Pregabalin Add-On vs. Dose Increase in Levetiracetam Add-On Treatment: A Real-Life Trial in Dogs With Drug-Resistant Epilepsy

Epilepsy is a common neurological disorder affecting 0.6–0.75% of dogs in veterinary practice. Treatment is frequently complicated by the occurrence of drug-resistant epilepsy and cluster seizures in dogs with idiopathic epilepsy. Only few studies are available to guide treatment choices beyond licensed veterinary drugs. The aim of the study was to compare antiseizure efficacy and tolerability of two add-on treatment strategies in dogs with drug-resistant idiopathic epilepsy. The study design was a prospective, open-label, non-blinded, comparative treatment trial. Treatment success was defined as a 3-fold extension of the longest baseline interseizure interval and to a minimum of 3 months. To avoid prolonged adherence to a presumably ineffective treatment strategy, dog owners could leave the study after the third day with generalized seizures if the interseizure interval failed to show a relevant increase. Twenty-six dogs (mean age 5.5 years, mean seizure frequency 4/month) with drug-resistant idiopathic epilepsy and a history of cluster seizures were included. Dogs received either add-on treatment with pregabalin (PGB) 4 mg/kg twice daily (14 dogs) or a dose increase in levetiracetam (LEV) add-on treatment (12 dogs). Thirteen dogs in the PGB group had drug levels within the therapeutic range for humans. Two dogs in the PGB group (14.3%; 2/14) and one dog in the LEV group (8.3%; 1/12) achieved treatment success with long seizure-free intervals from 122 to 219 days but then relapsed to their early seizure frequency 10 months after the study inclusion. The overall low success rates with both treatment strategies likely reflect a real-life situation in canine drug-resistant idiopathic epilepsy in everyday veterinary practice. These results delineate the need for research on better pharmacologic and non-pharmacologic treatment strategies in dogs with drug-resistant epilepsy.

Clinical course of acute canine polyradiculoneuritis following treatment with human IV immunoglobulin

Treatment of dogs with acute canine polyradiculoneuritis (ACP) is restricted to physical rehabilitation and supportive care. In humans with Guillain-Barré syndrome, the counterpart of ACP, randomized trials show that IV immunoglobulin (IVIg) speeds recovery. The authors of the current study hypothesized that dogs with ACP would tolerate IVIg well and recover faster than dogs managed with supportive treatment only. Sixteen client-owned dogs with ACP were treated with IVIg, and 14 client-owned dogs served as a retrospective control group. Diagnosis was confirmed using clinical features, electrodiagnostics, cerebrospinal fluid analysis, and muscle/nerve biopsies. The duration of the initial progressive phase, the time from IVIg administration until the dogs were ambulating without assistance, and the duration of the complete episode were evaluated. Adverse reactions (anaphylaxis, mild hematuria) were observed in two dogs. Dogs treated with IVIg were ambulating without assistance after a median of 27.5 days (range, 15-127 days) from onset of clinical signs. The control group was ambulatory without assistance at a median of 75.5 days (range, 5-220 days). Even though this result is not statistically significant, there is a clear trend toward faster recovery in dogs treated with IVIg.

Canine status epilepticus due to acute intoxication

OBJECTIVES

The purpose of this study was to describe the type of toxin ingested, clinical presentation and outcome of dogs with status epilepticus (SE) due to acute poisoning presented to a large referral veterinary hospital.

MATERIALS AND METHODS

Retrospective case series. Medical records of all dogs suffering from SE were reviewed (Jan 1, 2002 to April 30, 2009).

RESULTS

Fourteen dogs with SE due to acute intoxication were identified. Toxicological analyses (qualitative analysis with gas chromatography/mass spectrometry; n=11) detected poisonings with carbofuran, crimidine, paraoxone, metaldehyde, strychnine and diazinon. In the other three cases the uptake of a known poison was observed (zink phosphide, metaldehyde). None of the dogs showed evidence of neurological disease up to the day of presentation. The dogs were hospitalised for 2-10 days (median 5 days). The survival rate was 85.7%. None of the dogs experienced any more seizures after discharge (median observation period 2.6 years).

CONCLUSION AND CLINICAL RELEVANCE

Ancillary to the acute clinical presentation, preliminary reports (possible uptake of poisonous material) and an inconspicuous medical history may suggest a tentative diagnosis. Managed adequately, these patients can have a high survival rate. Clinicians should also keep uncommon intoxications in mind.

Unilateral and bilateral congenital sensorineural deafness in client-owned pure-breed white cats

BACKGROUND

Congenital sensorineural deafness has been reported frequently in experimental mixed-breed white cats but there is a paucity of data on occurrence of deafness in client-owned pure-breed white cats.

OBJECTIVE

To describe hearing status in client-owned pure-breed white cats.

ANIMALS

Eighty-four pure-breed client-owned cats with white coat color of 10 registered breeds presented for routine hearing evaluation before breeding (1995-2008).

METHODS

Hearing was assessed by click-evoked brainstem auditory evoked response.

RESULTS

Overall deafness prevalence was 20.2%; 9 cats (10.7%) were bilaterally deaf and 8 cats (9.5%) were unilaterally deaf. There was no association between sex and deafness status (P= .85). Deafness status was associated with iris color (P= .04).

CONCLUSIONS AND CLINICAL IMPORTANCE

Congenital sensorineural deafness frequently occurs in pure-breed cats with white coat color. Unilateral sensorineural deafness was as common as bilateral deafness.

Determination of the regression rate of a fast moving solid/liquid interface using ultrasonics

This paper reports on an ultrasonic measurement system and its application for in situ real-time measurement of very fast regression rates (>200 mm/s) of the melting interface (RRMI) produced when burning particular metals such as aluminium at high pressures. The RRMI is referred to as the rate at which a solid/liquid interface moves along a metallic rod while burning in an oxygen-enriched atmosphere. The ultrasonic transducer and associated equipment used to drive and record the transducer's output signal and conversion of this output into a regression rate is described. Aluminium rods were burned in pure gaseous oxygen at pressures up to 69 MPa (10,000 psia) where the RRMI was calculated at 204+/-2 mm/s. Other tests with a variety of sample materials, geometric shapes and test conditions were also conducted. The resulting RRMI's calculated with the ultrasonic measurement system compare excellently with rates obtained using a visual review of the same tests and with published results (where available).

Fistula between a posterior communicating artery aneurysm and the cavernous sinus

We report the angiographic appearance of a posterior communicating artery aneurysm with a fistula to the cavernous sinus, which had been misinterpreted as a direct carotid-cavernous fistula, on which endovascular repair was unsuccessfully attempted.