Highly relaxing gadolinium based MRI contrast agents responsive to Mg2+ sensing

[Abstract] A Gd complex based on a polyphosphonated pyridyl ligand shows a very high stability in aqueous solution (logKEuL = 25.7), a high relaxivity (8.5 mM−1 s−1 at 25 °C and 20 MHz) and a marked and selective relaxivity enhancement (37%) in the presence of Mg2+, opening interesting perspectives for the design of cation responsive contrast agents

Anal Sac Adenocarcinoma with Vertebromedullary Metastasis in a Cocker Spaniel

Background: Several neoplasms can affect the perianal region, being the hepatic adenoma and the anal sac adenocarcinoma (ASAC), which is considered the most frequent. The ASAC is a malignant neoplasm originating from the secretory epithelium of the perianal apocrine glands and is rarely seen in veterinary medicine. The ASAC occurs mainly in adult to elderly canines with high metastasis rates. Patients may be asymptomatic or manifest discomfort and behavioral changes. In the presence of metastasis, the most frequent clinical signs are inappetence, coughing, dyspnea, and colorectal obstruction. Given this scenario, this paper aims to describe the clinical presentation, diagnostic examination, and necropsy findings of a Cocker Spaniel with ASAC and metastasis in the vertebral body, spinal cord, and cauda equina. Case: A 8-year-old neutered male Cocker Spaniel (12 kg of body mass) with a clinical history of non-ambulatory paraparesis was evaluated. The patient also presented tenesmus, difficulty to defecate, and the presence of nodules in the anal sac area. On the neurological examination, asymmetrical changes compatible with injury between L4-S3 were found. A complete blood count, serum biochemistry, and imaging exams such as plain radiography, abdominal ultrasonography (US), and magnetic resonance imaging (MRI) were requested. Blood count revealed anemia and neutrophilic leukocytosis and hypercalcemia. The liver showed increased echogenicity and thickened pancreas in the abdominal US scan. A slightly heterogeneous, vascularized mass with irregular borders was identified in the topographic region of the sublumbar lymph nodes; MRI images demonstrated an expansile formation in the ventral region of the lumbosacral spine, corresponding to the sublumbar lymph nodes and interruption of the cerebrospinal fluid at L5, suggestive of compression of the spinal cord and cauda equina. A presumptive diagnosis of perianal neoplasm with metastasis was made based on the complementary exams. The dog was referred to necropsy, which revealed a 4 cm tumor in the perianal region that invaded the pelvic canal. Multifocal nodules were present on the lung surface, liver, and kidneys, suggesting metastasis. On the cross-section of the spine, one could note the presence of the tumor in the vertebral bodies, spinal cord, and cauda equina from L5 to S3. Even with histopathological evaluation of the tumor, only the immunohistochemical analysis allowed us to confirm the anal sac adenocarcinoma. Discussion: Adenomas and carcinomas are perianal gland neoplasms common in adult and elderly male dogs; the Cocker Spaniel breed is among the most affected. The clinical signs presented by the patient, such as tenesmus and difficulty in adopting the posture of defecation, are common, although neurological changes are rare. As for metastasis, carcinomas of the perianal region present high chances of metastasis to organs including the liver, kidneys, and lungs, both lymphatically and hematogenously, but few studies have related these factors to neurological alterations  due to metastasis. We concluded that metastases from carcinomas to the spine must be considered a possible differential diagnosis in cases of patients presenting clinical signs that are compatible with spinal cord compression and a history of previous neoplasm. Keywords: canine perianal carcinoma, neoplasm, spinal cord metastasis. Título: Adenocarcinoma de saco anal com metástase vertebro-medular em um Cocker Spaniel Descritores: carcinoma perianal canino, neoplasma, metástase medula espinhal.Introdução: Diversas neoplasias podem acometer a região perianal, sendo o adenoma hepático e o adenocarcinoma do saco anal (ASA), considerados os mais frequentes. O ASAC é uma neoplasia maligna originada do epitélio secretor das glândulas apócrinas perianais e raramente é visto na medicina veterinária. O ASA ocorre principalmente em cães adultos a idosos com altas taxas de metástase. Os pacientes podem ser assintomáticos ou manifestar desconforto e alterações comportamentais. Na presença de metástase, os sinais clínicos mais frequentes são inapetência, tosse, dispneia e obstrução colorretal. Diante desse cenário, este trabalho tem como objetivo descrever a apresentação clínica, exame diagnóstico e achados de necropsia de um Cocker Spaniel com ASAC e metástase no corpo vertebral, medula espinhal e cauda equina.Caso: Foi avaliado um macho castrado da raça Cocker Spaniel (12 kg de massa corporal) de oito anos de idade com história clínica de paraparesia não deambulatória. A paciente também apresentava tenesmo, dificuldade para defecar e presença de nódulos na região do saco anal. Ao exame neurológico, foram encontradas alterações assimétricas compatíveis com lesão entre L4-S3. Foram solicitados hemograma completo, bioquímica sérica e exames de imagem como radiografia simples, ultrassonografia (US) abdominal e ressonância magnética (RM). O hemograma revelou anemia e leucocitose neutrofílica e hipercalcemia. O fígado mostrou ecogenicidade aumentada e pâncreas espessado na US abdominal. Identificou-se massa pouco heterogênea, vascularizada e de contornos irregulares na região topográfica dos linfonodos sublombares; As imagens de RM demonstraram formação expansiva na região ventral da coluna lombossacral, correspondendo aos linfonodos sublombares e interrupção do líquido cefalorraquidiano em L5, sugestiva de compressão da medula espinhal e cauda equina. O diagnóstico presuntivo de neoplasia perianal com metástase foi feito com base nos exames complementares. A cadela foi encaminhada para necropsia, que revelou tumoração de 4 cm na região perianal que invadia o canal pélvico. Nódulos multifocais estavam presentes na superfície pulmonar, fígado e rins, sugerindo metástase. No corte transversal da coluna, notou-se a presença do tumor nos corpos vertebrais, medula espinhal e cauda equina de L5 a S3. Mesmo com a avaliação histopatológica do tumor, apenas a análise imuno-histoquímica permitiu confirmar o adenocarcinoma do saco anal.Discussão: Adenomas e carcinomas são neoplasias das glândulas perianais comuns em cães machos adultos e idosos; a raça Cocker Spaniel está entre as mais afetadas. Os sinais clínicos apresentados pelo paciente, como tenesmo e dificuldade em adotar a postura de defecar, são comuns, embora alterações neurológicas sejam raras. Quanto à metástase, os carcinomas da região perianal apresentam grandes chances de metástase para órgãos como fígado, rins e pulmões, tanto por via linfática quanto hematogênica, porém poucos estudos relacionam esses fatores às alterações neurológicas decorrentes da metástase. Concluímos que metástases de carcinomas para a coluna devem ser consideradas um possível diagnóstico diferencial em pacientes que apresentam sinais clínicos compatíveis com compressão medular e história de neoplasia prévia

