Rodenticides

Active monitoring of long-eared owl (Asio otus) nestlings reveals widespread exposure to anticoagulant rodenticides across different agricultural landscapes

The widespread use of anticoagulant rodenticides (ARs) poses a worldwide threat to farmland wildlife. These compounds accumulate in tissues of both target and non-target species, potentially endangering both direct consumers and their predators. However, investigations on ARs in blood of free-ranging predatory birds are rare. Here, the long-eared owl (Asio otus) has been used as a model predator to assess AR exposure in different agricultural landscapes from a Mediterranean semiarid region. A total of 69 owlets from 38 nests were blood-sampled over 2021 and 2022, aiming to detect AR residues and explore factors that determine their exposure, such as land uses. In addition, prothrombin time (PT) test was conducted to assess potential effects of AR contamination. Overall, nearly all the samples (98.6 %) tested positive for at least one compound and multiple ARs were found in most of the individuals (82.6 %). Among the ARs detected, flocoumafen was the most common compound (88.4 % of the samples). AR total concentration (ΣARs) in blood ranged from 0.06 to 34.18 ng mL-1, detecting the highest levels in the most intensively cultivated area. The analysis of owl pellets from 19 breeding territories showed relevant among-site differences in the contribution of rodents and birds into the diet of long-eared owls, supporting its high dietary plasticity and indicating AR presence at multiple trophic levels. Moreover, a positive and significant correlation was found between ΣARs and PT (Rho = 0.547, p < 0.001), which demonstrates the direct effect of ARs on free-living nestlings. Our results provide a preliminary overview of AR exposure in a little-studied owl species inhabiting agricultural and rural landscapes. Despite the low detected levels, these findings indicate widespread exposure -often to multiple compounds- from early life stages, which raises concern and draws attention to an ongoing and unresolved contamination issue.

Acute kidney injury from presumptive intramural ureteral hemorrhage secondary to diphacinone rodenticide exposure in a dog

OBJECTIVE

To describe the clinical features and outcome of a dog with anticoagulant rodenticide (diphacinone) exposure, which was subsequently diagnosed with a coagulopathy characterized by hemoperitoneum, and presumptive ureteral wall hemorrhage contributing to acute kidney injury (AKI).

CASE SUMMARY

A 4-year-old, female neutered Australian Cattle Dog was evaluated for an acute onset of lethargy, decreased appetite, and a mild right thoracic limb lameness. Radiographs and point of care ultrasound demonstrated retroperitoneal and peritoneal effusion. Diagnostic abdominocentesis confirmed hemorrhagic effusion. Complete blood count, biochemistry, and coagulation profile showed a regenerative anemia (PCV 32%), thrombocytopenia (platelets 96 × 10⁹ /L [96 × 10³ /µl]), azotemia (BUN 38.9 mmol/L [109 mg/dl], creatinine 512.8 µmol/L [5.8 mg/dl]), and coagulopathy (prothrombin time >100 s, activated partial thromboplastin time >42.3 s). The client reported access to anticoagulant rodenticide up to 72 hours prior to presentation. Ultrasonographic examination revealed bilateral pyelectasia and hydroureter with thickened distal ureteral walls at the level of the ureteral-vesicular junctions. The ultrasonographic conclusion was presumptive intramural ureteral hemorrhage resulting in ureteral obstruction. The patient was diagnosed with AKI with likely prerenal, renal, and postrenal components. Treatment included vitamin K and frozen plasma transfusion. The patient recovered fully and was discharged 3 days after presentation. Two days after discharge, the patient had improvement in azotemia (BUN 10.7 mmol/L [30 mg/dl], creatinine 176.6 µmol/L [2.0 mg/dl]). Gas chromatography-mass spectrometry confirmed presence of diphacinone in the blood. Repeat ultrasound and biochemistry 60 and 210 days, respectively, after discharge showed resolution of ureteral wall thickening, hydroureter, pyelectasia, and recovery of kidney parameters.

NEW OR UNIQUE INFORMATION

Although nephropathies secondary to anticoagulant therapy have been described in people, the authors believe this is the first report of diphacinone anticoagulant rodenticide exposure contributing to an AKI secondary to obstruction from ureteral wall hemorrhage in the veterinary literature.

