Distribution of locoweed toxin swainsonine in populations of Oxytropis lambertii

Oxytropis lambertii has been considered to be one of the major locoweeds responsible for livestock poisoning on rangelands, but there has been much confusion as to its taxonomic identity. The objective of this study was to conduct a field survey of several populations of each of the three varieties [var. lambertii Pursh; var higelovii A. Gray; var. articulata (E. Greene) Barneby] to document the presence or absence of the locoweed toxin, swainsonine. Swainsonine was found at detectable levels (>0.001% dry weight) in only five populations of var. higelovii in the southwest portion of its distribution in southern Utah, Arizona, and southwestern New Mexico, USA. No swainsonine was detected in populations in the northeast areas of its distribution (eastern Utah, Colorado, northeastern New Mexico, USA). The other varieties, articulata and lambertii, also did not contain swainsonine. It is suspected that a plant fungal endophyte may be responsible for the high variability in swainsonine content in populations of O. lambertii.

Common causes of poisoning in dogs and cats in a Brazilian veterinary teaching hospital from 1998 to 2000

A retrospective study at the University Veterinary Teaching Hospital of São Paulo city, Brazil, describes the pattern of poisoning that occurred from 1998 to 2000. During this period 5,136 animals were sent to the emergency sector, and 250 of these cases were reported as poisonings: 203 dogs (81.2%) and 47 cats (18.8%). The common causes of poisoning in dogs were 28.9% therapeutic products (86.4% non-steroidal anti-inflammatory drugs, 6.8% other drugs, 3.4% antibiotics, 3.4% tranquilizing agents), 15.8% rodenticides, 13.9% pesticides for farm use (39.3% organophosphorous and 35.7% carbamate insecticides, 25.0% amitraz), 11.8% unknown agents, 8.4% plants, 6.8% industrial products, and 5.0% pesticides for domestic use. The common causes of poisoning in cats were 29.9% therapeutic products (50.0% non-steroidal anti-inflammatory drugs, 42.8% others, 7.2% antibiotics), 27.6% pesticides for farm use (46.1% carbamate insecticides, 38.5% organophosphorous insecticides, 15.4% others), 14.9% pesticides for domestic use, 12.8% unknown agents, 10.6% rodenticides, and 4.2% industrial products. These data show it is essential to create an awareness of the toxicity of these agents to reduce poisoning incidence.

Newer antidotal therapies

Although the availability of an antidote for a toxic agent does not take away the primary responsibility of the clinician to manage the patient's clinical signs, the use of antidotes in appropriate situations can result in a more rapid recovery with potentially fewer long-term complications. Recent advances in pharmacology and molecular biology have resulted in the development of new and safer antidotal therapies for the management of toxicosis. The progress in immunotoxicotherapy over the last two decades continues and may ultimately lead to an era when the clinical toxicologist has a vast array of antibody fragments available for use with specific toxic agents. Development of specific pharmacologic antagonists for other agents should also enable the clinician to more reliably manage toxicoses. In spite of all these potential advances, the management of most toxicoses still relies on the application of sound veterinary medical principles.

Shortfalls using second-generation anticoagulant rodenticides

Second-generation anticoagulant rodenticides can give rise to unexpected casualties in nontarget species in zoos. The first two offspring of a pair of turkey vultures (Cathartes aura) died of brodifacoum toxicosis. The adult birds fed rodenticide-killed mice to their offspring. There are previous case reports of small carnivorous birds (Dacelo novae-guinae and Tockus deckeni) killed eating poisoned (difenacoum and brodifacoum) mice. Even a granivorous species (Rollulus roulroul) died, probably by contamination of its food by cockroaches that transported the rodenticide.

Selected herbal hazards

One of the most important considerations in treating herbal ingestions is product quality assurance. Although most herbal companies are reputable, there are numerous reports of adulterated products (addition of substances not noted on the label). This has been particularly true of Chinese herbal products, which frequently contain pharmaceutical agents. Plant identification errors occur, and entire batches of product have been mixed using the wrong herb. In some cases, labels are written in a foreign language or only contain directions for mixing, making interpretation difficult. In cases where a known ingestion produces unexpected clinical signs, the potential for adulteration or other errors should be considered. When a product is not standardized, a consumer cannot be sure what dose of active constituents has been used or how bioavailable the product may be. Standardization also provides assurance that the actual herb is in the product [26]. Clients who use herbal products should be advised to treat them as a medication and to keep them away from pets. Specifically, ask clients if they take or use any natural or herbal products. Many people do not consider these substances drugs or assume, "If natural, it is harmless." Clients should be encouraged to learn about the herbal and neutraceutical products they are taking or giving their pets. Owners need to discuss the proper use of herbal products in pets with their veterinarian. Clients can be encouraged to discuss alternative therapies by discussing a pet's diagnosis and suggested treatments thoroughly. Discuss the client's expectations and opinions of alternative and conventional medicine. Issues of safety and efficacy must be fully explained to clients. Clients should be encouraged to report potential adverse reactions or to discuss different routes of therapy if a pet's medical condition is not improving. Clients who want to use alternative medical treatments should obtain a thorough medical workup so as to make a correct diagnosis and be referred to a veterinarian trained in alternative medicine. In choosing an alternative medicine practitioner, the same criteria would be used as for any other specialist: education, training, and professionalism [14].