Extradural Synovial Cyst of the Cervical Spine in a Saint Bernard

Background: Extradural synovial cysts (ESC) originate from an extrusion of the synovium in unstable or degenerated joints. In the spine, this condition can cause neurological signs such as hyperesthesia, proprioceptive ataxia and paresis. Since extradural presentations of synovial cysts are unusual in dogs, the aim of this manuscript is to report a case of extradural synovial cyst of the cervical spine, as well as the clinical findings, diagnosis, surgical treatment and clinical evolution after therapy.Case: A 3-year-old spayed Saint Bernard weighing 60 kg was presented to a Veterinary Medical Teaching Hospital with a history of acute paraparesis that evolved to non-ambulatory tetraparesis five days after the appearance of the first clinical signs. Neurological examination revealed non-ambulatory tetraparesis, normal muscle tone and segmental spinal reflexes in the thoracic and pelvic limbs, as well as cervical pain associated with limited neck movement. According to the neurological examination, the likely lesion location was the C1-C5 spinal cord segment. The differential diagnosis list included intervertebral disc disease, caudal cervical spondylomyelopathy, neoplasm, infectious or noninfectious inflammatory disease, and cystic diseases. Complete blood (cell) count and serum biochemistry tests were within reference limits. The cerebrospinal fluid analysis revealed 35 mg/dL of protein (< 30 mg/dL) and 27 cells (up to 5 cells/mm3) with a predominance of lymphocytes. In plain radiography, bone proliferations of the C4 (caudal) C5 (cranial) articular processes were observed and, in myelography, extradural spinal cord compression was evident between C4-C5 on the right side. The animal underwent dorsal laminectomy for spinal cord decompression. An extradural synovial cyst and proliferated articular processes were removed. At 1,281 days after surgery, the dog was clinically normal and presented no neurological deficits.Discussion: The etiology of synovial cysts has not been well established. However, it is believed that osteoarthritic degeneration associated with joint mobility could cause a rupture in the articular capsule, leading to a synovial membrane protrusion, which would fill with synovial fluid and compress spinal structures. ESC in the cervical region have been reported, often associated with cervical neoplasm. The case we report had no evidence of bone or intervertebral disc compression in myelographic and radiographic exams, abnormalities that would appear in cervical neoplasm. The patient underwent dorsal laminectomy to confirm the presumptive diagnosis and decompress the spine. In the histopathological exam, the cystic material consisted of connective fibrous tissue with a synovial cell lining layer, compatible with synovial cysts. The fluid drained during surgery was also analyzed, showing similarities to synovial fluid drained from other conventional joints. Cerebrospinal fluid analysis revealed mononuclear pleocytosis, a common finding in ESC. The ESC should be included in the differential diagnosis of dogs with cervical myelopathy, especially in young animals and large breeds. A myelographic exam is an important but not definitive auxiliary tool for diagnosis and the therapeutic plan. Dorsal laminectomy is an effective technique for treating ESC

