ABSTRACT
OBJECTIVE: To investigate causes of seizure disorders in cats. DESIGN: Case series. ANIMALS: 30 cats referred to the Ontario Veterinary College for recurrent seizures. PROCEDURES: Signalment and seizure pattern were evaluated. Diagnostic procedures included physical, neurologic, and fundic examinations; CBC; serum biochemical analyses, including determination of pre- and postprandial bile acid concentrations; urinalysis; serologic assays for FeLV and feline immunodeficiency virus, feline infectious peritonitis, and Toxoplasma gondii, magnetic resonance imaging of the brain; CSF analysis; and neuropathologic examination of euthanatized cats and of surgical biopsy specimens. RESULTS: All cats were found to have structural brain diseases; nonsuppurative meningoencephalitis of unknown cause was found in 14 cats, feline ischemic encephalopathy in 6, meningioma in 2, polycythemia vera with secondary brain lesions in 2, posttraumatic epilepsy in 1, and cerebral abscess in 1. A definitive diagnosis could not be reached in 4 cats. CLINICAL IMPLICATIONS: The most common cause of seizures in cats is structural brain disease. Structural brain lesions often can be detected on the basis of seizure pattern and results of neurologic examination. Cerebrospinal fluid analysis and brain imaging are essential to determine the cause of these lesions. Causes of seizures found in the cats of this study differ from those reported to be the most common. Nonsuppurative meningoencephalitis of unknown origin appears to be a frequent cause of neurologic disorders in cats, including seizure disorders. Feline ischemic encephalopathy appears to exist in a milder form than the classic disease and may be a common cause of seizures in cats.
Subject(s)
Brain Diseases/veterinary , Cat Diseases/diagnosis , Seizures/veterinary , Animals , Bile Acids and Salts/blood , Blood Cell Count/veterinary , Blood Chemical Analysis/veterinary , Brain/pathology , Brain Diseases/complications , Brain Diseases/diagnosis , Brain Ischemia/complications , Brain Ischemia/diagnosis , Brain Ischemia/veterinary , Cat Diseases/etiology , Cats , Cerebrospinal Fluid/chemistry , Cerebrospinal Fluid/cytology , Female , Magnetic Resonance Imaging/veterinary , Male , Meningoencephalitis/complications , Meningoencephalitis/diagnosis , Meningoencephalitis/veterinary , Neurologic Examination/veterinary , Recurrence , Seizures/diagnosis , Seizures/etiology , Urinalysis/veterinaryABSTRACT
OBJECTIVE: To determine outcome of clinical management of cats with seizure disorders. DESIGN: Case series. ANIMALS: 30 cats referred to the Ontario Veterinary College for recurrent seizures. PROCEDURES: Treatment was dictated by the cat's seizure frequency and by the underlying cause. Cats that were having cluster seizures or status epilepticus at the time of admission were treated orally with phenobarbital and with constant IV administration of diazepam. The other cats were treated with long-term oral administration of phenobarbital if the frequency of their seizures justified it. Follow-up included evaluation of seizure frequency, serum antiepileptic drug concentrations, and hematologic and serum biochemical values. Outcome was documented on the basis of survival and seizure frequency at the end of the followup period, which ranged from 3 to 21 months. RESULTS: 6 cats were euthanatized without any therapeutic attempts at the owners' request. Twenty of the remaining 24 cats were alive at the time of final follow-up. Seventeen had a good outcome; 11 were not having any more seizures and 6 were having a low frequency of seizures. For 3 other cats, seizures were not well controlled. Four cats had been euthanatized (2 because of intractable seizures, 1 because of postcraniotomy complications, and 1 because the owners did not want to pursue treatment). CLINICAL IMPLICATIONS: Results suggest that severity of seizure disorder in cats is not a good predictor of outcome and that aggressive treatment is often rewarding, even in the most severe cases.
Subject(s)
Cat Diseases/therapy , Seizures/veterinary , Administration, Oral , Animals , Anticonvulsants/administration & dosage , Anticonvulsants/therapeutic use , Cats , Dexamethasone/administration & dosage , Dexamethasone/therapeutic use , Diazepam/administration & dosage , Diazepam/therapeutic use , Follow-Up Studies , Glucocorticoids/administration & dosage , Glucocorticoids/therapeutic use , Infusions, Intravenous/veterinary , Phenobarbital/administration & dosage , Phenobarbital/therapeutic use , Seizures/therapy , Treatment OutcomeABSTRACT
Seizures in cats are caused by active structural disease or secondary epilepsy. The most common structural causes are inflammatory diseases, many of which are probably viral (non-FIP) in origin. Toxoplasmosis, FIP, FeLV, and FIV are rare causes of recurrent seizures in cats. The incidence of primary epilepsy is unknown; it is unlikely to occur in domestic cats. The pattern (type and frequency) of the seizures and the age at onset of the seizures are important factors in establishing a differential diagnosis. More than 50% of cats with seizures experience nonconvulsive (mild generalized or partial complex) seizures. Though many cats experience severe cluster seizures and status epilepticus, severity of seizures is not a good predictor of outcome. Many cats stop having seizures or are controlled well with AEDs regardless of the severity of their seizure activity.
