Prevalence of portal vein and splanchnic venous thrombosis in dogs with chronic hepatitis.

OBJECTIVES: Alterations in haemostasis have been described in dogs and humans with chronic hepatitis. Portal vein thrombosis is a recognised complication of chronic hepatitis in humans; however, its prevalence in dogs with chronic hepatitis has not been reported. We aimed to estimate the prevalence of, and describe clinical and laboratory data of dogs with chronic hepatitis and portal vein thrombosis and splanchnic venous thrombosis. MATERIALS AND METHODS: Retrospective cross-sectional study. Medical records of dogs admitted to a veterinary teaching hospital between 2009 and 2019 were reviewed. Dogs were included if chronic hepatitis was histopathologically confirmed, and if diagnostic imaging or necropsy indicated the presence of thrombosis. Clinical and laboratory data (i.e. haematology, biochemistry, coagulation panels) were recorded. Descriptive statistics were used to characterise dogs with and without thrombosis. RESULTS: Records from 136 dogs with chronic hepatitis were identified. Three of these dogs, 2.2% (95% confidence interval: 0.8 to 6.3%) all females, were diagnosed with portal vein thrombosis. Five dogs in total, (3.7%; 95% confidence interval: 1.6 to 8.3%), including three with portal vein thrombosis, all females, were diagnosed with splanchnic venous thrombosis. Dogs with portal vein and splanchnic venous thrombosis often had hyperbilirubinaemia, increased serum gamma-glutamyl transferase activity, and decreased plasma antithrombin 3 activity. They also had relatively high alternative Child-Pugh scores for dogs (median 6 out of 13). CLINICAL SIGNIFICANCE: Portal vein and splanchnic venous thrombosis are potentially serious complications that were identified in a relatively low proportion of dogs with chronic hepatitis.

Treatment of portal vein thrombosis using vascular access port implantation in a Dalmatian dog: A case report.

Background: Portal vein thrombosis is a disease with potentially deleterious outcomes including portal vein hypertension and intestinal infarction. The factors contributing is various; however, dogs with with acute portal vein thrombosis or multiple thromboses are less likely to survive. Therefore, acute development of portal hypertension has a requires an immediate treatment. Case Description: A 10-year-old Dalmatian was referred for syncope and azotemia, hyperammonemia. After each examinations including computed tomography scan, we diagnosed with acute portal vein thrombosis with unknown cause. A portal vein port was inserted to prevent and control the portal vein thrombus. The port was placed in abdomen subcutaneously after the position of the catheter were stabilized. Low-molecular-weight heparin was injected from the port to manage thrombosis after the operation. This case responded well to this treatment. Syncope and azotemia, hyperammonemia resolved and no relapse of thrombosis was found 6 months after the operation. Conclusion: Implantable vascular access port is a drug delivery system with the advantage of dealing with treatment-resistant acute portal vein thrombosis.

2022 Update of the Consensus on the Rational Use of Antithrombotics and Thrombolytics in Veterinary Critical Care (CURATIVE) Domain 6: Defining rational use of thrombolytics.

OBJECTIVES: To systematically review available evidence and establish guidelines related to the use of thrombolytics for the management of small animals with suspected or confirmed thrombosis. DESIGN: PICO (Population, Intervention, Control, and Outcome) questions were formulated, and worksheets completed as part of a standardized and systematic literature evaluation. The population of interest included dogs and cats (considered separately) and arterial and venous thrombosis. The interventions assessed were the use of thrombolytics, compared to no thrombolytics, with or without anticoagulants or antiplatelet agents. Specific protocols for recombinant tissue plasminogen activator were also evaluated. Outcomes assessed included efficacy and safety. Relevant articles were categorized according to level of evidence, quality, and as to whether they supported, were neutral to, or opposed the PICO questions. Conclusions from the PICO worksheets were used to draft guidelines, which were subsequently refined via Delphi surveys undertaken by the Consensus on the Rational Use of Antithrombotics and Thrombolytics in Veterinary Critical Care (CURATIVE) working group. RESULTS: Fourteen PICO questions were developed, generating 14 guidelines. The majority of the literature addressing the PICO questions in dogs is experimental studies (level of evidence 3), thus providing insufficient evidence to determine if thrombolysis improves patient-centered outcomes. In cats, literature was more limited and often neutral to the PICO questions, precluding strong evidence-based recommendations for thrombolytic use. Rather, for both species, suggestions are made regarding considerations for when thrombolytic drugs may be considered, the combination of thrombolytics with anticoagulant or antiplatelet drugs, and the choice of thrombolytic agent. CONCLUSIONS: Substantial additional research is needed to address the role of thrombolytics for the treatment of arterial and venous thrombosis in dogs and cats. Clinical trials with patient-centered outcomes will be most valuable for addressing knowledge gaps in the field.

