Associations between aetiology and outcome in cats with seizures
Simone Schrell and others, Ludwig- Maximilians University, Munich
Epileptic seizures can be classified into three categories: reactive seizures secondary to metabolic or toxic conditions; symptomatic seizures caused by structural brain disease; and those cases with no identifiable cause.
The authors examined the clinical records from 91 cats with seizure disorders of which 22% were classed as reactive, 50% symptomatic and 25% idiopathic, with the remainder attributed to cardiac syncope. In 52% of cats the seizures were focal, with or without secondary generalisation, and in 48% they had primary generalised seizures with or without status epilepticus.
There was no clear link between aetiology and seizure type. Cats with idiopathic seizures had a one-year survival rate of 0.82, which was higher than that for those with reactive (0.5) or symptomatic disease (0.16). Cats with idiopathic disease also tended to be younger than those with other forms.
Journal of the American Veterinary Medical Association 233 (10): 1,591-1,597.
Magnetic resonance imaging in classifying canine intracranial meningiomas
Beverly Sturges and others, University of California, Davis
Meningiomas are the most common form of intracranial cancer in dogs, accounting for about 40% of primary tumours seen at necropsy. Magnetic resonance imaging has been shown to be helpful in classifying meningiomas in human patients allowing predictions about their behaviour and outcome. The authors examined 112 canine cases and found little evidence of significant associations between tumour types and their MRI characteristics. The high incidence of atypical tumours in dogs may contribute to their relatively poor response to treatment.
Journal of Veterinary Internal Medicine 22 (3): 586-595.
Extrapyramidal side-effects in a macaw treated with haloperidol and clomipramine
Simon Starkey and others, Cornell University, New York
A 14-year-old female blue and gold macaw (Ara ararauna) had a three-day history of neurological signs, including hyperactivity, ataxia and repetitive pacing and head bobbing. It had been treated with the antidepressant clomipramine and the anti-psychotic haloperidol for one month after presenting with feather plucking, aggression and destructive behaviour. A diagnosis was made of adverse extrapyrimidal signs, and the bird responded rapidly to diphenhydramine, when haloperidol was withdrawn and the clomipramine dose reduced.
Journal of Avian Medicine and Surgery 22 (3): 234-239.
Bartonella species antibodies and DNA in the cerebrospinal fluid of cats
Karyn Leibovitz and others, Colorado State University
Bartonella species are aerobic Gramnegative bacteria infecting humans and cats which cause disease with a range of clinical signs, sometimes including neurological signs of seizures, coma, behavioural changes, etc. A diagnosis may be difficult to confirm with blood or serum results and so the authors assess the value of taking cerebrospinal fluid. Among 36 of 100 cats with both central nervous system disease and Bartonella species IgG antibodies in serum, 11 had signs of antibody and 10 cats had detectable DNA in the CSF.
Journal of Feline Medicine and Surgery 10 (4): 332-337.
Primary hypothyroidism causing central nervous system atherosclerosis in a dog
Shauna Blois and others, University of Guelph, Ontario
A two-year-old Australian sheepdog was referred with a history of mild ataxia, obesity and lethargy first identified as a puppy. It had also experienced two episodes of ataxia and circling following which it had been treated for otitis externa. It had been diagnosed with with hypothyroidism one week earlier and was receiving levothyroxine. Despite treatment its ataxia worsened, it also developed cranial nerve abnormalities and was euthanased. Post mortem examination showed thyroid gland atrophy and widespread CNS atherosclerosis.
Canadian Veterinary Journal 49 (8): 789- 792.
Keratoconjunctivitis resulting from facial nerve dysfunction and hypothyroidism
Bianca Schwarz and others, University of Veterinary Medicine, Vienna
A six-year-old warmblood gelding was referred with a seven-month history of bilateral blepharospasm and head shaking. Clinical examination of the eyes, the results of Schirmer tear test and the animal’s dry nares indicated keratoconjunctivitis sicca attributable to parasympathetic facial nerve dysfunction. Serum thyroxine levels were low and hypothyroidism was confirmed by TSH stimulation tests. The horse responded to treatment with levothyroxine, resulting in the resolution of these neurological signs.
Journal of the American Veterinary Medical Association 233 (11): 1,761-1,766.
Evaluation of an immunohistochemistry protocol for diagnosing BSE
Lisa Manning and others, National Centre for Foreign Animal Disease, Winnipeg
A collaboration was established in 2001 between the NCFAD in Canada and the UK Veterinary Laboratories Agency to evaluate diagnostic methods for BSE surveillance. Brain samples from BSE cases diagnosed positive from clinical signs and histopathology were tested using an immunohistochemistry protocol. There was 100% sensitivity, specificity and reproducibility in the results from the two centres. The findings show that this method could be a useful adjunct to the ELISA-based techniques used in high throughput programmes.
Journal of Veterinary Diagnostic Investigation 20 (4): 504-508.
Histopathological classification of canine ocular gliomas
Carolina Naranjo and others, University of Wisconsin-Madison
Gliomas are neoplasms of the nonneuronal tissue of the central nervous system and may arise anywhere in the brain and spinal cord. The authors describe the histopathological features of 18 cases of glial tumours affecting the retina and optic nerve of dogs. Eleven cases were classified as highgrade, five as medium grade, and one as a low-grade astrocytoma, with one oligodendroglioma. The metastatic potential of these tumours appears to be low but ascending invasion into the ventral aspect of the brain is possible.
Veterinary Ophthalmology 11 (6): 356-362.
Wasting and neurological signs unrelated to CWD in a whitetailed deer
Amir Hamir and others, National Animal Disease Center, Ames, Iowa
Chronic wasting disease is a fatal transmissible spongiform encephalopathy of captive and freeranging cervids similar to BSE in cattle. A 6.5-year-old captive whitetailed deer (Odocoileus virginianus) showed evidence of weight loss and abnormal neurological signs and was euthanased following unsuccessful treatment with antibiotics and antiinflammatory drugs. Post mortem examination of the brain showed vacuolation and mineralisation of the blood vessels but no signs of abnormal prion proteins.
Journal of Wildlife Diseases 44 (4): 1,045- 1,050.
Effects of bovine viral diarrhoea virus on the bovine foetal brain
Donald Montgomery and others, University of Wyoming
Intrauterine exposure to bovine viral diarrhoea virus causes persistent infection in the affected calves. The virus has a tropism for nervous tissue and the brain is known to be a site of such persistent infection. The authors investigate the distribution of lesions in the brains of foetuses experimentally infected with BVDV at 190 days gestation. The pattern of BVDV immunolabelling revealed both similarities and differences to studies in post-natal calves, suggesting that viral infection in the brain is a dynamic and progressive process.
Veterinary Pathology 45 (3): 288-296.
Neurological deficits in cats and dogs with naturally occurring tick paralysis
Christopher Holland, 29 Dunkley Avenue, New Lambton, New South Wales
Tick paralysis is a common condition in Australian small animal practice, caused by toxins produced by Ixodes holocyclus) and showing clinical and neurophysiological signs similar to botulism. The author describes the epidemiological and clinical features in 27 cases in cats and dogs with asymmetrical focal neurological deficits. The recovery times for animals with facial paralysis were significantly longer than those for patients with generalised signs of tick paralysis but there was no difference for those with anisocoria, or asymmetrical pupils.
Australian Veterinary Journal 86 (10): 377-384.
