Foramen Magnum in Dogs of Small and Toy Breeds - Morphometric Study

Background: The foramen magnum is located in the occipital bone and communicates the cranial cavity with the spinal canal of the vertebral column. Variations in the shape and size of this foramen, such as the presence of a notch in its dorsal contour, characterize occipital dysplasia and may occur due to a defect in the supraoccipital bone ossification process during the gestational period. Occipital dysplasia has been reported primarily in small, toy, and brachycephalic breeds, and its clinical relevance remains controversial. The aim of the present study was to evaluate the size of the foramen magnum in asymptomatic dogs of small and toy breeds. Materials, Methods & Results: The study was conducted at the Veterinary Hospital of the Center for Rural Health and Technology of the Federal University of Campina Grande (UFCG), Patos Campus, located in Paraíba state, Brazil. Twelve (n = 12) asymptomatic, small and toy breed dogs, with variable sex and over 10 months of age, were referred to the Veterinary Hospital for elective surgical procedures and were used in this study. All dogs underwent complete neurological examination to confirm the asymptomatic status and were radiographed in rostrocaudal position, with their mouths closed and the hard palate at an angle of approximately 70º to 80º with the table of the X-ray apparatus. The foramen magnum of each specimen was evaluated in the radiographs using a precision caliper. The analyzed parameters included height (H), the height of the dorsal notch (N), total height (H+N), and width (W), and the obtained data were used to establish the degree of occipital dysplasia and determine the shape of the foramen magnum. Of the 12 animals studied, 75% (n = 9) exhibited a dorsal notch in the foramen magnum, which varied between 3.00 and 10.00 millimeters (mm) in height, characterizing occipital dysplasia. Among the affected animals, 77.77% (n = 7) were classified as grade 1 for the alteration, 11.11% (n = 1) as grade 2 and one animal (n = 1; 11.11%) as grade 3. The prevalent shape observed for the foramen magnum was oval (83.3%). Discussion: Although occipital dysplasia has been associated with the occurrence of nonspecific neurological clinical signs, such as tremors, ataxia, and epileptic seizures, the presence of this alteration in asymptomatic dogs indicates that the formation alone is just an anatomical variation, as demonstrated herein and in previous studies conducted over the past few years. This hypothesis has been increasingly supported by scientific evidence through publications that portray occipital dysplasia in dogs of various breeds and sizes without clinical manifestations. The clinical signs attributed to occipital dysplasia may originate in situations where there is a coexistence of other conditions. Occipital dysplasia has been reported several times in conjunction with other pathologies, such as occipital hypoplasia and syringomyelia, in symptomatic dogs. The dorsal notch-shaped occipital defect is covered by a fibrous tissue membrane in dogs affected by occipital dysplasia. The presence of this soft tissue membrane has been related to the late onset of syringomyelia due to the decompressive effect that it provides to the flow of cerebrospinal fluid. When occipital dysplasia is identified in symptomatic dogs, it is suggested that the lesion be correctly located within the nervous system and that, according to its neurolocalization, a thorough investigation of other underlying causes for the occurrence of the neurological clinical manifestation be carried out. To date, there is no evidence characterizing occipital dysplasia as a single entity causing neurological deficits. Keywords: anatomy, morphology, occipital bone, skull, occipital dysplasia, neurology

EFEITO DAS CONDIÇÕES CLIMÁTICAS DO SEMIÁRIDO SOBRE O COMPORTAMENTO FISIOLÓGICO DE CAPRINOS MESTIÇOS F1 SAANEN X BOER

This research aimed at evaluating the effect of the semiarid climatic conditions on the physiological behavior of F1 Saanen x Boer crossbred goats, created at an intensive system. The experiment was carried out in the Health and Rural Technology Center, in the Federal University of Campina Grande, in the town of Patos, Paraiba. Twenty-four animals were used, with ages varying between three and four months, being 12 females and 12 males, weaned and prevented against worms, receiving ad libitum water and controlled concentrate and roughage. The environmental variables were checked inside and outside the experiment place, as well as the physiological variables of all animals. Except for the humid bulb temperature, the variance analysis revealed shift effect (P<0.05) for all environmental variables. There was merely shift effect (P<0.05) for Cardiac Frequency and Rectal Temperature, and the averages of both, in the afternoon, overcame those observed in the morning. The obtained results based on the studied physiological and environmental variables conclude that crossbred goats, resulting of Boer (paternal) and Saanen (maternal), present a good resistance to heat, permitting their indication for the meat production in confinement on semiarid conditions

Development of an intervertebral disc prosthesis prototype for the canine cervical spine