Two–dimensional real-time ultrasonic biometry of ocular globe of dogs

Para realizar a biometria ultra-sonográfica em tempo real, foram utilizados 60 globos oculares de 30 cães oftalmologicamente sadios, com o objetivo de se obter medidas das distâncias no interior do globo ocular. Essas foram tomadas de imagens de cortes sagitais obtidas com os animais posicionados em decúbito esternal, contidos manualmente, e com a aplicação de colírio anestésico. Empregou-se transdutor setorial mecânico de 7,5 MHz sem almofada de recuo. As médias das medidas obtidas foram; para D1- distância entre a córnea e a cápsula anterior da lente 3,9 ±0,7mm, D2- espessura da lente 6,1 ±1,2mm, D3 diâmetro da lente 10.5 ±1,0mm, D4- profundidade da câmara vítrea 9,1 ±0,4mm e D5 distância córnea/retina 18,8 ±0,9mm. Foi observada diferença significativa entre os olhos direito e esquerdo somente em D1. __________________________________________________________________________________________ ABSTRACTSixty ocular globes of 30 health dogs were utilized to perform a real-time ultrasonic biometry, with the objective of getting distance measurement of intra-ocular structures. The measurements were taken from cross-sectional sagital image with the dogs in esternal recumbence, and manual containment, with the use of topical ocular anesthetic vehicle applied in the cornea. A 7.5 MHz transducer of a mechanical sector scanner without flotation pad was used. The measure averages were 3.9 ±0.7mm (D1) distance between the midcornea to anterior capsule; 6.1 ±1.2mm (D2) lens thickness; 9.1 ±0.4mm (D4) vitreous chamber depth; and 18.8 ±0.9mm (D5) midcornea to retinal distance. Significant difference was observed among the right and left eyes only in D1

Surgical Correction of Esophageal Stenosis by Right Aortic Arch Persistence in Two Cats

