Spontaneous ischaemic stroke in dogs: clinical topographic similarities to humans.

BACKGROUND: Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms. AIMS: The objective of this study was to compare clinical symptoms and infarct topography of naturally occurring ischaemic stroke in pet dogs with human ischaemic stroke. METHODS: Medical records and magnetic resonance imaging (MRI) of 27 dogs with spontaneous ischaemic stroke were retrospectively investigated with respect to clinical symptoms and infarct topography. Symptomatology and MRI characteristics were compared with humans. RESULTS: Seventy per cent were diagnosed with middle cerebral artery (MCA) occlusions. Motor dysfunction or sensory-motor dysfunction was reported in 78%, including specific signs of contra-lateral motor dysfunction in 11 of 27 (40%). Seizures were reported in 15 of 27 cases (56%). CONCLUSIONS: Spontaneously occurring ischaemic stroke in dogs share characteristics with human ischaemic stroke in terms of clinical symptoms and infarct topography. Investigating pet dogs with spontaneous ischaemic stroke may provide an alternative approach to the research of stroke injury mechanisms as they occur naturally, and should be further investigated.

Diagnosis and long-term outcome in dogs with acute onset intracranial signs.

OBJECTIVES: To investigate dogs with acute onset of intracranial signs suspected of stroke by primary veterinary clinicians, and establish possible differential diagnoses and long-term outcome. In addition, serum C-reactive protein and plasma cytokines were investigated as potential biomarkers of disease. MATERIALS AND METHODS: All cases were evaluated by neurologic examination, routine haematology and biochemistry and measurement of serum C-reactive protein, plasma cytokine concentrations (interleukin-2, -6, -8, -10, tumour necrosis factor) and low-field MRI. RESULTS: Primary veterinarians contacted the investigators with 85 suspected stroke cases. Only 20 met the inclusion criteria. Of these, two were diagnosed with ischaemic stroke. Other causes were idiopathic vestibular syndrome (n=6), brain tumour (n=5) and inflammatory brain disease (n=2); in five cases a precise diagnosis could not be determined. Median survival times were: brain tumour, 3 days, idiopathic vestibular syndrome, 315 days, ischaemic stroke, 365 days and inflammatory central nervous system (CNS) disease, 468 days. The median plasma concentrations of interleukin-2, -6, -8, -10 or tumour necrosis factor were not significantly increased in any of the diagnosis groups compared to healthy controls. Serum C-reactive protein was higher in dogs with brain tumours and inflammatory brain disease but not above the upper bound of the reference interval. CLINICAL SIGNIFICANCE: Dogs that present with acute onset intracranial disease may have ischaemic stroke but are more likely to have other causes. Many dogs with such acute onset of neurological dysfunction (brain tumours excluded) may recover within a couple of weeks despite their initial severe clinical appearance.

Prevalence and heritability of symptomatic syringomyelia in Cavalier King Charles Spaniels and long-term outcome in symptomatic and asymptomatic littermates.

BACKGROUND: Syringomyelia (SM) is common in the Cavalier King Charles Spaniel (CKCS). Dogs with syringes express clinical signs or might be clinically silent. OBJECTIVES: To investigate the prevalence and heritability of symptomatic SM, the association between clinical signs and magnetic resonance imaging (MRI) findings, and long-term outcome. ANIMALS: All CKCS registered in the Danish Kennel Club in 2001 (n = 240). METHODS: A cross-sectional questionnaire-based prevalence study validated by telephone interviews and clinically investigated clinical signs of SM. Dogs were 6 years at the time of investigation. A prospective observational litter study including clinical investigations, MRI and 5-year follow-up of symptomatic and asymptomatic siblings. Heritability was estimated based on the scale of liability in the study population and litter cohort. RESULTS: The cross-sectional study estimated a prevalence of symptomatic SM at 15.4% in the population. Thirteen symptomatic and 9 asymptomatic siblings participated in the litter study. Spinal cord syringes were confirmed in 21 of 22 littermates (95%). Syrinx diameter and mean syrinx : spinal cord ratio were significantly correlated with clinical signs (P < .01). Estimated heritability of symptomatic SM was 0.81. Symptomatic SM motivated euthanasia in 20%. Dogs with syringes, which expressed no clinical signs at the age of 6, remained asymptomatic in 14/15 cases (93%). CONCLUSIONS AND CLINICAL IMPORTANCE: The prevalence of symptomatic SM is high and genetics have a high impact on clinical disease expression. Further investigations of factors influencing the outbreak threshold of clinical signs of SM are desirable.

Characteristics and phenomenology of epileptic partial seizures in dogs: similarities with human seizure semiology.

Dogs with spontaneous occurring epilepsy with partial seizures express symptomatology resembling what is found in humans with partial epileptic seizures. Questionnaires on clinical signs from 70 dogs, with a confirmed diagnosis of epilepsy with partial seizures with or without secondary generalization, were reviewed in order to characterize and classify clinical signs of partial seizure activity in dogs and compare them to partial seizure phenomenology in humans. Signs of partial seizure activity were distributed into three categories: motor signs, autonomic signs and paroxysms of behavioral signs. Motor signs were described in 48 dogs (69%), autonomic signs in 16 dogs (23%) and paroxysms of behavioral signs in 56 dogs (80%). The majority of dogs expressed signs from more than one group. Sixty-one dogs (87%) had partial seizures with secondary generalization. Nine dogs (13%) had partial seizures without secondary generalization. The study shows a remarkable resemblance between the seizure phenomenology expressed in humans and canines with partial epileptic seizures.

Progressive myoclonus epilepsy in a beagle.

A nine-year-old, neutered female beagle was presented with a history of progressive myoclonic jerks. Clinical signs included mental depression and paroxysmal jerks of the head and forelimbs, apparently elicited by changes in light, noise or movements. Electroencephalographic findings were in accordance with myoclonus epilepsy. Postmortem histopathological findings included multiple periodic acid-Schiff-positive inclusion bodies throughout the central nervous system, but especially in the cerebellum, confirming the suspected diagnosis of Lafora's disease.

Survival and clinical outcome of dogs with ischaemic stroke.

The objectives of the present study were to investigate survival time, possible predictors of survival and clinical outcome in dogs with ischaemic stroke. A retrospective study of dogs with a previous diagnosis of ischaemic stroke diagnosed by magnetic resonance imaging (MRI) was performed. The association between survival and the hypothesised risk factors was examined using univariable exact logistic regression. Survival was examined using Kaplan-Meier and Cox regression. Twenty-two dogs were identified. Five dogs (23%) died within the first 30days of the stroke event. Median survival in 30-day survivors was 505days. Four dogs (18%) were still alive by the end of the study. Right-sided lesions posed a significantly increased risk of mortality with a median survival time in dogs with right-sided lesions of 24days vs. 602days in dogs with left sided lesions (P=0.006). Clinical outcome was considered excellent in seven of 17 (41%) 30-day survivors. Another seven 30-day survivors experienced new acute neurological signs within 6-17months of the initial stroke event; in two of those cases a new ischaemic stroke was confirmed by MRI. In conclusion, dogs with ischaemic stroke have a fair to good prognosis in terms of survival and clinical outcome. However, owners should be informed of the risk of acute death within 30days and of the possibility of new neurological events in survivors. Mortality was increased in dogs with right-sided lesions in this study.