ABSTRACT: Cervical arthroplasty with disc prosthesis has been proposed as a treatment option for dogs with Cervical Spondylomyelopathy. The present study developed a novel vertebral disc prosthesis for dogs. Sixteen Functional Spinal Units (C5-C6) were collected from dog cadavers with body weights ranging between 25 and 35 kg, and their vertebral measurements were used to design a prosthetic disc. The sizing of the prosthesis was performed based on the averages of the measurements of width, height, and length of the vertebral bodies from C5-C6 of all specimens. The prosthesis was developed using the Rhinoceros 3D® and SolidWorks® programs, and 3D prototyping was carried out to define the best design. The developed prosthesis consisted of two independent parts that are fixed to the cranial and caudal vertebral bodies, in the intervertebral space, and fitted together by metal-to-metal surfaces capable of moving in the lateral, ventral, and dorsal directions. Each part of the prosthesis is angled in two portions: vertically, in the intervertebral space, and horizontally, in contact with the ventral surface of the vertebral bodies, both of which are fixed by means of monocortical locking screws. The design of the developed prototype allowed a good fit in the intervertebral space between C4-C5, C5-C6, and C6-C7

Surgical treatment of lumbar extradural chondroma in a dog - Case report

Neoplasms originating in the spinal canal are uncommon in small animal veterinary clinic, but when present can cause significant neurological signs. Anatomically, these neoplasms can be classified as extradural, intradural-extramedullary and medullary. Extradural neoplasms are located outside the dura mater, but they can cause compression of the spinal cord. The chondromas are benign neoplasms characterized by the formation of cartilage and is rarely located in the spinal canal in both human and veterinary medicine. We describe a case of lumbar extradural chondroma in a dog that surgical decompression and removal of the mass allowed the resolution of clinical signs of paralysis with return of function of the hind limbs of the patient

Foramen Magnum in Dogs of Small and Toy Breeds - Morphometric Study

Background: The foramen magnum is located in the occipital bone and communicates the cranial cavity with the spinal canal of the vertebral column. Variations in the shape and size of this foramen, such as the presence of a notch in its dorsal contour, characterize occipital dysplasia and may occur due to a defect in the supraoccipital bone ossification process during the gestational period. Occipital dysplasia has been reported primarily in small, toy, and brachycephalic breeds, and its clinical relevance remains controversial. The aim of the present study was to evaluate the size of the foramen magnum in asymptomatic dogs of small and toy breeds. Materials, Methods &amp; Results: The study was conducted at the Veterinary Hospital of the Center for Rural Health and Technology of the Federal University of Campina Grande (UFCG), Patos Campus, located in Paraíba state, Brazil. Twelve (n = 12) asymptomatic, small and toy breed dogs, with variable sex and over 10 months of age, were referred to the Veterinary Hospital for elective surgical procedures and were used in this study. All dogs underwent complete neurological examination to confirm the asymptomatic status and were radiographed in rostrocaudal position, with their mouths closed and the hard palate at an angle of approximately 70º to 80º with the table of the X-ray apparatus. The foramen magnum of each specimen was evaluated in the radiographs using a precision caliper. The analyzed parameters included height (H), the height of the dorsal notch (N), total height (H+N), and width (W), and the obtained data were used to establish the degree of occipital dysplasia and determine the shape of the foramen magnum. Of the 12 animals studied, 75% (n = 9) exhibited a dorsal notch in the foramen magnum, which varied between 3.00 and 10.00 millimeters (mm) in height, characterizing occipital dysplasia. Among the affected animals, 77.77% (n = 7) were classified as grade 1 for the alteration, 11.11% (n = 1) as grade 2 and one animal (n = 1; 11.11%) as grade 3. The prevalent shape observed for the foramen magnum was oval (83.3%). Discussion: Although occipital dysplasia has been associated with the occurrence of nonspecific neurological clinical signs, such as tremors, ataxia, and epileptic seizures, the presence of this alteration in asymptomatic dogs indicates that the formation alone is just an anatomical variation, as demonstrated herein and in previous studies conducted over the past few years. This hypothesis has been increasingly supported by scientific evidence through publications that portray occipital dysplasia in dogs of various breeds and sizes without clinical manifestations. The clinical signs attributed to occipital dysplasia may originate in situations where there is a coexistence of other conditions. Occipital dysplasia has been reported several times in conjunction with other pathologies, such as occipital hypoplasia and syringomyelia, in symptomatic dogs. The dorsal notch-shaped occipital defect is covered by a fibrous tissue membrane in dogs affected by occipital dysplasia. The presence of this soft tissue membrane has been related to the late onset of syringomyelia due to the decompressive effect that it provides to the flow of cerebrospinal fluid. When occipital dysplasia is identified in symptomatic dogs, it is suggested that the lesion be correctly located within the nervous system and that, according to its neurolocalization, a thorough investigation of other underlying causes for the occurrence of the neurological clinical manifestation be carried out. To date, there is no evidence characterizing occipital dysplasia as a single entity causing neurological deficits. Keywords: anatomy, morphology, occipital bone, skull, occipital dysplasia, neurology

