Application accuracy of a frameless optical neuronavigation system as a guide for craniotomies in dogs.

BACKGROUND: Optical neuronavigation systems using infrared light to create a virtual reality image of the brain allow the surgeon to track instruments in real time. Due to the high vulnerability of the brain, neurosurgical interventions must be performed with a high precision. The aim of the experimental cadaveric study was to determine the application accuracy of a frameless optical neuronavigation system as guide for craniotomies by determining the target point deviation of predefined target points at the skull surface in the area of access to the cerebrum, cerebellum and the pituitary fossa. On each of the five canine cadaver heads ten target points were marked in a preoperative computed tomography (CT) scan. These target points were found on the cadaver skulls using the optical neuronavigation system. Then a small drill hole (1.5 mm) was drilled at these points. Subsequently, another CT scan was made. Both CT data sets were fused into the neuronavigation software, and the actual target point coordinates were identified. The target point deviation was determined as the difference between the planned and drilled target point coordinates. The calculated deviation was compared between two observers. RESULTS: The analysis of the target point accuracies of all dogs in both observers taken together showed a median target point deviation of 1.57 mm (range: 0.42 to 5.14 mm). No significant differences were found between the observers or the different areas of target regions. CONCLUSION: The application accuracy of the described system is similar to the accuracy of other optical neuronavigation systems previously described in veterinary medicine, in which mean values of 1.79 to 4.3 mm and median target point deviations of 0.79 to 3.53 mm were determined.

Post craniotomy pain management in Copenhagen rat by intraperitoneal or oral dosage of Tramadol: a comparative evaluation.

Calvarial craniotomy in animal models involves pain and distress. Moderate to severe pain in laboratory animals requires adequate pain management strategies. According to previous studies, the options available for suitable analgesia for rat calvarial craniotomy are very few. For most analgesic treatments, injectable routes of administration are predominantly used. However, these routes require restraining the animals, which may cause unnecessary pain, distress and suffering. As a well-fare measure, we focused on pain management by oral administration of analgesia. In this particular study, which is a sub-study of a major experiment on bone regeneration with different polymeric scaffold materials, we have compared the analgesic efficacy of intraperitoneal (I/P) and oral administration of tramadol (10 mg/kg) over a period of 96 h post-surgery in rat craniotomy models. The focus of our study is to evaluate the potential pain reduction efficacy of orally administered Tramadol without any restraining involved. We have used various non-invasive methods to assess the pain-alleviating efficacy of tramadol administered through different methods. We found that the efficacy of oral administration of tramadol is comparable to I/P administration in alleviating pain. Additionally, oral administration through drinking water has the benefit of not putting the animal under unwanted restraining stress.

A novel meningioma with tyrosine-rich crystals in a 6-year-old Great Dane.

A 6-year-old female spayed Great Dane was evaluated for acute onset cluster seizures. Magnetic resonance imaging (MRI) identified a mass in the olfactory bulbs with a large mucoid component caudal to the primary mass. The mass was removed via transfrontal craniotomy and histopathology revealed a tyrosine crystalline-rich, fibrous meningioma with a high mitotic index. Repeat MRI at 6 months showed no detectable tumor regrowth. The dog is clinically normal with no seizures at the time of publication 10 months after surgery. This meningioma subtype is rare in humans. This unique meningioma occurred in a dog of younger age and uncommon breed for intracranial meningioma. Biological progression of this tumor subtype is unknown; however, growth rate might be slow despite the high mitotic index.

Piezosurgical bone-cutting technology reduces risk of maxillectomy and mandibulectomy complications in dogs.

OBJECTIVE: To report the complication rate of dogs undergoing oral oncological surgery when using a bone-cutting piezoelectric unit for osteotomies. CLINICAL PRESENTATION AND PROCEDURES: Retrospective cohort evaluation of medical records from 2012 through 2022 for canine patients that underwent mandibulectomy or maxillectomy for the treatment of oral neoplasia at the Companion Animal Hospital at Cornell University. Cases were included if osteotomy was performed using a piezoelectric unit. Medical records were then reviewed for documentation of intraoperative hemorrhage and administration of blood products. RESULTS: 41 maxillectomies and 57 mandibulectomies met the inclusion criteria (98 in total). Only 1 (1.02%) case was associated with excessive surgical bleeding requiring administration of blood products. CLINICAL RELEVANCE: Results of this study show that intraoperative hemorrhage requiring the use of blood products during or immediately after a mandibulectomy or maxillectomy is rare when using a piezoelectric unit to perform osteotomies, and is substantially lower than that previously reported when using oscillating saws or other bone-cutting devices for maxillectomies.

