Electroretinographic changes after intravenous lipid emulsion therapy in a dog and a foal with ivermectin toxicosis

This case report describes ivermectin‐induced blindness in a dog and a foal with normal ophthalmic fundic examinations and attenuated electroretinography (ERG). Subsequent recovery in ERG was noted following intravenous lipid emulsion (ILE) therapy. A dog and a foal were evaluated for ivermectin‐induced blindness. Clinical signs included dull mentation, absent pupillary light reflexes (PLRs), and absent menace on presentation. The animals had normal fundoscopic examinations; however, in both cases ERG was consistent with neurosensory retinal dysfunction. Following ILE therapy for ivermectin toxicosis, return of menace, PLRs, and normal mentation were noted, as was improvement in ERG and serum ivermectin levels. These are the first documented cases of ivermectin‐induced blindness in a dog and a foal with normal fundic examinations and attenuated ERG. ERG improved in both animals after ILE therapy. ERG may assist in the diagnosis of ivermectin toxicosis in dogs and horses. ILE therapy may hasten recovery in treatment of ivermectin‐induced blindness.     

Permethrin toxicosis in cats

A retrospective analysis of all adverse experience reports received by the Australian Pesticides and Veterinary Medicines Authority's Adverse Experience Reporting Program for veterinary medicines since 1995, showed that permethrin toxicity in cats usually occurred after the owner applied a canine permethrin-containing product, typically a spot-on. Cats are also at risk from grooming or being in direct contact with recently treated dogs. This paper reviews permethrin toxicosis and its treatment in cats, incorporating information from the Australian and selected overseas veterinary pharmacovigilance programs.     

Intravenous lipid emulsion for treating permethrin toxicosis in a cat

A 2-year-old cat was presented with acute onset seizures, tremors, and hypersalivation. Permethrin toxicity was diagnosed based on a history of recent flea treatment. Measures were taken to minimize further absorption of permethrin, and methocarbamol and intravenous lipid emulsion were used to control tremors. The cat recovered and was discharged within 42 h.     

Suspected ivermectin toxicosis in a miniature mule foal causing blindness

A 9-week-old miniature mule foal presented to the Veterinary Medical Teaching Hospital for acute blindness, ataxia, and depression following an overdose of an over-the-counter ivermectin-based de-worming medication. Ophthalmic examination and electrodiagnostic evaluation eliminated outer retinal abnormalities as the primary cause of the bilateral blindness, implicating instead a central neurologic effect of the drug. With symptomatic and supportive care, the foal recovered fully and regained its vision.     

Intravenous administration of docetaxel to cats with cancer

Background: The safety of IV administration of docetaxel to cats with cancer has not been reported. Objectives: Document adverse effects of IV administration of docetaxel to cats. Animals: Twenty‐one client‐owned cats with any confirmed malignancy. Methods: Cats received up to 5 docetaxel treatments, administered IV every 3 weeks. The initial dosage was 1.0 mg/kg, and dosages were increased by increments of 0.25 mg/kg in cohorts of 3 cats. Adverse events were determined by a CBC at days 7 and 21, serum chemistry and urine specific gravity at day 21, and medical histories provided by the owners. Results: Cats received docetaxel dosages ranging from 1.0 to 2.5 mg/kg, for a median of 2 treatments. Dose‐limiting toxicoses included fever, neutropenia, and vomiting, seen in 2 of the 4 cats treated at 2.5 mg/kg. Hypersensitivity reactions were infrequent (4 of the 21 cats) and mild. The maximum tolerated dosage was 2.25 mg/kg. Conclusions and Clinical Importance: Docetaxel can be administered IV to cats with a low incidence of adverse effects.     