Clinical syndrome associated with zolpidem ingestion in dogs: 33 cases (January 1998-July 2000)

Zolpidem is a nonbenzodiazepine hypnotic of the imidazopyridine class that is used to treat insomnia in humans. Zolpidem binds selectively to the benzodiazepine omega-1 receptor and increases the frequency of chloride channel opening, which results in inhibition of neuronal excitation. A retrospective study was conducted of zolpidem ingestion in dogs that were reported to the ASPCA Animal Poison Control Center (APCC) between January 1998 and July 2000. Data analysis included amount ingested, clinical effects, and time of onset of signs. Thirty-three reports of zolpidem ingestion in dogs (ranging in age from 5 months to 16 years) were evaluated. Approximate ingested dosages ranged from 0.24 to 21 mg/kg. Clinical signs reported included ataxia (18 dogs; 54.5%), hyperactivity (10 dogs; 30.3%), vomiting (7 dogs; 21.2%), and lethargy (5 dogs; 15.2%), as well as panting, disorientation, nonspecific behavior disorder, and hypersalivation (4 dogs each sign; 12.1%). Other signs reported include tachycardia, tremors, apprehension, vocalization, hypersalivation, weakness, and hyperesthesia. In 85% percent of reports, clinical signs developed within 1 hour and usually resolved within 12 hours. Although central nervous system (CNS) depression is reported as a primary effect of zolpidem in humans and would also be expected in dogs, information obtained from this study indicates that some dogs may exhibit a paradoxical excitation reaction. This effect appears to vary among individual dogs.

How to evaluate toxicant exposures

Susceptibility of individual animals to any specific toxicant is influenced by many factors, including genetics, environment, age, gender, and preexisting disease. Because the relative influence of these factors on a specific toxicosis is often unknown and unmeasured, it is difficult to predict how an individual animal is likely to respond to a toxic challenge compared with the "average" animal in the population. Safety or uncertainty factors of 10 have been proposed to deal with intraspecies and interspecies variability in regard to LD50 values. These safety factors may be too conservative for many situations. Toxicant exposure is assessed in animals to determine if preventive treatment is warranted or for differential diagnosis purposes. Calculation techniques require converting English and apothecary units to metric units by either of several methods.

Diagnostic toxicology for the small animal practitioner

The successful diagnostic investigation involves an accurate history and appropriate antemortem and postmortem sampling. This chapter discusses factors such as sample size, shipping, test requests, and interpretation that must be considered when pursuing a small animal diagnostic investigation.

Persistence and retention of active ingredients in four granular cholinesterase-inhibiting insecticides in agricultural soils of the lower Fraser River valley, British Columbia, Canada, with implications for wildlife poisoning

The persistence and retention of active ingredients in granules of Thimet 15G (phorate 15% by weight), Dyfonate 10G (fonofos 10% by weight), Counter 15G (terbufos 15% by weight), and Furadan 10G (carbofuran 10% by weight) were determined in silt loam and organic muck agricultural soils typical of the lower Fraser River valley (BC, Canada). In June 1995, treatment bags made of polyester cloth (7.5 x 7.5 cm) containing granules of a single insecticide, either alone or with soil, were placed during spring planting in the bottom of the furrow and retrieved periodically until April 1996. The parent component of each insecticide declined monotonically except for carbofuran (logistic decline). In the silt loam (organic muck) soil, the average June-to-October first-order rate constants and half-lives were 0.009 (0.010)/d and 80 (71) d for fonofos, 0.012 (0.009)/d and 58 (82) d for phorate, and 0.032 (0.015)/d and 21 (47) d for terbufos; the half-life of carbofuran was 129 (97) d. By December, the average amounts of fonofos and phorate in silt loam (organic muck) were 26% (range: 17-40%; 14% [range: 3.4-21%]) and 21% (range: 15-30%; 10% [range: 5.0-24%]) of the initial amounts of active ingredients measured at time zero, respectively. By April, the percentages dropped to 16% (range: 7.8-24%; 2.3% [range: 0-7.7%]) and 7.3% (range: 1.9-25%; 0.6% [range: 0-1.9%]). During this period, about 95% of the active ingredients were granule bound, the rest remaining in the bag. Only low levels of terbufos and carbofuran persisted in both soils from December to April of the following year. Results indicate an enhanced probability for poisoning of waterfowl and raptors because of the high levels of active ingredients retained on granules of all four insecticides in both soils in the fall. The risk of acute poisoning by phorate and fonofos continued though the winter.