Detailed anatomic description of the lateral, transzygomatic approach to the middle fossa and rostral brainstem and its use in three dogs.

OBJECTIVE: To describe a craniectomy using a lateral, transzygomatic approach to the middle fossa and rostral brainstem, and to report clinical outcomes and complications in three dogs. ANIMALS: Two cadaver dogs and three client-owned dogs. Two of the client-owned dogs with middle fossa lesions, and one with a rostral brainstem lesion. METHODS: Two cadavers were used to describe the lateral, transzygomatic surgical approach to the middle fossa and rostral brainstem. The medical records of three dogs undergoing this surgical approach were reviewed for data on signalment, preoperative and postoperative neurological status, diagnostic imaging, surgical technique, complications, and outcome. RESULTS: Indications for this surgical approach included incisional biopsy (n = 1) and debulking surgery for brain lesions (n = 2). Definitive diagnoses were achieved in two cases, and tumor volume reduction in all cases. Two of the three dogs developed postoperative facial nerve paralysis ipsilateral to the surgical site, which resolved within 2 and 12 weeks after surgery. CONCLUSION: The lateral, transzygomatic approach provided useful access to ventrally located cerebral/skull base lesions in dogs without major complications.

Craniectomies for Dogs With Skull Multilobular Osteochondrosarcoma Using the Misonix Bone Scalpel: Cadaveric Evaluation and Retrospective Case Series.

To evaluate the Misonix bone scalpel (MBS) for craniotomies in dogs and describe clinical findings and surgical experience in 3 dogs with large multilobular osteochondrosarcoma (MLO) of the skull. Cadaver evaluation and retrospective case series. One canine cadaver; 3 client-owned dogs. Craniotomies of different sizes and at different locations were performed with MBS. Dural tear and bone discoloration were recorded. Clinical, imaging, and surgical findings of dogs diagnosed with MLO and where MBS was used for craniectomies were retrospectively included. Cadaveric evaluation identified MBS as an efficient tool for rapid craniectomies (>5minutes) albeit dural tears and some small foci of bone discoloration were observed. Craniectomies could be performed without complications in 3 dogs with MLO without dural tear or bone discoloration. .Excision was in complete in all cases. The short-term outcome was good, and the long-term outcome was fair to good. Piezoelectric bone surgery with the Misonix bone scalpel is an alternative technology to perform craniectomies in dogs. It was not associated with complications in 3 dogs diagnosed and surgically treated for MLO. Dural tears and suspected bone necrosis can occur. Great care should be taken when using CT to establish disease free surgical osteotomy.

Use of a telovelar approach for complete resection of a choroid plexus tumor in a dog.

OBJECTIVE: To describe a telovelar approach to the fourth ventricle for excision of a choroid plexus tumor within the ventricle. ANIMAL: A 3-year-old entire male Chihuahua. STUDY DESIGN: Case report METHODS: A 3-year-old dog with two-month history of progressive vestibular signs and subdued mentation was diagnosed with a fourth ventricle tumor. Gross total resection of the tumor was achieved through a telovelar approach to the fourth ventricle. RESULTS: Complete removal of the tumor was confirmed on immediate postoperative MRI. The dog recovered from the surgical procedure without complications, displaying some neurological deficits as preoperatively. His neurological examination was normal 2 weeks after surgery and remained so until the time of writing this case report (28 months) without additional treatment. CONCLUSION: The telovelar approach allowed complete excision of a choroid plexus tumor located in the fourth ventricle of the dog reported here.

Indications, complications, and mortality rate following craniotomy or craniectomy in dogs and cats: 165 cases (1995-2016).