 Background: Vascular ring anomaly is considered a hereditary change. It occurs when the fourth right aortic arch persists instead of the fourth left aortic arch, forming a vascular ring that compress the esophagus causing esophageal dilatation cranial to the compression site. Diagnosis is based upon anamnesis, physical examination, clinical signs and complementary exams (radiograph, complete blood count and biochemical tests). The clinical treatment is inadequate, since the dilatation persists and tends to progress causing irreversible tissue injury. Surgical correction is indicated and consists of the arterial ligament resection and correction of the esophageal stenosis.Case: The objective of the current study is to report two case of persistence of right aortic arch in two cats referred to the Veterinary Hospital of the Federal University of Santa Maria. On physical examination the patients were alert, in good nutritional status, adequately hydrated and presented normal colored mucous membranes. Each animal underwent radiog­raphy and esophagogram with barium sulphate. The exam demonstrated partial esophageal dilation cranial to the cardiac silhouette, suggestive of vascular ring anomaly. An exploratory thoracotomy was performed in order to achieve the definitive diagnosis. The arterial ligament was resected and esophageal stenosis corrected. Anesthesia, surgery and the postoperative period undergo without any complications. Patients remained hospitalized in the first 24 h for observation and were dis­charged after this period. Ten days surgery they returned for revaluation and removal of the skin suture. Four months after the surgical correction the animals underwent a new radiography and esophagogram examination. Radiographic findings evidenced persistence of esophageal dilation and narrowing of the esophageal lumen. Patients were evaluated periodically up to 10 months after surgery, verifying excellent quality of life and remission of clinical signs.Discussion: Vascular ring anomalies affects both dogs and cats, occurring more commonly in purebred dogs than in mixed breed. The literature reports cases in young Siamese and Persian cats, although the absolute numbers are insufficient to make conclusions about the racial predisposition. This case report enrolled two cases of PRAA in adult mixed breed cats (one male and one female from the same litter). Surgical correction is the recommended treatment for PRAA, either con­ventional or minimally invasive techniques. To assist the dissection of the fibrous ring and correction of esophageal stenosis we utilized a 22 Fr Foley catheter, introduced through the oral cavity to the esophageal stenotic area. The inflation of the balloon on the constricted area allows visualization of residual fiber rings and facilitates its dissection and removal. The PRAA mortality is associated with late diagnosis and the coexistence of aspiration pneumonia. Therefore, surgery should be performed as soon as possible after the onset of clinical signs, in order to reduce damage to the esophageal muscles and nerves. It is estimated that 80% of cases survived the postoperative period. In both cases, no clinical signs were observed, and there was a reduction of the esophageal diameter compared with the previous dilation, as well as better esophageal transit. Ten months after surgery, the animals returned for revaluation, presenting adequate body development and good quality of life. As shown in this case report, surgical intervention allowed for the accurate diagnosis and correction of PRAA in cats, with remission of clinical signs and full recovery of the animal.Keywords: cat, regurgitation, megaesophagus, thoracotomy, anomaly

Postoperative Analgesia with Transdermal Fentanyl or Intramuscular Methadone in Dogs Submitted to Thoracolumbar Hemilaminectomy

Background: Postoperative care after thoracolumbar hemilaminectomy in dogs generally includes rest, physical therapy, and analgesics such as opioids. Currently, there is no established standard for the management of postoperative pain in patients undergoing hemilaminectomy. Ideally, an analgesic protocol should provide adequate pain relief with limited sedation, low adverse effects, and postoperative patient comfort. Therefore, this study aimed to evaluate postoperative analgesia using transdermal fentanyl or intramuscular methadone in dogs undergoing thoracolumbar hemilaminectomy associated with intervertebral disc fenestration (HT) for the treatment of intervertebral disc extrusion (IVDE).Materials, Methods &amp; Results: Eight dogs from the Department of Neurology and Neurosurgery of a veterinary teaching hospital, submitted to HT for the treatment of IVDE, were included. The dogs were randomly distributed into two groups of equal numbers, namely the transdermal fentanyl (FT) group and the intramuscular methadone (IM) group. At the end of the surgical procedure, a fentanyl adhesive patch was applied to the animals in the FT group, which remained there for 72 h. In the IM group, analgesia was induced by intramuscular administration of methadone at intervals of 6 h until 72 h after surgery. The animals were evaluated using the short form of the Glasgow Composite Pain Scale (SF-GCPS). Evaluations of physiological parameters, side effects, and pain were performed by two assessors who had experience using the pain scale and were blinded to the analgesic protocol. Pain evaluations were performed every 2 h (from T4) until 24 h after the surgical procedure. Evaluations were performed every 4 h from 24 h to 48 h after the surgical procedure and at intervals of 24 h from 48 h to 72 h.Discussion: Transdermal fentanyl provided the lowest pain scores, when evaluated by the SF-GCPS, for both assessors. These data are presented as a function of time in Figure 1, which shows the variation in pain scores by SF-GCPS over time. It should be noted that, for both assessors, animals in the FT group had lower pain scores than animals in the IM group. There was also less variation in pain scores in the FT group, indicating better analgesic quality. This can be explained by the maintenance of the drug’s plasma concentrations in a stable manner, avoiding periods of greater or lesser pain throughout the evaluation period due to the absence of increases or decreases in plasma concentration. In the IM group, three analgesic rescues were required; in the FT group, there was no rescue. Although the data indicate that IM was responsible for a greater occurrence in the number of rescues, it is worth noting that this information is based on a small group of animals. One dog needed two rescues (at T4 and T8), regarding which both assessors agreed, while another required one rescue (at T18), but there was a difference of one point between the raters. However, pain scores in all of the cases were considered to be mild, not moderate or severe, with rescues occurring on scores of 5/20. Both fentanyl used by the transdermal route and intramuscular methadone promoted analgesia in the first three postoperative days in dogs undergoing HT. Better stability in postoperative pain scores without the need for analgesic rescue and less occurrence of adverse effects were observed in dogs treated with FT.Keywords: fentanyl patch, neurosurgery, dogs, analgesia, pain.Título: Analgesia pós-operatória com Fentanil transdérmico ou Metadona intramuscular em cães submetidos à hemilaminectomia toracolombar Descritores: adesivo fentanil, neurocirurgia, cães, analgesia, dor

