Heightened risk of canine chocolate exposure at Christmas and Easter

A survey of animal poisonings in New Zealand veterinary practices: perceptions of incidence and frequency of poisoning cases

AIMS

To survey New Zealand veterinary practices on the incidence and frequency of animal poisonings encountered over a 1-year period.

METHODS

A national questionnaire-based cross-sectional online survey was made available to all members of the New Zealand Veterinary Association, active as of 2010, via an email supplying a link to the questionnaire. Veterinary practices listed by the Veterinary Council of New Zealand were also contacted via email or phone. Respondents entered their information on the online survey site or provided a hard copy of their responses, which were then entered by the authors into the database. The questionnaire contained a mixture of tick box options and short answer questions. Responses were analysed using descriptive statistics.

RESULTS

Of 463 veterinary practices deemed eligible to complete the survey, 120 (25.9%) responded to the survey. However, only 94 (78.3%) questionnaire entries (78.3%) were deemed adequate for analysis. Veterinary practices (45 mixed practices, 38 companion animal-only practices, nine large animal practices, and two equine-only practices) from 14/16 regions of New Zealand were represented. All respondents affirmed that in the last 12 months, cases of suspected poisoning in animals were attended by veterinarians at their practices and estimated a total of 5,326 poisoning cases. The subcategories most commonly associated with estimated cases of poisoning were pasture mycotoxins (2,133/5,326; 40%), anticoagulant rodenticides (753/5,326; 14.1%), plants (469/5,326; 8.8%), slug/snail baits (305/5,326; 5.7%) and chocolate (221/5,326; 4.1%). Except for anticoagulant rodenticides (once a month), and slug/snail baits, human prescription or over-the-counter drugs, and chocolate (once a year), the majority of respondents reported toxicants caused poisonings seasonally or infrequently.

CONCLUSIONS

A variety of poisons were encountered with environmental toxins and household pest control agents being the most common cause of poisoning for animals attended by veterinarians in New Zealand. Most cases of poisoning in animals occurred seasonally or infrequently. Further research is needed to determine the actual number of animals poisoned, the affected species, and the seasons when poisoning occurs in New Zealand.

CLINICAL RELEVANCE

This report provides baseline information on cases of poisoning in animals in New Zealand which could be used for case management, prevention through client education, and poisoning risk assessment.

Chocolate ingestion in 156 dogs

OBJECTIVES

To describe the clinical features and outcome of dogs after chocolate ingestion.

MATERIAL AND METHODS

Retrospective evaluation of clinical signs, clinical pathological findings, therapy and outcome of 156 dogs after chocolate ingestion. The concentration of methylxanthines (theobromine, caffeine) was calculated based on the type of chocolate and the amount ingested.

RESULTS

One hundred and twelve dogs had no clinical signs. Forty-four dogs had clinical signs of chocolate intoxication. Twenty-eight of these 44 dogs ingested dark and bitter chocolate. Reasons for presentation were agitation (33), tremor (22), vomiting (21), panting (11), polyuria/polydipsia (seven) and diarrhea (two). Common clinical findings were sinus tachycardia (28), tachypnea/panting (14), hyperthermia (10) and dehydration (seven). Clinical pathological findings in 34 of 44 dogs consisted of hyperlactataemia (23), hypokalaemia (16), mild hyperglycaemia (16) and mild alanine aminotransferase (ALT) and aspartate aminotransferase (AST) elevation (14). After decontamination (apomorphine, activated carbon) and symptomatic treatment (fluid therapy, esmolol, forced diuresis, sedatives), 43 of the 44 dogs survived.

CLINICAL SIGNIFICANCE

In dogs with potential chocolate intoxication, the type and amount of chocolate and the time of ingestion are important factors. Cardiovascular, neurological and gastrointestinal signs are the most common clinical signs. In this case series, the prognosis after decontamination and symptomatic therapy was good, with a mortality rate of less than 3%.

Case of suspected theobromine poisoning in dairy cattle

High-yielding dairy cows collapsed and died displaying signs of a disturbed central nervous system (muscle tremor, convulsion) and a considerably reduced body condition score. An intense diagnostic screening did not allow to confirm a definite diagnosis. Therefore, further analyses including an evaluation of feeds and feeding were initiated. The herd was fed a total mixed ration (TMR) based on corn and grass silage of moderate nutritive value supplemented with various amounts of chocolate chips. In retrospect, the amount of chocolate chips added to the respective TMR batches could not be quantified. These chips were purchased from a company producing bakery and chocolate products for human consumption and added to the silage and therefore to the TMR in order to increase the energy intake of the animals. Because the TMR, which was fed during the time of the incidence, was no longer available, a sample of a later batch of silage was examined. The amount of chocolate chips was quantified (0.44% per fresh matter), and a theobromine analysis was performed in the chocolate chips of the available batch (69.7 mg/100 g fresh matter). Because of the possible link between chocolate intake and observed signs, an immediate cessation of using the chocolate chips was recommended in addition to an optimisation of the TMR, that is an increase of the energy density. Even though the theobromine intake during the time of the incidence is unknown and information about toxicity of theobromine in ruminants is limited, we suspect that the feeding of chocolate in this case caused all signs including the sudden death of the cows. Further reasons are that no differential diagnoses were established and the problems at the farm stopped after removing the chocolate from the TMR.