OBJECTIVE: To determine the most common indications for cranial surgery and identify risk factors associated with the occurrence of complications and death in the perioperative period following cranial surgery. ANIMALS: 150 dogs and 15 cats. PROCEDURES: For this multi-institutional retrospective case series, medical records of dogs and cats that underwent cranial surgery at any of the 4 participating institutions between 1995 and 2016 were reviewed. Variables were evaluated included species, sex, age, neurolocalization, history of preoperative seizures, surgical approach, histological results, perioperative complications, and outcome. Logistic regression analysis was performed to assess for risk factors for complications. RESULTS: The most common neurolocalization was the forebrain (110/165 [66.7%]), with 94 (57.0%) animals having had seizures preoperatively. The rostrotentorial (116/165 [70.3%]) and caudotentorial (32/165 [19.4%]) surgical approaches were most commonly reported. The most common indication was the treatment of meningioma (75/142 [52.8%]). Complications arose in 58 of the 165 (35.2%) cases within 24 hours and in 86 (52.1%) cases 1 to 10 days postoperatively. Perioperative complications included hypotension (38/165 [23.0%]) and anemia (27/165 [16.4%]). During the postoperative period, the most common complications were neurologic deficits, seizures, postoperative anemia, and aspiration pneumonia. The mortality rate with death or euthanasia perioperatively or ≤ 10 days postoperatively was 14.5% (24/165). Long-term complications occurred in 65 of the 165 (39.4%) animals, with seizures and neurologic deficits being the most common. CLINICAL RELEVANCE: Cranial surgery was performed most commonly for the removal of neoplastic lesions in dogs and cats, and most complications were not life-threatening.

Sinonasal mycosis following transfrontal craniotomy in three dogs.

CASE DESCRIPTION: Three dogs were presented for investigation of chronic nasal discharge and epistaxis 141, 250, and 357 days after undergoing transfrontal craniotomy to treat an intracranial meningioma (2 dogs) or a meningoencephalocele (1 dog). CLINICAL FINDINGS: CT findings were consistent with destructive rhinitis and frontal sinusitis in all 3 dogs, with results of histologic examination and fungal culture of samples obtained during frontal sinusotomy confirming mycotic infection. Frontal sinusotomy revealed fungal plaques covering a combination of bone and residual surgical tissue adhesive at the site of the previous craniotomy in all 3 dogs. Aspergillus spp were identified in all 3 dogs, and Chrysosporium sp was also identified in 1 dog. TREATMENT AND OUTCOME: Surgical curettage was followed by antifungal treatment (topical clotrimazole in 2 dogs and oral itraconazole for 3 months in 1 dog). Nasal discharge improved in the short-term but recurred in all dogs 99, 118, and 110 days after frontal sinusotomy. One dog received no further treatment, 1 dog received an additional 8.5 months of oral itraconazole treatment, and 1 dog underwent 2 additional surgical debridement procedures. At last follow-up, 2 dogs were alive 311 and 481 days after frontal sinusotomy; the third dog was euthanized because of status epilepticus 223 days after frontal sinusotomy. CLINICAL RELEVANCE: Sinonasal mycosis should be considered as a potential complication in dogs developing persistent mucopurulent nasal discharge, intermittent epistaxis, and intermittent sneezing following transfrontal craniotomy. The pathophysiology may be multifactorial, and potential risk factors, including use of surgical tissue adhesive in the frontal sinus, require further investigation.

Transorbital craniectomy for treatment of frontal lobe and olfactory bulb neoplasms in two dogs.

CASE DESCRIPTION: An 8-year-old spayed female Shih Tzu crossbreed dog (dog 1) and a 13-year-old neutered male Miniature Fox Terrier (dog 2) were evaluated for removal of neoplasms involving both the frontal lobe and olfactory bulb. CLINICAL FINDINGS: Physical examination revealed decreased menace response and behavioral changes in both dogs. For dog 1, neuroanatomic localization of the lesion was the left forebrain region; for dog 2, neuroanatomic localization of the lesion was the right forebrain region. Both dogs underwent CT, and dog 1 also underwent MRI. Results of diagnostic imaging were consistent with frontal lobe and olfactory bulb neoplasia in both cases. Dog 1 had lysis of the frontal bone adjacent to the neoplasm. TREATMENT AND OUTCOME: Both dogs underwent a transorbital craniectomy to permit surgical tumor removal. Dog 1 was discharged from the hospital 48 hours after surgery, at which time its mentation and cranial nerve examination findings were considered normal. Dog 2 developed neurologic deterioration after surgery but was ultimately discharged from the hospital after 72 hours, at which time its mentation appeared normal. CLINICAL RELEVANCE: The transorbital approach to the cranium provided excellent access to facilitate removal of frontal lobe and olfactory bulb neoplasms in these 2 dogs.

Staged mandibular lip flap for closure of a large palatal defect after maxillectomy in a dog.

