Tremorgenic neuromycotoxicosis in 2 dogs ascribed to the ingestion of penitrem A and possibly roquefortine in rice contaminated with Penicillium crustosum

Two dogs developed alarming tremorgenic nervous stimulation shortly after ingesting discarded rice that had been forgotten in a refrigerator for an undetermined period and that was covered with a grey-green mould. Both dogs exhibited vomition followed by slight salivation, tremors and ataxia and 1 showed such severe agitation and seizures that it necessitated anaesthesia with thiopentone followed, on recovery, by xylazine. The other dog was only sedated with xylazine. They made an uneventful recovery. The rice vomitus yielded a pure culture of Penicillium crustosum. On chemical analysis it was negative for organochlorine, organophosphor and carbamate insecticides, as well as for strychnine, but contained 2.6 microg/g of the mycotoxins penitrem A as well as 34 microg/g of roquefortine as determined by LC-MS and confirmed by MS-MS. This is the 1st South African case of naturally occurring penitrem A toxicosis and also the 1st case where quantification of the levels of mycotoxins in dog vomitus is reported. The tremorgenicity of roquefortine and its contribution towards this syndrome, is questioned.     

Intoxication of dogs with the mycotoxin penitrem A

Mycotoxicosis caused by ingestion of moldy cream cheese was suspected in two dogs with severe muscle tremors and generalized seizures. Penicillium crustosum and its toxin, penitrem A, were isolated from the moldy cream cheese.     

Acute penitrem A and roquefortine poisoning in a dog

Penitrem A and roquefortine poisonings were diagnosed in a Laborador retriever following garbage consumption. Clinical signs of mycotoxicosis included polypnea, tachycardia, and ataxia that quickly progressed to lateral recumbency and seizures. Removal of the mycotoxins from the stomach soon after ingestion allowed the dog to recover within 72-96 hours.     

Intoxication by tremorgenic mycotoxin (penitrem A) in a dog

A 1-year-old Siberian Husky dog presented with severe muscle tremors after ingestion of a mouldy hamburger bun. Penicillium crustosum and the tremorgenic mycotoxin penitrem A were isolated from the remaining portion of the hamburger bun. When grown in pure culture, the isolate of P. crustosum produced large amounts of penitrem A, along with other penitrem compounds. This is the first reported Australian case of toxicosis by naturally occurring penitrem A.     

Treatment of ibuprofen intoxication with charcoal haemoperfusion in two dogs

ABSTRACT

Case history: Two dogs presented separately to the Small Animal Hospital, University of Florida (Gainsville, FL, USA) for ingestion of ibuprofen. The first dog ingested 561.8?mg/kg ibuprofen in addition to paracetamol and caffeine and vomited prior to admission. This patient also received fluid therapy for 8 hours prior to charcoal haemoperfusion. The second dog ingested 500?mg/kg of ibuprofen and the owners induced vomiting with hydrogen peroxide prior to presentation. Due to the severity of clinical signs, both patients were treated with charcoal haemoperfusion.

Clinical findings: The concentrations of ibuprofen in the blood of the dogs prior to treatment were 478 and 301?mg/L. During the treatment ibuprofen concentrations were reduced by 95.8% and 45.5%, respectively, with no treatment side effects and minimal clinical signs after treatment.

Diagnosis: Toxicity due to ingestion of ibuprofen toxicity that was successfully treated with charcoal haemoperfusion.

Clinical relevance: In the cases described here minimal benefit was seen after 3 hours of treatment using one haemoperfusion cartridge. This is in contrast to a previously published report in which dogs were treated for 6 hours with two charcoal haemoperfusion cartridges. This suggests that one cartridge may be sufficient. The amount of ibuprofen ingested was not a reliable predictor of the concentration in blood at the initiation of treatment. Charcoal haemoperfusion is an effective means of reducing plasma concentrations of ibuprofen, however, its use may be limited by its cost and availability.     

Barbiturate intoxication in two dogs confirmed by toxicological urinalysis

Two dogs were presented within 24 hours to the Department of Small Animal Medicine and Surgery at the University of Veterinary Medicine Hannover for investigation of the sudden onset of neurological abnormalities following a walk in the same park. One dog was observed ingesting a piece of meat. Analysis of urine by gas chromatography-mass spectrometry from each of the dogs identified the presence of barbiturates. Both dogs recovered with supportive treatment. This is the first report to describe the use of toxicological urinalysis with gas chromatography-mass spectrometry for the diagnosis of barbiturate intoxication in dogs.     

