Pre-operative Hemostatic Status in Dogs Undergoing Splenectomy for Splenic Masses.

Portal system thrombosis is a rare but potentially fatal complication of splenectomy in dogs. The mechanism behind development of post-operative portal system thrombosis is unclear but may include alterations of portal blood flow following surgery, acquired hypercoagulability and endothelial dysfunction. The aim of the study was to evaluate hemostatic biomarkers in hemodynamically stable (heart rate <130 beats/min, blood lactate < 2.5 mMol/L) and non-anemic (hematocrit >35%) dogs prior to splenectomy for splenic masses. Our hypothesis was that this population of stable dogs would have pre-existing laboratory evidence of hypercoagulability unrelated to shock, bleeding, anemia, or other pre-operative comorbidities. Pre-operatively, abdominal ultrasonography was performed and blood was collected for platelet enumeration, prothrombin time (PT), activated partial thromboplastin time (aPTT), kaolin-activated thromboelastography (TEG), fibrinogen, von Willebrand factor activity (vWF:Ag), antithrombin and thrombin-antithrombin complex (TAT). Histopathological diagnosis and 30-day survival were recorded. None of the 15 enrolled dogs had pre-operative sonographic evidence of portal system thrombosis. Three of fifteen dogs were thrombocytopenic, three had thrombocytosis, three were hyperfibrinogenemic, one had low vWF:Ag, three had mild prolongations of PT and none had abnormal aPTT. Based on the TEG G value, 13/15 dogs were hypercoagulable (mean ± SD 13.5 ± 5.4 kd/s). Antithrombin deficiency was identified in 9/15 dogs (mean ± SD 68.7 ± 22.7%) with 5/9 having concurrently elevated TAT suggesting active thrombin generation. No dogs developed portal system thrombosis and all achieved 30-day survival. Pre-operative hypercoagulability was recognized commonly but its association with post-operative thrombosis remains undetermined.

Retrospective analysis of hops toxicosis in dogs (2002-2014): 71 cases.

OBJECTIVE: To describe a population of dogs with hops toxicosis, including clinical signs observed, treatments performed, patient outcome, and overall prognosis. Clinical findings and treatment interventions were evaluated for their potential effects on outcome. This study also aims to review hops toxicosis and treatment options. DESIGN: Retrospective observational study. SETTING: Poison Control Center. ANIMALS: Seventy-one dogs presenting for hops ingestion. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Records of 71 dogs with known hops ingestion from the ASPCA - Animal Poison Control Center (ASPCA-APCC) database and the Tufts University medical record system were reviewed. Fifty-nine (77%) of the dogs survived. The most common clinical signs on presentation were hyperthermia and tachycardia, with presenting temperatures and heart rates significantly higher in nonsurvivors. There was no significant difference between survivors and nonsurvivors in regard to signalment. Time to presentation was shorter in survivors (5.0 vs 5.5 h; P < 0.0001). The median amount of hops ingested was higher in nonsurvivors (2 vs 2.5 oz; P < 0.0001). Hops ingestion caused hyperthermia in 96% (68/71) of dogs. The median time to death in the nonsurvivor group was 10.7 hours (2-30 h). None of the decontamination, cooling, or treatment measures (dantrolene, cyproheptadine, sedatives) evaluated in this population were associated with improved survival. After adjusting for cooling, time to presentation, and dantrolene administration, every degree of elevation in temperature was associated with a 78% increased chance of death. All dogs that survived to discharge had complete resolution of clinical signs. CONCLUSIONS: Hops toxicosis can result in significant hyperthermia, tachypnea, and tachycardia. Seventy-seven percent of dogs survived with intensive treatment. Continued education of the potential for hops toxicosis is advised.

Outcome and treatments of dogs with aortic thrombosis: 100 cases (1997-2014).