Long-term follow-up of portal vein thrombosis in an American Cocker Spaniel with lobular dissecting hepatitis: a case report.

BACKGROUND: Lobular dissecting hepatitis (LDH) is a rare form of canine liver cirrhosis that may be accompanied by portal hypertension in American Cocker Spaniels. In human patients with liver cirrhosis, portal vein thrombosis (PVT) is a common complication. However, PVT has not been reported in dogs with LDH. Herein, we describe the long-term follow-up of PVT in an American Cocker Spaniel with LDH. CASE PRESENTATION: An 8-year-old neutered male American Cocker Spaniel presented with a 1-month history of severe abdominal effusion. The dog was histopathologically diagnosed with LDH and treated with low-dose prednisolone on day 14. On day 115, computed tomography angiography (CTA) confirmed the presence of a thrombus in the portal vein. Therefore, the dog was subcutaneously administered with the anticoagulant dalteparin, and low-dose prednisolone was continued. As a follow-up for PVT, CTA examinations were performed on days 207, 515, 886, and 1168, and the dog's antithrombin and D-dimer levels were measured. Following anticoagulant therapy, the dog was confirmed to have gradually increased antithrombin activity and decreased D-dimer concentrations. In addition, although the thrombus was confirmed to be in the same area of the portal vein system by CTA, atrophy and increased CT values due to organization were observed during the follow-up period. The dog's condition remained stable without clinical signs until day 1112 when it developed hepatic encephalopathy. The dog died on day 1208. On postmortem examination, histopathologically, the liver showed marked bile duct hyperplasia and fibrosis with chronic thrombus in the portal vein. CONCLUSIONS: This case demonstrated that low-dose glucocorticoid combined with dalteparin allowed long-term follow-up of PVT in an American Cocker Spaniel with LDH.

MANAGEMENT OF MEDICAL COMPLICATIONS ASSOCIATED WITH A PRESUMED TETANUS INFECTION IN A NORTHWEST BORNEAN ORANGUTAN (PONGO PYGMAEUS PYGMAEUS).

An 18-yr-old female orangutan (Pongo pygmaeus pygmaeus) developed opisthotonus after sustaining conspecific bite wounds 3 wk earlier. The orangutan developed progressive tetraparesis and dysphagia, despite normal mentation, suggestive of tetanus. A tetanus vaccine had been administered at 2 yr of age, but none since. Brain magnetic resonance imaging, computed tomography, cerebral spinal fluid tap, and bloodwork were unremarkable. Viral, Baylisascaris, and tetanus toxin testing were negative. A femoral central venous catheter (CVC) was placed to provide medications, fluids, and parenteral nutrition. The orangutan received human tetanus immunoglobulin, tetanus toxoid, penicillin, methocarbamol, and analgesia. After 1 wk, the catheterized limb became edematous; a deep vein thrombosis (DVT) was diagnosed ultrasonographically. A cephalic CVC was placed, the limb casted, intravenous therapy reinitiated, and enoxaparin started. The orangutan became mobile days later, and progressively improved. Despite no compliance with enoxaparin, the DVT resolved without residual signs. This is the first reported case of presumptive tetanus and DVT in a great ape.

Successful management of portal vein thrombosis in a Yorkshire Terrier with protein-losing enteropathy.

BACKGROUND: Portal vein thrombosis (PVT) is a rare presentation in dogs with protein-losing enteropathy (PLE). Rivaroxaban, an oral, selective, direct factor Xa inhibitor, has not been reported to be administrated for canine PVT and the effect is unclear in dogs with PLE. CASE PRESENTATION: An 11-year-old Yorkshire Terrier presented with moderate ascites. The dog had severe hypoalbuminemia (1.2 g/dL), and a portal vein thrombus was confirmed on computed tomographic angiography (CTA). On endoscopic examination, it became apparent that the hypoalbuminemia was caused by PLE, which was consequent of lymphatic dilation and lymphoplasmacytic enteritis. Therefore, the dog was initially treated with oral administrations of spironolactone and clopidogrel, with dietary fat restriction. However, a follow-up CTA showed no changes in the ascites, thrombus, and portal vein to aorta (PV/Ao) ratio. Therefore, the dog was additionally prescribed rivaroxaban and low-dose prednisolone for the portal vein thrombus and hypoalbuminemia due to lymphoplasmacytic enteritis, respectively. Following the treatment, the PV/Ao ratio decreased because of a decrease in the thrombus and the ascites disappeared completely with an elevation of albumin concentration (1.9 g/dL). CONCLUSIONS: This case report demonstrated that oral administration of rivaroxaban combined with low-dose glucocorticoid was effective management for PVT in a dog with PLE.

