Acta Scientiae Veterinariae

Secretory Mammary Carcinoma In Situ in a Cat

2024-09-30T14:37:07-03:00

Background: Secretory carcinoma is a rare mammary neoplasm observed in humans and animals. It was 1st called juvenile carcinoma. Secretory carcinoma is characterized by eosinophilic secretory material, both intra- and extracellularly, and neoplastic cells with a signet ring appearance. It is usually invasive, with a few rare reports of its non-invasive form, secretory carcinoma in situ, in humans. In veterinary medicine, only 2 cases of secretory carcinoma have been reported, both in dogs. This case is the 1st report of secretory carcinoma in a cat and the 1st instance of secretory carcinoma in situ in veterinary medicine, highlighting its histopathological, histochemical and immunohistochemical features.

Case: A 15-year-old female mixed-breed cat was presented with multiple small nodules located in the right mammary chain. The cat underwent a mastectomy to remove the affected tissue. Upon histological examination of the cranial abdominal mammary gland (A1), a well-delimited neoplasm was identified. The tumor exhibited tubular and cluster formations of cells, with no evidence of invasion beyond the basal membrane. There was a significant deposition of both inter- and extracellular eosinophilic material, and the neoplastic cells showed prominent vacuolation, giving them a signet ring appearance. To further support the suspected diagnosis of secretory carcinoma, histochemical and immunohistochemical tests were conducted. Histochemical staining using Periodic Acid-Schiff (PAS), both with and without diastase digestion, revealed positive results for the neoplastic cells, indicating the presence of secretory material. Additionally, the cells tested positive for the alpha-lactalbumin antibody, further supporting the diagnosis of secretory carcinoma. The Ki67 proliferation index was measured at 30%, which is considered relatively high, indicating a notable degree of cell proliferation. Furthermore, immunohistochemical analysis confirmed the presence of myoepithelial cells surrounding the tubules and cell clusters, as demonstrated by the positivity for alpha-smooth muscle actin and p63. This confirmed the in situ nature of the neoplasm, as the absence of invasion was confirmed, leading to the definitive diagnosis of secretory carcinoma in situ. Unfortunately, no follow-up information was available regarding the cat's post-surgical condition.

Discussion: The diagnosis of secretory mammary carcinoma in animals can be made based on the characteristic morphology, which includes the presence of both intra- and extracellular eosinophilic secretion and the vacuolated, signet ring appearance of the neoplastic cells. Histochemical and immunohistochemical techniques are essential to confirm the diagnosis. PAS staining, with and without the diastase reaction, is useful in identifying the secretory material within the cells. Furthermore, the positivity for alpha-lactalbumin in both the cytoplasm of the neoplastic cells and the extracellular secretion helps corroborate the diagnosis. It is important to differentiate secretory carcinoma in situ from other tumor types with a similar morphology, given the potential for aggressive behavior associated with this neoplasm. However, in the present case, the prognosis is likely more favorable due to the absence of invasion and metastasis, as evidenced by the in situ nature of the tumor. More cases of secretory carcinoma and secretory carcinoma in situ need to be diagnosed and described in veterinary medicine to gain a better understanding of their biological behavior and prognosis.

Keywords: feline, alpha-lactalbumin, mammary neoplasm, PAS, secretion.

Cystic Duodenal Duplication in a Cat

2024-08-10T15:26:58-03:00

Background: Cystic duodenal duplication in felines is a rare congenital malformation. Although well-documented in humans and other animal, such as dogs and cats, its occurrence is rare in felines. Clinically, this condition manifests as cysts containing histological structures similar to the gastrointestinal tissue, which can be found at different levels of the digestive tract. Thus, this case report aimed to describe the main aspects of cystic duodenal duplication, its clinical symptoms, its diagnostic methods, and its treatment options.

Case: A 8-month-old neutered, female cat, weighing 2.5 kg, was attended for clinical evaluation. Major complaints reported by the guardian were weight loss and constant emesis, with presence of bile and as many as 8th episodes in a day. During the physical examination, no changes in vital parameters were observed. Laboratory tests such as blood count, biochemistry, histopathology, and abdominal ultrasound were performed, revealing a tubular, homogeneous anechoic structure approximately 2.51 cm in length and adjacent to the duodenal serous/muscular layer. For a definitive diagnosis, histopathological analysis of the structure observed during the imaging exam was requested. The patient was then referred to the surgical ward and underwent exploratory celiotomy. An oval-shaped cystic structure with a serous appearance adhered to the duodenal-pancreatic section was dissected, stored in 10% buffered formalin, and sent for histopathological analysis. Results were suggestive of cystic enteric duplication, with lesion margins comprising a muscular layer and inflammatory cells.

Discussion: Cystic duodenal duplication is a congenital malformation accounting for approximately a 3rd of the duplications occurring in the gastrointestinal tracts of cats. However, there are more reports describing these cysts in dogs than in cats. The aggravating factor in cats and dogs tends to be partial or total obstruction of the duodenum, which may or may not be associated with tenesmus. Furthermore, although rare, duplication cysts of the gastrointestinal tract, characterized by embryological malformations, cause important clinical signs, such as emesis and anorexia, corroborating what was observed in this case. These are important for the differential diagnosis of animals with chronic gastrointestinal signs, and those that do not respond to pharmacological therapy. Duplication cysts are characterized considering 3 main criteria. They must be associated with the gastrointestinal tract, and they must have a muscular layer and epithelium similar to that of the gastrointestinal tract on histopathological analysis. Moreover, its presentation on ultrasound is usually associated with the formation of a rim sign by the hypoechoic muscle layer along with the serosa with greater echogenicity and an anechoic center due to the presence of fluid. Herein, only a homogeneous anechoic structure was observed on ultrasound, and histopathological examination revealed a structure compatible with cystic enteric duplication associated with inflammatory cells. Therefore, it is crucial not to rule out the diagnosis of an enteric duplication cyst on the basis of ultrasound solely, as this is an auxiliary method of diagnosis, and is used to plan surgical approaches.

