Pollen beetle (Astylus atromaculatus)-associated gastroenteric disease in cattle: report of 6 natural outbreaks.

Astylus atromaculatus is a pollen beetle native to South America, commonly found in crop flowers. Experimental intoxication of sheep and guinea pigs by this beetle resulting in fibrinonecrotizing enteritis has been reported. We describe here 6 natural outbreaks of intoxication in cattle associated with consumption of alfalfa (5 of 6) and mixed native (1 of 6) pastures heavily contaminated with A. atromaculatus. The outbreaks occurred during the summer (January-February) of 2023 in Argentina (n = 4) and Uruguay (n = 2), in beef cattle under extensive or semi-extensive rearing systems, with overall cumulative incidence and mortality of 22.3% and 17.8%, respectively. The main clinical signs included acute onset of anorexia, lethargy, hyperthermia, hindlimb weakness, reluctance to move, and diarrhea, for up to 15 d. In 2 outbreaks, sudden death was observed. Eight Hereford, Angus, and/or crossbreed heifers, cows, steers, and/or calves were autopsied. Gross and microscopic findings included multifocal necrosis with fibrinous pseudomembranes in the forestomachs and/or small and large intestines. Fragments or whole specimens of A. atromaculatus were identified in the ruminal content of all animals. Testing for multiple gastroenteric pathogens was negative as was testing of A. atromaculatus for cantharidin and batrachotoxin. GC-MS and LC-MS/MS performed on the beetles did not identify any known toxic compounds. Based on the exposure to A. atromaculatus-contaminated pasture, gross and microscopic lesions, and negative results of all testing for multiple gastroenteric pathogens, a diagnosis of intoxication by A. atromaculatus is proposed. Disease caused by A. atromaculatus consumption has not been reported previously in cattle, to our knowledge.

Yellow oleander (Thevetia peruviana) toxicosis in 4 goats.

Four alpine goats developed diarrhea soon after the owner placed plant clippings believed to be yellow oleander (Thevetia peruviana) into their pen on a suburban property near Palm Desert, CA, USA. A 1-y-old female goat died suddenly ~1 h after eating the plant clippings and was submitted to the San Bernardino Branch of the California Animal Health and Food Safety Laboratory System for postmortem examination. The main autopsy and histopathologic findings were myocardial hemorrhage and necrosis, consistent with cardiac glycoside intoxication. Rumen contents were analyzed by LC-MS/MS; peruvoside, a cardiac glycoside, was detected, but oleandrin, the cardiac glycoside of common oleander (Nerium oleander), was not. An LC-high-resolution MS (LC-HRMS) analysis revealed the presence of peruvoside and neriifolin in the rumen contents and in a tested plant fragment, indicating that the plant was a member of the Thevetia genus. A clipping from the plant fed to the goats and submitted by the owner was identified as yellow oleander, Thevetia peruviana (also known as Cascabela thevetia).

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.

Reference intervals for mineral concentrations in whole blood and serum of bighorn sheep (Ovis canadensis) in California.

Whole blood and serum mineral concentrations were measured in diverse bighorn sheep (Ovis canadensis) metapopulations in California, and 90% reference intervals were determined. While there were some statistical differences between median concentrations among the different metapopulations, detected values were generally in good agreement with concentrations reported for other bighorn sheep populations and with reference ranges widely accepted for domestic sheep (Ovis aries). Although median whole blood selenium and serum copper concentrations were within adequate ranges reported for domestic sheep, some metapopulations had substantial numbers of individuals whose concentrations would be considered suboptimal for domestic sheep. There are a number of factors that can influence mineral concentrations in wildlife species such as bighorn sheep and that make the establishment of reference ranges challenging. However, the establishment of mineral reference ranges is important for such species, as their health and productivity are increasingly scrutinized and actively managed.

Commercial and industrial chemical hazards for ruminants.

There are many potentially hazardous commercial or industrial products used in or around ruminant environments. Although some products are highly toxic, their proper storage and use minimize their hazard to ruminants. Although most exposures to such materials occur via ingestion, inhalation or dermal exposures also are possible. The diagnosis of intoxication requires both thorough antemortem and postmortem examination of affected animals and thorough investigation of their environment. Fortunately, intoxications from such materials are relatively infrequent. The possibility of residues affecting meat or milk from exposed animals always needs to be considered.

Poisonous plants.