Ivermectin toxicity in 17 collies

Ivermectin is widely used in veterinary medicine as an anthelminthic and generally has a wide margin of safety, but Collies are prone to ivermectin toxicity. Two groups of Collies were presented to the University of California Veterinary Medical Teaching Hospital (VMTH) with ivermectin toxicity. The medical records of the 2 groups of Collies were reviewed retrospectively. Group I comprised 5 adult Collies that received at least 400 microg/kg ivermectin p.o. and were presented to the VMTH 3 hours after intoxication. These Collies showed marked clinical signs on presentation. Three of these dogs required mechanical ventilation and were euthanized for financial reasons; the remaining 2 dogs were comatose but recovered in 5-7 days. Group II was comprised of 12 adult Collies presented to the VMTH 2 days (n = 10) and 5 days (n = 2) after subcutaneous injection of 200-250 microg/kg ivermectin. These animals showed greater variation in severity of illness among individuals; 5 animals progressed to stupor or coma, whereas 4 animals remained ambulatory. Most of these dogs' clinical signs deteriorated from the day of intoxication until approximately day 6, from which time they showed gradual but steady improvement. All of the Collies in this group survived, but it took 3 weeks for most of them to recover. Collies suffering from ivermectin toxicity can have a severe and prolonged clinical course requiring intensive nursing care. Respiratory, cardiovascular, and nutritional support may all be required. With appropriate care, however, the prognosis for complete recovery is good.

Retrospective study of morbidity and mortality of raptors admitted to Colorado State University Veterinary Teaching Hospital during 1995 to 1998

A retrospective study was conducted to identify causes of morbidity and mortality of free-living raptors in northeast Colorado and the surrounding areas of Nebraska and Wyoming. The study included 409 raptors, representing 23 species, admitted to the Colorado State University Veterinary Teaching Hospital, Fort Collins, Colorado, USA, from 1995 to 1998. Causes of morbidity and mortality were identified as trauma (66.3%), orphaned young (15.6%), unknown (9.0%), infectious disease (4.4%), metabolic and nutritional disease (2.2%), toxicosis (2.0%), and degenerative disease (0.5%). Trauma was the most frequent cause of morbidity and mortality for all species and during all seasons.

Diagnosis and approach to poisoning in the horse

Poisoning in the horse can present a highly complex case. The practitioner, owner, toxicologist, and pathologist play important roles, and all contribute information that may be important to the case. Once all the information is available, all the evidence is collected (historical, clinical, pathologic, and analytic), and proper sampling of specimens has occurred, a complete summary of the findings can be provided to the client. Based on identification of a potential toxic source and, ultimately, the diagnosis, specific treatment of affected animals and prevention of additional cases can be initiated. Consultation with a veterinary toxicologist aids in the follow-up of a poisoning case and can help to provide a thorough background to assist in preventing reoccurrence.

Toxic feed constituents in the horse

Poisoning cases in horses associated with dietary exposures can encompass a wide variety of etiologies that can be caused by natural or man-made components. Feed mixing errors and ingestion of feed formulated for other species are the most common means by which poisonings from man-made materials occur. Ionophore feed additives and antibacterial agents are especially toxogenic to horses. Effects of ionophores in horses include clinical, clinicopathologic, and pathologic changes associated with cardiac, muscular, and neurologic tissues involvement. The acute effects of ionophores, however, can result in long-term cardiac dysfunction. Antibacterial effects are associated with changed microbial populations in the digestive tract that results in bacterial toxin liberation. These bacterial toxins damage the mucosa, and they result in systemic effects. For either type of feed-associated poisoning, it is critical that samples be analyzed for an accurate diagnosis.

Mycotoxins

Horses consume feed grains and forages that can produce a range of mycotoxins resulting from mold invasion. Toxicosis of horses often occurs from fumonisins or aflatoxin in grains, from the tremorgenic mycotoxins in dallis grass, or from slaframine in red clover. Fumonisin toxicosis often is severe and fatal, and aflatoxin can be acute or chronic and debilitating. Other mycotoxins reported in horses may cause moderate to mild signs that regress when the contaminated feedstuff is removed. Overall, horses appear to have a relatively low prevalence of reported mycotoxicoses among domestic animals, but they are extremely sensitive to the fumonisins. Since there are no good therapies for mycotoxin poisoning, attention to providing high quality grains and forages to prevent mycotoxicoses is the most effective means for reducing the risk of mycotoxins in horses.

Toxic effects in dairy cattle following the ingestion of a large volume of canola oil

The clinical and laboratory findings of a group of 9 dairy cattle that accidentally ingested large volumes of canola oil are described. Four of the animals died, and 3 were necropsied. No specific cause of death was found, although a number of theories are advanced. This is the first report of such an occurrence.

