Kristin Opdal Seljetun

This Research Topic "Emerging Challenges in Companion Animal Toxicology" presents eight manuscripts that improve our knowledge and understanding of poisoning agents and treatment protocols. Initial management of poisoning in veterinary cases usually involves gastric decontamination, typically induction of emesis and administration of activated charcoal as an adsorbent. Apomorphine, a dopamine agonist, has long been the main emetic used in dogs, but the novel dopamine-2 specific agonist ropinirole has also been licensed for this indication. Lee et al. evaluated the effect of ophthalmic ropinirole compared to intravenous apomorphine in dogs. The work found ropinirole non-inferior to apomorphine. Ropinirole had a longer time to onset of effect and more protracted vomiting but had a similar incidence of adverse effects and efficacy compared to apomorphine. Activated charcoal is another commonly used treatment in small animal intoxications, due to its ability to bind to a variety of toxicants (Murphy, 2011;Wilson and Humm, 2013). Activated charcoal binds to compounds in the gastrointestinal tract, resulting in decreased adsorption, thus reducing or preventing systemic toxicity (AACT and EAPCCT, 2005). Hypernatremia is a recognized adverse effect of charcoal administration and Young et al. carried out a retrospective study from 2018 to 2023 on the incidence of hypernatremia after such treatment. The research found that administration of a single dose of activated charcoal, with or without coadministration of a cathartic in dogs with acute toxicant ingestion was not associated with the development of hypernatremia.Intravenous lipid emulsion (ILE) is used in the management of poisoning with a number of different substances, usually lipophilic compounds but also cardiotoxic substances. The mechanism of effect of ILE is not fully understood but is commonly described as a 'lipid sink' or 'shuttle' (Fettiplace and Weinberg, 2018). The study by Jones et al. examined the effect of ILE on the blood concentration of baclofen, ibuprofen, and bromethalin in dogs. ILE therapy was only effective at reducing bromethalin concentrations, supporting the lipid sink theory, and it was concluded that ILE therapy may have other means of significantly decreasing lipophilic drug concentrations in cases of toxicosis.Other studies and case reports presented within this research topic demonstrate the variety of potentially harmful substances in our environment. Natural toxins are a potential risk, such as stinging insects. The case report by Lee et al. describes multiple organ failure in a small dog following multiple stings from a paper wasp. Cases of multiple stings from bees and wasps are reported in dogs but this is the first report involving paper wasps.In another case report, McDermott et al. describe a case of thallium poisoning in a dog and this case serves to remind us that substances that are no longer used are still a risk to pets if not stored or disposed of safely. In this case the national poison center played an essential role in advising on management and accessing the antidote, Prussian Blue. Poison centers are a vital resource in the management of veterinary and human poisoning. The World Health Organization states that 'poison centres are sources of specialised expertise to address the fact that health professionals could not be expected to know about the toxicity of every chemical substance and product and also to provide a focus for toxicological research' (WHO, 2020). This is equally true for veterinary as well as human poison centers.Petronzio et al. call our attention to the risk of side effects from therapeutic doses of medications. The case report describes a case of bone marrow suppression suspected after febantel administration, a compound metabolized to fenbendazole and oxyfenbendazole. The previously healthy dog was treated with febantel, combined with praziquantel and pyrantel pamoate prescribed for empirical treatment of giardia, although the dog was neither symptomatic nor fecal antigen positive. Bone marrow suppression has been reported with fenbendazole and albendazole, another benzimidazole anthelminthic, but not with febantel. Other causes of bone marrow toxicity were ruled out and the authors suspect that metabolism to fenbendazole, an active metabolite, resulted in an idiosyncratic drug reaction. This case serves as a reminder that adverse effects can occur from commonly used medications even when dosed appropriately.The article by Klainbart et al. demonstrates the increasing trend of exposure to illicit drugs in pets. The study describes confirmed cases of drug of abuse exposure in pets from a Californian laboratory and found the most common drugs were amphetamine-type stimulants. In almost half the cases, however, more than one drug was found and a number of cases involved animal cruelty. The research shed light on malicious poisoning of animals and the need for further studies in this area.Ingestion of human medication in dogs is a frequent call to animal poison centers (ASPCA, 2025;Handley, 2025). The review by Lohmann-Menezes et al. highlights the importance of species differences in both therapeutic usage and risk of toxicosis using the example of the non-steroidal anti-inflammatory drug (NSAID) diclofenac in dogs. The study emphasises the importance of seeking veterinary advice before administering drugs to pets.In conclusion, the articles included in this Research Topic illustrate some of the circumstances in which companion animal poisoning can occur. All these studies highlight the wide variety and complexity in cases emergency veterinary clinicians can encounter, and together they contribute to our knowledge of the risks and management of poisoning in companion animals.

