Case report: Disseminated intravascular coagulation in a dog following treatment with melarsomine for Dirofilaria immitis.

Disseminated intravascular coagulation following melarsomine therapy for Dirofilaria immitis (D. immitis) is reported in a 9-year-old female intact pit bull-type dog. The dog had been diagnosed with D. immitis (antigen and microfilaria positive) and treated with imidacloprid, moxidectin, doxycycline and 3 doses of melarsomine over a 92-day period. Seven days after the third melarsomine injection, the patient was presented to her family veterinarian due to right pelvic limb swelling. Prothrombin and activated partial thromboplastin times were prolonged beyond the detectable range. Treatment included vitamin K1 and fresh frozen plasma (FFP) prior to referral to the authors' institution. At this time the patient remained coagulopathic. Further investigations included thoracic radiographs, abdominal ultrasound and an echocardiogram. The patient was administered multiple units of packed red blood cells and FFP, sildenafil, dexamethasone SP, aminocaproic acid and vitamin K1. Repeat CBC approximately 20 h after admission showed persistent anemia and thrombocytopenia. Despite ongoing administration of FFP, a repeat coagulation panel showed worsening of the coagulopathy with prothrombin time of 84.2s [reference interval (RI) 7.0-9.3s], activated partial thromboplastin time >140s (RI 10.4-12.9s) and fibrinogen <50 mg/dL (RI 109-311 mg/dL). Following discussion with the owners, the patient was euthanized. Necropsy was performed and confirmed heartworm infection with severe pulmonary arterial thrombosis, vascular remodeling, and intraluminal degenerate nematodes. Multifocal subcutaneous and organ hemorrhage was apparent. Although coagulopathy has been described in caval syndrome associated with heartworm disease and is listed as a potential side effect of melarsomine administration, this is the first report of documented disseminated intravascular coagulation following melarsomine treatment for D. immitis. Potential mechanisms for the coagulopathy are discussed and the case report highlights a rare, but serious complication of adulticide therapy.

Retrospective evaluation of fresh platelet concentrate administration in dogs: Patient characteristics, outcomes, and transfusion practices in 189 transfusion episodes (2008-2019).

OBJECTIVE: To describe patient characteristics, underlying disease processes, clinical outcomes, transfusion dose and type (therapeutic or prophylactic), platelet count changes, and adverse events associated with platelet concentrate (PC) administration in dogs. DESIGN: Retrospective study. SETTING: University teaching hospital. ANIMALS: A total of 149 dogs, representing 189 PC transfusion episodes. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: In this population, 39 of 149 dogs (26.2%) were diagnosed with primary immune-mediated thrombocytopenia, 22 of 149 (14.8%) had decreased bone marrow production, 12 of 149 (8.0%) received PC during a massive transfusion, 3 of 149 (2.0%) had congenital thrombocytopathia, 59 of 149 (39.6%) had severe thrombocytopenia of other causes, and 14 of 149 (9.4%) underwent transfusion for miscellaneous causes without a documented severe thrombocytopenia. In 117 of 149 dogs (78.5%), >1 site of hemorrhage was noted. The most common sites of hemorrhage were the gastrointestinal (GI) tract in 89 of 149 (59.7%) and the skin in 78 of 149 (52.3%). Overall survival to discharge was 59.1% (88/149). The median PC dose was 0.8 units per 10 kg of body weight per transfusion episode (range: 0.2-6.7). Of 189 episodes, 29 of 189 (15.7%) were prophylactic, and 158 of 189 (83.6%) were therapeutic. For 99 of 189 transfusion episodes, paired pre- and postplatelet counts were available within 24 hours. The median platelet count change was 5.0 × 109 /L (5000/µL; range: -115 × 109 /L to 158 × 109 /L [-115,000 to 158,000/µL]); the posttransfusion platelet count was significantly higher than pretransfusion (P < 0.0001). The increase in platelet count after transfusion was greater in the prophylactic group than the therapeutic group (P = 0.0167). Transfusion reactions were suspected during 2 of 168 episodes (1.2%). CONCLUSIONS: Immune-mediated thrombocytopenia was the most common disease process that resulted in PC transfusion. PC was more frequently administered to animals with active hemorrhage rather than prophylactically, and most dogs had evidence of hemorrhage in multiple organ systems, particularly the GI tract and skin. PC transfusions typically appeared safe, and the median platelet count increased after transfusion.

Prevalence of dog erythrocyte antigen 1 in a population of dogs tested in California.