BACKGROUND: Aortic thrombosis (ATh) is an uncommon condition in dogs, with limited understanding of risks factors, outcomes, and treatments. OBJECTIVES/HYPOTHESIS: To describe potential risk factors, outcome, and treatments in dogs with ATh. ANIMALS: Client-owned dogs with a diagnosis of ATh based on ultrasonographic or gross necropsy examination. METHOD: Multicentric retrospective study from 2 academic institutions. RESULTS: One hundred dogs were identified. Anti-thrombin diagnosis, 35/100 dogs were nonambulatory. The dogs were classified as acute (n = 27), chronic (n = 72), or unknown (n = 1). Fifty-four dogs had at least one comorbidity thought to predispose to ATh, and 23 others had multiple comorbidities. The remaining 23 dogs with no obvious comorbidities were classified as cryptogenic. Concurrent illnesses potentially related to the development of ATh included protein-losing nephropathy (PLN) (n = 32), neoplasia (n = 22), exogenous corticosteroid administration (n = 16), endocrine disease (n = 13), and infection (n = 9). Dogs with PLN had lower antithrombin activity than those without PLN (64% and 82%, respectively) (P = .04). Sixty-five dogs were hospitalized with 41 subsequently discharged. Sixteen were treated as outpatient and 19 euthanized at admission. In-hospital treatments varied, but included thrombolytics (n = 12), alone or in combination with thrombectomy (n = 9). Fifty-seven dogs survived to discharge. Sixteen were alive at 180 days. Using regression analysis, ambulation status at the time of presentation was significantly correlated with survival-to-discharge (P < .001). CONCLUSIONS/CLINICAL IMPORTANCE: Dogs with ATh have a poor prognosis, with nonambulatory dogs at the time of presentation having worse outcome. Although the presence of comorbid conditions associated with hypercoagulability is common, an underlying cause for ATh was not always identified.

Compartment syndrome of the muscles of mastication in a working dog following a traumatic training incident.

OBJECTIVE: To describe acute compartment syndrome (CS) of the muscles of mastication in a working dog associated with a traumatic training event. CASE SUMMARY: A 2.5-year-old male Belgian Malinois was evaluated for acute blindness, severe diffuse swelling of the head, and inability to close the jaw following a traumatic incident during a bite training drill. During the exercise, the maxillary canine teeth were locked on a bite sleeve. Magnetic resonance imaging of the head and ocular system identified diffuse muscle swelling and hyperintensity, most severe in the muscles of mastication. Ocular abnormalities were not identified. Rhabdomyolysis, CS, and indirect optic nerve injury were supported by measurement of increased intramuscular pressure. Bilateral decompressive fasciotomies over the masseter and temporalis muscles resulted in immediate and marked resolution of the swelling and jaw movement. Blindness, however, did not resolve. NEW OR UNIQUE INFORMATION PROVIDED: CS involving the muscles of mastication may occur as a complication of bite training and may result in irreversible and even life-threatening complications. Emergent decompressive fasciotomy is indicated to reverse swelling; however, visual deficits may not resolve.

Acute tracheal compression in a large breed dog due to a dorsal tracheal membrane abscess.

OBJECTIVE: To describe a case of acute tracheal compression due to a dorsal tracheal membrane abscess in a dog. CASE SUMMARY: A 3-year-old intact male Bluetick Coonhound presented for evaluation of 36 hours of marked inspiratory dyspnea and stridor. A radiographic diagnosis of tracheal collapse was made on thoracic radiographs, which was confirmed to be static compression by tracheoscopy. Dorsal extraluminal tracheal compression from a fluid filled structure adjacent to the trachea was suspected based on ultrasonography. Endoscopic-guided transtracheal fine needle aspiration yielded septic suppurative inflammation. At surgery an abscess in the dorsal tracheal membrane was identified, lanced, and lavaged, which resulted in restoration of normal tracheal diameter. The dog developed bilateral pneumothorax, which was treated medically by thoracostomy tube placement and manual evacuation of the accumulated air. Postoperative radiographs also revealed evidence of pneumomediastinum. Pneumothorax and pneumomediastinum likely occurred secondary to the surgical approach, worsened by positive pressure ventilation. Cultures of the abscess isolated a nonhemolytic Streptococcus species but with no evidence of anaerobic bacteria. The dog made a full functional recovery. NEW OR UNIQUE INFORMATION PROVIDED: Tracheal compression is a rare diagnosis in dogs. To the authors' knowledge, this represents the first report of an abscess in the dorsal tracheal membrane, diagnosed by endoscopic-guided transtracheal fine needle aspiration, causing clinically relevant acute tracheal obstruction.

Transfusion practices for treatment of dogs undergoing splenectomy for splenic masses: 542 cases (2001-2012).