Therapeutic Aspects of Dogs with Presumptive Diagnosis of Idiopathic Epilepsy

Background: Epilepsy is a chronic neurological condition characterised by recurrent epileptic seizures. Various antiepileptic drugs are used for the management of canine idiopathic epilepsy. Phenobarbital is the drug of choice for long-term treatment in dogs. Although it is well tolerated, phenobarbital can cause liver injury if administered alone or in combination with other drugs. Therefore, the main of this study was to identify dogs with presumptive diagnosis of idiopathic epilepsy and information about the antiepileptic drugs, the dose and frequency of administration, period of treatment, frequency of the seizure before and after start the treatment, complementary exams and adverse effects.Materials, Methods &amp; Results: In this study were included 21 dogs with idiopathic epilepsy. All dogs were examined and having blood taken for blood count, biochemical tests (ALT, AST, AP, total protein, albumin, creatinine, urea, amylase, lipase, cholesterol and triglycerides), measurement of serum phenobarbital and/or potassium bromide and, some dogs, free T4 by dialysis and canine TSH. In this study, it was observed monotherapy (phenobarbital) in 76.19% (16/21), double therapy (phenobarbital and potassium bromide) in 19.05% (4/21) and triple therapy (phenobarbital, potassium bromide and gabapentin) in 4.76% (1/21) of dogs. The phenobarbital was used as monotherapy with dose between 1.4 and 12 mg kg-1 and the median of serum concentration was 26.41 μg kg-1. There was significant reduction in the frequency of the seizure after start the treatment. There was refractory to antiepileptic drugs in two dogs (9.5%). In blood analysis, there was increase serum activities of AP (23.81%) and ALT (14.20%), decrease total protein (42.29%), hypoalbuminemia (9.5%) and it was not increased AST activities. The main adverse effects were nodularliver damage and hypothyroidism.Discussion: In most cases of dogs with idiopathic epilepsy, monotherapy is preferred, because it tends to avoid complications that may arise from drug interactions and may also improve compliance by providing a simple treatment regimen. In this study, the phenobarbital controlled the seizures when used as monotherapy. It is considered success of an antiseizure drug when there is a reduction of seizure frequency by at least 50%, with minimal drug side effects. Approximately 20-30% of dogs with epilepsy do not have satisfactory seizure control or experience intolerable adverse effects with appropriate conventional medical treatment. In this study, there was refractory to antiepileptic drugs in 9.5%, one dog treated with phenobarbital and other with phenobarbital and potassium bromide. The long-term use of phenobarbital causes increase in liver enzymes, ALT and, mainly, ALP, these are attributed to enzymatic induction and to low degree of liver damage. ALT and AP increased the values and this does not necessarily indicate clinically significant liver damage or the need to stop therapy. The risk of liver toxicity appears to be greater with concentrations higher than 35 μg mL-1 or when multiple potentially hepatotoxic drugs are used. Other factors associated to the long-term use of anticonvulsant, such phenobarbital, potassium bromide or both, for the treatment of idiopathic epilepsy in dogs is acute pancreatitis and hypothyroidism. In this study, it was not observed acute pancreatitis, but there were two dogs with hypothyroidism. The long-term use of phenobarbital did not cause significant side effects, even with changes in the biochemical tests

Immobilizer Removable Articulate in Rehabilitation of Dogs Submitted to Tenorrhaphy Patellar