A large number of plants can cause adverse effects when ingested by animals or people. Plant toxicity is due to a wide diversity of chemical toxins that include alkaloids, glycosides, proteins and amino acids. There are several notable toxic plants for which a specific chemical responsible for toxicity has not been determined. There are many examples of species differences in terms of their sensitivity to intoxication from plants. Pets, such as dogs and cats, and people, especially children, are frequently exposed to the same toxic plants due to their shared environments. On the other hand, livestock are exposed to toxic plants that are rarely involved in human intoxications due to the unique environments in which they are kept. Fortunately, adverse effects often do not occur or are generally mild following most toxic plant ingestions and no therapeutic intervention is necessary. However, some plants are extremely toxic and ingestion of small amounts can cause rapid death. The diagnosis of plant intoxication can be challenging, especially in veterinary medicine where a history of exposure to a toxic plant is often lacking. Analytical tests are available to detect some plant toxins, although their diagnostic utility is often limited by test availability and timeliness of results. With a few notable exceptions, antidotes for plant toxins are not available. However, general supportive and symptomatic care often is sufficient to successfully treat a symptomatic patient.

In vitro study of the effectiveness of three commercial adsorbents for binding oleander toxins.

INTRODUCTION: Oleander (Nerium oleander) poisoning is a common problem found in many parts of the world. The oleander toxicity is due to oleandrin and its aglycone metabolite oleandrigenin. Activated charcoal is a useful gastrointestinal decontamination agent that limits the absorption of ingested toxins. A relatively new clay product, Bio-Sponge, containing di-tri-octahedral smectite as the active ingredient, is also recommended for adsorbing bacterial toxins in the gastrointestinal tract. Bio-Sponge has been used to prevent gastrointestinal absorption of oleander toxins in livestock but the efficacy of activated charcoal and Bio-Sponge for adsorbing oleandrin and oleandrigenin has not yet been studied. METHODS: An in vitro experiment to compare the efficacy of three commercially available adsorbents was performed. The adsorbents include Bio-Sponge, ToxiBan granules, and a generic grade activated charcoal. RESULTS: ToxiBan granules have the highest adsorptive capacity, followed by the generic grade activated charcoal, and finally, Bio-Sponge. DISCUSSION: Bio-Sponge did not adsorb oleandrin and oleandrigenin at concentrations that are expected to be present in the gastrointestinal tract of poisoned animals. CONCLUSIONS: On the basis of this in vitro study, products containing activated charcoal are more effective for binding oleander toxins and providing gastrointestinal decontamination than products containing di-tri-octahedral smectite. However, the ability of these adsorbents to alter the clinical outcome in oleander-poisoned animals or humans is yet to be evaluated.

Comparison of selenium determination in liver samples by atomic absorption spectroscopy and inductively coupled plasma-mass spectrometry.

Selenium (Se) is an essential trace element that is often deficient in the natural diets of domestic animal species. The measurement of Se in whole blood or liver is the most accurate way to assess Se status for diagnostic purposes. This study was conducted to compare hydride generation atomic absorption spectroscopy (HG-AAS) with inductively coupled plasma-mass spectrometry (ICP-MS) for the detection and quantification of Se in liver samples. Sample digestion was accomplished with magnesium nitrate and nitric acid for HG-AAS and ICP-MS, respectively. The ICP-MS detection was optimized for 82Se with yttrium used as the internal standard and resulted in a method detection limit of 0.12 microg/g. Selenium was quantified by both methods in 310 samples from a variety of species that were submitted to the Toxicology Laboratory at New Bolton Center (Kennett Square, PA) for routine diagnostic testing. Paired measurements for each sample were evaluated by a mean difference plot method. Limits of agreement were used to describe the maximum differences likely to occur between the 2 methods. Results suggest that under the specified conditions ICP-MS can be reliably used in place of AAS for quantitation of tissue Se at or below 2 microg/g to differentiate between adequate and deficient liver Se concentrations.

Herbal medicine: potential for intoxication and interactions with conventional drugs.

The use of herbal remedies for the prevention and treatment of a variety of illnesses in small animals has increased tremendously in recent years. Whereas most herbal remedies, when used as directed and under the supervision of knowledgeable individuals, are safe, the potential for adverse effects or intoxications certainly exists. Due to inherent toxicity, some herbal remedies should not be used under any circumstance. In addition, because nearly all herbal remedies contain multiple, biologically active constituents, interaction with conventional drugs is a concern. It is incumbent upon clinicians to be aware of those herbs that can cause intoxication, and to be cognizant of potential herb-drug interactions. There are a number of evidence-based resources available to assist clinicians in the safe use of herbal remedies.