Salmonella-Based Biorodenticides: Past Applications and Current Contradictions

The idea of using pathogens to control pests has existed since the end of the 19th century. Enterobacteria from the genus Salmonella, discovered at that time, are the causative agents of many serious diseases in mammals often leading to death. Mostly, the strains of Salmonella are able to infect a wide spectrum of hosts belonging to vertebrates, but some of them show host restriction. Several strains of these bacteria have been used as biorodenticides due to the host restriction until they were banned in many countries in the second part of the 20th century. The main reason for the ban was their potential pathogenicity for some domestic animals and poultry and the outbreaks of gastroenteritis in humans. Since that time, a lot of data regarding the host specificity and host restriction of different strains of Salmonella have been accumulated, and the complexity of the molecular mechanisms affecting it has been uncovered. In this review, we summarize the data regarding the history of studying and application of Salmonella-based rodenticides, discuss molecular systems controlling the specificity of Salmonella interactions within its multicellular hosts at different stages of infection, and attempt to reconstruct the network of genes and their allelic variants which might affect the host-restriction mechanisms.

Vitamin D Deficiency in Farm Animals: A Review

One of the most effective vitamins in the musculoskeletal structure and immune system of farm animals is Vitamin D. The widespread risk of Vitamin D deficiency states is known widely resulting in autoimmune diseases, diabetes, rickets, metabolic bone diseases, and cancers. The aim of this review is to address the subject of Vitamin D deficiency in farm animals and the role of vitamin D in health and deficiency states. Although Vitamin D deficiency is generally defined as < 20 ng/mL in serum, but this level remains to be discussed. Vitamin D synthesis in the skin is the major source of Vitamin D in the body and is influenced by genetic and several environmental factors, such as length of sun exposure, season, and latitude. Sun exposure might be limited during winter in some areas, such as northern latitudes. Thus, food sources can play essential roles in supplying the demand for vitamin D. Some animal species have more sensitivity to Vitamin D deficiency due to their different metabolism, homeostasis, and adaptation to specific diets and environments. Farm animal species, such as cattle, pigs, llamas, Alpacas, small ruminants, and broiler chickens are more sensitive to Vitamin D deficiency. However, some farm animal species including horses and donkeys usually have a low risk of Vitamin D deficiency. Therefore, the management of Vitamin D deficiency and its consequences are critical in some species. The inclusion of Vitamin D in the body of farm animals depended on farming practices, sun exposure in different seasons, and the content of diets. Due to the diversity of species, regulation of many ongoing processes in animals’ bodies, the complexity of Vitamin D metabolism, and different metabolites, more studies are necessary to find the vital roles of vitamin D in the prevention and control of diseases in farm animals.

Retrospective Evaluation of Clinical Bleeding in Dogs With Anticoagulant Rodenticide Toxicity—A Multi-Center Evaluation of 62 Cases (2010–2020)

Objective

To evaluate the most common locations of hemorrhage in dogs diagnosed with anticoagulant rodenticide intoxication.

Animals

Dogs presenting with hemorrhage secondary to anticoagulant rodenticide intoxication between at two university veterinary teaching hospitals.

Procedures

Medical records were searched from the years 2010 through 2020 and all records from dogs treated for hemorrhage secondary to anticoagulant rodenticide intoxication were reviewed. Dogs were diagnosed with anticoagulant rodenticide intoxication based on the combination of known exposure and prolonged coagulation testing, including prothrombin and activated thromboplastin time, or based on gas chromatography-mass spectrometry (GCMS). The diagnosis of hemorrhage was made based on physical exam findings, point-of-care ultrasound findings or radiography.

Results

Sixty-two dogs met the inclusion criteria and were included in the study. The most common sites of hemorrhage included: pleural space (hemothorax 37%), pulmonary parenchyma (24%), abdomen (24%), skin/subcutaneous (21%), gastrointestinal tract (18%), pericardium (13%), oral cavity (13%), nasal cavity (11%), ocular (8%), and urinary tract (7%). Overall, forty-five dogs (73%) had evidence of cutaneous or mucosal hemorrhage while thirty-three (53%) of dogs had evidence of cavitary hemorrhage. Forty-five percent of dogs had hemorrhage noted at only one site, while 55% experienced hemorrhage at more than one site. The location of hemorrhage and total number of hemorrhagic sites was not associated with survival or transfusion requirement.