Use of Thromboelastography in Clinical Practice.

Viscoelastic testing, such as thromboelastography or thromboelastometry, is performed on whole-blood samples, which include both soluble plasma factors as well as blood cells and platelets bearing tissue factor and phospholipid. This methodology allows identification of fibrinolysis and can provide analysis of platelet function. Viscoelastic testing has become increasingly accessible and popular in emergency and critical care settings in recent years and can provide important information for the diagnosis and management of patients with hemostatic disorders. This article discusses the principles and interpretation of viscoelastic testing, application to small animal emergency and critical care medicine, and potential advantages and disadvantages.

The Use of Antithrombotics in Critical Illness.

Hypercoagulable tendencies may develop in critically ill dogs and to a less known extent, cats. Although the use of antithrombotics is well-established in critically ill people, the indications and approach are far less well-known in dogs and cats. The goal of this article was to review the relevant CURATIVE guidelines, as well as other sources, and to provide recommendations for critically ill patients with directions for future investigation.

A case of acute splenic vein thrombosis in a dog.

An 11-year-old, castrated male, Yorkshire Terrier was presented with acute vomiting after chicken bone ingestion. The dog had been diagnosed with hyperadrenocorticism previously and showed acute splenomegaly and signs of systemic inflammatory response syndrome during hospitalization. On diagnostic imaging, acute splenic vein thrombosis was found, concurrent with pancreatitis and gastritis. The spleen showed marked enlargement and hypoechoic lacy appearances on ultrasonography, mimicking splenic torsion. On the histopathologic report, only splenic hemorrhage and congestion with large splenic vein thrombosis were identified. After splenectomy, the dog completely recovered and was discharged.

Vascular injury in spontaneous subacute toxicosis caused by organic arsenic in cattle / Injúria vascular na toxicose subaguda espontânea causada por arsênio orgânico em bovinos

Monosodium methanearsonate (MSMA) is an organic form of arsenic present in the formulations of some herbicides. Accidental ingestion of pasture contaminated with arsenic may lead to toxicosis in cattle. Almost 200 head of cattle maintained in an area sprayed with MSMA presented with intense diarrhea and dehydration after grazing. Subsequently, 16 of these animals died. Toxic levels of arsenic (>1.5µg/g) were detected in the kidney, liver, urine, and skeletal muscle of 6 animals. At gross inspection were observed multifocal to coalescent ulcers in the mucosa from on the forestomachs associated with hemorrhagic areas and marked wall edema. Microscopic examination mainly showed fibrinoid necrosis of vessels with multifocal thrombosis associated with ischemic infarction that were characterized by large transmural necrotic areas in the forestomachs. The clinical and pathological changes interestingly showed that this form of arsenic although considered less toxic, has caused severe vascular injury in forestomachs of cattle.(AU)

Metano-arseniato ácido monossódico (MSMA) é uma forma orgânica de arsênio, presente nas formulações de alguns herbicidas. A ingestão acidental de pasto contaminado por arsênio pode levar a toxicose em bovinos. Aproximadamente 200 bovinos que estavam em uma pastagem pulverizada com MSMA manifestaram intensa diarreia e desidratação após o pastejo. Subsequentemente, 16 animais morreram. Níveis tóxicos de arsênio (>1.5µg/g) foram detectados no rim, fígado, urina e músculo esquelético de 6 animais. A inspeção macroscópica revelou úlceras multifocais a coalescentes na mucosa de pré-estômagos, adjacentes a focos de hemorragia e intenso edema de parede. A avaliação microscópica revelou, predominantemente, necrose fibrinoide de vasos com trombose multifocal associada a infarto, caracterizado por grandes áreas de necrose transmural em pré-estômagos. As alterações clínicas e patológicas, interessantemente, demonstraram que esta forma de arsênio, apesar de ser considerada menos tóxica, causou severa injúria vascular em pré-estômagos de bovinos.(AU)

Histiocytic Sarcoma and Bilateral Facial Vein Thrombosis in a Siberian Hamster (Phodopus sungorus).

