Acta Scientiae Veterinariae, 2015. 43(Suppl 1): 90. CASE REPORT Pub. 90 ISSN 1679-9216 1 Received: 18 December 2014 Accepted: 28 June 2015 Published: 30 July 2015 1 Laboratório de Cirurgia Experimental (LACE), Universidade Federal de Santa Maria (UFSM), Santa Maria, RS, Brazil. 2 Curso de Medicina Veterinária, Universidade Federal do Pampa (UNIPAMPA), campus Uruguaiana, Uruguaiana, RS, Brazil. 3 Departamento de Clínicas Veterinárias, Universidade Es- tadual de Londrina (UEL), Londrina, PR, Brazil. CORRESPONDENCE: R.O. Chaves [rafaelochaves@hotmail.com - Tel.: +55 (55) 3220-9400 R. 24]. Departamento de Clínica de Pequenos Animais, UFSM. Avenida Roraima n.1000, Bairro Camobi. CEP 97105-900 Santa Maria, RS, Brazil. Síndrome do tremor responsivo ao corticosteroide em cães Syndrome Tremor Responsive to Corticosteroids in Dogs Rafael Oliveira Chaves 1 , Diego Vilibaldo Beckmann 2 , João Pedro Scussel Feranti 1 , Bruna Copat 1 , Luis Felipe Dutra Corrêa 1 , Andrei Kelliton Fabretti 3 , Daniel Curvello de Mendonça Müller 2 & Alexandre Mazzanti 1 ABSTRACT Background: Syndrome responsive to corticosteroid tremor (SRCT) is an immune-mediated cerebellitis commonly observed among young adults small dogs. The main clinical sign of this disorder is a tremor of high frequency and low intensity of head, trunk and limbs. The diagnosis is based on the signalment, the historical, and examinations, physical, neurological and laboratory. The aim of this study was to report four cases of SRCT in dog, stressing the importance of the neurological examination and anamnesis data for location of the lesion in the central nervous system, to establish a list of differential diagnoses and treatment to be instituted. Cases: Two mixed breed dogs, one Shih tzu and one Poodle, being three females and one male, aged between four and six years, with a history of generalized tremors between one and seven days, which ceased when they slept, were presented to a veterinary neurologist at the Veterinary Medical teaching Hospital of the UFSM. The onset of clinical signs was acute, with no progressive evolution. The dogs had no history of intoxication, trauma, or use of medications. Clinical and neuro- logical examination was performed complete, the latter consisting of: observation of mental status (level of consciousness and behavior), evaluation of gait and posture, postural reactions, spinal segmental reflexes, cranial nerves and nocicep- tion (pain deep). Opposite the historical, clinical, neurological and laboratory test findings, a presumptive diagnosis was SRCT. With a presumptive diagnosis, all dogs were subjected to treatment with corticosteroids in immunosuppressant doses with subsequent gradual decrease. The patients had a satisfactory clinical improvement within the first month after onset of clinical signs. Discussion: The SRCT affects small breed dogs, and most dogs have between one and five years of age, weighing less than 15 kg. In dogs of this report, only one had more than five years of age and all had less than 15 kg. The patient’s medical history and neurological examination are essential for the localization of the lesion in the nervous system. On neurological examination, no changes were observed in mental statusin the evaluation of locomotion was observed cerebellar ataxia characterized by dysmetria (hypermetria) in three dogs and intention tremor (head, trunk and limbs) in all cases, which are intensified to start a movement, as when the head was coming from a particular place, for example, in attempts to feed, drink or smell something. These tremors decreased at rest and ceased during sleep. The animals also showed broad-based stance and absence of proprioceptive deficits, characteristic of cerebellar lesions. The segmental spinal reflexes and muscle tone were normal. The final diagnosis was established after exclusion of differential diagnosis and the response to treat- ment with immunosuppressive doses of corticosteroids. Discontinue therapy early in treatment may lead to recurrence. In general, clinical improvement is expected in the first three days, however, some dogs are less responsive and can take two weeks or more remission of clinical signs. In three dogs were observed reduction of tremors in three days and complete remission of up to 15 days of treatment. Treatment was discontinued at 42 days in the four dogs, as had remission of clinical signs. Recurrence may occur after months or years, and may be required imposition of new treatment or continu- ous administration of the drug. The SRCT, although uncommon, can be observed in the clinical routine of small animals and should be considered as a differential diagnosis in dogs with cerebellar signs. For the above, it is concluded that the abnormality has good prognosis when dogs responding at the start of immunosuppressive treatment with corticosteroids. Keywords: generalized tremors, shaker dog syndrome, corticosteroids, neurology, dogs. Descritores: tremores generalizados, síndrome do cão tremedor, corticosteroide, neurologia, cães.