Decompressive craniectomy surgery in a dog with intracranial extradural hematoma following blunt force trauma.

A young miniature poodle was presented following blunt force trauma to the head. The dog initially responded well to medical management before developing clinical signs associated with increased intracranial pressure 48 h post-injury that became refractory to hyperosmolar therapy. A computed tomography scan obtained 76 h post-injury showed a short, oblique, non-displaced, complete fissure in the right temporal bone and a second short, oblique, non-displaced, complete fissure in the ventral aspect of the temporal bone. A biconvex, moderately hyperattenuating, space-occupying temporoparietal lesion was visualized immediately adjacent to the area of the temporal fractures. These findings were consistent with a diagnosis of intracranial extradural hematoma. Decompressive craniectomy successfully evacuated the extradural hematoma to alleviate increased intracranial pressure. The dog's neurologic function recovered quickly postoperatively. At follow-up physical examinations at 14 and 437 d, excellent return to function was noted. Key clinical message: This report describes the diagnosis and surgical management of an intracranial extradural hematoma in a dog with increased intracranial pressure refractory to medical management. Furthermore, this report describes the diagnostic imaging findings used to diagnose this particular form of primary brain injury.

Chirurgie de craniectomie décompressive chez un chien présentant un hématome extradural intracrânien à la suite d'un traumatisme contondant. Un jeune caniche miniature a été présenté à la suite d'un traumatisme contondant à la tête. Le chien a initialement bien répondu à la prise en charge médicale avant de développer des signes cliniques associés à une augmentation de la pression intracrânienne 48 heures après la blessure, qui sont devenus réfractaires au traitement hyperosmolaire. Une tomodensitométrie obtenue 76 heures après la blessure a montré une fissure complète courte, oblique, non déplacée dans l'os temporal droit et une deuxième fissure complète courte, oblique, non déplacée dans la face ventrale de l'os temporal. Une lésion temporo-pariétale biconvexe, modérément hyperatténuée et occupant de l'espace a été visualisée immédiatement à côté de la zone des fractures temporales. Ces résultats concordaient avec un diagnostic d'hématome extradural intracrânien. La craniectomie décompressive a réussi à évacuer l'hématome extradural pour atténuer l'augmentation de la pression intracrânienne. La fonction neurologique du chien s'est rétablie rapidement après l'opération. Lors des examens physiques de suivi à 14 et 437 jours, un excellent retour au fonctionnement a été noté.Message clinique clé:Ce rapport décrit le diagnostic et la prise en charge chirurgicale d'un hématome extradural intracrânien chez un chien présentant une augmentation de la pression intracrânienne réfractaire à la prise en charge médicale. En outre, ce rapport décrit les résultats de l'imagerie diagnostique utilisée pour diagnostiquer cette forme particulière de lésion cérébrale primaire.(Traduit par Dr Serge Messier).

Electrocution as an alternative euthanasia method to blunt force trauma to the head followed by exsanguination for non-viable piglets.

BACKGROUND: On farms, the currently approved and most widely practised method of euthanising non-viable piglets is blunt force trauma to the head followed by exsanguination. However, the use of this method is criticised due to public perceptions and aversion to the methodology by caretakers. Therefore, electrocution after electrical stunning was examined as an alternative approach in 80 hybrid piglets. Initially, electrocution was simulated with finite element analysis using a computer piglet-model, where current density in the heart was visualised and size and position of the electrodes were defined. The following step investigated electrical parameters for electrocution in anaesthetised piglets; first, with a constant voltage power source and then with a constant current power source. The electrical stunning was examined using the constant current supply. Finally, the results of electrical stunning and electrocution were verified in 25 healthy piglets with a body weight between 1 and 2 kg. Unconsciousness was proven by testing palpebral, corneal and nociceptive reflexes. Time of death was confirmed by electroencephalography (EEG) and electrocardiography (ECG) records. RESULTS: Stunning succeeded with the preset of 1.3 A and 50 Hz, placing the electrodes on both sides of the head between the eyes and ears using different timespans between 8 and 20 s. Prolonged electrical flow resulted in reduced paddling movements after the epileptic seizure, and allowed undisturbed reflex tests and installation of electrodes for EEG and ECG recording during electrocution. Using 0.75 A and 400 Hz, pin-shaped electrodes were first positioned on both sides of the chest for 5 s, followed by a break of 20-30 s and a second current flow, whereby the electrodes were placed above the withers and the sternum for 5 s. Cardiac arrest and an isoelectric EEG were induced within 3 min after the onset of the electrical flow through the chest. The most obvious indicator of effective stunning and electrocution was termination of rhythmic breathing. Piglets with cardiac arrest showed only single gasps lasting up to 3 min after electrocution. CONCLUSIONS: The evaluated stunning and electrocution protocol might ease concerns about timely piglet euthanasia. However, this should be verified in non-viable piglets to exclude influencing factors like dehydration and diseases.