OBJECTIVE: To report closure of an oronasal defect secondary to maxillectomy with a staged mandibular lip flap. STUDY DESIGN: Case report ANIMALS: One 9-year-old female spayed golden retriever. METHODS: A combined dorsolateral and intraoral approach was used to perform a central maxillectomy to excise a 2.4- × 2- × 2.7-cm oral osteosarcoma with 1-cm margins. A buccal mucosal flap was used to close the palatal defect but the site subsequently dehisced. A staged mandibular lip flap was performed to close the defect. An incision was made on the mandible at the intersection of the buccal mucosa and gingiva from the mandibular canine to the level of the commissure. A second incision was made 3 cm ventral to the lip margin. The flap pedicle was based at the commissure. The flap was rotated to cover the palatal defect from rostral to the canine tooth to the fourth premolar. A second procedure was performed 4 weeks after flap placement to desquamate the haired skin and transect the flap pedicle. RESULTS: Partial dehiscence at the caudal aspect of the flap occurred after the first revision. The defect was closed after pedicle transection on day 41, with acceptable cosmesis. The dog was eating canned food with no evidence of discomfort 159 days after the maxillectomy. Recurrence was noted on day 270 postoperatively. CONCLUSION: Closure of a large palatal defect with a staged mandibular lip flap led to good cosmesis and function.

Magnetic resonance imaging findings and clinical management of suspected intracranial hypovolemia after transfrontal craniotomy in a dog.

OBJECTIVE: To report the diagnosis and clinical management of a case of suspected intracranial hypovolemia (IH) in a dog after resection of a large fronto-olfactory chordoid meningioma. STUDY DESIGN: Clinical case report. ANIMAL: One 8-year-old border collie with forebrain neurological signs caused by a fronto-olfactory extra-axial mass diagnosed by using MRI. METHODS: The dog underwent bilateral transfrontal craniotomy for excision of the mass by using ultrasonic aspiration. Immediate postsurgical MRI revealed complete gross resection with no evidence of early-onset complications such as edema, hemorrhage, mass effect, or pneumoencephalus. However, diffuse symmetric meningeal thickening and contrast enhancement were noted. No complications were noted during surgery or while under anesthesia. RESULTS: Neurological deterioration was observed postoperatively. No abnormalities were detected systemically. Thus, early MRI-confirmed findings and neurological deterioration were suspected to be caused by IH. Conservative treatment consisting of bed rest, gabapentin, and intravenous theophylline was then initiated in addition to steroids, antiepileptic drugs, and antibiotics. A gradual neurological improvement was observed, and the dog was discharged completely ambulatory with moderate proprioceptive ataxia 15 days after surgery. CONCLUSION: The clinical and MRI-confirmed findings reported here are consistent with IH, a well-described syndrome in man. This is the first report of a dog with MRI-confirmed findings consistent with IH describing subsequent response to medical management. CLINICAL SIGNIFICANCE: Intracranial hypovolemia after craniotomy should be considered when there is neurological deterioration and characteristic MRI-confirmed findings.

Retrospective evaluation of labetalol as antihypertensive agent in dogs.

BACKGROUND: To evaluate the effect on arterial blood pressure (ABP) of labetalol infusion as treatment for perioperative non nociceptive acute hypertension in dogs. The clinical records of dogs receiving intra or postoperative labetalol infusion were retrospectively reviewed. Invasive systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressure and heart rate (HR) before labetalol infusion (T0) and 15, 30, 45 and 60 min (T1, T2, T3 and T4 respectively) after infusion were retrieved. The dose rate of labetalol infusion and use of concurrently administered drugs that could have potentially affected ABP and/or HR were also recorded. ANOVA for repeated measures and Dunnett's multiple comparison test were used to determine the effect of labetalol on ABP and HR. Differences were considered significant when p < 0.05. RESULTS: A total of 20 dogs met the inclusion criteria, and hypertension was documented after craniotomy (12/20), adrenalectomy (4/20) and other procedures (4/20). Five dogs received labetalol intraoperatively, 14 postoperatively, and 1 during the surgical procedure and recovery. Median infusion duration and rate were 463 (60-2120) minutes and 1.1 (0.2-3.4) mg/kg/h respectively. Median loading dose was 0.2 (0.2-0.4) mg/kg. Labetalol produced a significant decrease in SAP and DAP at all time points compared to T0 (p < 0.05), while the effect was not significant at T1 for MAP (p = 0.0519). Median maximum MAP decrease was 31 (20-90) mmHg. Heart rate did not increase significantly during treatment (p = 0.2454). Acepromazine given before or during labetalol treatment did not reduce significantly ABP (p = 0.735). CONCLUSIONS: Labetalol produced a reliable and titratable decrease in ABP with non significant increase in HR.