Pharmacokinetics of ivermectin in cats receiving a single subcutaneous dose

Ivermectin is effective against ecto- and endoparasites. It is included in a plan of the Filariasis Division, Thailand for filariasis control and prevention by interrupting transmission of Brugia malayi-microfilariae from cat reservoirs to humans via mosquitoes. The pharmacokinetics of ivermectin in eight healthy cats receiving a single subcutaneous dose of 0.2mg/kg was investigated. Jugular blood samples were collected periodically for up to 30days after dosing. The serum ivermectin concentrations were measured by high performance liquid chromatography with fluorescence detection. The pharmacokinetic parameters (mean+/-S.D.) derived from one-compartment model analysis were as follows: T(max) 1.22+/-0.49day, C(max) 16.75+/-4.04ng/mL, k(ab) 2.62+/-1.86day(-1), t(1/2)(ab) 0.27+/-0.25day, k(el) 0.27+/-0.14day(-1), t(1/2)(el) 2.53+/-2.24day, V(d)/F 9.81+/-5.41L/kg, Cl/F 2.21+/-0.69L/kg/day and AUC(0-->infinity) 98.31+/-30.52ngday/mL. In conclusion, the pharmacokinetics of ivermectin in cats receiving a single dose of 0.2mg/kg by subcutaneous injection revealed a rapid absorption, high distribution, slow elimination and high possibility for the elimination of B. malayi-microfilariae from currently endemic regions.     

A Retrospective Study of Pemoline Toxicosis in Dogs: 101 Cases (1987–1997)

Pemoline is a central nervous system stimulant commonly used for Attension Deficit Disorder in humans. This study describes the clinical syndrome associated with pemoline ingestion as well as its treatment. Ten years worth (1987–1997) of records from the ASPCa National Animal Poison Control Center involving pemoline ingestion in dogs were reviewed. The data suggests that most dogs ingesting pemoline show signs of central nervous system and cardiovascular stimulation including hyperactivity, tremors, ataxia, seizure, tachycardia, hyperthermia, and mydriasis. Blood chemistry alterations included electrolyte imbalances in some dogs. The minimum dose reported to cause clinical signs was 2.8 mg/kg and the minimum dose reported to have caused death was 10 mg/kg. Dogs generally showed clinical signs within 30 minutes to 24 hours of ingestion. The duration of clinical signs ranged from 15 hours to four days. Ninety-four percent of the dogs recovered with supportive treatment. (Vet. Emerg. & Crit. Care, 9:203–207, 1999)     

The urinary lipid profile in cats with idiopathic cystitis

Although feline idiopathic cystitis (FIC) distresses of many cats, its pathogenesis is unknown and the diagnosis is challenging. Polyunsaturated fatty acids (PUFAs) are metabolized into various lipid mediators. Lipid mediators such as prostaglandins (PGs) modulate inflammation and many of them are excreted into the urine. Thus, the investigation of the urinary lipid profile may reveal pathogenesis and help diagnosis of FIC. We collected urine samples from five FIC cats by spontaneous urination and analyzed 158 types of lipid mediators in urines using liquid chromatography-mass spectrometry. The urinary levels of PUFAs were higher in FIC compared to those of the healthy group. The excretions of a major inflammatory mediator, PGD₂, were less in FIC. Other well-known inflammatory mediators such as PGE₂, PGI₂, and their metabolites did not show a difference. In contrast, the levels of PGF_2α and its 2 metabolites and PGF_3α were higher in FIC. These results may provide new insights into the future management of cat FIC.     

Insulin therapy in cats with diabetes mellitus

Thirteen cats with diabetes mellitus were evaluated. Clinical signs included polydipsia, polyuria, polyphagia, lethargy, and weight loss. Results of physical examination included obesity, hepatomegaly, mild seborrhea sicca, muscle wasting, and dehydration. One cat walked plantigrade and was suspected of having a diabetic neuropathy. Persistent hyperglycemia, glucosuria, high liver enzyme activities, hypercholesterolemia, hyperproteinemia, and low electrolyte concentrations were the common laboratory findings. In 3 cats diabetes mellitus developed after megestrol acetate therapy; 2 of these cats required only temporary insulin treatment. In a 3rd cat, which had no history of receiving diabetogenic drug therapy, remission of diabetes mellitus also was observed. Serum insulin and plasma glucose concentrations were determined in 6 cats after administration of an intermediate-acting insulin (isophane insulin) and in 3 cats after administration of a long-acting insulin (protamine zinc insulin). The insulin concentration peaked 2 to 6 hours after the injection of intermediate-acting insulin and 6 to 12 hours after the injection of long-acting insulin. The lowest glucose concentration was recorded 4 to 8 hours after injection of intermediate-acting insulin, and 6 to 12 hours after injection of long-acting insulin. It was concluded that, although insulin therapy must be adjusted to the individual, the diabetic cat usually requires twice-daily administration of isophane insulin; however, the protamine zinc insulin can be given once daily for satisfactory control.