Conclusions and Clinical Relevance

In conclusion, this study highlights that dogs with anticoagulant rodenticide intoxication present with diverse locations of hemorrhage and the majority of dogs had non-cavitary hemorrhage noted.

Determining an approximate minimum toxic dosage of diphacinone in horses and corresponding serum, blood, and liver diphacinone concentrations: a pilot study

Poisoning of nontarget species is a major concern with the use of anticoagulant rodenticides (ARs). At postmortem examination, differentiating toxicosis from incidental exposure is sometimes difficult. Clotting profiles cannot be performed on postmortem samples, and clinically significant serum, blood, and liver AR concentrations are not well-established in most species. We chose diphacinone for our study because, at the time, it was the publicly available AR most commonly detected in samples analyzed at the University of Kentucky Veterinary Diagnostic Laboratory. We determined an approximate minimum toxic dosage (MTD) of oral diphacinone in 3 horses and measured corresponding serum, blood, and liver diphacinone concentrations. Diphacinone was administered orally to healthy horses. Prothrombin time (PT), activated partial thromboplastin time (aPTT), and serum and blood diphacinone concentrations were measured daily. At the study endpoint, the horses were euthanized, and diphacinone concentration was measured in each liver lobe. The horse that received 0.2 mg/kg diphacinone developed prolonged (>1.5× baseline) PT and aPTT; the horse that received 0.1 mg/kg did not. This suggests an approximate oral MTD in horses of 0.2 mg/kg diphacinone. Median liver diphacinone concentration at this dosage was 1,780 (range: 1,590–2,000) ppb wet weight. Marginal (model-adjusted) mean diphacinone concentrations of liver lobes were not significantly different from one another ( p = NS). Diphacinone was present in similar concentrations in both serum and blood at each time after administration, indicating that both matrices are suitable for detection of diphacinone exposure in horses.

An in vitro study of canine cryopoor plasma to correct vitamin K-dependent coagulopathy in dogs

OBJECTIVE

To compare the efficacy of fresh frozen plasma (FFP) with cryopoor plasma (CPP) to treat vitamin K-dependent factor deficiency in a canine in vitro setting.

DESIGN

In vitro laboratory study.

SETTING

University veterinary medical teaching hospital.

ANIMALS

Seven units of FFP and 6 units of CPP from unique canine donors from the university veterinary blood bank.

INTERVENTIONS

Canine FFP was adsorbed by oral barium sulfate suspension to mimic vitamin K-dependent coagulopathy. A sequential mixing study was completed by adding FPP or CPP to the adsorbed plasma. Measurements of prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, and factor activities of factors II, VII, and IX (FII, FVII, and FIX) were compared between the 2 treatment groups.

MEASUREMENTS AND MAIN RESULTS

When comparing the sequential addition of CPP or FPP to adsorbed plasma, the following had no statistical significance: PT (P = 0.94), aPTT (P = 0.66), FII (P = 0.05), and FIX (P = 0.90). There was a dose-dependent decrease with PT and aPTT and a dose-dependent increase with FII and FIX. In contrast, after the addition of either CPP or FFP, there was a significant difference between the treatment groups for the concentration of fibrinogen (P = 0.005) and activity of FVII (P = 0.044), with FFP resulting in a greater concentration of fibrinogen and CPP resulting in a greater concentration of FVII. Measurements of factor X (FX) were initially included in the study but were later excluded because FX appeared to be continually adsorbed even after the addition of CPP or FFP.

CONCLUSIONS

CPP partially corrected the coagulation times and concentration of vitamin K-dependent coagulation factors to the same degree as FFP. CPP, generally less expensive than FFP, may provide an alternative treatment option for vitamin K-dependent coagulopathies, although in vivo testing is needed.