Long-term observation of subclinical chronic copper poisoning in two sheep breeds

Fourteen castrated male sheep of two breeds, the Mutton Merino (MMB) and Blackhead Suffolk cross breed (BSC), were exposed to an oral copper (Cu) intake of 3.7 mg/day per kg body weight for 84 days (high Cu group, HCu), and 11 castrated male sheep received a daily oral Cu intake of 0.16 mg/day per kg body weight (controls). Liver Cu concentration was measured in liver biopsies until 2.7 years after Cu overdose. Haematologic parameters, plasma Cu, enzymes and metabolites were analysed and post-mortem examinations were carried out. No haemolytic crises occurred. The highest liver Cu concentrations (133-677 mg/kg wet weight) were measured in HCu sheep around day 110 with significantly higher values in BSC than in MMB. The very slow decreases of liver Cu concentration of HCu sheep after day 215 showed individual half-life periods of 175 +/- 91 days. A progressive Cu retention in the liver of HCu sheep during Cu supplementation indicates strong Cu binding and storage in the liver. High values of glutamate dehydrogenase (20-940 U/l) measured frequently until day 700 and a diminished plasma clearance of bromosulphthalein as well as pathohistological findings of focal liver necrosis confirm the markedly chronic character of Cu poisoning.

Therapeutic efficacy of oxime reactivators in fenitrothion toxicity in buffalo calves (Bubalus bubalis)

The therapeutic efficacy of 2-pyridine aldoxime methochloride and diacetylmonoxime (DAM) alone and in combination with atropine was determined in oral fenitrothion toxicity in buffalo calves. DAM alone and in combination with atropine constitute the most effective therapy of fenitrothion poisoning. As compared to 2-pyridine aldoxime methochloride, DAM was also more effective in reactivating the fenitrothion-inhibited erythrocyte and plasma acetylcholinesterase and serum carboxylesterase enzymes and reversing fenitrothion-induced hyperglycaemia, hyperproteinaemia and hypercreatinaemia in animals.

Health effects following chronic dosing with tungsten-iron and tungsten-polymer shot in adult game-farm mallards

Permanent approval of shot composed of tungsten-iron and tungsten-polymer for waterfowl hunting by the U.S. Fish and Wildlife Service was pending the results of the present study that examined the health and reproductive effects of the two shot types on mallards (Anas platyrhynchos) over a 150-day period. We collected data pertaining to the effects of tungsten-iron and tungsten-polymer shot on mortality, body weight, organ weight, tissue pathology, and shot erosion. Thirty-two bird groups (sexes equal) of adult mallards were dosed orally with eight #4 steel shot (control), eight #4 tungsten-iron shot, or eight #4 tungsten-polymer shot on days 0, 30, 60, 90, and 120 of a 150-day trial (26 January 1998 to 25 June 1998). An additional 12 mallards (sexes equal) were dosed orally with eight #4 lead shot (positive control) on day 0 of the study. All lead-dosed ducks died by day 25, whereas no ducks died in the other treatment groups. Significant liver hemosiderosis was present in all control and tungsten-iron-dosed males, in five of eight control and three of eight tungsten-iron-dosed females, and in one tungsten-polymer-dosed male examined. The rate of shot erosion was highest for tungsten-polymer shot (99%), followed by tungsten-iron (72%), and steel (55%) shot. Tungsten-iron or tungsten-polymer shot repeatedly administered to adult mallards did not have deleterious health effects during the 150-day trial based on mortality, body weights, organ weights, and histology of the liver and kidneys.

Organophosphate poisoning in a group of replacement heifers and dry cows

Terbufos ingestion caused acute organophosphate poisoning in 67 Holstein heifers and dry cows, 7 months to 5 years old. Overall mortality was 31%, with attack rates of 4% and 48% for the dry cows and heifers, respectively. Less severely affected animals were treated with atropine sulfate for 7 days.

The use of a Daphnia magna bioassay for rapid screening of acute intoxications with insecticides in dogs and cats

Sudden death due to acute insecticide intoxications occurs frequently in dogs and cats. The absence of characteristic lesions at autopsy often renders post-mortem diagnosis dependent on the analysis of samples taken from the carcase at autopsy. In the present study, a bioassay utilizing Daphnia magna was proposed and tested as a rapid screening method for acute intoxications in dogs and cats. The bioassay was shown to be highly sensitive for detecting carbamate and organophosphate insecticides in the stomach contents. Generally. the mean survival time of the waterfleas in the control group was 5.17 h (SD = 1.24) and in the intoxicated group 1.32 h (SD = 1.49). during a 6 h observation period. If a cut-off is set at 4 h, this Daphnia bioassay gave 5.5% false negative results and 18.2% false positive results. using the results of toxicological analyses as a gold standard.