Keywords: feline, enteric duplication cyst, duodenum.

Título: Duplicação duodenal cística em gato

Descritores: felino, cistos de duplicação entérica, duodeno.

Multimodal Anesthesia in Gallus gallus domesticus for Therapeutic Ovariohysterectomy

2024-08-20T11:48:46-03:00

Background: Egg retention and yolks in the oviduct of birds is a common pathology that is treated by surgical removal of the oviduct itself and its appendages. For the bird's comfort and to reduce the painful stimulus, it is essential to use analgesia correctly, as well as systemic anti-inflammatories, in order to reach different phases of the nociceptive pathway. Local anesthetic blocks can also be used, which can reduce the need for systemic drugs and inhaled anesthetics. The aim of this report is to describe a multimodal analgesic approach with spinal anesthesia in a domestic hen who underwent ovariohysterectomy due to egg retention.

Case: A domestic hen (Gallus gallus domesticus) was referred to the University Veterinary Hospital (HVU) of the Federal University of Santa Maria (UFSM) with egg retention in the oviduct and the treatment of choice was therapeutic ovarian-salpingohysterectomy (OSH). Pre-anesthetic medication was combined with opioid, dissociative and benzodiazepine. The hen was induced into general anesthesia with isoflurane diluted in 100% oxygen via face mask, followed by intubation and venous access puncture in the left medial tibiotarsal vein. After which it was placed in the sternal decubitus position for anesthetic block via local spinal anesthesia. Anesthesia was maintained using a Baraka non-rebreathing gas system, with spontaneous and manual assisted ventilation. During the surgical period, heart rate, respiratory rate, peripheral oxygen saturation, temperature and carbon dioxide fraction at the end of expiration were monitored. After the end of the procedure, within 1 h, the patient began to respond to external stimuli and 1 h and 30 min after the end of the procedure, she was released for anesthetic discharge and sent to hospital, demonstrating the immediate anesthetic success of the procedure.

Discussion: Surgical removal of the oviduct and its appendages, as the ovary, was performed as indicated in the literature. The anesthetic team used drugs from the opioid, benzodiazepine and disociative classes as pre-anesthetic medication, which proved to be beneficial, since previous studies show that the combination brings analgesic comfort, muscle relaxation and sedation, reducing the need for inhaled anesthetics at the time of induction. Induction was carried out using an isoflurane mask diluted in 100% oxygen and lasted just 2 min, allowing the bird to be intubated and monitored using the multiparameter monitor. The anesthesiologist in charge performed a spinal neuroaxis block, an uncommon practice in birds, which contributes to blocking different nociceptive pathways in the trans-operative period. During the trans-surgical period, bradycardia was noted through monitoring, which was soon corrected through the intravenous application of atropine. There was a decrease in the bird's spontaneous ventilation in the final 35 min of the procedure, so the bird was ventilated manually until it returned to spontaneous ventilation, which may have been due to the inhaled anesthetic and the dorsal decubitus position, plus the weight of the surgical drapes. The bird was then sent to anesthetic recovery, where it was warmed up using a neonatal incubator and discharged from anesthesia after 1 h and 30 min. This result proved satisfactory for the team, who quickly directed the patient, which was the expectation of the anesthetic and surgical teams.

Keywords: egg retention, analgesia, domestic hen, chicken, bird, surgery.

Título: Anestesia multimodal em Gallus gallus domesticus para ovariohisterectomia terapêutica.

Descritores: retenção de ovos, galinha doméstica, ave, multimodal, anestesia.

Jejuno-Jejunal Intussusception in an Adult Creole Horse

2024-01-16T23:15:57-03:00

Background: Colic syndrome is a leading cause of death in horses. Anatomical peculiarities predispose horses to morphophysiological changes. Intussusception, an important cause of colic in foals, is uncommon in adult horses. It is characterized by the invagination of an intestinal segment into an adjacent aboral segment. Small intestinal intussusception is believed to develop because of abnormal intestinal peristalsis, causing acute and progressive abdominal discomfort. Herein, we aimed to report a rare case of intussusception of the jejuno-jejunal portion of the small intestine in a 10-year-old Criollo horse.

Case: A 10-year-old Crioulo horse, weighing 400 kg, was referred to the veterinary hospital with acute colic syndrome. On the property, the horse demonstrated signs of being in intense pain. A sudden feed change without a gradual transition was reported. The horse was treated with nonsteroidal anti-inflammatory drugs to relieve the pain, and a nasogastric tube was inserted. However, he continued to demonstrate signs of being in severe pain, and his condition was not stable. Therefore, he was referred to the hospital for further management. Upon arrival, a blood test was performed, which revealed a hematocrit below the reference value and a leukogram with numerous platelet clusters. On physical examination, the horse’s heart rate, respiratory rate, and rectal temperature were within normal limits, and the mucous membranes were pale. Transabdominal ultrasound revealed thick walls in the small intestinal segment and overlapping loops. To confirm the diagnosis, an exploratory laparotomy was performed with the horse in a dorsal decubitus position and under inhalation anesthesia. On inspection, the loops of the small intestine were congested and distended, and the intussusception was identified in the middle-to-distal 3rd of the jejunum. The origin of the invagination was located, and the intussusceptum was separated from the intussuscipien. Because of the injuries caused to the mucosa by strangulation, the affected intestinal portion was excised using the technique of intestinal wall reduction, resection, and anastomosis. The colon was washed and repositioned, and celiorrhaphy was performed on the 3rd postoperative day, an abdominal ultrasound was performed. It demonstrated normal intestinal flow, indicating that the surgical intervention had effectively corrected the condition and restored intestinal function.