Biomarkers Potency to Monitor Non-target Fauna Poisoning by Anticoagulant Rodenticides

The widespread use of pesticides to control agricultural pests is a hot topic on the public scene of environmental health. Selective pest control for minimum environmental impact is a major goal of the environmental toxicology field, notably to avoid unintended poisoning in different organisms. Anticoagulant rodenticides cause abnormal blood coagulation process; they have been widely used to control rodents, allowing inadvertent primary and secondary exposure in domestic animals and non-target predatory wildlife species through direct ingestion of rodenticide-containing bait or by consumption of poisoned prey. To report toxic effect, the most common approach is the measurement of liver or plasma residues of anticoagulant rodenticides in dead or intoxicated animals showing clinical symptoms. However, one major challenge is that literature currently lacks a hepatic or plasma concentration threshold value for the differentiation of exposure from toxicity. Regarding the variation in pharmacology properties of anticoagulant rodenticides inter- and intra-species, the dose-response relationship must be defined for each species to prejudge the relative risk of poisoning. Beyond that, biomarkers are a key solution widely used for ecological risk assessment of contaminants. Since anticoagulant rodenticides (AR) have toxic effects at the biochemical level, biomarkers can serve as indicators of toxic exposure. In this sense, toxicological knowledge of anticoagulant rodenticides within organisms is an important tool for defining sensitive, specific, and suitable biomarkers. In this review, we provide an overview of the toxicodynamic and toxicokinetic parameters of anticoagulant rodenticides in different animal species. We examine different types of biomarkers used to characterize and differentiate the exposure and toxic effects of anticoagulant rodenticide, showing the strengths and weaknesses of the assays. Finally, we describe possible new biomarkers and highlight their capabilities.

Accidental chlorophacinone exposure of lactating ewes: Clinical follow-up and human health dietary implications

Anticoagulant rodenticides are widely used for rodent control in agricultural and urban settings. Their intense use can sometimes result in accidental exposure and even poisoning of livestock. Can milk, eggs or meat derived from such accidently exposed animals be consumed by humans? Data on the pharmacokinetics of chlorophacinone in milk of accidently exposed ewes were used to estimate the risk associated with its consumption. Three days after accidental ingestion, chlorophacinone was detected in plasma of 18 ewes, with concentrations exceeding 100 ng/mL in 11 animals. Chlorophacinone was detected in milk on day 2 post-exposure and remained quantifiable for at least 7 days in milk of these 11 ewes. Concentrations in milk were much lower than in plasma and decreased quickly (mean half-life of 2 days). This study demonstrated dose-dependent mammary transfer of ingested chlorophacinone. Variation in prothrombin time (PT) on Day 3 suggested that some of the ewes that ingested chlorophacinone may have been adversely affected, but PT did not facilitate estimation of the quantity of chlorophacinone consumed. Using safety factors described in the literature, consumption of dairy products derived from these ewes after a one-week withdrawal period would pose low risk to consumers.

Successful Management of Severe Bromethalin Toxicosis in a Dog

ABSTRACT The use of bromethalin rodenticides has risen since 2011, and in some states, it is the most common rodenticide ingestion reported to poison control. Although intravenous lipid emulsion (ILE) has been previously reported to lower serum desmethylbromethalin levels in an asymptomatic dog, and repeated mannitol has been investigated in a laboratory setting, there are no published reports of successful treatment of symptomatic bromethalin toxicosis in dogs. A 9 yr old castrated male Norwich terrier was evaluated for obtunded mentation, seizures, cranial nerve deficits, and tetraparesis secondary to bromethalin toxicosis. The patient was treated with ILE, mannitol, and ginkgo biloba and returned to normal neurological function. Bromethalin exposure was confirmed by serum desmethylbromethalin levels. Previous literature indicates that the prognosis for patients who suffer from symptomatic bromethalin toxicosis is poor to grave, and the return to normal neurological function after severe toxicosis has not been reported. ILE, mannitol, and ginkgo biloba are readily available and relatively inexpensive, and in combination may be of benefit in symptomatic bromethalin intoxication.

Intravenous vitamin K1 normalises prothrombin time in 1 hour in dogs with anticoagulant rodenticide toxicosis

Four dogs with anticoagulant rodenticide toxicosis were treated with intravenous vitamin K₁ in lieu of plasma transfusion due to client cost constraints. Two dogs experienced a suspected anaphylactoid reaction, necessitating cessation of the treatment in one dog. Prothrombin time was rechecked 1 h after treatment in the remaining three dogs and all results were within the normal reference range. All four dogs were discharged from hospital within 48 h of presentation. Intravenous vitamin K₁ rapidly reverses the coagulopathic state in dogs with anticoagulant rodenticide toxicosis. It is a viable alternative therapy to plasma transfusion if circumstances preclude its use; however, patients must be monitored for anaphylactoid reactions.