Accumulative sodium poisoning in Brazilian swine fed whey

Fifty 3-4-mo-old piglets died of accumulative sodium poisoning, but none of the 60 adult pigs with the same feeding and management did. The average ambient temperature throughout the period was 32 C. The herd had been regulary fed whey, ground corn and vegetables, but for at least 2 d the pigs were deprived of water and then water was offered ad libitum. Twenty hours later 20 piglets had died and the remaining exhibited classical nervous signs and died within 14 h. Only the piglets had a high degree of dehydration caused by water deprivation and exacerbated by the high average ambient temperature. Pulmonary edema was evident in most piglets. Acute cerebral edema and meningoencephalitis were present in all animals, but there was no polioencephalomalacia. The sodium accumulation was caused by the continuing intake of whey which contained 10,810 mg sodium/L. To produce the whey, 2 kg of sodium chloride had been added to every 100 kg of milk.

Food chain aspects of chlordane poisoning in birds and bats

We have observed recurring chlordane poisonings of large numbers of common grackles (Quiscalus quiscula), European starlings (Sturnus vulgaris), and American robins (Turdus migratorius) at suburban roosts in New Jersey during the month of July. This paper describes aspects of the food chain uptake of chlordane that account for the periodicity of these poisonings. Chlordane concentrations ranged from < 0.02 to 20.3 microg/g wet weight in 11 soil samples collected from residential lawns and a golf course near one roost. Of the 10 species of insects and soil invertebrates collected from the area, two scarab beetles, the oriental beetle (Anomala orientalis) and Japanese beetle (Popilla japonica), had the highest concentrations of chlordane-related compounds (15.1 and 5.9 microg/g wet weight, respectively). Concentrations in the other eight species ranged from < 0.04 to 1.3 microg/g. Oriental and Japanese beetles collected from a rural location had concentrations of 0.03 and < 0.02 microg/g, respectively. Emergence of adult beetles peaked in mid- to late July, when bird mortality also peaked. Fecal pellets collected near the roost (n = 24) contained the remains of 1-5 beetles each (mean = 2), and scarab beetles accounted for 40% of the total number of insect parts in the stomach contents of common grackles (n = 8). Unlike soil samples, in which cis- and trans-chlordane predominated, beetles contained large amounts of the more toxic metabolites heptachlor epoxide and oxychlordane. Total chlordane-related compounds ranged from < 0.05 to 18.4 microg/g in Japanese beetles collected from 16 sites in New Jersey and 2 sites in Ohio. The highest concentrations were found in beetles from suburban areas and golf courses. We also analyzed brain tissue from insectivorous bats (15 big brown bats, Eptesicus fuscus, and 5 little brown bats, Myotis lucifugus) that were submitted to the New Jersey Rabies Laboratory in late June/July 1998 and 1999 but found to be rabies-negative. We suggest that high concentrations in three of the bats caused debility or abnormal behavior that may have precipitated submission for rabies testing.

[Vitamin D3 poisoning--case report]

Over 650 pigs died within a couple hours in a fattening unit with approximately 3,000 fattening spaces. The pigs showed vomiting, dyspnea, kyphosis, sunken flanks, diarrhea, and polyuria. Another striking symptom of the pigs, besides the apathy, was the aphonia, due to the calcification of the vocal cords. An acute vitamin D3-intoxication was found to be the cause. The pathologic findings, especially the histologic detection of calcification processes of the soft tissues, lead to the suspect of an intoxication with a vitamin D-like substance. Between 39,000 and 196,000 IU/kg of vitamin D3 have been detected in a ready-to-use food mix. 8.8 million IU/kg of crystaline vitamin D3 were found in an open whey bag. An explanation how vitamin D came into the bag could not be clarified to this point.

Selenosis

Despite more than six decades of research, some aspects of the natural history of selenosis remain confused in modern texts. The primary targets of acute Se toxicity in food animal species are the cardiovascular, gastrointestinal, and possibly hematopoietic systems. Swine may develop neurologic lesions; however, the signs of poliomyelomalacia are quite distinct from those described as "blind staggers" by early workers. The most characteristic signs of chronic selenosis are hair and hoof loss; however, other, less specific, damage to the immune system and reproduction are economically more important. Given the numerous interactions of chronic Se with other dietary factors, it is very important to examine the whole environment when dealing with a potential selenosis case.

Diagnostic toxicology for the food animal practitioner

In most competent veterinary diagnostic laboratories, analytic findings are interpreted by a veterinary toxicologist to determine the significance of the finding in light of historical, clinical, and pathologic findings. A veterinary toxicologist also provides consultation about possible toxic rule-outs for a case, treatment of affected animals, and prevention of additional cases. Once all of the information is available, a complete summary of the findings can be provided to the client. When the procedures outlined herein are followed, including a systematic approach to collecting all the evidence (historical, clinical, pathologic, and analytic), using proper sampling techniques, and maintaining good communication among the clinician, client, and laboratory, the usefulness of the toxicology investigation is maximized.