Schedule feasibility and workflow for additive manufacturing of titanium plates for ranioplasty in canine skull tumors.

BACKGROUND: Additive manufacturing has allowed for the creation of a patient-specific custom solution that can resolve many of the limitations previously reported for canine cranioplasty. The purpose of this pilot study was to determine the schedule feasibility and workflow in manufacturing patient-specific titanium implants for canines undergoing cranioplasty immediately following craniectomy. RESULTS: Computed tomography scans from patients with tumors of the skull were considered and 3 cases were selected. Images were imported into a DICOM image processing software and tumor margins were determined based on agreement between a board-certified veterinary radiologist and veterinary surgical oncologist. Virtual surgical planning was performed and a bone safety margin was selected. A defect was created to simulate the planned intraoperative defect. Stereolithography format files of the skulls were then imported into a plate design software. In collaboration with a medical solution centre, a custom titanium plate was designed with the input of an applications engineer and veterinary surgery oncologist. Plates were printed in titanium and post-processed at the solution centre. Total planning time was approximately 2 h with a manufacturing time of 2 weeks. CONCLUSIONS: Based on the findings of this study, with access to an advanced 3D metal printing medical solution centre that can provide advanced software and printing, patient-specific additive manufactured titanium implants can be planned, created, processed, shipped and sterilized for patient use within a 3-week turnaround.

Sevoflurane with opioid or dexmedetomidine infusions in dogs undergoing intracranial surgery: a retrospective observational study.

This study reports the clinical use of two sevoflurane-based anesthetic techniques in dogs undergoing craniectomy. Twenty-one animals undergoing elective rostrotentorial or transfrontal craniectomy for brain tumor excision, anesthetized with sevoflurane, were enrolled in this retrospective, observational study. Anesthetic records were allocated to two groups: Sevo-Op (sevoflurane and short acting opioid infusion): 8 dogs and Sevo-Dex (sevoflurane and dexmedetomidine infusion): 13 dogs. Average mean arterial pressure (MAP), heart rate, end-tidal carbon dioxide, end-tidal sevoflurane and intraoperative infusion rates during surgery were calculated. Presence of intra-operative and post-operative bradycardia, tachycardia, hypotension, hypertension, hypothermia, hyperthermia was recorded. Time to endotracheal extubation, intraoperative occurrence of atrioventricular block, postoperative presence of agitation, seizures, use of labetalol and dexmedetomidine infusion were also recorded. Data from the two groups were compared with Fisher's exact test and unpaired t tests with Welch's correction. Odds ratio (OR) and 95% confidence interval (CI) were calculated for categorical variables. Intra-operatively, MAP was lower in Sevo-Op [85 (± 6.54) vs. 97.69 (± 7.8) mmHg, p = 0.0009]. Time to extubation was longer in Sevo-Dex [37.69 (10-70) vs. 19.63 (10-25), p = 0.0033]. No differences were found for the other intra-operative and post-operative variables investigated. Post-operative hypertension and agitation were the most common complications (11 and 12 out of 21 animals, respectively). These results suggest that the infusion of dexmedetomidine provides similar intra-operative conditions and post-operative course to a short acting opioid infusion during sevoflurane anesthesia in dogs undergoing elective rostrotentorial or transfrontal intracranial surgery.

Delayed asymptomatic progressive intraventricular pneumocephalus in a dog following craniotomy.

Delayed pneumocephalus developed in a 9-year-old dog following transfrontal craniotomy and implantation of an experimental local chemotherapy into a partially resected oligodendroglioma, but the animal appeared to be asymptomatic. MRI evidence of increasing intracranial pressure, including progressive ventricular dilatation and compression of periventricular parenchyma, led to the recommendation for exploratory craniotomy. The barrier between the intracranial cavity and frontal sinus was enhanced, and pneumocephalus resolved on MRI at both 1 and 3 months following the repair.

Prolonged survival after craniectomy with skull reconstruction and adjuvant definitive radiation therapy in three dogs with multilobular osteochondrosarcoma.