A 21-mo-old, male Siberian hamster (Phodopus sungorus) presented with left-sided facial swelling, proptosis of the left eye, and blepharospasm of the right eye. The hamster had been used only for breeding. Because of the poor prognosis, the hamster was euthanized without additional diagnostic assays or treatments. Routine gross pathologic evaluation demonstrated exophthalmos and presumptive hyphema of the left eye, bilateral facial edema, freely movable nodules within the mesentery, white foci within the liver, and a large mass effacing the cranial pole of the right kidney. On histologic evaluation, the mesenteric nodules and liver foci expressed histiocytic marker CD163 and thus were diagnosed as sites of histiocytic sarcoma, whereas the kidney mass was a well-differentiated renal cell carcinoma. The facial swelling resulted from bilateral, chronic, severe, branching thrombi in many facial veins. Additional age-related histopathologic findings were observed in other organs, including diffuse glomerulopathy, nesidioblastosis (pancreatic islet neoformation), and multiple foci of severe cartilage degeneration in the axial skeleton. To our knowledge, this report provides the first description of histiocytic sarcoma in a Siberian hamster.

Avaliação do efeito trombogênico da perfusão regional intravenosa com gentamicina em equinos / Evaluation of intravenous regional perfusion thrombogenic effect with gentamicin in equine

A extremidade distal dos equinos é frequentemente afetada por processos sépticos de difícil tratamento. A perfusão regional intravenosa de antimicrobianos é uma opção de tratamento para esses processos, pois aumenta a concentração do fármaco no local mediante pequenas doses. Entretanto, apesar de ser muito utilizada recentemente, ainda apresenta várias questões. O objetivo deste trabalho foi avaliar as possíveis complicações da técnica, com o uso da gentamicina na dose de 2,2mg/kg na veia cefálica de equinos. Utilizaram-se 15 equinos hígidos divididos aleatoriamente em três grupos de cinco animais: grupo somente com torniquete (GT), grupo que recebeu 40mL de solução fisiológica (GSF) e grupo que recebeu gentamicina na dose de 2,2mg/kg, acrescida de solução fisiológica até completar o volume de 40mL (GSG). O membro perfundido foi avaliado por termografia e ultrassonografia duplex em cores ao longo do tempo. Os dados foram submetidos à análise pelos testes de Tukey e de Dunnett, e o nível de significância adotado foi de P<0,05. Todos os grupos apresentaram escore trombótico zero, e não houve diferença significativa entre os grupos quanto ao diâmetro médio da veia e da temperatura dos membros. A antibiose intravenosa regional com 2,2mg/kg de gentamicina, em dose única, não acarretou o desenvolvimento de trombose na veia cefálica...

The distal end of the horse is often affected by septic processes that are difficult to treat. The intravenous regional perfusion of antimicrobials is a treatment option for these processes, increasing the local concentration of the drug using small doses, and is currently widely used, but still presenting various issues. The aim of this study was to evaluate the possible complications of the technique, using gentamicin at a dose of 2.2mg/kg in the cephalic vein of horses. Fifteen healthy horses were assigned to three groups of 5 animals. Group 1, tourniquet group (TG), group 2, tourniquet and 40mL of physiologic saline solution (SPG) and group 3, tourniquet and 2.2mg/kg gentamicin completed to 40mL by the addition of physiologic saline solution (ASG). The perfused limb was evaluated by thermography and ultrasound Duplex color over time. The data were analyzed by Tukey's and Dunnett's method, and the accepted significance level was P<0.05. All groups showed thrombotic score zero and there was no significant difference between groups in the average diameter of the vein and member temperatures. The intravenous regional antibiosis with 2.2mg/kg of gentamicin as a single dose did not affect the development of thrombosis in the cephalic vein...

Caudal vena caval thrombosis following treatment of deep digital sepsis.

A diagnosis of caudal vena caval thrombosis was made by ultrasonography of a Holstein cow presented for lethargy and poor milk production. Medical treatment was unsuccessful and the cow was euthanized. The diagnosis was confirmed at necropsy and Fusobacterium necrophorum was isolated from the thrombus. This paper discusses potential novel sources of caval thrombosis in this case.

Portal vein thrombosis in 33 dogs: 1998-2011.

