Case summary A 16-year-old spayed female domestic shorthair cat with methimazole-treated hyperthyroidism presented with a chronic progressive history of a stiff gait progressing to recumbency. A neurological examination revealed continuous excessive muscle tone with myokymia, which exacerbated with exercise and persisted during general anaesthesia. An electromyographic study revealed myokymic discharges in all tested muscles, as well as complex repetitive discharges, fibrillation potentials and positive sharp waves. Blood tests, urinalysis and abdominal ultrasound did not reveal significant abnormalities. A histological examination of a muscle biopsy showed no specific abnormalities. A clinical diagnosis of acquired neuromyotonia with myokymia was formulated. Phenytoin treatment resulted in temporary improvement, but excessive muscle tone recurred resulting in episodes of dyspnoea. Euthanasia was elected 3 weeks after presentation. Relevance and novel information To the best of the authors’ knowledge, this is the second report of an acquired neuromyotonia in a cat. In contrast with the previous report, treatment with phenytoin resulted in only partial and temporary improvement of signs. Subsequent progression of the disease, including signs of dyspnoea and dysuria, led to the decision to euthanase the cat. In humans, acquired neuromyotonia (Isaacs syndrome) is usually due to an autoimmune response to proteins associated with voltage-gated potassium channels. More rarely, it has also been described in humans with thyroid disorders. A link with methimazole treatment or hyperthyroidism in the cat reported here could not be excluded.
In 20 dogs and I cat a diagnosis of tetanus was made based on the typical clinical signs and a possible wound history. In 7 animals a tooth abnormality was considered as the entrance way of the bacteria. By means of radiography of the thorax several animals were evaluated for the presence of possible complications such as aspiration pneumonia, megaoesophagus or hiatal hernia. The treatment existed mainly of metronidazole as an antibiotic, acetylpromazine to control the muscle spasms and additional supportive therapy. The survival rate was 71%.
Two male neutered domestic shorthair cats were evaluated for generalised tremors. On neurological examination both cats showed whole-body tremors, worsening with stress. A mainly cerebellar disorder was suspected. Blood examination, cerebrospinal fluid analysis and electrophysiological examination of both cats and magnetic resonance imaging of the brain in one cat were normal. Idiopathic generalised tremor syndrome (IGTS) was suspected owing to the exclusion of underlying causes and the clinical similarities with the syndrome in dogs. Treatment as recommended for dogs was initiated and resulted in improvement. This report describes the first cases of IGTS in cats.
To evaluate the evolution of clinical signs and their correlation with results of magnetic resonance imaging (MRI) and transcranial magnetic stimulation (TMS) and to assess potential prognostic variables after conservative medical treatment for disk-associated cervical spondylomyelopathy (DA-CSM) in dogs.Prospective cohort study.21 client-owned dogs with DA-CSM.After neurologic grading, dogs underwent low-field MRI and TMS with measurement of onset latencies and peak-to-peak amplitudes from the extensor carpi radialis and cranial tibial muscles. Dimensions calculated from MRI images were remaining spinal cord area, spinal cord compression ratio, vertebral occupying ratio, vertebral canal height-to-body height ratio, vertebral canal height-to-body length ratio, and vertebral canal compromise ratio. Intraparenchymal signal intensity changes were graded. Dogs were reevaluated 1, 3, 6, 12, and 24 months after initial diagnosis.Outcome was successful in 8 of 21 dogs. Negative outcomes were characterized by rapid progression of clinical signs. All dogs with more severe clinical signs of DA-CSM 1 month after diagnosis had unsuccessful outcomes. Outcome was associated with the remaining spinal cord area and vertebral canal compromise ratio. Prognosis was not associated with severity of clinical signs or results of TMS. There were no significant correlations among clinical signs, MRI findings, and TMS results.Conservative medical treatment of DA-CSM was associated with a guarded prognosis. Selected MRI variables and clinical evolution 1 month after diagnosis can be considered prognostic indicators. The lack of correlation among clinical signs, results of diagnostic imaging, and results of electrophysiologic evaluation in dogs with DA-CSM warrants further investigation.
SAMENVATTINGIn deze retrospectieve studie worden dertien yorkshire terriërs beschreven waarbij necrotiserende encefalitis bevestigd werd op basis van histopathologisch onderzoek.Alle honden vertoonden progressieve neurologische symptomen die wezen op een aandoening van de grote hersenen en/of de hersenstam.Bij bloedonderzoek werd vaak een gestegen serum creatinine kinase (CK) gevonden.De analyse van het cerebrospinaal vocht toonde meestal een eiwittoename en een mononucleaire pleocytose.Bij computer tomografisch (CT) onderzoek zag men op de precontrastbeelden hypodense zones en hydrocephalus of ventrikulomegalie.Na de toediening van intraveneus contrast zag men op de CT-beelden een duidelijke contrastcaptatie.Alle dertien honden werden geëuthanaseerd wegens het progressieve verloop van deze hersenaandoening en het gebrek aan een effectieve behandeling.
Far-lateral intervertebral disk extrusions (IVDEs) have been reported infrequently in dogs in veterinary literature, mostly affecting the caudal lumbar intervertebral disks. We describe the clinical findings, computed tomography (CT) and magnetic resonance imaging (MRI) findings, treatment, and outcome in 10 dogs with cervical far-lateral IVDEs. Patient databases of 3 small animal hospitals and 1 veterinary teleradiology service were retrospectively searched for patients in which imaging studies (CT or MRI) identified the presence of intervertebral disk material outside the limits of the intervertebral foramen. Presenting clinical signs included: episodic signs of cervical pain (6/10, 30%), persistent signs of cervical pain (3/10, 50%), nerve root signature or lameness (5/10, 50%), and abnormal cervical posture only (excluding nerve root signature) (1/10, 10%). Affected IVD spaces (for 11 IVDEs in 10 dogs) included: C3-4 (6/11, 55%), C5-6 (3/11, 27%), and C2-3 (2/11, 18%). Nerve root signature was not reported for C2-3 IVDEs. All cases were managed medically (without surgery). The top 3 used medications were gabapentinoids (10/10, 100%), non-steroidal anti-inflammatory drugs (NSAIDs) (10/10, 100%), and paracetamol (3/10, 30%). Median treatment duration was 25 days (range 10–84). Short-term outcome (<3 months) was recorded in 9/10 (90%) cases. Resolution of clinical signs was reported in 7/9 (78%) cases. Long-term follow-up was available for 6/10 (60%) cases (median 11.5 months, range 5.5–30 months); 5/6 (83%) showed resolution of clinical signs. Recurrence of clinical signs was reported in 1 case (9 months later), managed medically again, with successful outcome. In conclusion, cervical far-lateral disk extrusions are a rare clinical entity in dogs, but can result in severe, persistent or episodic, pain. Medical management is associated with a positive short- and long-term outcome in most cases.