OBJECTIVE: To describe transfusion practices for treatment of dogs undergoing splenectomy for splenic masses. DESIGN: Retrospective case series. ANIMALS: 542 client-owned dogs. PROCEDURES: Medical records of dogs that underwent splenectomy for splenic masses at 2 referral institutions were reviewed. Variables of interest were compared between dogs that did and did not undergo transfusion. Multiple logistic regression analysis was performed to assess associations of transfusion with death during hospitalization and with 30- and 180-day survival rates. RESULTS: Transfusions were administered to 240 of 542 (44%) dogs; packed RBCs were the most frequently administered blood product. On admission, dogs that subsequently received transfusions had higher mean illness severity score, heart rate, respiratory rate, blood lactate concentration, and prothrombin time, with lower mean PCV, platelet count, serum total solids and albumin concentrations, and base deficit than dogs that did not receive transfusions. Hemoperitoneum and malignancy, especially hemangiosarcoma, were more common in the transfusion group. Overall, 500 of 542 (92%) dogs survived to discharge. Dogs that received transfusions had higher odds of death or euthanasia while hospitalized and lower odds of surviving to 30 or 180 days after hospital discharge than dogs that did not. CONCLUSIONS AND CLINICAL RELEVANCE: Evidence of shock, anemia, and hypocoagulability were apparent triggers for the decision to perform blood transfusion in dogs undergoing splenectomy for splenic masses and were likely attributable to hemoperitoneum and related hypovolemia. Dogs undergoing transfusion more commonly had malignant disease and had greater odds of poor long-term outcome, compared with dogs that did not undergo transfusion.

Transfusion practices for treatment of dogs hospitalized following trauma: 125 cases (2008-2013).

OBJECTIVE: To describe transfusion practices for treatment of dogs hospitalized because of traumatic injuries. DESIGN: Retrospective case series. ANIMALS: 125 client-owned dogs. PROCEDURES: Medical records of dogs that sustained trauma and were hospitalized for ≥ 24 hours after emergency stabilization were reviewed. Admission characteristics and transfusion-specific data were assessed. Receiver operating characteristic curves were plotted to evaluate diagnostic utility of PCV and serum total solids concentration as predictors of transfusion in the study population. RESULTS: 45 of 125 (36%) dogs received transfusions. Packed RBCs were the most commonly administered blood product (42/45 [93%]). Common reasons for transfusion included perioperative hemodynamic support and treatment of shock or worsening anemia. Dogs that underwent transfusion had higher mean heart rate, blood lactate concentration, and animal trauma triage scores, with lower mean PCV, serum total solids concentration, and rectal temperature at admission than dogs that did not undergo transfusion. Total solids concentration and PCV at admission were specific but insensitive predictors of subsequent transfusion. Most (109/125 [87%]) dogs survived to hospital discharge. Significantly fewer dogs that had transfusions survived, compared with dogs that did not have transfusions. Seven of 10 dogs that received massive transfusions survived to discharge. CONCLUSIONS AND CLINICAL RELEVANCE: Apparent clinical triggers for the decision to perform blood transfusion in dogs hospitalized following traumatic injury included evidence of shock or worsening anemia on admission and requirement for perioperative hemodynamic optimization. Although dogs that received transfusions had a lower survival rate than dogs that did not, this was likely attributable to greater severity of injuries in the transfusion group.

Risk factors for perioperative death in dogs undergoing splenectomy for splenic masses: 539 cases (2001-2012).

OBJECTIVE: To determine the perioperative mortality rate, causes of death, and risk factors for perioperative death in dogs undergoing splenectomy for splenic mass lesions. DESIGN: Retrospective case series. ANIMALS: 539 dogs. PROCEDURES: Medical records of dogs that underwent splenectomy for known splenic masses were reviewed. Perioperative mortality rate and causes of death were determined. Associations between potential prognostic factors and perioperative death were evaluated by multivariable logistic regression analysis. RESULTS: 41 of 539 (7.6%) dogs died during the perioperative period. Thrombotic and coagulopathic syndromes and uncontrolled bleeding from metastatic lesions were the most common causes of death. Of the variables selected for multivariable analysis, platelet count at admission, whether PCV at admission was < 30%, and development of ventricular arrhythmias during surgery were significantly associated with outcome. For each decrease in platelet count of 10,000 platelets/µL, odds of death increased by approximately 6%. For dogs with PCV < 30%, odds of death were approximately twice those for dogs with PCV ≥ 30%, and for dogs that developed intraoperative arrhythmias, odds of death were approximately twice those for dogs that did not. CONCLUSIONS AND CLINICAL RELEVANCE: Marked preoperative thrombocytopenia or anemia and development of intraoperative ventricular arrhythmias were identified as risk factors for perioperative death in dogs with splenic masses. The risk of death may be limited by efforts to prevent thrombotic and coagulopathic syndromes and to control all sources of intra-abdominal hemorrhage.