BACKGROUND: Multiple studies have evaluated the breed-specific prevalence of dog erythrocyte antigen (DEA) 1 in various geographic regions. However, few large-scale studies exist that describe breed prevalence of DEA 1 in the United States. KEY FINDINGS: From January 2000 to October 2020, 6469 dogs had their RBC antigen type determined and were included in the study. The overall prevalence of DEA 1 in all dogs was 61.2%. Of 50 breeds with sample sizes ≥20, 8 breeds had a high prevalence (≥90%) of DEA 1-positive blood type: Basset Hound, Bernese Mountain Dog, Brittany, Dachshund, Miniature Pinscher, Miniature Schnauzer, Pug, and Rottweiler. Four breeds had a high prevalence (≥90%) of DEA 1-negative blood type: Boxer, English Bulldog, Flat-Coated Retriever, and French Bulldog. Numerous breeds with a sample size <20 and ≥5 were found to have 100% prevalence of a DEA 1 blood type, although these findings need to be confirmed with a larger sample size. No statistical difference in any breed based on sex was found. The results in this study are consistent with previously reported data in other countries. SIGNIFICANCE: Knowledge of regional breed differences in DEA 1 prevalence can help to improve selection and recruitment of appropriate blood donor dogs.

Manual plasma exchange to treat an accidental overdose of intravenous lipid emulsion in a dog with baclofen toxicosis.

CASE DESCRIPTION: An approximately 2-year-old sexually intact male German Shorthair Pointer was presented for treatment of baclofen toxicosis. CLINICAL FINDINGS: The dog had signs of severe baclofen toxicosis (no gag reflex, intermittent vocalization, and stupor) and received intravenous lipid emulsion (142 mL/kg) as a constant rate infusion over 11 hours. Severe hypertriglyceridemia (29,221 mg/dL; reference interval, 19 to 133 mg/dL) developed, followed by cardiovascular depression (poor peripheral perfusion, hyperlactatemia, and hypertension), severe hypoglycemia (26 mg/dL), acute kidney injury (serum creatinine, 3.6 mg/dL), intravascular hemolysis, and coagulopathy (hypocoagulable thromboelastogram and marked bilateral epistaxis). TREATMENT AND OUTCOME: Therapeutic plasma exchange was performed in 4 stages to treat the hypertriglyceridemia. For each stage, an approximately 500-mL aliquot of blood (22 mL/kg) was removed and centrifuged, and the patient's RBCs and allogenic fresh-frozen plasma were returned to the dog. Approximately 1.2 times the dog's plasma volume was exchanged, reducing the serum triglyceride concentration to 1,349 mg/dL and improving the dog's cardiovascular function and coagulation. Hours after the procedure was completed, the dog regurgitated and developed acute respiratory distress as a result of presumptive aspiration pneumonia, and the owner elected to have the dog euthanized. CLINICAL RELEVANCE: Veterinarians should be aware of possible complications associated with administration of intravenous lipid emulsion, and veterinary-specific guidelines for the maximum dose of intravenous lipid emulsion should be developed to help prevent adverse effects. TPE appears to be an effective method for treating iatrogenic hypertriglyceridemia in dogs.

Gastrointestinal obstruction secondary to activated charcoal granule impaction in a dog.

OBJECTIVE: To describe a serious adverse event of gastrointestinal obstruction requiring surgery following routine administration of multiple doses of activated charcoal (AC) granules, which were prescribed for carprofen toxicosis. CASE SUMMARY: A 2-year-old female neutered Airedale Terrier presented for ingestion of 207 mg/kg of carprofen. Decontamination was initiated with apomorphine to induce emesis. Along with additional supportive care, the dog received an initial dose of 75 mL of AC suspension containing sorbitol by mouth (15.6 g of AC, or 0.6 g/kg), followed by 50 g of AC granules every 8 hours for 4 additional doses. While hospitalized, the dog experienced clinical signs, including vomiting and black diarrhea, as well as bloodwork changes including mild to moderate elevations in kidney and liver enzymes. Given clinical improvement after 72 hours of hospitalization, the patient was discharged for monitoring and ongoing care at home. Two days later, the patient presented again for nausea, dark diarrhea with frank blood, and panting. Abdominal ultrasound showed findings suspicious for partially obstructive foreign material or atypical impacted fecal material partially occluding the distal ileum. Despite medical management overnight, recheck ultrasound the following day demonstrated persistent obstruction with ileal foreign material. Exploratory laparotomy and enterotomy revealed moderate distension and obstruction of the distal ileum with black granular foreign material consistent with charcoal granules. The patient remained in hospital for supportive care for 4 days following the procedure, and all clinical signs were resolved at the time of discharge. NEW OR UNIQUE INFORMATION PROVIDED: This report documents a serious adverse event of gastrointestinal obstruction associated with routine multidose AC administration, which has been occasionally reported in people but not in dogs. The potential for this complication should be taken into account when prescribing multiple doses of AC granules.

Evaluation of pulse oximetry as a surrogate for PaO2 in awake dogs breathing room air and anesthetized dogs on mechanical ventilation.