Update on sulfur-related polioencephalomalacia

Sulfur-related polioencephalomalacia is frequently associated with a high total sulfur intake by ruminants. The onset of clinical signs coincides with excessive ruminal sulfide production. Measurement of ruminal gas cap hydrogen sulfide makes it possible to identify cattle with potentially hazardous total sulfur intake. Evaluation of all potential sulfur sources is necessary to estimate total dietary sulfur concentration, which can lead to prevention strategies.

[Intoxication with propylene glycol in two horses]

Two horses were accidentally administered propylene glycol instead of mineral oil. After discovery of the mistake intensive medical therapy with intravenous fluids, etc. was started, and both animals recovered fully from their clinical symptoms. Veterinarians use propylene glycol as well as paraffin routinely for the treatment of their patients. Mistakes are likely to be made because both medicines and sometimes their packing have a similar appearance. Several incidents have been reported in other countries. A large amount of propylene glycol given to a horse, but also to other animals, can be dangerous and immediate adequate intervention is necessary. The major cause of the problems in case of a propylene glycol intoxication is the high concentration of D-lactate that arises. Clinically, this primarily results in a depression of the central nervous system and in metabolic acidosis. Furthermore colic, diarrhoea and respiratory problems may occur.

Effect of clinoptilolite on serum biochemical and haematological characters of broiler chickens during aflatoxicosis

Clinoptilolite (CLI, a natural zeolite) incorporated into the diet at 1.5 and 2.5 per cent were evaluated for their ability to reduce the deleterious effects of 2.5 mg total aflatoxin (AF) kg(-1)diet on broiler chickens from 1 to 21 days of age. In total 360 broiler chicks were divided into six equal treatment groups (control, AF, CLI (1.5 per cent), AF plus CLI (1.5 per cent), CLI (2.5 per cent) and AF plus CLI (2.5 per cent)). When compared with the controls, AF treatment significantly decreased serum total protein, albumin, inorganic phosphorus, uric acid, total cholesterol and the values of haematocrit, red blood cell counts, mean corpuscular volume, haemoglobin, thrombocyte counts, percentage of monocyte counts; increased values of white blood cell and heterophil counts. The addition of CLI (1.5 per cent) and CLI (2.5 per cent) to the AF -containing diet reduced the adverse effects of AF and should be helpful in a solution to the aflatoxicosis problem in poultry.

Acetyl- and pseudo-cholinesterase activities of plasma, erythrocytes, and whole blood in male beagle dogs using Ellman's assay

Organophosphate and carbamate ester insecticides, main causes of pesticide poisoning, inhibit cholinesterase (ChE) enzymes. The aim of this study was to measure and compare baseline values for pseudocholinesterase and acetylcholinesterase (AChE) enzyme activities of different blood fractions in the dog to aid in diagnosis of anticholinesterase poisoning. After collecting blood samples from 23 6-24-mo-old male beagle dogs, Ellman's colorimetric assay was run on plasma, red blood cells (RBC), and whole blood fractions prepared in triplicate. The procedure described in a commercially available kit was applied to plasma and RBC. Hemolyzed whole blood fractions (final dilution 1:8) avoided the time-consuming and laborious separation of plasma and RBC. In addition to the kit substrate acetylthiocholine (ASCh), we used butyrylthiocholine (BSCh) as substrate. Whatever the substrate, ChE activity was lower in RBC than in other blood preparations. It was higher when using ASCh rather than BSCh as substrate (mean IU/L+/-SD): 563+/-144 and 303+/-45 respectively, in contrast to plasma (1640+/-310 and 2510+/-450). Whole blood enzyme activity did not differ significantly according to substrate: ASCh, 1590+/-190; BSCh, 1620+/-250) with a 2 to 3% within-day coefficient of variation. Enzyme activity was significantly lower in dogs <1-y old. This study confirms the low ChE activity in dog RBC compared to other species and other blood fractions. It shows that using whole blood instead of separating RBC from plasma minimizes the variability of ChE activity in the hemoglobin-rich fraction.

[Chronic thallium intoxication in five German pointers of one litter]

The difficulty of diagnosis and therapy of chronic thallium intoxication is described in five German Pointers with the same skin disease. The detection of thallium in cases of skin lesions like the cutaneous erythema with oedema and crusts or in chronic cases with multifocal alopecia is difficult. The first diagnostic information was gathered in this case from the high thallium level in the urine. The thallium concentration in the hair is subject to great variations, even in physiologic conditions. The trichogramme showed in this case pathognomonic changes like adhesion of the hair follicles. Differential diagnosis for this symmetric alopezia without pruritus are hormonal disturbances or, in puppies, the generalized form of demodicosis. The five affected dogs were treated with Fe III-Hexacyanoferrat. The clinical appearance of the skin improved slowly during a period of 1-2 months.