Discussion: The diagnosis of intussusception was established on the basis of clinical signs, ultrasound findings, and macroscopic changes observed during a laparotomy. Jejunal intussusception is uncommon in adult horses, and it is more prevalent in young animals aged 6 months to 3 years. Although intussusception is uncommon in adult animals, its incidence in this age group cannot be underestimated because it can cause serious pathologies, requiring immediate diagnosis and surgical intervention to avoid irreversible damage. Abrupt changes in the diet may be an important predisposing factor, regardless of the animal’s age. Ultrasonography is a good diagnostic tool for intussusception, which appears as a characteristic “target lesion” or “bull’s eye.” Exploratory laparotomy is the most appropriate treatment choice, allowing confirmation of the diagnosis of intussusception and effective resolution of the symptoms.

Keywords: equine colic, exploratory laparotomy, ultrasonography.

Título: Intussuscepção jejuno-jejunal em cavalo adulto da raça Crioula

Descritores: laparotomia exploratória, síndrome cólica equina, ultrassonografia.

Septic Nonunion in Radius and Ulna in a Dog: Treatment with Orthogonal Plating Associated with Corticospongious Bone Autograft

2024-09-09T01:20:36-03:00

Background: A fracture stabilization strategy must be able to withstand the loads to which the bone will be subjected and be appropriate for the individual patient. Fractures of the radius and ulna are common in dogs; however, the incidence of complications is relatively high. Inadequate repair can result in complications. The treatment of long bone diaphyseal fracture-nonunion is challenging. While considering biological needs, a stable mechanical environment is pertinent for fracture healing. The aim of this study was to describe the treatment of a septic nonunion in the radius and ulna in a large breed dog which had suffered amputation of the contralateral forelimb through stabilization with orthogonal plating and the use of corticospongious bone autograft.

Case: A 5-year-old male mixed breed dog, weighing 47 kg, with amputation of the right forelimb had been previously treated for fracture of the left radius and ulna with external immobilization for several weeks. The patient was admitted to our veterinary service 120 days after the initial trauma without effective bone consolidation and refracture after minimal load. The septic nonunion in the left radius and ulna was successfully treated with a custom locked plate 4.5 mm thick on the cranial surface of the left radius, a 3.5 mm thick locked plate on the lateral surface of the left ulna and application of a corticospongious bone autograft from the left iliac crest. Satisfactory return to function and clinical union were achieved at 20 and 75 days postoperatively, respectively. After consolidation, dynamization was performed in 3 stages until complete removal of the implants. The treatment provided an early return of limb function, complete bone consolidation and a good prognosis for the dog.

Discussion: The healing of fractures of the radius and ulna can be problematic, and a poor choice of stabilization method can lead to complications such as delayed union, non-union, malunion and angular limb deformities. External immobilization proved to be the least effective technique in the treatment of diaphyseal fractures of the radius and ulna in dogs, even in larger breeds, when compared with the use of external skeletal fixators or plates and screws. The choice of external immobilization may explain the failure of the primary repair in this case. The patient only had this thoracic limb for support, which, in addition to a nonunion, also had osteomyelitis. Thus, rigid stabilization was necessary and, given the biological conditions presented, the use of autograft and antimicrobial treatment against bone infection were favorable for bone repair. Bone grafts have many functions, including improving the biological repair of skeletal defects and reducing time to healing in delayed unions and non-unions, as they stimulate early bridging callus formation. It is already known that to maximize the treatment against infection, bone vascularization in the focus must be present, in such a way, the use of autograft was again justified. Constructions with dual bone fixation (radial and ulnar) allow a significant increase in resistance to axial compression and caudocranial flexion when compared to the use of a radial plate alone and perform better under load-to-failure cycles than other constructions. The use of 2 plates in the present case was considered essential, due to the characteristics of the fracture and the patient. In this way, it was possible to achieve successful treatment by restoring limb functions, such as support and ambulation in a short period of time.

Keywords: bone plates, complications, dynamization, fracture healing, osteomyelitis.

Traumatic Lumbar Instability in a Red Fox (Vulpes vulpes): Evaluation of Pedicle Screw-Rod Fixation

2024-10-25T03:57:43-03:00

Background: Fox injuries can occur throughout the year. The primary causes of injuries include traffic accidents, entanglement in fences or wire mesh, trapping incidents, poisoning, self-inflicted injuries from mange irritation, and attacks by domestic animals or other foxes, particularly when weakened and partially helpless due to other circumstances. This case presentation delves into the clinical and radiographic findings, anesthesia applications, surgical procedures, and prognosis of a red fox (Vulpes vulpes) that suffered a lumbar vertebral fracture due to trauma. It stands as a pioneering study in the literature on this specific topic.

Case: An approximately 1-year-old female Red Fox (Vulpes vulpes) weighing 3.7 kg, presenting with hind limb paralysis. Clinical and neurological examination was conducted. Radiography and Computer Tomography imaging were performed. The neurological examination, radiological and computed tomography images confirmed a fracture in the corpus vertebra of L6. Pedicle screw-rod fixation was used to achieve stabilisation. Postoperative examinations revealed no complications. Remarkably, the fox was able to stand up on the first day post-operation and exhibited swift walking abilities. Improvement in the use of the right hind limb was noted, with the ability to exert pressure on the left hind limb. In conclusion, we posit that incorporating new data on Fox and similar species into the literature would prove advantageous for clinicians specializing in exotic animals. Furthermore, evaluating the outcomes of the pioneering Pedicle screw-rod fixation application in a fox and similar species contributes valuable insights to the existing knowledge in this field.