Background: Mushroom poisoning may result in a variety of signs ranging from mild, mostly gastroenteritis, to organ failure and death. To increase the knowledge of prevalence, treatment and outcome in dogs, information regarding mushroom ingestion was collected. Materials and methods: This retrospective study analysed all inquiries of mushroom ingestion in dogs to the Norwegian Poison Information Center from 2011 to 2022. Mushrooms were identified by a mycologist or Norwegian‐certified mushroom expert. Differences in mushroom species, clinical findings, treatments and outcome were evaluated. Results: A total of 421 mushroom ingestions in dogs were included. The mushrooms were identified as non‐poisonous in 45% of cases. The most frequently involved toxin group was gastrointestinal mushrooms, followed by muscarinic mushrooms and mushrooms containing isoxazoles. About 64% of cases were managed at home, 33% were hospitalised and received treatment, and 3% were observed by a veterinarian without treatment. The survival rate was 98.6%, with death occurring after ingestion of Amanita muscaria , Cortinarius rubellus , Amanita virosa , Clitocybe rivulosa and Inocybe sp. Conclusions: This study demonstrated the importance of rapid and accurate identification of the mushroom. This could prevent delays in therapeutic intervention and avoid unnecessary treatment of these dogs. With early, correct identification of mushrooms, our results demonstrated a good prognosis for dogs after ingestion.

Rodent control is necessary to prevent damage and spread of disease, and the most common pesticides used for urban and rural rodent control are anticoagulant rodenticides. The aim of this present study was to present data on suspected exposure to rodenticides in humans and domestic animals in Norway based on inquiries to the Norwegian Poison Information Centre in the 16-year period from 2005 through 2020. A total of 4235 inquiries regarding suspected exposures to rodenticides were registered in the study period. Of these, 1486 inquiries involved humans and 2749 animals. Second generation anticoagulants were involved in 68% of human exposures and 79% of animal exposures. Dogs were the most frequent species involved in the animal exposures with 93% of the inquiries, while cats were second most frequent involved. Around 50% of the human inquiries concerned children at the age of 0–4 years. Only 2% of the cases were in the age group 10–19 years, while adults comprised 35% of the inquiries. Acute poisonings accounted for almost 100% of the inquiries among both humans and animals. The exposure was accidental in 99% of the animal exposures and in 85% of the human exposures. In humans, only 14 inquiries were regarding occupational related accidents. Misdeed or self-inflicted injury accounted for 15% of the human inquiries and were the cause of 79% of the severe poisonings. Severe poisoning was only assessed in 1% of the cases involving children under 5 years. In contrast, 17% of the inquiries concerning adults (≥20 years) were assessed as severe. Subsequently, to prevent human and animal rodenticide exposure, we urge the use of non-chemical methods such as sanitation, rodent proofing (a form of construction which will impede or prevent rodents access to or from a given space or building) and mechanical traps. Restricting the use of rodenticides to professional pest controllers (or other persons with authorisation), reinforcing high quality education of these persons, and securing compliance of the best codes of practice could be advocated to reduce accidental exposure to rodenticides in humans and animals.