Phenol poisoning in three dogs

Three adult dogs were evaluated following oral administration of phenol by the owner. All three dogs experienced severe oral and gastric ulceration. Hematological abnormalities included neutropenia with the presence of toxic neutrophils, thrombocytopenia, and increased muscle enzymes. Endoscopic examination was performed, and biopsies yielded a diagnosis of gastric mucosal necrosis in two of the dogs. Following supportive care, the dogs recovered completely. Phenol is a caustic, highly poisonous derivative of coal tar. The dogs of this report were poisoned inadvertently by their owner who received misinformation concerning the use of this chemical via the Internet.

[Peracute mortality in common cranes (Grus grus)]

Out of a nonbreeding group of cranes, 10 birds died peracutely at the end of April 1998. The pathological investigation showed changes in the intestine, liver and kidneys caused probably by an intoxication; but corresponding analyses did not result in a specified poison. The proof of E. coli, Cl. perfringens and Campylobacter jejuni is to be interpreted as a subordinate result. 7 of 8 cranes had a low to high infestation with endoparasites (Porrocaeum spp., Eimeria pusilla, Echinostoma spp.). 5 of 8 birds showed leaness, possibly as a result of the migration exertion. Further on, the analysis results of a 9th crane found at another place are included in this paper.

5-Hydroxytryptophan toxicosis in dogs: 21 cases (1989-1999)

OBJECTIVE

To determine epidemiologic characteristics, clinical findings, and treatment outcome of 5-hydroxytryptophan (5-HTP) toxicosis in dogs.

DESIGN

Retrospective study.

ANIMALS

21 dogs with evidence of accidental 5-HTP ingestion.

PROCEDURE

Information was retrieved from the National Animal Poison Control Center database. Records of dogs ingesting 5-HTP between January 1989 and February 1999 were reviewed for information on signalment, dose ingested, clinical signs (onset, severity, duration), treatments administered, and outcome.

RESULTS

Clinical signs of toxicosis developed in 19 of 21 (90%) dogs. Neurologic signs included seizures (9 dogs), depression (6), tremors (5), hyperesthesia (5), and ataxia (4). Gastrointestinal tract signs included vomiting or diarrhea (12 dogs), signs of abdominal pain (3), and hypersalivation (2). Other clinical signs were hyperthermia (7 dogs) and transient blindness (3). Three dogs died. No important clinical laboratory or necropsy findings were reported. The doses of 5-HTP ingested ranged from 2.5 to 573 mg/kg (1.1 to 260 mg/lb) of body weight; the minimum toxic dose reported in our study was 23.6 mg/kg (10.7 mg/lb), and the minimum lethal dose was 128 mg/kg (58.1 mg/lb). Onset of signs ranged from 10 minutes to 4 hours after ingestion, and signs lasted up to 36 hours. Of 17 dogs with clinical signs of toxicosis that received treatment, 16 recovered; treatment consisted of decontamination, seizure control, thermoregulation, fluid therapy, and supportive care.

CONCLUSIONS AND CLINICAL RELEVANCE

Ingestion of 5-HTP in dogs can result in a potentially life-threatening syndrome resembling serotonin syndrome in humans, which requires prompt and aggressive care.

Acute ibuprofen toxicosis in a ferret

A 20-month-old 1.44-kg (3.2-lb) castrated male ferret was examined because of vomiting, defecating in an abnormal location, dyspnea, and signs of depression. Within 5 minutes of initial evaluation, the ferret became nonresponsive to all stimuli except deep pain. Despite intensive supportive treatment, the ferret died. Toxicologic analyses for ibuprofen were performed on serum, urine, and liver, using gas chromatography and mass spectrophotometry. Serum ibuprofen concentrations were 245 micrograms/g before and 269 micrograms/g after death. Acute ibuprofen toxicosis may cause severe lethargy progressing to coma, apnea, and death in ferrets. Ibuprofen toxicosis should be considered in differential diagnoses for ferrets with signs of depression, with or without clinical signs of gastrointestinal tract dysfunction.

Emergency approach to intoxications

Many compounds, when absorbed or ingested, can cause harm to animals and people. Veterinarians are commonly faced with companion animals that have been exposed to these harmful compounds. Most poisonings are the result of curious exploration by the pet and a quest to taste everything in their path. Some poisonings are the result of malice, and many simply result from owner ignorance when pets are given medications without regard to dose or compatibility. It is the responsibility of the emergency clinician encountering these cases to prevent further exposure to the poison, enhance its elimination, and provide supportive and antidotal care. Antidotes when available are of little value if the animal has lost any vital functions. It is the purpose of this article to focus on the emergency management of intoxications by reviewing the general principles of triage and emergency care, and to discuss available procedures to stop the exposure, prevent further absorption, and hasten elimination of poisons from the patients body.