Discussion: As this case marks the inaugural investigation into lumbar vertebral fractures in the fox, a comprehensive analysis was undertaken, drawing references from existing canine and feline literature while there are existing studies in wolves. In the observed case, a fracture of the corpus of L6 was identified. L6 fractures can cause severe low back pain, hindering standing, and surgical stabilization is often indicated. Based on the literature review, although there are many techniques, but, a specific surgical technique for treating L6 fractures in dogs remains unclear. In this case, pedicle screw-rod fixation was employed, and good fixation was observed in the postoperative period. The biomechanical advantage of these dorsally applied fixation devices lies in their resistance to ventral bending forces associated with thoracolumbar sacrocaudal luxation since the implant is positioned on the tension side of the vertebral column, limiting flexion or extension. As far as we are aware, this study represents the first documentation of traumatic spinal injuries in foxes. Introducing new data on foxes and similar species to the literature can be valuable for clinicians working with exotic animals. Additionally, the assessment of results from the application of pedicle screw-rod fixation, a procedure performed for the 1st time in a fox and similar species, would contribute to the existing knowledge in this field. The use of pedicle screw-rod application is considered to be straightforward, less invasive, and has shown favorable outcomes in the postoperative period. It has the potential to promote neurological and motor function recovery following surgery.

Keywords: Patellar reflexes, pain test, sciatic reflexes, spinal fracture, luxation.

Canine Intestinal Pythiosis - Doppler Flowmetry

2024-07-27T13:21:57-03:00

Background: Pythiosis is a chronic pyogranulomatous infection of the gastrointestinal tract caused by the oomycete of the genus Pythium, which inhabits soil and aquatic environments. This disease has a global distribution, predominantly affecting horses, canines, and humans. In dogs, the gastrointestinal form is more prevalent than the cutaneous form. Pythiosis leads to thickening of the gastrointestinal wall and obliteration of its layers. Histopathologically, it is characterized by a pyogranulomatous inflammatory reaction with a marked eosinophilic component. Diagnosis can be confirmed through immunohistochemistry or other techniques, such as isolation and molecular evaluation. This study aims to report a case of canine gastrointestinal pythiosis, detailing the clinical, ultrasonographic, histopathological, and immunohistochemical findings.

Case: A 3-year-old male Pointer dog was presented to the Veterinary Hospital at the Federal University of Paraíba (UFPB), Areia, Brazil, with a one-month history of anorexia, vomiting, and progressive weight loss. On physical examination, a mass was palpated in the medial portion of the abdomen. Ultrasonography revealed thickening of the gastrointestinal wall, with areas showing both normal and obliterated layers. Vascularization was observed within the thickened wall via Color Doppler. Based on these findings, the dog underwent an exploratory celiotomy. Due to the extensive nature of the lesions and an unfavorable prognosis, euthanasia was performed. Macroscopic evaluation revealed wall thickening from the distal duodenum to the middle third of the jejunum, along with obliteration of the jejunal lumen layers and the presence of a large serosal mass (8 cm). Cytology demonstrated rare, uniform, linear, elongated, branched, and poorly septated hyphae within a pyogranulomatous and eosinophilic inflammatory reaction. Tissue samples were fixed in 10% formalin, routinely processed, embedded in paraffin, and stained with hematoxylin and eosin. Histopathological examination revealed multinucleated giant cells, macrophages, neutrophils, and numerous eosinophils extending from the mucosa to the serosa. Hyphae were observed in some areas, surrounded by eosinophilic and pyogranulomatous inflammation. Grocott methenamine silver staining showed positivity for branched and irregularly septated hyphae. In the immunohistochemical evaluation, positive staining confirmed the diagnosis of Pythium insidiosum infection.

Discussion: Gastrointestinal pythiosis typically presents with nonspecific clinical signs and should be considered a differential diagnosis in adult dogs with gastrointestinal disorders. This disease occurs in a significant percentage of canines in suburban areas, often without documented exposure to environments with water accumulation and high temperatures, as described in this case. The diagnosis of intestinal pythiosis in this report was based on a combination of clinical, epidemiological, ultrasonographic, microbiological, histopathological, and immunohistochemical findings. This case exhibited characteristics consistent with previous reports, but notably, the gastric wall was not involved. Due to the extensive lesions extending from the end of the duodenum to the middle third of the jejunum and the poor prognosis, euthanasia was elected. Consequently, the treatment typically recommended in the literature, which includes surgical resection combined with postoperative antifungal therapy, was not pursued.

Keywords: canine, intestine, pyogranulomas, ultrasound, stains.

Título: Pitiose intestinal em cão - Dopplerfluxometria

Descritores: canino, intestino, piogranulomas, ultrassom, colorações.

Insufficiency of the Cranial Cruciate Ligament, Medial Patellar Luxation and Proximal Valgus Deviation of the Tibia in a Dog - Treatment with Association of Modified TPLO and Double-cut Osteotomy

2024-08-04T10:58:37-03:00

Background: Cranial cruciate ligament insufficiency (CCLI) is one of the most common causes of lameness in dogs. This debilitating condition typically affects adult large-breed dogs. There is a subset of dogs where CCLI occurs alongside proximal tibial deformity (tibial varus or valgus), tibial torsion, excessive tibial plateau angle, or patellar luxation. A high frequency of reports notes patients with concomitant medial patellar luxation (MPL) and CCLI. The objective of this study is to report the use of combined modified TPLO and double cut medial crescentic closing wedge osteotomy techniques for the treatment of CCLI associated with MPL and proximal tibial valgus deformity in a bitch.