Brain Tissue Pulmonary Embolism Due to Severe Blunt Force Head Trauma in a Dog.

A 9-week-old male puppy was submitted for necropsy examination after a reported history of developing acute melaena and vomiting blood before death. Grossly, the animal had multiple skull fractures, mostly affecting the occipital region and cranial floor, associated with extensive regions of subcutaneous, periosteal and subdural haemorrhages, as well as petechial haemorrhages within the right middle and caudal lung lobes. Histopathology of the brain revealed multifocal acute meningeal and parenchymal haemorrhage with laceration of the cerebellar folia. In the lung, multiple small- and medium-calibre branches of pulmonary arteries were occluded by aggregates of brain tissue, which exhibited weak immunoreactivity for glial fibrillary acidic protein and strong labelling for neuron specific enolase on immunohistochemistry. These findings were consistent with brain tissue pulmonary embolism, an infrequent phenomenon following severe head trauma. To the best of the authors' knowledge, this is the first reported case of canine brain tissue pulmonary embolism.

Trauma-induced exostosis of multiple suture lines causing partial bilateral nasolacrimal duct obstruction in a 7-year-old Thoroughbred mare.

A definitive diagnosis of extensive suture line exostoses affecting the nasofrontal, nasolacrimal, nasomaxillary, frontolacrimal, lacrimozygomatic and lacrimomaxillary suture lines in a 7-year-old Thoroughbred mare with chronic bilateral epiphora and facial deformation was achieved using standing computed tomography (CT) examinations. Positive contrast dacryocystorhinography using CT revealed partial bilateral obstruction of the nasolacrimal ducts. Minimally displaced depression fractures of the right nasal bone, the right maxillary bone and right frontal bone were also demonstrated. The cosmetic appearance of the periosteal reaction associated with the suture line exostosis and epiphora significantly improved within 3 months of diagnosis and treatment.

Blunt Force Trauma in Veterinary Forensic Pathology.

Veterinary pathologists commonly encounter lesions of blunt trauma. The development of lesions is affected by the object's mass, velocity, size, shape, and angle of impact and by the plasticity and mobility of the impacted organ. Scrape, impact, and pattern abrasions cause localized epidermal loss and sometimes broken hairs and implanted foreign material. Contusions are best identified after reflecting the skin, and must be differentiated from coagulopathies and livor mortis. Lacerations-traumatic tissue tears-may have irregular margins, bridging by more resilient tissue, deviation of the wound tail, crushed hairs, and unilateral abrasion. Hanging or choking can cause circumferential cervical abrasions, contusions and rupture of hairs, hyoid bone fractures, and congestion of the head. Other special forms of blunt trauma include fractured nails, pressure sores, and dog bites. Ocular blunt trauma causes extraocular and intraocular hemorrhages, proptosis, or retinal detachment. The thoracic viscera are relatively protected from blunt trauma but may develop hemorrhages in intercostal muscles, rib fractures, pulmonary or cardiac contusions or lacerations with subsequent hemothorax, pneumothorax, or cardiac arrhythmia. The abdominal wall is resilient and moveable, yet the liver and spleen are susceptible to traumatic laceration or rupture. Whereas extravasation of blood can occur after death, evidence of vital injury includes leukocyte infiltration, erythrophagocytosis, hemosiderin, reparative lesions of fibroblast proliferation, myocyte regeneration in muscle, and callus formation in bone. Understanding these processes aids in the diagnosis of blunt force trauma including estimation of the age of resulting injuries.

Hyphema: Considerations in the Small Animal Patient.