Multilobular osteochondrosarcoma is an uncommon canine tumor but presents a treatment challenge when arising on the skull. This retrospective case series study aimed to describe outcome of a multimodality treatment approach involving aggressive surgical resection and adjuvant definitive radiation therapy in a group of dogs with multilobular osteochondrosarcoma of the calvarium. Clinical, imaging, treatment, and outcome data were collected from retrospective review of medical records. Three dogs met inclusion criteria. The presenting clinical complaint was the presence of a mass effect of the skull in all three dogs and concurrent neurologic abnormalities in one dog. Advanced imaging revealed aggressive lytic and proliferative tumors arising from the calvarium in all three dogs. All dogs were treated surgically with a modified craniectomy, repaired with a titanium mesh-polymethyl methacrylate bone cement implant or a low prolife titanium mesh plate and followed by adjuvant definitive radiation therapy with 2.5 Gy per fraction for 22 daily fractions. There were no major immediate surgical complications and radiation was well tolerated overall. Neurologic improvement was seen in the patient that presented with neurologic disease. Survival times from surgery were 387, 422, and 730 days and from the time of radiation were 358, 397, and 677 days. Findings in this sample of three dogs supported the use of aggressive therapy with a combination of surgical craniectomy and cranioplasty utilizing a titanium mesh implant and high dose definitive radiation therapy for local control and prolonged survival times in dogs with multilobular osteochondrosarcoma of the skull.

Impact of intracranial hypertension on the short-term prognosis in dogs undergoing brain tumor surgery.

The present study used data from anesthetic records to analyze variables of intracranial pressure (ICP) during brain tumor surgery or in the early postoperative period as prognostic indicators in dogs. Data from 17 dogs which were scheduled to undergo elective craniotomy for brain tumor surgery from 2009 to 2012 were included. Of these, five (29.4%) died during 14 days after the surgery because of respiratory failure following pneumonia (n=2), euthanasia due to difficulty in treatment of status epilepticus (n=1), tumor-bed hematoma (n=1), and unknown reason (n=1). In the 12 surviving dogs, neurological signs were improved or resolved at discharge. All dogs were administered midazolam and droperidol-fentanyl as premedication. General anesthesia was induced using propofol maintained on isoflurane and oxygen. Direct ICP was obtained via a Codman Microsensor strain gauge transducer. ICP hypertension (>13 mmHg) measured after 15 min of recovery from the moment after discontinuation of anesthesia by turning off the vaporizer dial was associated with poor prognosis (odds ratio, 20.00; 95% confidence interval, 1.39-287.60, P=0.028). This suggests that intracranial pressure influences the postoperative mortality rate in dogs undergoing brain tumor surgery.

Modified lateral orbitotomy with combined partial zygomatic arch and vertical ramus ostectomies for excision of a frontal and parietal bone osteoma in a dog.

OBJECTIVE: To describe modifications to the lateral orbitotomy for surgical excision of tumors affecting the frontal, parietal, palatine, or temporal bones. STUDY DESIGN: Case report. ANIMAL: A 5-year-old female spayed American pit bull terrier. METHODS: The dog presented for excision of a bone tumor affecting the right frontal and parietal bones. A modified lateral orbitotomy was performed with combined partial zygomatic arch and vertical ramus ostectomies to increase working space and allow drilling of the calvarium ventral to the mass. RESULTS: The dog tolerated the procedure well, and there were no complications from either the ostectomies or the craniectomy. Histopathological examination was consistent with complete excision of an osteoma. The dog survived 2 years with no recurrence and was euthanized due to an intestinal mass. CONCLUSION: The lateral orbitotomy approach can be modified with combined partial zygomatic arch and vertical ramus ostectomies to increase exposure and working space for resection of tumors affecting the frontal, parietal, palatine, or temporal bones.

Surgical management of a brain abscess due to plant foreign body in a dog.

Background: Intracranial abscesses as a result of grass awn migration have been rarely described in the veterinary literature. The identification of their radiological features is mandatory for proper diagnosis. As occurs with abscesses in other organs, surgical drainage and directed antibiotic therapy should be considered the treatment of choice. Case Description: A clinical case of a Great Dane dog with forebrain signs and magnetic resonance imaging and computed tomography findings compatible with intracranial abscess associated with inflammatory changes in orbital musculature is described. An exploratory rostro-tentorial craniotomy with durotomy was performed, allowing the drainage of purulent content and the extraction of a plant foreign body from the cerebral parenchyma. Antibiotic treatment was instituted and the patient was discharged without recurrence of neurological deficits other than quarterly seizures. Six months later, revision magnetic resonance was performed, revealing the resolution of the intracranial lesion and the normalization of the extracranial tissues. Conclusion: This is the first case in veterinary literature in which a grass awn has been surgically extracted from the brain of a dog with long-term outcome described. Observed changes in the extracranial musculature were fundamental to establish the pre-surgical diagnosis of a migratory foreign body.