Case: A 4-year-old spayed bitch mixed-breed, weighing 9.5 kg, was presented at the Veterinary Hospital of the University (HV-UFLA), Lavras, Brazil, with a 30-day history of left pelvic limb (LPL) lameness. On physical examination, the patient exhibited functional disability with non-weight-bearing lameness of the LPL. Orthopedic examination of the stifle joint revealed CCLI by positive drawer and tibial compression tests. A meniscal click was also observed in the tibial compression test. Additionally, the patella could be medially luxated and was classified as grade 2. Radiographic examinations of the LPL were performed in different projections to identify radiographic findings suggestive of CCLI and to evaluate the angular deviations of the tibia and femur. Radiographic evaluation of the stifle joint revealed cranial displacement of the tibia relative to the femur, suggesting CCLI. The tibial plateau angle (TPA) was calculated and approximated to 29°. Radiographic examination of the tibia in the craniocaudal projection revealed proximal tibial valgus deformity, with an increased mechanical medial proximal tibial angle (mMPTA) of 101°. As a surgical technique for stabilizing the stifle joint with CCLI and correcting MPL and proximal tibial valgus deformity, the modified TPLO technique combined with a double cut medial crescentic closing wedge osteotomy was chosen. The surgical procedure began with medial arthrotomy in the stifle joint to assess the integrity of the menisci, revealing a bucket-handle tear in the caudal pole of the medial meniscus, which led to partial meniscectomy. Corrective ostectomies were then performed. To treat the proximal tibial valgus deformity, a crescent-shaped wedge ostectomy was performed with medial closing using a semicircular oscillating saw, aiming for a mMPTA of 93°. A caudal rotation and medial translation of the proximal tibial segment were then performed to realign the quadriceps extensor mechanism, stabilizing the patella in the femoral trochlear groove. The proximal tibial segment was rotated to achieve a target postoperative TPA of approximately 5°. The ostectomy was then stabilized with a TPLO locking plate. Immediate postoperative radiographs were taken to evaluate implant positioning and measure the angles achieved. A TPA of 5° and a mMPTA of 91° were achieved. At the 1-week postoperative follow-up, significant improvement in lameness was already observed, with partial weight-bearing of the operated limb.

Discussion: The results of this case demonstrate that the combination of modified TPLO and a double cut medial crescentic closing wedge osteotomy techniques performed in a single surgical procedure was effective in treating CCLI, proximal tibial valgus deformity, and MPL in a bitch. This approach appears to be a viable option for patients with these comorbidities in the stifle joint.

Keywords: dog, tibial osteotomies, tibial plateau, angular bone deformity, small animals, orthopedics.

Título: Insuficiência do ligamento cruzado cranial, luxação medial de patela e desvio valgo proximal da tíbia em uma cadela - tratamento com associação de TPLO modificada e de osteotomia duplo corte

Descritores: cão, osteotomias tibiais, platô tibial, deformidade angular óssea, pequenos animais, ortopedia.

Parathyroid Neuroendocrine Tumor Located in the Trachea of one Bitch

2024-06-09T21:52:56-03:00

Background: Neuroendocrine tumors make up a family of neoplasms that can be found in different tissues and organs, including those that do not usually contain neuroendocrine cells. These tumors are diagnosed based on histopathological examination and the presence of neuroendocrine markers in the immunohistochemical examination, including neuron-specific enolase (NSE), chromogranin A and synaptophysin. This paper describes the occurrence of a parathyroid neuroendocrine tumor located in the lumen of the trachea of one bitch, and characterizes its clinical evolution.

Case: A 10-year-old bitch of Siberian Husky breed, suffering for a week from reported symptoms of coughing and dyspnea, was treated at the private Veterinary Hospital Petmania, São Luís, MA, Brazil. After a clinical evaluation, additional tests were requested, including a chest X-ray, complete blood count, assessment of renal (urea, creatinine) and liver function (albumin, ALT, AST, alkaline phosphatase), and abdominal ultrasound, all of which fell within the normal limits. The chest X-ray revealed a 2.1 cm x 1.2 cm formation in the region of the thoracic trachea. An electrocardiogram was performed, but revealed no changes. The patient underwent a tracheoscopy for excisional biopsy of the mass, using a polyp forceps. The biopsy material was subjected to histopathological and immunohistochemical analysis, which confirmed that it was a parathyroid neuroendocrine tumor containing immunoreactive neuron-specific enolase and calcitonin. A chest tomography was requested, but was not performed. After a parathyroid neuroendocrine tumor was diagnosed, additional complementary tests were carried out to examine changes in the thyroid and parathyroid, which included measurement of ionized calcium, post-dialysis free T4, total T4, sodium, chlorine, potassium and cervical ultrasound. These tests indicated mild hypercalcemia and hyponatremia. The patient was monitored clinically for 30 days, after which the symptoms of dyspnea and cough returned. The patient was subjected to tracheoscopy, which revealed a new tumor growth in the same location. Soon thereafter, the patient died.

Discussion: Parathyroid neuroendocrine tumors are rare in dogs, and no reports were found of this type of neoplasm located in the trachea. The patient in this case report presented a mass in the intraluminal portion of the thoracic trachea, which led to the manifestation of respiratory obstruction. Neuroendocrine tumors may develop in tissues that do not contain neuroendocrine cells, such as the trachea. Furthermore, malignant neoplasms have the characteristic of inducing the dissemination of tumor cells that can implant themselves in other tissues, although no neoplastic lesion was found other than in the trachea in the patient of this case report. The treatment of tracheal neoplasms involves surgical resection and tracheal anastomosis. However, this is a complex surgical procedure, especially if it involves the intrathoracic trachea. In this patient, no surgical treatment was performed due to the rapid evolution of the disease and the lack of tomographic diagnosis for adequate surgical planning. Neuroendocrine tumors, albeit rare, have been described before in different anatomical locations in dogs. It is concluded that the neuroendocrine tumor of the patient in this case demonstrated an aggressive evolution with a poor prognosis and low survival rate after diagnosis.