Background: In cases of patellar tendon ruptures, there is a need for primary repair by sutures aiming to restore the extensor mechanism of the knee and prevent degenerative sequelae. Even though the need for temporary immobilization of the joint reconstruction surgeries involving tendons and ligaments, seeks to avoid or minimize the undesirable effects of disuse without any interference at the surgical site. Thus, the objective of this research was to propose a model of joint immobilization adjustable in dogs undergoing patellar tenorrhaphy to allow, in the immediate postoperative period, the achievement of physical therapy modalities without interfering with the healing of the involved structures.Materials, Methods &amp; Results: The dogs were randomly divided into two groups called fixed immobilization or GF (6 dogs) and adjustable or GA (5 dogs) immobilization. Once on plane and restrained in dorsal decubitus, lateral incision was performed on the right knee in dogs GF and GA for total section of the patellar tendon at its insertion 10 mm at the tibial crest. Immediately, it was made with tenorrhaphy modified Kessler suture pattern using monofilament nylon wire nº 1, followed by a Wolff point involving modified Kessler suture with the same type of wire. In both groups, the joint was immobilized femorotibiopatelar percutaneous external fixation biplanar at an angle of 110° for 30 days. The groups differed by the material used to connect the percutaneous pins, being employed in the GF acrylic resin, and in GA dogs was made adjustable apparatus which consisted of two stainless steel plates with rounded ends with three equally spaced holes 2.5 mm between them in the central part of the plate and the edge of 6mm, which is joined with the other plate by a nut and bolt and allowing to adjust the desired angle of the device. Were utilized four Steinmann pins 2.5 mm, two in the femur and two tibia, introduced perpendicularly to the bone. The assembled apparatus was encased in percutaneous pins and stuck with stainless steel nuts and lock washers causing immobilization of the knee joint, however adjustable in the period of application of physiotherapy protocol. The results demonstrated a reduction in measures in the period of 30 days, indicating that there was muscle atrophy. At 60 days post-operative values demonstrating increased muscle mass gain probably the bearing of the affected limb to the ground. In this study, was possible to observe that the values at 60 days did not return to the same found preoperatively, and the dogs GF and GA were on average 92.19% of the initial values. As for gait analysis, all dogs GF and GA were grade 5, 1 and 3 of lameness in the preoperative period and after 30 and 60 days after surgery, respectively.Discussion: The joint immobilization in dogs submitted to tenorrhaphy is required, however, the member cannot be used properly, which can lead to sequelae such as muscle atrophy from disuse and especially joint blockage. Currently in human medicine assisted rehabilitation in the immediate post-operative recovery involving the reconstruction of tendons and ligaments, without the need for joint immobilization is required, because patients are instructed to restrict the movements postoperatively. In veterinary medicine, however, it becomes risky this type of conduct, especially the lack of control the movements made by animals, arousing interest in this research to propose joint that could be undone each day to allow implementation of a method of immobilization physiotherapy and at the end of the session, the joint was immobilized again. According to the results, we can conclude that the temporary immobilization with adjustable articulating fixator in dogs submitted to patellar tenorrhaphy allows the use of a physical therapy protocol during the period of immobilization, without interfering with the healing of tendon anastomosis

Intradural Disc Extrusion in a Dog

Background: Intervertebral disc extrusion is an important cause of spinal cord dysfunction in dogs. Intradural localization of the extruded disc material is rare, and is generally associated with a traumatic event or with recurrence of disc extrusion at a previously affected site. We report the clinical presentation, diagnostic workup, and treatment of a dog with intradural intervertebral disc extrusion not preceded by a traumatic event.Case:  A 6-year-old male Dachshund was referred for neurological evaluation due to acute onset of hind-end paralysis preceded by claudication of the left hindlimb. The patient had been receiving conservative treatment to no effect. Neurological examination revealed asymmetric non-ambulatory paraparesis, absence of postural reactions and decreased muscle tone in both hindlimbs, a bilaterally diminished patellar reflex, and a hindlimb withdrawal reflex which was normal on the right and greatly diminished to absent on the left. The lower back was tender to epaxial palpation. Plain radiographs of the lumbar spine in the lateral projection showed calcified material within the spinal canal between the third and fourth lumbar vertebrae. Myelography was suggestively abnormal at the same level, with epidural leakage of contrast at L3-L4. Considering the clinical history, breed, age, neurological signs, and radiographic findings, intervertebral disc disease was suspected despite the inconclusive myelography findings. A dorsolateral lumbar hemilaminectomy was performed. Intraoperatively, the diagnosis was confirmed by visualization of a discolored spinal cord and absence of extradural material. The intradural space was accessed via durotomy. A firm, straw-yellow material was seen compressing the spinal cord and removed. Subsequent histopathological examination confirmed that this material consisted of extruded intervertebral disc contents. Postoperatively, the patient underwent physiotherapy and achieved a satisfactory recovery.Discussion: The most common cause of paraparesis in chondrodystrophic dog breeds is intervertebral disc extrusion. Intradural extrusion of the intervertebral disc is a rare phenomenon, often associated with vigorous exercise that causes laceration of the dura mater, allowing penetration of disc material into the intradural space. Although there were no classic signs of intervertebral disc disease on plain radiography, radiopaque material was visible within the spinal canal, which can occur in cases of calcified intervertebral disc extrusion. Myelography was inconclusive, but the decision was made to operate nevertheless, considering that the patient had not responded to conservative treatment and that surgicaltreatment is the most suitable approach for dogs with non-ambulatory paraparesis or paraplegia secondary to intervertebral disc extrusion. The surgical technique consisted of a hemilaminectomy and durotomy. Our diagnostic suspicion was confirmed intraoperatively, as in most cases of intradural disc extrusion in humans. Intradural disc extrusion is anuncommon phenomenon in dogs, and the diagnosis is usually only established intraoperatively. This unusual variant of intravertebral disc disease should be included in the differential diagnosis of spinal cord dysfunction in chondrodystrophic breeds, even in the absence of a history of trauma or preexisting intervertebral disc disease. Clinical treatment appears ineffective in these cases. Conversely, surgical treatment can yield good outcomes, and even functional recovery

