therapeutic Drug Monitoring and Clinical Toxicology, Stuttgart, Germany, October 2–6, 2011. Corresponding authors: H. Naegeli, Prof. Dr. med. vet., Institute of Pharmacology and Toxicology; and C.C. Schwarzwald, PD Dr. med. vet., PhD, Dipl. ACVIM & ECEIM, Equine Department, Vetsuisse Faculty, Winterthurerstrasse 260, CH-8057 Zurich, Switzerland; e-mails: naegelih@vetpharm.uzh.ch and cschwarzwald@ vetclinics.uzh.ch. Submitted October 11, 2011; Revised November 4, 2011; Accepted November 29, 2011. Copyright

Prevalence of nuclear cataract in Swiss veal calves and its possible association with mobile telephone antenna base stations

The purpose of this study was to valuate the prevalence of nuclear cataract in veal calves and to elucidate a possible impact by mobile phone base stations (MPBS). For this experiment a cohort study was conducted. A follow-up of the geographical location of each dam and its calf from conception through the fetal period up to slaughter was performed. The first trimester of gestation (organogenesis) was particularly emphasized. The activities of selected protective antioxidants (superoxide dismutase, catalase, glutathione peroxidase [GPx]) were assessed in aqueous humor of the eye to evaluate the redox status. Of 253 calves, 79 (32 %) had various degrees of nuclear cataract, but only 9 (3.6 %) calves had severe nuclear cataract. Results demonstrate a relation between the location of veals calves with nuclear cataracts in the first trimester of gestation and the strength of antennas. The number of antennas within 100 to 199 meters was associated with oxidative stress and there was an association between oxidative stress and the distance to the nearest MPBS. Oxidative stress was increased in eyes with cataract (OR per kilometer: 0.80, confidence interval 95 % 0.62,0.93). It has not been shown that the antennas actually affected stress. Hosmer-Lemeshow statistics showed an accuracy of 100 % in negative cases with low radiation, and only 11.11 % accuracy in positive cases with high radiation. This reflects, that there are a lot of other possibilities for nuclear cataract beside MPBS. Further studies on the influence of electromagnetic fields during embryonic development animal or person at risk are indicated.

[A retrospective study of animal poisoning reports to the Swiss Toxicological Information Centre (1997 - 2006)].

The purpose of this retrospective study was to analyse the etiology, frequency and outcome of toxicological cases recorded by the consultation service of the Swiss Toxicological Information Centre (STIC) hotline over a 10-year period, from 1997 to 2006. A detailed analysis of this database indicates that common human drugs not intended for use in animals, as well as pesticides and toxic plants represent the most prominent hazards involved in the reported cases of animal poisonings. The comparison with a previous survey from the years 1976 - 1985 revealed new toxic risks due to the accidental uptake of cannabis products, castor seeds or chocolate by dogs. In addition, there is a striking increase of serious poisonings with pyrethroids in cats. The follow-up reports delivered by veterinarians also reflect novel pharmacological and technological trends in the management of poisonings.

Treatment of chronic copper poisoning in dairy sheep with oral ammonium molybdate and sodium sulphate

Four weeks after the introduction of a new ration, a herd of sheep in the Swiss midland area was affected by depression, anorexia, decreased milk production, anemia, hemoglobinuria and frequent recumbency. Seventeen ewes died within a few days. A diagnosis of chronic copper poisoning was based on the results of feed analysis, histopathological findings and the toxicological examination of liver tissue. The remaining sheep were treated with oral ammonium molybdate and sodium sulfate, which together provide an inexpensive alternative to the chelator D-penicillamine.This combination not only prevents further copper intake, but also supports its elimination from the hepatocellular storage compartments. Serum copper levels have been determined to monitor the mobilization of copper following this antidote therapy.

Bromadiolon-Vergiftung bei Füchsen

Bromadiolon ist ein gerinnungshemmendes Rodentizid, welches die Reaktivierung von Vitamin K1 durch das Enzym Vitamin-K1-Epoxidreduktase hemmt. Der vorliegende Bericht entstand als Folge eines Einsatzes von Bromadiolon zur Bekampfung der Grossen Wuhl- oder Schermaus (Arvicola terrestris) im Kanton Thurgau. Auf Grund der unsachgemassen Anwendung eines Koders, der 0.02 % Bromadiolon enthielt, sind mindestens 40 Fuchse (Vulpes vulpes) gestorben. Der Verdacht auf eine Vergiftung mit einem gerinnungshemmenden Coumarinderivat konnte aufgrund der Sektionsbefunde gestellt werden. Die Bestatigung dieser Verdachtsdiagnose erfolgte durch den Nachweis von Bromadiolon in Blut, Thorax- und Abdominalflussigkeit.

Influence of non ionizing radiation of base stations on the activity of redox proteins in bovines

BackgroundThe influence of electromagnetic fields on the health of humans and animals is still an intensively discussed and scientifically investigated issue (Prakt Tierarzt 11:15-20, 2003; Umwelt Medizin Gesellschaft 17:326-332, 2004; J Toxicol Environment Health, Part B 12:572–597, 2009). We are surrounded by numerous electromagnetic fields of variable strength, coming from electronic equipment and its power cords, from high-voltage power lines and from antennas for radio, television and mobile communication. Particularly the latter cause’s controversy, as everyone likes to have good mobile reception at anytime and anywhere, whereas nobody wants to have such a basestation antenna in their proximity.ResultsIn this experiment, the NIR has resulted in changes in the enzyme activities. Certain enzymes were disabled, others enabled by NIR. Furthermore, individual behavior patterns were observed. While certain cows reacted to NIR, others did not react at all, or even inversely.ConclusionThe present results coincide with the information from the literature, according to which NIR leads to changes in redox proteins, and that there are individuals who are sensitive to radiation and others that are not. However, the latter could not be distinctly attributed – there are cows that react clearly with one enzyme while they do not react with another enzyme at all, or even the inverse. The study approach of testing ten cows each ten times during three phases has proven to be appropriate. Future studies should however set the post-exposure phase later on.

Carbofuran-Vergiftung bei wildlebenden Stockenten

Carbofuran, ein Pestizid aus der Wirkstoffgruppe der Carbamate, kam auf einer kleinen Wiese am Luganersee zwecks Bekampfung von Bodenschadlingen zum Einsatz. Am nachsten Morgen wurden die ersten von insgesamt 19 Todesfallen bei Stockenten (Anas platyrhynchos) beobachtet. Durch Hemmung der enzymatischen Spaltung des Neurotransmitters Acetylcholin fuhren die Carbamate zu einer exzessiven Stimulation des Parasympathicus. Daneben kommt es wegen anhaltender Reizung der neuromuskularen Ubertragung zu Lahmungen der Skelettmuskulatur. Im Extremfall sterben die Tiere an Asphyxie. Im vorliegenden Bericht konnte die Verdachtsdiagnose auf Grund des chemischen Nachweises von Carbofuran in Mageninhalt, Blut, Muskel- und Nierengewebe der betroffenen Enten bestatigt werden.