Keywords: tracheal tumors, neuron-specific enolase, calcitonin.

Título: Tumor neuroendócrino de paratireóide localizado na traqueia de uma cadela

Descritores: tumor traqueal, neuro enolase específica, calcitonina.

Arrhythmogenic Right Ventricular Cardiomyopathy in English Bulldog with Brachycephalic Obstructive Airway Syndrome (BOAS)

2024-08-24T16:33:26-03:00

Background: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a hereditary disorder where right ventricular cardiomyocytes are replaced by fibrofatty tissue, disrupting myocardial electrical continuity. Causes may include mutations in the striatin gene or cardiac ryanodine receptor gene. Brachycephalic Obstructive Airway Syndrome (BOAS) involves congenital abnormalities in brachycephalic dogs, such as stenotic nares and elongated soft palate, which can lead to right-sided cardiac remodeling and heart failure. This report aimed to present a case of category III ARVC in an English Bulldog with BOAS.

Case: A 9-year-old male English Bulldog, presented with episodes of syncope, postprandial cyanosis, and respiratory difficulty. The dog exhibited severe stenosis of the nares, characteristic of BOAS, along with signs of heart failure. Physical and complementary exams revealed chronic respiratory acidosis, hyponatremia, hypochloremia, and anemia. Echocardiography indicated significant remodeling of the cardiac chambers, particularly in the right ventricle, with tricuspid and pulmonary valve insufficiency, suggesting ARVC. Myocardial biopsy could not be performed. The electrocardiogram showed sinus tachycardia and other irregularities. Thoracic radiographs revealed cardiomegaly and signs of congestive heart failure (CHF). Analysis of abdominal transudate revealed significant peritoneal effusion. The dog succumbed 1 month after initial presentation, without a definitive ante mortem diagnosis and without authorization for necropsy.

Discussion: The definitive diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC) is made through myocardial biopsy, a procedure often performed post mortem due to its difficulty in living animals. ARVC presents in 3 clinical forms: Category I is asymptomatic with few arrhythmias; Category II involves syncope and easy fatigue with monomorphic extrasystoles; and Category III, which is rare, includes signs of congestive heart failure (CHF), ventricular tachyarrhythmias, and occasionally atrial fibrillation. In English Bulldogs, ARVC is more likely to cause supraventricular arrhythmias. This breed often shows CHF signs such as edema and syncope, with a high prevalence of arrhythmias and CHF symptoms. Most ARVC cases have normal left ventricular function, but any deviations can significantly impact survival. Echocardiography typically reveals right heart chamber enlargement and tricuspid valve insufficiency. Conventional ECG detects premature ventricular complexes but may miss some arrhythmias, making Holter monitoring a better tool for long-term assessment. Thoracic radiography may show cardiomegaly and CHF signs, while abdominal imaging can reveal effusion indicating right-sided CHF. Although definitive diagnosis usually requires myocardial biopsy, complementary tests and clinical findings in this case suggest Category III ARVC. Treatment involves managing arrhythmias with antiarrhythmics like sotalol or mexiletine and addressing any CHF with standard protocols. Prognosis varies based on disease presentation, with a generally reserved to unfavorable outlook due to risks of sudden death or worsening heart function. This case underscores the complexity of diagnosing and managing ARVC in brachycephalic dogs with BOAS. Early and accurate identification of these conditions is crucial for effective interventions, although achieving a definitive in vivo diagnosis remains challenging. The case highlights the necessity for continuous monitoring and a multidisciplinary approach in managing dogs with multiple cardiac and respiratory comorbidities.

Keywords: cardiac remodeling, congestive heart failure, cyanosis, echocardiography, electrocardiogram, peritoneal effusion.

Fungal Discospondylitis in a White Swiss Shepherd Bitch Caused by Aspergillus sp.

2024-08-19T20:21:05-03:00

Background: Several infectious agents can cause discospondylitis, primarily due to hematogenous dissemination, with bacterial infection being the most common. Fungal discospondylitis is rare and can result from infection by various agents, including Aspergillus spp. Disseminated aspergillosis, which may cause discospondylitis, is more prevalent in German Shepherd dogs, possibly due to genetic defects in cellular and humoral immune responses. Given the rarity of this condition, the aim of this report is to describe a case of fungal discospondylitis in a young White Swiss Shepherd bitch caused by Aspergillus sp.

Case: A 1-and-a-half-year-old White Swiss Shepherd bitch was presented with a history of acute-onset paraparesis that progressed to paraplegia. Neurological examination revealed grade IV thoracolumbar syndrome, characterized by paraplegia with loss of superficial sensation in the pelvic limbs, absence of the cutaneous trunk reflex caudal to the 6th thoracic vertebra, and pain on manual palpation of the spine at T4/T5/T6. Radiographs of the thoracic spine were performed, but the results were inconclusive, leading to referral for computed tomography (CT). CT revealed lytic areas in the T4-T5 vertebral bodies and a presence of an amorphous structure with soft tissue density in the extradural space at T4/T5, causing spinal cord compression, consistent with a diagnosis of discospondylitis. Abdominal ultrasound and urine culture were conducted to investigate the primary source of infection, but the results were inconclusive. The patient's condition deteriorated despite antibiotic therapy, leading to cerebrospinal fluid analysis and hemilaminectomy for spinal cord decompression and collection of disc material between T4/T5 for fungal and bacterial culture. The fungal culture of the granuloma and disc material was positive for Aspergillus sp. Consequently, antibiotic therapy was discontinued, and treatment with itraconazole was started. Two months after starting antifungal treatment, there was no improvement in the neurological and clinical condition, and the patient was euthanized.