Hypoperfusion and acute traumatic coagulopathy in severely traumatized canine patients.

OBJECTIVE: To determine the incidence of acute traumatic coagulopathy in dogs suffering severe trauma and to investigate the association of markers of hypoperfusion with coagulation abnormalities. DESIGN: A prospective observational study performed June, 2009 to February, 2011. SETTING: A university teaching hospital. ANIMALS: Thirty client-owned dogs weighing >5 kilograms that were presented to the Tuft's Cummings School of Veterinary Medicine following severe trauma as defined by an animal trauma triage score (ATT) ≥5 and having received no resuscitation with IV fluids or blood products prior to blood sampling. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Prior to resuscitation, data obtained at the time of admission to the emergency service included HCT, platelet count, lactate concentration, pH, base excess, thromboelastrogram (TEG), prothrombin time, activated partial thromboplastin time, fibrinogen level, and protein C activity. Rectal temperature and ATT were recorded for all dogs. Neither HCT nor platelet count was significantly decreased in any of the dogs. Based on G values as measured by TEG, 10/30 dogs (33%) showed evidence of hypercoagulability. Hypocoagulability as determined by prothrombin time, activated partial thromboplastin time, or TEG was not shown in any of the 30 dogs. CONCLUSION: Dogs with severe trauma may experience hypercoagulability that is unrelated to fluid resuscitation or transfusion therapy. Future studies are warranted to better characterize coagulation changes in dogs with severe trauma, particularly in relationship to fluid therapies and/or hemorrhage.

Identification of hypercoagulability in dogs with primary immune-mediated hemolytic anemia by means of thromboelastography.

OBJECTIVE: To evaluate whole blood hemostasis by means of thromboelastography in dogs with primary immune-mediated hemolytic anemia (IMHA) to determine whether these dogs had evidence of hypercoagulability prior to the administration of immunosuppressant medications, blood transfusion products, or anticoagulant agents. DESIGN: Evaluation study. ANIMALS: 11 client-owned dogs admitted to a teaching hospital for management of primary IMHA and 20 clinically normal dogs. PROCEDURES: Citrated whole blood samples were obtained from all dogs for performance of kaolin-activated thromboelastography. Citrated plasma was harvested from blood samples of dogs with IMHA for plasma-based coagulation testing, including activated partial thromboplastin time, prothrombin time, D-dimer concentration, fibrinogen concentration, and antithrombin activity. RESULTS: Compared with control dogs, dogs with primary IMHA had evidence of hypercoagulability as indicated by a significantly lower median (range) clot formation time (0.8 seconds [0.8 to 2.0 seconds] vs 1.9 seconds [1.3 to 3.8 seconds]), higher median angle (76.1° [59.2° to 84.6°] vs 64.0° [45.4° to 71.0°]), higher median maximum amplitude (75.9 mm [66.3 to 86.3 mm] vs 55.7 mm [49.9 to 63.6 mm]), and higher median clot strength (15,000 dyne/cm(2) [9,900 to 31,400 dyne/cm(2)] vs 6,100 dyne/cm(2) [4,900 to 8,700 dyne/cm(2)]). CONCLUSIONS AND CLINICAL RELEVANCE: Dogs with primary IMHA had hypercoagulability as demonstrated by thromboelastography at the time of initial diagnosis and prior to treatment. Such hypercoagulability may be a precursor to clinically evident thrombosis as a complication of the disease process.

Use of human immunoglobulin in addition to glucocorticoids for the initial treatment of dogs with immune-mediated hemolytic anemia.

