Cycad (Zamia puertoriquensis) toxicosis in a group of dairy heifers in Puerto Rico

Azodyrecins A-C: Azoxides from a Soil-Derived Streptomyces Species

Azoxy compounds belong to a small group of natural products sharing a common functional group with the general structure RN = N⁺(O^-)R. Three new azoxides, azodyrecins A-C (1-3), were isolated from a soil-derived Streptomyces sp. strain P8-A2. The cis-alkenyl unit in 1-3 was found to readily isomerize to the trans-congeners (4-6). The structures of the new compounds were determined by detailed spectroscopic (1D/2D NMR) and HRMS data analysis. Azodyrecins belong to a new class of natural azoxy compounds and are proposed to derive from l-alanine and alkylamines. The absolute configurations of 1-6 were defined by comparison of ECD spectra. While no antimicrobial effects were observed for 1 against Staphylococcus aureus, Vibrio anguillarum, or Candida albicans, azodyrecin B (2) exhibited cytotoxicity against the human leukemia cell line HL-60 with an IC₅₀ value of 2.2 μM.

Plant and Fungal Hepatotoxicities of Cattle in Australia, with a Focus on Minimally Understood Toxins

Plant- and fungus-derived hepatotoxins are a major cause of disease and production losses in ruminants in Australia and around the world. Many are well studied and described in the literature; however, this is not the case for a number of hepatotoxicities with economic and animal welfare impacts, such as acute bovine liver disease (ABLD), brassica-associated liver disease (BALD) and Trema tomentosa, Argentipallium blandowskianum and Lythrum hyssopifolia toxicity. Additionally, significant overlap in the clinical presentation and pathology of these conditions can present a diagnostic challenge for veterinarians. This review summarizes the current and most recently published knowledge of common plant- and fungus-associated hepatotoxins affecting cattle in Australia, with a focus on the mechanisms of toxicity and distinguishing diagnostic features. Consolidation of the current understanding of hepatotoxic mechanisms in cattle provides insight into the potential mechanisms of lesser-known toxins, including cellular and subcellular targets and potential metabolic pathways. In the absence of specific etiological investigations, the study of epidemiological, clinical and pathological features of hepatotoxicity provides valuable insights into potential toxic mechanisms and is integral for the successful diagnosis and management of these conditions.

Presumptive Cycad Toxicosis in a Dog. Clinical and Magnetic Resonance Imaging Findings: A Case Report

Cases of cycad toxicosis have been described in dogs that have presented with gastrointestinal, hematologic, hepatic, neurological, and carcinogenic signs. This case report describes brain magnetic resonance imaging (MRI) lesions in a dog with gastrointestinal and neurological signs secondary to cycad toxicosis. A 5-year-old neutered female Jack Russell terrier presented with a 2-days history of gastroenteric signs, progressive generalized tremors, and altered mentation after possible ingestion of Cycad revoluta. Neurologic examinations revealed disorientation, a wide-based stance, severe spasticity of the four limbs, intention tremors, severe cerebellar ataxia, decreased postural reactions in all four limbs, and intermittent decreased menace response in both eyes—all of which are consistent with a multifocal intracranial disorder involving the forebrain and cerebellum. A brain MRI showed diffuse/ill-defined, intra-axial bilateral and symmetrical changes, predominantly affecting the white matter of the cerebral hemispheres, thalamus, hippocampus, and cerebellum. A presumptive diagnosis of toxic-metabolic encephalopathy was made. Medical management of the clinical signs was performed, and the dog was discharged 7 days after presentation with no neurological abnormalities. Two and 8 weeks later, complete blood count (CBC), chemistry, electrolytes, and 8 weeks later brain MRI were performed, revealing no abnormalities. To the best of the authors' knowledge, this is the first case report describing lesions detected by brain MRI secondary to cycad toxicosis as well as a complete resolution of brain lesions on a follow-up MRI 8 weeks later.

Cycad Palm Toxicosis in 14 Dogs from Texas

The goal of this study is to report clinical information, diagnostic findings, and treatment modalities; assess variables that may help distinguish survivors from nonsurvivors; and review the outcome of cycad palm toxicosis in dogs. Fourteen client-owned dogs with confirmed cycad palm ingestion were identified by reviewing the medical record database at Gulf Coast Veterinary Specialists. Information on signalment, time of ingestion to presentation, clinical signs, physical examination findings, initial and peak/nadir laboratory abnormalities, radiographic and ultrasonographic findings, treatment modalities, liver histopathology, and clinical outcome was retrieved. Of the 14 dogs, nine (64%) died as a direct result of cycad palm intoxication, and three survivors had persistently elevated liver enzymes, signifying residual liver damage. Despite decontamination, patients continued to display evidence of illness, indicating rapid absorption of toxins. When evaluating initial and peak/nadir laboratory values, nadir serum albumin levels and nadir platelet counts were significantly lower in nonsurvivors compared to survivors (1.25 g/dL [0.4–2.1 g/dL] versus 2.6 g/dL [1.7–3.4 g/dL] and 21 × 103 [0–64 × 103] versus 62 × 103 [6–144 × 103], respectively). In this cohort of dogs, the case fatality rate was higher than previously reported. Nadir serum albumin levels and nadir platelet counts may help distinguish potential survivors from nonsurvivors.