Discussion: Most reports of aspergillosis in dogs in Brazil involve the respiratory tract; therefore, the case described in this study is likely the 1st report of fungal discospondylitis caused by Aspergillus sp. in a canine in the country. German Shepherd dogs and their variations, such as the White Swiss Shepherd, may be more susceptible to fungal infection by Aspergillus spp. due to an inherited immunological defect related to lower levels of immunoglobulin A. Discospondylitis can be diagnosed by radiographic examination; however, in this patient, no endplate lysis or bone proliferation was observed, which could occur in the early stages of the disease, as radiographic changes can take 2 to 6 weeks to appear. Therefore, advanced imaging, such as computed tomography, was necessary. Given that bacterial discospondylitis is much more common than fungal infection, antibiotic therapy was initiated, but without improvement in the condition, leading to the collection of disc material for microbiological analysis. Hence, it is important to include fungal discospondylitis and disseminated aspergillosis in the differential diagnosis for German Shepherd dogs and their variations with rapidly progressive spinal syndromes that do not respond to antibacterial treatment.

Keywords: canine, mycose, aspergillosis, Aspergillus spp., discoespondylites, White Swiss Shepherd.

Título: Discoespondilite fúngica em uma cadela Pastor Suíço Branco causada por Aspergillus sp.

Descritores: canino, micose, aspergilose, Aspergillus spp., discoespondilite, Pastor Branco Suíço.

Colitis and Proctitis Caused by Pythium insidiosum in a Dog

2024-07-07T16:52:11-03:00

Background: Gastrointestinal pythiosis, caused by Pythium insidiosum, is a severe and underdiagnosed disease in dogs, posing significant diagnostic and treatment challenges. Brazil ranks 2nd globally in reported pythiosis cases, with 29 cases occurring in dogs, which exhibited the highest fatality rate among reported cases in the country, with most showing gastrointestinal involvement. Understanding this condition’s epidemiology and diagnostic intricacies is crucial for improving management strategies and outcomes in affected animals. We aimed to elucidate the clinical presentation, diagnostic findings, and outcomes of a gastrointestinal pythiosis case in a young dog from Mossoró, Brazil.

Case: A 1-year-and-1-month-old, 20 kg male mixed-breed dog presented with gastrointestinal symptoms (vomiting, diarrhea, hematochezia, and weight loss) following the rainy season in Mossoró, Brazil. The dog, which had access to a balcony and brick-paved yard, had no direct rain exposure but fell ill shortly after the rainy period. Initial veterinary examination revealed eosinophilia (3,432 eosinophils/mm³), suggesting bacterial or parasitic gastroenteritis. Treatment included deworming, enrofloxacin, and multivitamins, leading to initial improvement. However, symptoms recurred, and 5 months later, the dog exhibited worsened symptoms, including significant weight loss (from 20 kg to 13 kg) and increased eosinophilia (4,224 eosinophils/mm³), prompting further evaluation. Abdominal ultrasonography indicated thickened colon walls (0.99 cm), loss of wall stratification, and a suspected neoplasm (4.25 cm × 2.90 cm). Exploratory laparotomy revealed extensive intestinal adhesions and hypervascularization, leading to euthanasia due to poor prognosis. Necropsy revealed whitish necrotic areas in the colon and rectum with enlarged lymph nodes showing necrotic foci. Histopathological examination confirmed transmural pyogranulomatous inflammation with fibrous tissue proliferation and infiltrating macrophages, plasma cells, eosinophils, and neutrophils. Multinucleated giant cells surrounded caseous necrotic areas containing intralesional fungal hyphae (4–10 μm in diameter, irregular branching). Grocott-Gomori's methenamine silver (GMS) staining highlighted these hyphae, with strong immunostaining for P. insidiosum using immunohistochemistry.

Discussion: This report describes a case of colitis, proctitis, and lymphadenitis in a young mixed-breed dog from Rio Grande do Norte's semi-arid region, caused by P. insidiosum infection confirmed via immunohistochemistry. Post mortem diagnosis, following exploratory laparotomy, revealed advanced intestinal involvement that precluded surgical resection, highlighting the critical need for early diagnosis to improve prognosis. A previous case in the same region involved anal mucocutaneous junction lesions treated with itraconazole and terbinafine. In this present case, clinical signs including vomiting, diarrhea, hematochezia, and weight loss initially suggested parasitic gastroenteritis. Histopathological analysis confirmed pyogranulomatous inflammation with eosinophilic infiltrates and necrotic areas indicative of P. insidiosum hyphae, visualized with GMS staining. Immunohistochemistry confirmed P. insidiosum involvement, which was essential for a definitive diagnosis. This case highlights the diagnostic complexities and severe outcomes of gastrointestinal pythiosis in dogs, emphasizing the need for early detection and precise management to improve treatment outcomes in affected animals.

Keywords: fungal-like infection, gastrointestinal infection, histopathology, immunohistochemistry, oomycetes, pythiosis.

Partial Limb Amputation and Successful Prosthetic Adaptation in a Thoroughbred Mare

2024-07-30T10:26:03-03:00

Background: Traditionally, severe limb injuries in horses often result in euthanasia. However, advancements in veterinary medicine allow for the treatment and rehabilitation of many of these injuries. Partial limb amputation, combined with the use of prosthetics, can offer a viable alternative to euthanasia, providing the animal with a good quality of life. Studies indicate that mares and stallions have continued to reproduce after partial limb amputation. This approach, however, requires intensive postoperative care and significant lifelong investment. This case report aims to describe a case of a mare that underwent amputation and prosthetic device placement in the left thoracic limb.