Treatment of severe lipophilic intoxications with intravenous lipid emulsion: a case series (2011-2014)

The objective of this retrospective study was to describe the responses to treatment with intravenous lipid emulsion (ILE) and the outcomes for a variety of severe intoxications. This case series includes 10 client-owned animals, 9 dogs and 1 cat, that underwent treatment with ILE for a variety of severe intoxications over a 4-year period. History, physical examination findings, clinical signs, clinicopathological test results, treatment, response to treatment, and outcome were recorded. Eight of the 10 patients survived to discharge. The toxicities included in this case series were baclofen, ivermectin and spinosad plus milbemycin oxime, baclofen and tadalafil, carbamate, methamphetamine, dextroamphetamine sulfate, amlodipine, bromethalin, and organophosphate. The two patients who died were intoxicated with bromethalin and an organophosphate. Six of the 10 patients developed lipemia secondary to ILE administration, and there were no other known adverse effects. Overall, ILE was a safe therapeutic option. This case series provides clinical evidence of successful treatment with ILE as an antidote for previously unpublished toxicities (amlodipine, carbamate, methamphetamine, and dextroamphetamine sulfate), additional evidence of success in treating baclofen and ivermectin toxicosis, as well as unsuccessful treatment of bromethalin and organophosphate toxicities.

Wild boar offal as a probable source of Aujeszky’s disease virus for hunting dogs in Poland

Introduction: Aujeszky’s disease (AD), most often related to infection of domestic and feral swine, may also concern other mammals, including dogs. The disease in carnivores, related to consumption of raw meat or offal contaminated with AD virus, is manifested by severe neurological disorders and inevitably leads to animal’s death.

Material and Methods: Karelian bear dog was euthanised due to nervous symptoms that started two days after participation in wild boar hunting. After exclusion of rabies the dog’s carcass was subjected to standard necropsy. Tissue samples were collected for histological examination. Samples of the brain were tested for ADV by real-time PCR and virus isolation. Samples of the liver were collected for toxicological examination.

Results: The presence of ADV was confirmed by real-time PCR and virus isolation. Toxicological examination revealed anticoagulant poisoning. This is the first case of Aujeszky’s disease (AD) in a hunting dog in Poland after exposure to ADV from offal of wild boar.

Conclusion: This infection should be taken into consideration in differential diagnosis of syndromes of neurological disorders in dogs. Since AD is found in both domestic pigs and wild boar in Poland, special care must be taken to prevent spread of infection to other species.

Anticoagulant rodenticide screening in dogs: 123 cases (1996-2003)

OBJECTIVE

To identify dogs with anticoagulant rodenticide (AR) screens submitted, determine whether detected concentrations of the anticoagulants correlated with severity of clinical signs for dogs with positive results on AR screens, and identify the most common disease processes present and the prognosis for those with negative AR screens.

DESIGN

Retrospective case series.

ANIMALS

123 dogs.

PROCEDURES

History, signalment, clinical signs, physical examination findings, PCV, total solids concentration, prothrombin time, activated partial thromboplastin time, platelet count, AR concentrations, duration of hospitalization, blood products administered, final diagnosis, and outcome were recorded from medical records of dogs that underwent AR toxicology screenings.

RESULTS

75 of 123 (60.9%) dogs tested positive for AR. Dogs tested positive for brodifacoum, diphacinone (also called diphenadione), and chlorophacinone. Dogs with positive AR screenings weighed significantly less, received significantly more fresh frozen plasma, had significantly longer initial prothrombin time, and were significantly more likely to survive, compared with those with negative screens. Anticoagulant rodenticide concentrations ranged from trace amounts to 1,120 parts per billion and were not correlated with any recorded parameter. The most common conditions diagnosed in the 48 dogs with negative screens included neoplasia in 15 (31.3%), immune-mediated disease in 7 (14.6%), and gastrointestinal bleeding in 5 (10.4%) dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

AR concentrations were not correlated with severity of clinical signs or the degree of prolongation of coagulation times in this series of patients. Patients with severe coagulopathies but negative results of AR screening had a poor prognosis, with neoplasia as the most common diagnosis. Anticoagulant rodenticide intoxication had the best prognosis, with a survival rate of 98.7% in this study.