Use of a locking plate “notched head T-plate®” for the fixation of an ilial body fracture in a dog

Vários tipos de implantes são utilizados no tratamento de fraturas de íleo em cães, sendo a osteossíntese com uso de placa a mais descrita e recomendada pela literatura. O tipo de placa, assim como o tipo de parafuso, são fatores preponderantes no sucesso da osteossíntese. Tem sido defendido o uso de placas bloqueadas, que não permitem movimentação entre a unidade placa-osso-parafuso, conferindo estabilidade angular e rigidez ao sistema. Objetivou-se descrever o uso inédito da placa bloqueada “notched head T-plate” no tratamento de fratura caudal de corpo de íleo. Um cão, macho, sem raça definida, de dois anos de idade foi atendido apresentando histórico de queda de terceiro andar, com dois dias de evolução. O animal apresentava-se em estação e durante a avaliação ortopédica observou-se deambulação com impotência funcional do membro pélvico direito, instabilidade e crepitação em corpo do íleo direito com aumento de volume considerável e muita dor. Diagnosticou-se fratura completa caudal do corpo do íleo com diminuição do diâmetro do canal pélvico, através de exame radiográfico. O paciente foi submetido à cirurgia e a fratura foi estabilizada com o uso de uma placa LCP em “T” com a cabeça chanfrada. O paciente apresentou evolução satisfatória com bom apoio do membro 24 horas após a cirurgia e completa recuperação com alta médica aos 60 dias de pós-operatório com consolidação da fratura.Several types of implants may be used to treat iliac fractures in dogs, of which osteosynthesis with plate is the most described and recommended in the literature. The type of plate and screw are major factors in osteosynthesis success. The use of locking plates has been advocated for this purpose, as they do not allow the plate-bone-screw unit to shift, providing angular stability and rigidity to the system. The present study aimed to describe the unprecedented use of a locking notched head T-plate in the treatment of a caudal body of ilium fracture. A two year old male mongrel dog was attended after falling from a third floor height, with two days of evolution. The animal was in standing position, and during orthopedic examination non-weight bearing lameness of the right hind limb, instability, and crepitus in the right body of ilium, with considerable swelling and pain. The radiographic examination allowed diagnosing a complete fracture of the caudal body of ilium with decrease of the pelvic canal diameter. The patient underwent surgery, and the fracture was stabilized with an LCP notched head T-plate. The patient evolved satisfactorily, with good weight-bearing of the affected limb within 24 hours of surgery, and complete recovery with medical discharge after 60 days of postoperative period, with consolidation of the fracture

Fratura cominutiva e articular distal de úmero tratada com fixador esquelético externo transarticular em três gatos