Classification, diagnosis, and treatment of hemorrhage into the anterior chamber of the eye, or hyphema, can be a challenging and frustrating process for many practitioners, especially in emergency situations. This review outlines an inclusive list of causes, diagnostics, and treatments for traumatic and nontraumatic hyphema in both canine and feline patients. The review is tailored to small animal practitioners, especially in emergency practice, and is designed to provide concise but thorough descriptions on investigating underlying causes of hyphema and treating accordingly.

Resolution of hyphaema following intracameral injection of tenecteplase in a Stock Horse.

Intracameral injection of tissue plasminogen activator has been suggested as a means of hastening the clearance of blood from the anterior chamber and reducing the risk of synechia and fibrotic membrane formation in horses with hyphaema. The following report describes a case of ocular trauma in which intracameral injection of tenecteplase (TNK), a new-generation plasminogen activator, resulted in rapid resolution of hyphaema and successful outcome. However, a large dose (1 mg) was administered and may have been associated with retinopathy and keratopathy. TNK may be an effective treatment for equine hyphaema and further controlled clinical or experimental studies are required to determine its efficacy and safety profiles.

Surgical treatment of a traumatic intracranial epidural haematoma in a dog.

A 10-month-old Czech wolf dog was unconscious after being kicked in the head by a horse. The following day, the dog was ataxic and collapsed after several steps. The level of consciousness was decreased. Cranial nerve examination was normal and right postural reactions were decreased. Spinal reflexes were intact in all limbs. The diagnostic work-up included a computed tomography (CT) scan of the head with IV contrast. A lenticular shaped, hyperdense, non-enhancing lesion was observed in the left fronto-parietal region. A diagnosis of intracranial epidural haematoma was made. Two craniotomies were performed on a different day and most of the haematoma was removed. Corticosteroids and antimicrobial therapy were administered. Fifteen days after the surgery, the clinical examinations were unremarkable. Fifteen months later, the owners considered the dog normal. Intracranial subdural or intraparenchymal haematomas have been described in the veterinary literature. To the authors' knowledge, this is the first report of the successful management of an intracranial epidural haematoma in the dog. In humans, these lesions are well described. Common locations are temporal, parietal and frontal regions or a combination of these regions. Patients can be asymptomatic, present with varying clinical signs, or be unconscious. Based on the human literature, following trauma to the head, a CT scan should be performed even if the patient is asymptomatic. Some authors believe that there are not any absolute indications for conservative management versus surgical management.

Secondary hypothyroidism following head trauma in a cat.

An 18-month-old female neutered domestic short hair cat was examined because of marked polydipsia and stunted growth following head trauma when it was 8 weeks old. Diagnostic evaluation revealed hyposthenuric urine, low concentrations of thyroid hormone and undetectable thyroid stimulating hormone concentrations which did not rise following thyroid releasing hormone administration. Lateral radiographs of the left and right tibiae revealed incomplete mineralisation of the greater tubercle and open physis. An almost empty sella turcica and a greatly reduced pituitary were visible on magnetic resonance images of the brain. A presumptive diagnosis of secondary hypothyroidism and central diabetes insipidus following head trauma was made.

Jugular venous emboli of brain tissue induced in sheep by the use of captive bolt guns.

Emboli of central nervous tissue were detected in the jugular venous blood of two of 15 sheep stunned with a conventional cartridge-operated captive bolt gun and in two of 15 sheep stunned with a pneumatically activated gun. No emboli were detected in arterial blood from these sheep or in venous blood from sheep stunned electrically. Emboli from an animal with BSE could transmit the disease to people.

Effect of impact on different regions of the head of lambs.

The heads of anaesthetized lambs aged 4-5 weeks were subjected to impact (temporal, frontal or occipital) of constant strength with a humane stunner. Two hours later, the brains were perfusion-fixed with 4% paraformaldehyde and serial whole coronal slices processed by routine methods. Sections were stained with haematoxylin and eosin or labelled with a monoclonal antibody to amyloid precursor protein, a sensitive marker of axonal injury and neuronal reaction. Microscopical evaluation of axonal, neuronal and vascular damage was performed with a quantitative grid system. Frontal impact produced the greatest damage, followed by occipital then temporal impact. An unusual lesion found in the majority of lambs subjected to impact was multifocal necrosis of the cerebellar granular layer. The findings should assist clinicians in evaluating the probable outcome of traumatic head injury in domestic animals.