Vitamin D metabolism and rickets in domestic animals: a review

Rickets and osteomalacia are increasing in prevalence in people because of cultural practices, breast-feeding, decreased sun exposure, and increased sunscreen usage. Several hereditary forms of rickets owing to either renal phosphate wasting or defects in vitamin D metabolism are also reported in people. Rickets is well recognized in domestic animals, but published reports are not always supported by microscopic findings, and diagnoses based on clinical signs and radiology are unreliable. Most cases in domestic animals are caused by dietary deficiency of either vitamin D or phosphorus, but occasional inherited forms are reported in pigs, sheep, cats, and dogs. There is variation between species in susceptibility to dietary vitamin D and phosphorus deficiency and in the ability to manufacture vitamin D in their skin. A number of mouse models have been discovered or created to study human skeletal diseases and skeletal homeostasis. With the discovery that vitamin D is involved in not only calcium and phosphorus homeostasis but also in the immune system and cancer, there is great potential for new and existing animal models to generate valuable information about vitamin D and its many functions. This review presents an overview of vitamin D metabolism and rickets in domestic and laboratory animals and makes comparisons where appropriate with the disease in humans.

Evaluation of a bench-top coagulation analyzer for measurement of prothrombin time, activated partial thromboplastin time, and fibrinogen concentrations in healthy dogs

OBJECTIVE

To evaluate a bench-top coagulation analyzer for determination of prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen concentration in healthy dogs.

ANIMALS

55 healthy adult dogs.

PROCEDURES

PT, APTT, and fibrinogen concentration were determined by use of the coagulation analyzer. Values were compared with results obtained independently by a conventional laboratory.

RESULTS

Correlations (with 95% confidence intervals) between the coagulation analyzer and conventional laboratory values were 0.760 (0.610 to 0.857), 0.700 (0.448 to 0.721), and 0.896 (0.878 to 0.918) for PT, APTT, and fibrinogen concentration, respectively. Using linear regression, comparison of data from the coagulation analyzer and the conventional laboratory provided equations relating the coagulation analyzer values with values from the conventional laboratory and suggested that APTT and fibrinogen values from the coagulation analyzer and conventional laboratory were approximately the same within expected random variation. Prothrombin time values for the coagulation analyzer were significantly offset from the PT values for the conventional laboratory but still were correlated reasonably well with the conventional laboratory values.

CONCLUSIONS AND CLINICAL RELEVANCE

By use of the mechanical method of analysis, fibrinogen concentrations obtained with a bench-top coagulation analyzer correlated well with results for a conventional laboratory, indicating that the coagulation analyzer is a reliable instrument for determination of this coagulation variable. Coagulation analyzer results for PT and APTT correlated less strongly with those for the conventional laboratory, but they would still be considered clinically reliable.

Critique of the considerations for establishing the tolerable upper intake level for vitamin D: critical need for revision upwards

The tolerable upper intake level (UL) for vitamin D is 50 mcg/d (2000 iu/d) in North America and in Europe. In the United Kingdom a guidance level exists for vitamin D, 25 mcg/d (1000 iu/d), defined as the dose "of vitamins and minerals that potentially susceptible individuals could take daily on a life-long basis, without medical supervision in reasonable safety." Exposure of skin to sunshine can safely provide an adult with vitamin D in an amount equivalent to an oral dose of 250 mcg/d. The incremental consumption of 1 mcg/d of vitamin D3 raises serum 25-hydroxyvitamin D [25(OH)D ] by approximately 1 nmol/L (0.4 microg/L). Published reports suggest toxicity may occur with 25(OH)D concentrations beyond 500 nmol/L (200 microg/L). Older adults are advised to maintain serum 25(OH)D concentrations >75 nmol/L. The preceding numbers indicate that vitamin D3 intake at the UL raises 25(OH)D by approximately 50 nmol/L and that this may be more desirable than harmful. The past decade has produced separate North American, European, and U.K. reports that address UL or guidance-level values for vitamin D. Despite similar well-defined models for risk assessment, each report has failed to adapt its message to new evidence of no adverse effects at higher doses. Inappropriately low UL values, or guidance values, for vitamin D have hindered objective clinical research on vitamin D nutrition, they have hindered our understanding of its role in disease prevention, and restricted the amount of vitamin D in multivitamins and foods to doses too low to benefit public health.