Outbreak of copper poisoning in cattle fed poultry litter

In a feedlot of about 1,000 head of cattle, 146 animals died within a period of a few months affected by a disease characterized by anorexia, icterus, hemoglobinuria, constipation, or diarrhea. The clinical course of the disease lasted a few days. Postmortem findings were generalized icterus and a yellow discolored liver. The kidneys were dark brown, and the urinary bladder was filled with urine of the same dark-brown color. The main histopathological findings were centrolobular coagulative necrosis, apoptosis, bilestasis, and proliferation of bile ducts in the portal space. Changes in the kidneys included nephrosis and the presence of bile and precipitates, and cylinders of albumin and of hemoglobin in the uriniferous tubules. Liver samples, collected from 3 animals on which postmortem examinations were performed, had 2,008, 2,783 and 4,906 ppm copper in their dry matter. Two samples of poultry litter fed to the cattle contained 362 and 323 ppm copper. The green forage that formed the rest of their feed only had 4.7 ppm copper. Copper poisoning was diagnosed, most probably caused by feeding litter from poultry that had been fed a ration treated with copper sulfate to avoid aspergillosis.

Mortality of sea lions along the central California coast linked to a toxic diatom bloom

Over 400 California sea lions (Zalophus californianus) died and many others displayed signs of neurological dysfunction along the central California coast during May and June 1998. A bloom of Pseudo-nitzschia australis (diatom) was observed in the Monterey Bay region during the same period. This bloom was associated with production of domoic acid (DA), a neurotoxin that was also detected in planktivorous fish, including the northern anchovy (Engraulis mordax), and in sea lion body fluids. These and other concurrent observations demonstrate the trophic transfer of DA resulting in marine mammal mortality. In contrast to fish, blue mussels (Mytilus edulus) collected during the DA outbreak contained no DA or only trace amounts. Such findings reveal that monitoring of mussel toxicity alone does not necessarily provide adequate warning of DA entering the food web at levels sufficient to harm marine wildlife and perhaps humans.

Respiratory failure attributable to moxidectin intoxication in a dog

A 5-month-old 22-kg (48.4-lb) sexually intact male Collie was examined after ingesting a moxidectin-containing deworming medication. The dog was comatose and had respiratory arrest after progressively worsening lethargy, ataxia, and seizures. Exposure was confirmed by isolation of moxidectin from a biopsy specimen of adipose tissue, using liquid chromatography-mass spectroscopy methods. Treatment included use of intermittent positive-pressure ventilation, activated charcoal and cathartic administered enterally, nutrients administered via nasogastric tube, and intensive supportive care. The dog was weaned from a ventilator on day 6 after ingestion and was discharged on day 10. The dog was considered clinically normal during examination 24 days after ingestion. On the basis of the dog reported here and toxicologic data provided by the manufacturer of the deworming product, some Collies may have increased susceptibility to products containing high doses of moxidectin.

Toxicology of Astragalus lusitanicus Lam

Astragalus lusitanicus is a toxic legume grown in Morocco and in some other Mediterranean countries. In small ruminants, poisoning by this plant is dominated by nervous signs characterized by many cycles of excitement-depression. Macroscopic examination of poisoned animals showed congestive lesions and oedema in the brain and lungs. Microscopic lesions consisted mainly of vacuolar degeneration in neurons, hepatocytes and in spleen and kidney cells. Serum activity of AST and CK as well as blood glucose and urea were increased as a result of poisoning. However, serum activity of alpha-mannosidase was not modified as is the case in locoism. Chemical investigations showed that A. lusitanicus does not contain swainsonine or miserotoxin and its selenium concentration is very low. However, this legume contains indolizidin alkaloids and a first compound was purified and identified.

Animal poisonings: the 10-year experience of a veterinary analytical toxicology laboratory

Data on 10-y of chemical toxicological analyses carried out in a veterinary laboratory in Barcelona, Spain for suspected wild and domestic animal poisonings are summarized. The 218 cases involved more than 1 million animals, some 7,500 of which died. Pesticides, especially insecticides (46.6%) and rodenticides (37.9%), were frequently involved. Strychnine (n = 11) and aldicarb (n = 10) were the most usual toxic agents in baits prepared for intentional poisonings; other cases involved pentachlorophenol, hexachlorocyclohexane or anticoagulant rodenticides. Service to veterinarians and others could be improved if a coordinated network of national and regional Animal Poison Centers were created.

Attempted induction of chronic copper poisoning in boma confined impala

Induction of chronic copper poisoning in ten boma-confined impala was attempted in a randomized, single dose, parallel designed, titration study using five increasing oral doses, ranging between 125 mg/kg to 1000 mg/kg, of copper oxide needles. Two untreated impala were kept as controls. Impala (n = 1) from each treatment group were culled 52 d and 105 d after treatment and examined for tissue copper accumulation and signs of chronic copper poisoning. Despite the high doses of copper administered to the impala and liver copper concentrations above 150 ppm WM achieved in two animals, no clinical signs related to chronic copper poisoning were observed. Faecal copper concentrations indicated that the major portion of copper oxide particles was excreted in the faeces.