Tremorgenic mycotoxicosis in four dogs from a single household

Mycotoxins are fungal metabolites that induce undesirable effects. The effects of these mycotoxins vary depending on the chemical structure of the toxin and degree of toxicity. Mycotoxins that induce muscle tremors, ataxia, and convulsions are termed tremorgenic mycotoxins. Our report documents the clinical course of 4 dogs from a single household that were simultaneously affected by tremorgenic mycotoxins. Diagnosis of tremorgenic mycotoxicosis was confirmed by stomach content analysis from 1 of the dogs. The mycotoxins identified were penitrem A and roquefortine, which are both produced by Penicillium spp. Treatment goals following tremorgenic mycotoxin ingestion include minimizing absorption, controlling tremors and seizures with methocarbamol and pentobarbital sodium administration, and providing supportive care. Two of the affected dogs required ventilatory support. With early aggressive treatment, prognosis is good and recovery is complete without sequelae. It is helpful for the clinician to be familiar with the typical clinical signs at the time of admission, treatment, and clinical course of dogs with tremorgenic mycotoxicosis.     

Tremorgenic mycotoxins paxilline, penitrem and lolitrem B, the non-tremorgenic 31-epilolitrem B and electromyographic activity of the reticulum and rumen of sheep

The mycotoxic tremorgens penitrem, paxilline and lolitrem B had profound effects on electromyographic (EMG) activity of smooth muscle of the reticulorumen in conscious sheep, with a similar time course of action to their respective characteristic effects on the induction (1 to 2, 15 to 20 and 20 to 30 minutes) and the duration (1 to 2, 1 to 2 and 8 to 12 hours) of tremoring. Responses to penitrem revealed a greater sensitivity of smooth muscle than skeletal muscle. Effects included an inhibition of the vagally-dependent cyclical A and B sequences of contraction of the reticulorumen, an increase in their amplitude and an excitation of local intrinsic activity contributing to elevated baselines and the occurrence of chaotic activity of the reticulum. The excitatory local effects were partially blocked by atropine, indicating that stimulation of muscarinic cholinoceptors was involved. Increased local activity may mediate a reflex inhibition of cyclical contractions. A non-tremorgenic isomer of lolitrem B (31-epilolitrem B) had no effect on the reticulorumen. The intensity and duration of the effects of lolitrem B, up to 12 hours, indicate that severe disruption of digestion may occur in animals grazing endophyte-infected pasture.     

Survival and prognostic indicators for cycad intoxication in dogs

Background: Cycad palms are commonly used in landscaping and ingestion by dogs can cause disease or death. Objectives: Determine the morbidity and case fatality of cycad palm toxicosis in dogs from Louisiana, and examine putative prognostic factors. Animals: Thirty‐four client‐owned dogs with confirmed cycad palm toxicosis between 2003 and 2010. Methods: Retrospective cohort study. Search of all medical records for animals with cycad palm toxicosis. Results: Seventeen of 34 (50%) dogs died or were euthanized as a direct consequence of cycad intoxication. There were no differences in presenting signs and physical examination findings between survivors and nonsurvivors. Nonsurvivors had higher serum alanine transaminase activity (median 196 U/L; range 16–4,123 versus 113.5; 48–1,530) and total bilirubin concentration (0.5 mg/dL; 0.1–6.2 versus 0.25; 0–1.7) upon presentation, and their initial serum concentrations of albumin (2.9 g/dL; 1.4–4.1 versus 3.3; 2.2–3.9) were lower than those of survivors. Nadir serum albumin concentration was also lower in nonsurvivors (1.9; 1.4–3.7 versus 3.2; 1.8–3.5). A higher proportion of nonsurvivors had prolonged coagulation times, prothrombin time. and partial thromboplastin time. In a multivariate model, administration of charcoal at initial presentation was associated with longer survival (heart rate [HR] 0.019, 95% CI 0.001–0.644), while high serum aspartate aminotransferase activity was a negative prognostic factor (HR 118.2, 95% CI 2.89–4,826). Conclusions and Clinical Importance: Cycad intoxication is associated with a higher case fatality than previously published. Several laboratory parameters might help differentiating potential nonsurvivors from survivors. Administration of charcoal as part of the emergency treatment appears to have a protective effect.     