Hypercalcaemia in two dogs caused by excessive dietary supplementation of vitamin D

A three-year-old Border collie was presented with a two-week history of lethargy, stiff gait, polydipsia and polyuria. Biochemical analysis revealed hypercalcaemia. Serum concentrations of 25-hydroxyvitamin D (25[OH]D) and 1,25-dihydroxyvitamin D (1,25[OH]2D) were markedly elevated and parathyroid hormone was undetectable. Subsequent analysis of the dog's diet revealed that the food contained excessive amounts of vitamin D. The hypercalcaemia resolved following treatment with bisphosphonates and dietary change. Hypervitaminosis D was diagnosed in a second unrelated dog, which had been fed the same brand of dog food as case 1. The dog was also hypercalcaemic and had markedly elevated serum concentrations of 25(OH)D and 1,25(OH)2D. Hypervitaminosis D in dogs has been reported to occur secondarily to ingestion of either rodenticides containing cholecalciferol or antipsoriatic ointments that contain vitamin D analogues. Hypervitaminosis D has also been reported following the treatment of hypoparathyroidism. To the authors' knowledge, this is the first report of hypervitaminosis D in dogs following the accidental over supplementation of a commercial diet with vitamin D. While the benefits of adequate dietary vitamin D are well established in dogs, the potential deleterious effects of over supplementation of vitamin D should also be acknowledged.

Diagnosis of Zinc Phosphide Poisoning in Chickens Using a New Analytical Approach

Approximately 200 chickens were found dead after the flooring of a slat-and-litter house was breached. No clinical signs of illness were observed in the surviving birds. During necropsy, rolled oats were found in the chickens' crops and gizzards, and the contents had a petroleum-like odor. Histopathologic examination revealed severe pulmonary edema and congestion of the chickens' lungs, hearts, livers, and kidneys. Based on the history and necropsy findings, zinc phosphide exposure was suspected. Diagnosis of zinc phosphide poisoning has previously been based on history of exposure, identification of the bait material in the gastrointestinal tract, and chemical detection of phosphine gas. However, currently available diagnostic methods are nonconfirmatory, and may produce false positive results. The objective of this case report was to determine whether the sudden death described in these chickens was caused by the ingestion of zinc phosphide, by developing a sensitive and highly specific gas chromatography/mass spectrometry (GC/MS) methodology for analysis of the gastrointestinal samples submitted to the laboratory. It was also found that the determination of zinc concentrations in liver or kidney tissue or stomach contents is not a reliable indicator of zinc phosphide poisoning.

New and unusual causes of acute renal failure in dogs and cats

This article provides a source for easy reference, summarizing in one location newly recognized and unusual causes of acute renal failure (ARF) in dogs and cats. Several of the causes discussed in this article have been described previously. New or unusual causes of ARF in dogs and cats include infectious diseases (leptospirosis,borreliosis, and babesiosis), nephrotoxicants (aminoglycosides,vitamin D, and nonsteroidal anti-inflammatory drugs), and plant material (lilies and raisins/grapes).

Haemorrhage in seven cats with suspected anticoagulant rodenticide intoxication

Clinical features were evaluated in seven adult cats (six males, one female) with haemorrhage and presumptive anticoagulant rodenticide intoxication. Haemorrhage appeared as thoracic haemorrhage, otic bleeding, haematoma, melena, haematochezia, and petechiation. The most common other presenting signs were lethargy, anorexia, and tachypnoea or dyspnoea. Six cats were anaemic, four cats were mildly thrombocytopenic (58000-161000/ microL), and three had slightly decreased plasma protein or albumin values. The prothrombin time (30.3->100 s, reference range: 16.5-27.5 s) and activated partial thromboplastin time values (32.6->100 s; reference range: 14-25 s) were markedly prolonged in all cats. All cats received vitamin K(1)subcutaneously or orally (3.7-5 mg/kg body weight initially) and depending on severity of signs five cats were transfused with fresh whole blood. Plasma coagulation times improved in all cats and returned to normal in 1-5 days. Rodenticide poisons represent an important but relatively rare cause of haemorrhage in cats and can be effectively treated.