Facial Paralysis Secondary to Hypothyroidism in a Dog

Background: Secondary neurological disorders hypothyroidism is unusual in dogs, especially when compared with other clinical signs, such as lethargy, weight gain and dermatological alterations. When manifested, these signals refer to the peripheral or central nervous system and the most common include: vestibular disease, seizures, laryngeal paralysis, poly­neuropathy and paralysis of the facial nerve. Several reports of neurological disorders associated with hypothyroidism are found in literature, basically international. In the national literature, however, there are few reports on the subject. Thus, the aim of this study was to report a case of facial paralysis associated with hypothyroidism in a dog.Case: A male canine, the boxer race, with 7-year-old were referred to the Veterinary Medical Teaching Hospital of the UFSM with a history of difficult water and food intake and asymmetry of the face for seven days. On neurological ex­amination, the animal found itself alert and locomotion, postural reactions and segmental reflexes without changes. In the evaluation of the cranial nerves, there was a menace response absent the right side, however with preserved vision, palpebral and lip ptosis of the right side and reflection palpebral absent on the same side. Opposite the historical, clinical, neurological and laboratory test findings, the diagnosis was facial paralysis secondary to hypothyroidism. As differential diagnoses were listed, inner otitis neoplasm in inner ear, trauma and idiopathic facial paralysis. After the diagnosis, clini­cal treatment was instituted with levothyroxine sodium, at a dose of 0.02 mg kg orally every 12 h, being observed total improvement of clinical signs (no changes for water intake and food, menace response and reflection palpebral normal and symmetry of the face) in 32 days.Discussion: The diagnosis of facial paralysis associated with hypothyroidism was based on the history, clinical and neurological examination findings, laboratory assessment of thyroid function by observing low serum free T4 and high concentrations of TSH, the therapeutic response after supplementation levothyroxine sodium, and exclusion of other pos­sible causes, such as otitis interna and traumatic. The pathogenesis of this change associated with hypothyroidism is not completely understood, although it is believed that cranial nerve paralysis (trigeminal, facial and vestibulocochlear) may result from the resulting compression of myxedema deposit nerve or in the tissues of the head and neck, demyelination caused by disordered metabolism of Schwann cells, decreased blood perfusion of the inner ear secondary to hyperlipidemia and increased blood viscosity or metabolic defects ranging from change in axonal transport to severe axonal loss. Treatment consists of supplementation of levothyroxine and most dogs with neurological disorders associated with hypothyroidism will present partial or total improvement of clinical signs between two and four months, generally being observed improve­ment within the first week of treatment. In the dog this report, after the beginning of treatment, improvement was observed partial and total clinical signs in 15 and 32 days, respectively. Therefore, with appropriate treatment, hypothyroidism is a disease with an excellent prognosis. The report brings to clinical relevance, the importance of hypothyroidism in the dif­ferential diagnosis of facial paralysis in dogs with face asymmetry history, the laboratory evaluation of thyroid function and response to therapy with levothyroxine sodium supplementation essential for definitive diagnosis. Keywords: neurology, facial nerve, peripheral neuropathy, dogs