A comparison of two pamidronate dosing protocols on bone turnover in normal dogs and dogs with osteosarcoma

Introduction: Dogs with appendicular osteosarcoma (OSA) excrete higher concentrations of urine cross‐linked N‐telopeptide of type I collagen (NTx) than normal dogs. NTx is a specific biochemical marker of osteoclastic activity. Pamidronate is a bone‐modulating agent that exerts potent inhibitory effects on osteoclasts. The use of pamidronate is currently being evaluated for the management of osteolytic bone pain in dogs with appendicular osteosarcoma. Despite pamidronate's increasing usage in veterinary oncology, optimal dosing has yet to be determined. Commonly utilized dosages range from 1–2 mg/kg, given intravenously (IV) as a 2‐hour constant rate infusion every 28 days. The purpose of this prospective study was to compare the biological activity of two pamidronate doses (1 mg/kg vs. 2 mg/kg) in the suppression of urine NTx excretion in normal dogs and dogs with appendicular osteosarcoma. Methods: Seventeen OSA dogs receiving single‐agent pamidronate as palliative therapy were evaluated. Group 1A (n = 10) received a dose of 1 mg/kg and group 2A (n = 7) received a dose of 2 mg/kg IV. Urine NTx level were measured at day 0 and 28 using a commercial ELISA (Ostex International). Urine NTx level were also measured in 6 normal dogs: Group 1B (n = 3) received a dose of 1 mg/kg and group 2B (n = 3) received a dose of 2 mg/kg. In normal dogs, urine NTx levels were recorded weekly for six consecutive weeks. Results: In dogs with osteosarcoma, greater reductions in urine NTx excretion from baseline values were demonstrated at 2 mg/kg versus 1 mg/kg (57% and 23%, respectively). Likewise, in normal dogs, urine NTx excretion was suppressed to a greater extent with a dosage of 2 mg/kg versus 1 mg/kg (69% and 23%, respectively). Conclusion: Pamidronate possesses biologic activity in both normal dogs and in dogs with osteosarcoma, as assessed by reductions in urine NTx excretion. Based upon reductions in urine NTx excretion, a dosage of 2 mg/kg appears more effective than 1 mg/kg.     

Myotonia associated with hyper-adrenocorticism in two dogs

Two dogs developed a disabling gait abnormality characterised by stiffness. The abnormality was consistent with a diagnosis of myotonia secondary to hyper-adrenocorticism. The first dog had iatrogenic hyperadrenocorticism, and its signs improved substantially after corticosteroid administration was gradually withdrawn. The second had pituitary-dependent hyperadrenocorticism, but myotonic signs progressed despite effective mitotane therapy. Procainamide administration reduced the myotonic stiffness in the second case.     

Infection with Basidiobolus ranarum in two dogs

Basidiobolus ranarum is a saprophytic fungus in the environment that also is a part of the endogenous microflora in the gastrointestinal tract of several vertebrates. These organisms may penetrate skin or muscosa of humans and other animals, causing granulomatous inflammation. Two dogs infected with B. ranarum had prolonged or repeated exposure to water or soil in their environment. One dog had progressive subcutaneous infection of all the limbs, and the other dog had recurrent coughing and dyspnea caused by tracheobronchitis. In both dogs, secondary bacterial infection of the lesions was evident. Treatment of the dog with subcutaneous infection involved cutaneous dressings and sequential use of enrofloxacin and itraconazole; however, this resulted in suspected liver damage without clinical improvement. Subsequent treatment with potassium iodide and a lipid formulation of amphotericin B was also unsuccessful, and the dog was euthanatized. The other dog was treated alternately with enrofloxacin and itraconazole. When the clinical signs and infection returned, combination treatment with both drugs was more effective; however, the dog developed liver damage. Subsequent treatment with enrofloxacin on an intermittent basis controlled the dog's coughing during a 3-year period.     

Hyperosmolemic changes following experimental ethylene glycol intoxication in dogs

Experimental ethylene glycol toxicosis in dogs produced a marked increase in serum osmolality. By comparing measured and calculated serum osmolality and relating this difference to plasma ethylene glycol, it was determined that ethylene glycol was primarily responsible for the hyperosmolemia. Osmometry may provide a useful adjunct to other diagnostic tests in identifying ethylene glycol intoxicated dogs during the early, most treatable, stage of toxicosis.     

Tremorgenic syndrome in a cattle herd after feeding silage contaminated with A. clavatus

The clinical signs, pathological and laboratory findings of cattle suffering from a tremorgenic syndrome are described. Animals on a farm with a total of 22 cows, 18 heifers and 9 calves were fed mouldy grass and spent malt-grain silage. Five heifers were affected with muscular tremor, hyperexcitability and hypersensitivity. They were ataxic or in sternal recumbency, while their appetite remained normal. Haematology and blood chemistry in two heifers as well as cerebrospinal fluid from one sick animal were unremarkable. The pathological examination of one animal brought no macroscopic changes to light. Histological examination, however, revealed the degeneration of motor neurones in the midbrain, brain stem and spinal cord. Analysis of a silage sample provided evidence of the presence of Aspergillus clavatus, a mould capable of producing neurotoxic tremorgenic mycotoxins. Epidemiology, clinical findings, pathology and microbiological examination suggest that the five cattle were suffering from neuromycotoxicosis.