OBJECTIVE: To determine the utility of human intravenous immunoglobulin (hIVIG) for the initial treatment of canine immune-mediated hemolytic anemia (IMHA). DESIGN: Blinded, randomized, clinical trial. SETTING: Veterinary teaching hospital. ANIMALS: Twenty-eight, client-owned dogs with primary IMHA. INTERVENTIONS: At enrollment, after diagnosis of IMHA, dogs were randomly assigned to receive either hIVIG or placebo, in a blinded fashion. For the next 14 days, all dogs received glucocorticoids as the sole immunosuppressant agent. All dogs received low-molecular-weight heparin as an anticoagulant. D-dimer concentrations were evaluated at the beginning and end of the study protocol to monitor for thromboembolic complications. MEASUREMENTS AND MAIN RESULTS: Twenty-five of 28 dogs (89%) were discharged from the hospital. Thirteen of those received hIVIG and 12 received placebo. Twenty-four dogs (86%) were alive 14 days after enrollment, and of these 13 received hIVIG and 11 received placebo. D-dimer concentrations were elevated in 86% of all dogs at the time of diagnosis. CONCLUSIONS: For initial treatment of dogs with IMHA, the addition of hIVIG to corticosteroid treatment did not improve initial response, nor did it shorten hospitalization.

Use of mycophenolate mofetil as a rescue agent in the treatment of severe generalized myasthenia gravis in three dogs.

OBJECTIVE: To describe the use of IV and oral mycophenolate mofetil (MMF) as adjunctive therapy in 3 dogs with severe generalized myasthenia gravis. CASE SERIES SUMMARY: Three dogs suffering from severe generalized myasthenia gravis as confirmed by acetylcholine antibody titers were treated with MMF as part of their treatment regimens. All 3 dogs had radiographic evidence of megaesophagus and suffered from severe regurgitation. Each dog was initially treated with pyridostigmine and supportive agents. When clinical remission was not achieved, IV MMF was administered to all dogs. Signs of clinical remission were apparent within 48 hours and all dogs were later maintained on oral MMF following resolution of regurgitation. NEW OR UNIQUE INFORMATION PROVIDED: This is the first report of the use of IV MMF as adjunctive treatment in dogs with severe generalized myasthenia gravis. Outcome was favorable in all 3 dogs and no adverse effects were noted from the MMF.

The use of thrombolytic agents.

Thrombi and thromboemboli are organized fibrin clots that may result in partial or total occlusion of arterial or venous blood flow. Consequences of occlusion of blood flow vary with the organ affected.Thrombolytic agents have been used for the dissolution of pathologic thrombi since the 1980s. While similar in their mechanisms of action and side effects, these agents differ in their specificity for fibrin and duration of activity. Newer thrombolytic agents have been developed to improve clot dissolution and minimize side effects. Their use in veterinary medicine has been reported, but guidelines for such use have not been published.

Volvulus of the colon in four dogs.

Four dogs were examined because of vomiting of 7 to 48 hours' duration. Gas-distended segments of intestine were identified radiographically in all dogs, but the affected portion of the intestinal tract could not always be identified as the colon. Volvulus of the colon was diagnosed during surgery in all 4 dogs. Gastrocolopexy was performed following derotation of the colon in 3 of the dogs. In 1 dog, a colectomy and an ileorectal anastomosis were performed. All 4 dogs survived. Volvulus of the colon should be considered as a cause of vomiting of short duration in dogs for which there is radiographic evidence of intestinal dilatation.

Cryptococcosis of the central nervous system in a dog.

A 3-year-old female German Shepherd Dog was evaluated for progressive mental obtundation and vestibular signs. Central nervous system cryptococcosis was diagnosed on the basis of growth of Cryptococcus neoformans in fungal culture of CSF, as well as detection of the organism in CSF via microscopy. Cryptococcal capsular latex antigen agglutination titer was 1:262,144 in CSF and 1:1,048,576 in serum samples. Imaging with magnetic resonance augmented diagnosis. The dog improved after long-term treatment with fluconazole. Fluconazole is useful in the treatment of CNS cryptococcosis, because it attains high concentration in the CNS. Long-term therapy is often required for resolution of clinical signs, and affected animals may require long-term follow-up with periodic evaluation of CSF via fungal culture and latex agglutination tests. Monitoring serum latex agglutination test results may provide a safe, less invasive means of monitoring response to treatment.