BACKGROUND: Portal vein thrombosis (PVT) has been reported infrequently in dogs. OBJECTIVES: To characterize the presentation, associated disease conditions, and outcome in dogs with PVT. ANIMALS: Client-owned dogs with a diagnosis of PVT and a complete medical record. METHODS: Records were retrospectively analyzed for presentation, history, physical examination, clinicopathologic data, diagnostic imaging, treatment, and outcome. RESULTS: Thirty-three dogs were included. Common clinical signs were vomiting, diarrhea, abdominal pain, ascites, and signs of hypovolemic shock. Associated disease conditions included hepatic (14/33), neoplastic (7/33), immune (5/33), and infectious (4/33) diseases, protein-losing nephropathy (3/33), hyperadrenocorticism (2/33), protein-losing enteropathy (1/33), and pancreatitis (1/33). Fourteen dogs were receiving glucocorticoids at the time of diagnosis. Twenty-nine dogs had at least 1 predisposing condition for venous thrombosis, and 11 had 2 or more. Thrombocytopenia (24/33), increased liver enzyme activity (23/33), and hypoalbuminemia (20/33) were common laboratory abnormalities. Clinical syndromes at the time of PVT diagnosis included shock (16/33), systemic inflammatory response syndrome (SIRS), (13/33) and disseminated intravascular coagulation (3/33). Twenty-four dogs had acute and 9 had chronic PVT. Multiple thrombi were found in 17/33 dogs. Nineteen dogs survived to discharge. Dogs treated with anticoagulant therapy were more likely, whereas those with acute PVT, multiple thromboses or SIRS were less likely to survive. CONCLUSIONS AND CLINICAL IMPORTANCE: Hepatic disease is a common pre-existing condition in dogs with PVT. PVT should be considered in dogs with risk factors for venous thrombosis presenting with abdominal pain, ascites, and thrombocytopenia. Studies evaluating anticoagulant therapy in the management of PVT are warranted.

Thrombosis of the cranial vena cava in a cow with bronchopneumonia and traumatic reticuloperitonitis.

This paper reports the clinical findings, surgical and medical management, and necropsy of a 6-year-old cow with thrombosis of the cranial vena cava and thrombo-embolic pneumonia following traumatic reticuloperitonitis. The clinical diagnosis was confirmed by necropsy.

Cranial vena caval syndrome secondary to central venous obstruction associated with a pacemaker lead in a dog.

This report describes the case of an 11-year-old castrated male Shih Tzu who developed chylothorax three years following implantation of a transvenous pacemaker. Imaging demonstrated one definitive obstruction in the cranial vena cava and 3 additional suspected filling abnormalities within both external jugular veins, brachiocephalic veins and cranial vena cava. A thrombus was visualized in the cranial vena cava via transesophageal echocardiography. Thoracic duct ligation and cisterna chyli ablation were performed, with a resultant change in the nature of the fluid from chylous to a modified transudate. Repeat angiography and computed tomography three months later demonstrated a stenosis within the cranial vena cava. Balloon angioplasty was attempted, however it was unsuccessful in decreasing pleural effusion. Palliative thoracocentesis was continued until the patient developed a lung lobe torsion, at which time euthanasia was elected. Necropsy confirmed cranial vena caval syndrome secondary to transvenous pacemaker implantation induced fibrous proliferation within the vessel lumen.

Chylothorax associated with thrombosis of the cranial vena cava.

This study reviewed confirmed cases of concurrent chylothorax and cranial vena caval (CrVC) thrombosis in dogs and cats, and determined predisposing factors for the development of chylothorax associated with CrVC thrombosis. The extent and location of the thrombus, the treatment regime, and the outcome are described. In all 4 cases, implantation of a jugular device was a predisposing factor to thrombosis of the CrVC, and there was extensive thrombosis of the CrVC extending from at least 1 jugular vein to just cranial to the heart. Chylothorax resolved in 3 of the 4 cases after medical and/or surgical intervention. The development of chylothorax concurrently with thrombosis of the CrVC in dogs and cats is likely dependent on the extent and location of the thrombus. Veterinary patients with indwelling jugular devices that develop acute respiratory signs should be assessed for chylothorax associated with thrombosis of the CrVC.

Caudal vena cava thrombosis-like syndrome in a horse.

A 9-year-old Quarter horse was presented for chronic refractory pneumonia. On necropsy, an hepatic abscess, caudal vena cava thrombosis, pulmonary thromboembolism, and embolic pneumonia were identified. Similar lesions have been reported in cattle as caudal vena cava thrombosis syndrome, however this syndrome has not previously been reported in horses.