Case: A 7-year-old Thoroughbred mare, weighing 370 kg, was referred to the Veterinary Hospital (HV) of the Federal University of Paraná (UFPR) in Curitiba, Paraná, Brazil with a 3-year history of complete contracture of the left thoracic limb at the fetlock, along with a wound in the carpal region with granulation tissue. Radiographs revealed subluxation, hyperextension, and bone proliferation of the lateral sesamoid bones and phalanges, along with ligament involvement. After confirming the need for surgery, partial amputation of the left thoracic limb at the metacarpal level was performed, followed by the adaptation of a prosthesis. The amputation involved the sectioning of vessels, nerves, and tendons, while the prosthesis was made of synthetic plaster, aluminum, and vulcanized rubber. During the 1st week of dressing changes, the stump wound was cleaned daily with potassium permanganate, and the dressing was changed. The patient adapted well to the prosthesis, moving without assistance after 10 days. After 2 months of the prosthesis placement, the patient was able to lie down and get up without assistance.

Discussion: Partial limb amputation and the adaptation of prosthetic devices could save animals that would otherwise be euthanized due to severe limb injuries. There are few reports in the literature on equine amputations, with some reported causes being chronic septic joints, osteomyelitis, and comminuted open fractures. Partial limb amputation and prosthetic adaptation should be discussed with owners, considering the high complication rates and the quality of life for these horses. One of the main issues related to amputation is the failure of stump healing, especially if infection was present before surgery. Another problem is laminitis in the contralateral limb, due to the excessive weight supported by this limb. Patients with prolonged problems before amputation and those who do not adapt well to the prosthesis are more prone to developing rotation of the 3rd phalanx in the opposite limb. The main complications include severe flexor tendinitis in the early postoperative days and, at 6 months, signs of arthritis and exostosis in the metacarpophalangeal joint. Despite the complications, complete healing can occur between 6 months to a year. Removing hair in the lesion area reduces surface contamination during healing, and antimicrobial or antiseptic agents can be used to facilitate the process. Completely replacing a horse's limb with an equally versatile device is still not possible, but the idea is to approximate the limb's mechanics. Equine prostheses are made of carbon fiber, fiberglass, stainless steel, and various types of polypropylene. The new generation of prosthetic devices in horses includes a shock absorption mechanism, which helps reduce pressure on the stump. In the present case report, the base made of vulcanized rubber provided this impact absorption. The need for antimicrobial therapy should be justified before starting, as antibiotics may not be necessary for all wounds. In conclusion, despite high complication rates and chronic treatment needs, amputation can be a viable alternative, particularly for distal limb regions, improving the horse's quality of life.

Keywords: horse, partial limb amputation, prosthesis, rehabilitation.

Título: Amputação parcial de membro e adaptação protética em uma égua Puro-Sangue Inglês

Descritores: equino, amputação parcial de membro, prótese, reabilitação.

Management of Recurrent Skin Dehiscence by Subcutaneous Ureteral Bypass Shunting Port in a Bitch - Efficacy of Doxycycline

2024-08-04T12:21:52-03:00

Background: Ureteral obstruction compromises renal function depending on duration, requiring immediate evaluation and renal decompression. Less invasive interventional techniques increasingly supplement traditional surgical treatments. In dogs, double pigtail ureteral stents are commonly used; however, subcutaneous ureteral bypass devices should be treatment options when stents fail due to complications. Doxycycline, a tetracycline antibiotic, has been shown to have anti-inflammatory and immunomodulatory properties by various mechanisms. This report demonstrates the efficacy of doxycycline for managing recurrent skin dehiscence caused by a local immune response to a SUB shunting port in a bitch.

Case: A 10-year-old spayed bitch toy poodle weighing 4.1 kg, was referred for recurrent skin dehiscence at the SUB shunting port placement site. The bitch had been diagnosed with right ureteral obstruction caused by a ureteral calculus 15 months ago, and unilateral SUB placement had been performed. The animal underwent 3 reconstructive surgeries with broad-spectrum antibiotics treatment at the local animal hospital. Despite these interventions, skin dehiscence recurred at the SUB shunting port placement site. On presentation, the shunting port was exposed on the right side of the midline, with a mild exudate around the port. Cytology examination and bacterial culture were negative for infection. Laboratory tests revealed elevated blood urea nitrogen, alkaline phosphatase, C-reactive protein, and monocytosis. Diagnostic imaging showed severely irregular margins of both kidneys, bilateral renal and right ureteral calculi, with the SUB device correctly placed and no evidence of fluid leakage or displacement. Based on the patient’s history and these findings, the skin dehiscence was determined to be caused by a local immune response. Treatment with doxycycline, known for its anti-inflammatory and immunomodulatory effects, was selected. SUB replacement with skin debridement was performed under general anesthesia, and doxycycline was administered orally for 4 weeks. At the 3-week post-surgery follow-up, the skin had completely healed, demonstrating the successful treatment outcome. At 3 months post-surgery, no complications were observed, and the overall condition remained stable.

Discussion: To our knowledge, this is the 1st report of recurrent skin dehiscence caused by a subcutaneous ureteral bypass shunting port. The implantation of medical devices triggers a complex signaling cascade with the host’s immune system, resulting in foreign body reactions. The lack of response to previous antibiotic treatments at the local animal hospital, the absence of bacterial infection evidence, and the clinical improvement with doxycycline suggest that the immune and inflammatory response to the medical device was modulated through mechanisms such as matrix metalloproteinase inhibition, decreased pro-inflammatory cytokine levels, and reduced reactive oxygen species. Although these complications with subcutaneous ureteral bypass devices are rare, immune responses should be considered in cases of poor response to treatments. These foreign body reactions are highly complex, and their mechanisms are not fully understood, making diagnosis and treatment challenging. Since the limited therapeutic options available to mitigate these responses with minimal adverse effects, doxycycline presents a viable alternative for managing complications associated with medical devices in dogs.

Keywords: canine, dog, ureteral obstruction, subcutaneous ureteral bypass, skin dehiscence, doxycycline, immunomodulatory agent.