Background: Exposure to anticoagulant rodenticides (ARs) in dogs is among the most common causes of poisoning in small animal practice, but information about toxicokinetic of these rodenticides in dogs is lacking. We analysed blood and faeces from five accidentally exposed dogs and 110 healthy dogs by reversed phase ultra-high performance liquid chromatography-tandem mass spectrometry. The aim of the study was to estimate elimination of brodifacoum, bromadiolone and difenacoum after acute exposure, calculate the half-lives of these rodenticides in dogs, estimate faecal elimination in a litter of puppies born, and further to identify the extent of AR exposure in a healthy dog population.Results: Three dogs were included after single ingestions of brodifacoum; two dogs ingested bromadiolone and one dog ingested difenacoum. Maximum concentrations in faeces were found after day 2–3 for all ARs. The distribution half-lives were 1–10 days for brodifacoum, 1–2 days for bromadiolone and 10 days for difenacoum. Brodifacoum and difenacoum had estimated terminal half-lives of 200–330 days and 190 days, respectively. In contrast, bromadiolone had an estimated terminal half-life of 30 days. No clinical signs of poisoning or coagulopathy were observed in terminal elimination period. In blood, the terminal half-life of brodifacoum was estimated to 8 days. Faeces from a litter of puppies born from one of the poisoned dogs were examined, and measurable concentrations of brodifacoum were detected in all samples for at least 28 days after parturition. A cross-sectional study of 110 healthy domestic dogs was performed to estimate ARs exposure in a dog population. Difenacoum was detected in faeces of one dog. Blood and faecal samples from the remaining dogs were negative for all ARs.Conclusions: Based on the limited pharmacokinetic data from these dogs, our results suggest that ARs have a biphasic elimination in faeces using a two-compartment elimination kinetics model. We have shown that faecal analysis is suitable and reliable for the assessment of ARs exposure in dogs and a tool for estimating the AR half-lives. Half-lives of ARs could be a valuable indicator in the exposed dogs and provides important information for veterinarians monitoring AR exposure and assessment of treatment length in dogs.

Exposure of wildlife and domestic animals to anticoagulant rodenticides (ARs) is a worldwide concern, but few methods exist to determine residue levels in live animals. Traditional liver detection methods preclude determining exposure in live wildlife. To determine the value of assessing AR exposure by fecal analysis, we compared fecal and liver residues of ARs in the same animals. We collected liver and fecal samples from 40 apparently healthy red foxes (Vulpes vulpes) potentially exposed to ARs, and quantified brodifacoum, bromadiolone, coumatetralyl, difenacoum, difethialone, and flocoumafen residues by liquid chromatography–tandem mass spectrometry. Residues of ARs were detected in 53% of the fecal samples and 83% of the liver samples. We found good concordance between AR residues in feces and liver for coumatetralyl, difenacoum, and difethialone. Bromadiolone occurred in significantly greater frequency in livers compared to feces, but no significant difference in concentration between feces and liver in individual foxes could be detected. Brodifacoum displayed a significant difference in concentration and occurrence of positive samples between liver and feces. Our findings demonstrate that fecal analysis of ARs provides a feasible and valuable non-lethal means of determine AR exposure in live wildlife.

Accidental poisoning with anticoagulant rodenticides is not uncommon in dogs, but few reports of the elimination kinetics and half-lives in this species have been published. Our objectives were to develop and validate a new method for the quantification of anticoagulant rodenticides in canine blood and faeces using reversed phase ultra-high performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) and apply the method on a case of anticoagulant rodenticide intoxication. Sample preparation was liquid–liquid extraction. Six anticoagulant rodenticides were separated using a UPLC® BEH C18-column with a mobile phase consisting of 5 mM ammonium formate buffer pH 10.2 and methanol. MS/MS detection was performed with positive electrospray ionization and two multiple reaction monitoring transitions. The limits of quantification were set at the levels of the lowest calibrator (1.5–2.7 ng/mL or ng/g). The method was successfully applied to a case from a dog accidentally poisoned with anticoagulant rodenticide. Coumatetralyl and brodifacoum concentrations were determined from serial blood and faecal samples. A terminal half-life of at least 81 days for coumatetralyl in blood was estimated, which is longer than previous reported in other species. A slow elimination of brodifacoum from the faeces was found, with traces still detectable in the faeces at day 513. This study offers a new method of detection and quantification of six frequently used anticoagulant rodenticides in canine faeces. Such drugs might cause serious health effects and it is important to be able to detect these drugs, to initiate proper treatment. The very long elimination half-lives detected in our study is important to be aware of in assessment of anticoagulant rodenticide burden to the environment.

Objective: To describe the clinical course, treatment, and outcome of 5 dogs following ingestion of mushrooms belonging to theInocybegenus.Case Series Summary: Five dogs with witnessedInocybeingestions were presented with clinical signs compatible with poisoning. Vomiting, ptyalism, diarrhea, depression, and tachycardia were common clinical findings in the dogs in this case series. The prognosis withInocybetoxicosis appears to be excellent as all dogs fully recovered following supportive care.New or Unique Information Provided: This is the first reported case series ofInocybemushroom ingestions in dogs where identification of the mushrooms were confirmed by an expert mycologist.