Background: Humeral fractures account for 13% of all fractures in cats and commonly affect the middle diaphysis and supracondylar region with comminution. They are usually the result of high energy traumas such as falls, car accidents and firearm injuries. There are few treatment options for these types of fractures and since they are joint injuries, early surgical repair is mandatory to achieve perfect anatomical reduction, to maintain joint congruence and to allow early weight bearing. Our purpose is to report four subacute and chronic fractures of the distal diaphysis associated with comminuted supra and intercondylar fractures, stabilized with transarticular external skeletal fixator in three domestic felines.Cases: (1)- A 3-year-old male docile Siamese cat with 3.7 kg of body weight was presented for consultation with a 14-day history of high rise syndrome after falling from a 12-meter high. It presented distal comminuted humeral fracture that involved the inter and supracondylar regions. It also had right carpal-ulnar subluxation and comminuted right olecranon fracture involving the articular surface in the left thoracic limb. Fracture and joint stabilization was achieved by use of a transarticular hybrid external skeletal fixator on the right front limb. Fracture healing was observed at 150 days postoperatively. (2)- A 10-year-old female aggressive mixed breed cat with 4.1 kg of body weight was presented for consultation with a 16-day history of high rise syndrome after falling from a 9-meter high. The cat had a comminuted right humeral articular fracture with supra and intercondylar involvement and scapular fracture on the contralateral limb. The humerus fracture was treated with a transarticular linear external skeletal fixator and fracture healing was obtained at 240 postoperative days. (3)- A 1-year-old female unsociable mixed breed cat with 4.5 kg of body weight was presented for consultation with a 15-day history of humeral fractures after falling from a 12-meter high building. The cat had comminuted bilateral humeral articular fracture with supra and intercondylar involvement. Fracture stabilization was achieved by use of a transarticular hybrid external skeletal fixator on both limbs. Fracture healing was achieved after 60 days on the right front limb, and after 120 days on the left front limb.Discussion: Patients with distal humeral diaphyseal fractures should be assessed for peripheral nerve injury. None of the reported cases had neurological damage despite having suffered high energy trauma. Surgical approach to humeral distal fractures may be craniolateral, medial or caudal or even combined. In chronic fractures like those in our study, (fractures with more than 14 days of evolution), perfect anatomic reduction wasn’t considered due to presence of fibrous tissue that would require excessive manipulation, leading to injuries to soft tissues and blood supply, what would increase the risk of infection and bone sequestrum. The gold standard for the treatment of articular fractures is rigid internal fixation by means of compressive screws and compressive plates, and they require open reduction. Whenever anatomical reduction can not be performed, due to either the fracture’s evolution period or by the diminished bone length, closed reduction is indicated and stabilization with transarticular fixators is an alternative. Hybrid constructs are well tolerated by patients since they are lighter than circular apparatus and more versatile than linear fixators. In our study, transarticular fixators were used based on the location of the fractures and fracture period. Despite the ankyloses of the humeral-radio-ulnar joint, all patients adapted to the fixator devices very well and presented satisfactory ambulation weight bearing on the first postoperative day already. A disadvantage of the skeletal fixators is the postoperative care, which includes daily dressings, e-collaring, resting and co-operation on behalf of the owner. Two animals presented aggressive/unsocial behavior and still the prolonged postoperative management and adaptation to the fixator were successful. The results suggest that comminuted humeral distal articular fractures can be treated by the use of transarticular external skeletal fixators in cats

Tenorrhaphy of the Common Calcaneal Tendon in Dogs and Cats

Background: Common calcaneal tendon (CCT) is usually affected by injuries in dogs and less frequently in cats. The Achilles mechanism consists of the convergence of three distinct structures: the tendons of the gastrocnemius muscle, superficial digital flexor muscle and the common tendons of the biceps femoris, gracilis, and semitendinosus muscles. Classification of lesions is based upon their location, severity and chronicity. Clinical signs include lameness, plantigrade stance and various degrees of tarsal hyperflexion according to the injury’s severity. The purpose of this study is to report four cases of reconstruction of the common calcaneus in three dogs and a cat.Cases: Case 1. A 10-year-old male canine, Brazilian Terrier, 7.7 kg of body weight, with a 6-month history of nonweightbearing lameness of the right hind limb attended consultation. Orthopedic examination showed plantigrade stance, hyperflexion of the right tibial-tarsal joint (TTJ) and swelling with fibrous thickening of the distal portion of the CCT. Surgical tendon repair was achieved through insertion of a locking screw on the calcaneo-tibial, tenorrhaphy and suture of a titanium plate on the caudal aspect of the CCT. Case 2. A 2-year-old female mongrel canine, with 13.3 kg of body weight was presented with the complaint of chronic left hind leg lameness. The owner described trauma at the area of the hock six months prior to consultation. On orthopedic exam, severe lameness was noted, swelling with fibrous thickening of the distal portion of the common calcaneal tendon and hyperflexion of the left TTJ (plantigrade position) were visible. Tendon repair was performed in the same manner as in case 1, except that in this case a bovine pericardium graft preserved in glycerin 98% was sutured over the tendon/plate conjunction. Case 3. A 6-year-old female mongrel canine, with 18.6 kg of body weight was attended with a 22-day history of right hind limb lameness. On physical exam intermittent lameness during gait performance and non-weight-bearing position in stance were noted. The distal portion of the limb was internally rotated with plantigrade stance and discontinuity of the CCT was palpable. Tenorrhaphy was performed similarly to case 2. Case 4. A 6 kg, 3-year-old, mixed breed male feline was admitted with a wound on the CCT region for 7 days. The wound was originated after animal interaction with a stray feline. On clinical examination the animal was non-weight bearing on the right hind limb, with plantigrade posture and with a 1 cm wound on the caudal portion of the CCT with tendon exposure. Surgical repair was performed by tenorrhaphy with placement of a surgical steel plate on the caudal aspect of the CCT. A bovine pericardium graft preserved in glycerin 98% was sutured on top of the plate. The TTJ was immobilized with a type II transarticular external fixator.Discussion: Ultrasonography is the test of choice to monitor tendon healing after tenorrhaphy. At this report, this exam was crucial to determine when the calcaneal-tibial screw could be removed. Two dogs and the cat from this report received an association of plate and bovine pericardium preserved in glycerin 98%. The purpose of this association was to increase the strength of the tenorrhaphy, and the pericardium graft had also the function of reducing the formation of peritendinous adhesions. Immobilization of the TTJ has the purpose of opposing muscle forces to avoid stress at tenorrhaphy suture increasing the strength of the healed tendon allowing early weight bear while minimizing the recurrence risk and avoiding limb contracture. We chose to perform the procedure with hyperextension of the TTJ in order to promote greater relaxation of the tendon since there was need to remove large portions of calcaneal fibrous tissues of the dogs and devitalized tissue in the cat from this report. Surgical treatment of injuries of the Achilles mechanism has good prognosis in complete closed lesions treated by tenorrhaphy associated with suture of a plate, suture of bovine pericardial graft preserved in 98% glycerin, calcaneal-tibial locking screw and splint for six weeks.Keywords: Achilles tendon, rupture, calcaneo-tibial screw, locking-loop suture pattern

Lumbar Myelography in a Crab-Eating Raccoon (Procyon cancrivorus)

 Background: The Crab-eating raccoon (Procyon cancrivorus) is a nocturnal mammal and lives in savannah, but loss of their natural habitat makes increase cases of traffic accidents on the roads. A growing number of wildlife are treated in veterinary hospitals, but we have some limitation about the correct interpretation of the diagnostic test, specially because, even the tests were not described. Myelography is a radiographic technique indicated for compressive lesions of the spinal cord that are not seen on plain radiographs. The present report aims to describe, for the first time, a lumbar myelogram performed in a paraplegic crab-eating raccoon after it suffer a traffic trauma.Case: A free living adult, 8-kg, female raccoon was presenting acute paraplegia and swelling in the region of the left humerus was referred at veterinary hospital. The patient was alert and aggressive, good body score and no signs of active bleeding. The animal temper did not allow approaching it; therefore, physical and neurological examinations were not feasible. The raccoon was tranquilized (1.6 mL of nilperidol® intramuscular), anesthetized (propofol, dose-effect intra­venous) and tracheal intubation to provide oxygen and the patient was monitored continuously, followed by referred for radiology service. The simple radiograph showed a complete transverse fracture in the humerus and compression fracture of the twelfth thoracic vertebra (T12), being then indicated the myelographic examination to assess the extent of spinal cord compression. The lumbar region was surgical antisepsis prepared. After being properly positioned in lateral decubitus with moderate cranial flexion of the trunk, the patient underwent lumbar puncture by inserting a spinal needle between the 5th and 6th intervertebral lumbar spaces. The spinal needle was introduced slightly caudolaterally to the spinous process of the 6th lumbar vertebra and cranioventrally directed at an angle of 45º. Then, the needle was pierced through the ligamentum flavum and the dura mater while, concomitantly, we observed the tail moving and the cerebrospinal fluid (CSF) output while the contrast was injected. The contrast iohexol (300 mg/mL) was used at a dose of 0.25 mL/kg. Immediately after the slow injection of contrast (approximately 3 min), radiographs were taken in the latero-lateral and ventrodorsal projections to identify the location of the spinal cord disorder. The extension degree of the lesion was evidenced by the reduction of the contrast column width at the location of instability. The patient was referred for surgical decompression and stabilization.Discussion: In cases where paraplegia results from trauma, spinal radiography and myelography are important means to confirm the diagnosis, specially the extent of the compression and prognosis. There are certain risks inherent in the myelography procedure as arrhythmias and bradycardia during collection, transient apnea during contrast injection and seizures during recovery. Furthermore, deteriorating neurological signs, emesis, urinary retention and hyperthermia are other possible complications. Most of these complications are seen predominantly during cervical myelography compared to lumbar puncture because in the first exam, the contrast hardly reaches the brain and there is no risk of iatrogenic injury to the medulla oblongata. To minimize the neurotoxic effects, the ideal contrast should be radiopaque, water soluble, mis­cible with the cerebrospinal fluid (CSF), nontoxic and removed from the CSF by physiological processes. Iohexol contrast was used effectively, without neurotoxicity upon clinical evaluation while the volume used was sufficient to determine the injury site. The reported case demonstrated the possibility of performing lumbar myelography on Procyon cancrivorus effectively without significant complications or difficulties.Keywords: wildlife, neurology, myelographic examination, Procyon cancrivoru