OBJECTIVE: To evaluate the ability of arterial hemoglobin oxygen saturation measurement via pulse oximetry (SpO2 ) to serve as a surrogate for PaO2 in dogs. DESIGN: Two-part study: prospective observational and retrospective components. SETTING: University teaching hospital. ANIMALS: Ninety-two dogs breathing room air prospectively enrolled on a convenience basis. Retrospective evaluation of 1,033 paired SpO2 and PaO2 measurements from 62 dogs on mechanical ventilation. INTERVENTIONS: Dogs with concurrent SpO2 and PaO2 measured on room air had a data sheet completed with blood gas analysis. SpO2 , PaO2 , and FiO2 values were collected from medical records of dogs on mechanical ventilation. MEASUREMENTS AND MAIN RESULTS: Predicted PaO2 was calculated from SpO2 using the dog oxyhemoglobin dissociation curve. The correlation coefficient between measured and predicted PaO2 was 0.49 (P < 0.0001) in room air dogs and 0.74 (P < 0.0001) in ventilated dogs. In room air dogs, Bland-Altman analysis between measured minus predicted PaO2 versus the average showed a mean bias of -6.0 mm Hg (95% limit of agreement, -35 to 23 mm Hg). The correlation coefficient between PaO2 /FiO2 and SpO2 /FiO2 ratios was 0.76 (P < 0.0001). After combining data sets, receiver operating characteristic curve analysis showed the optimal cutoff value for detecting hypoxemia (PaO2  < 80 mm Hg) was an SpO2 of 95%, with sensitivity and specificity of 77.8% and 89.5%, respectively. Using this cutoff, 6.9% of SpO2 readings failed to detect hypoxemia, whereas 7.2% predicted hypoxemia that was not present. CONCLUSIONS: The SpO2 was not clinically suitable as a surrogate for PaO2 , though it performed better in mechanically ventilated dogs. As sensitivity for the detection of hypoxemia was poor, pulse oximetry does not appear to be an acceptable screening test. The SpO2 /FiO2 ratio may have value for evaluation of anesthetized dogs on supplemental oxygen. Arterial blood gas analysis remains ideal for assessment of oxygenation.

Severe hypernatremia and transient azotemia in a cat following inadvertent intravenous administration of a commercial polyethylene glycol solution.

OBJECTIVE: To describe the clinical signs, clinicopathologic abnormalities, treatment, and outcome after IV administration of polyethylene glycol 3350 (PEG3350) in a cat. CASE SUMMARY: A cat was inadvertently administered 6 g/kg of PEG3350 in electrolyte solution, IV, resulting in severe hypernatremia (203 mmol/L), diffuse encephalopathy, hemolysis, and moderate azotemia. The hemolysis and acute kidney injury observed immediately following PEG3350 administration resolved with supportive care. Administration of IV and oral electrolyte-free water slowly corrected the hypernatremia and the neurologic signs subsequently improved. Complete resolution of clinical signs was documented one month following hospital discharge. The PEG3350 concentrations in serum, plasma, and urine samples confirmed toxic exposure to PEG3350. Efficacy of treatment was evident by decreasing concentrations of PEG3350 in serum after the first 24 hours of treatment. Renal elimination of PEG3350 was significant and PEG3350 was still detected in the urine 17 days after exposure. NEW INFORMATION PROVIDED: This is the first report to describe the clinical signs and clinicopathologic abnormalities in a cat intoxicated with IV PEG3350. Potential pathophysiologic mechanisms are discussed, and the successful supportive medical treatment is outlined.

Validation of a smartphone-based point-of-care hemoglobin assay for use in dogs.

OBJECTIVE: To validate a smartphone-based spectrophotometric assay for point-of-care (POC) measurement of hemoglobin (Hgb) concentration against the standard measurement method in dogs without increases in serum lipemia, hemolysis, or bilirubin. DESIGN: Prospective observational study. SETTING: University teaching hospital. ANIMALS: One hundred thirty-nine dogs that had a CBC and corresponding biochemical profile submitted to the clinical pathology laboratory. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Blood tubes submitted for CBC were collected for hemoglobin (Hgb) measurements performed on a POC smartphone device. Each whole blood sample was run on the smartphone in duplicate using 2 strips, for a total of 4 POC Hgb readings per dog. Data collected for each dog included CBC Hgb value, 4 POC Hgb values, and select biochemistry values (bilirubin, lipemia, hemolysis, icterus). A calibration equation was estimated using a weighted linear regression: estimated CBC = (avgPOC-0.4871)/1.0015. For each dog, the percent error was computed between estimated and actual Hgb values; 95% of the percent errors ranged from -13.2% to 20.1%. The standard deviation of percent errors was 7.9% overall. When samples were further divided according to CBC Hgb concentration (low, normal or high), the standard deviation of percent error was 6.7% when Hgb<13 g/dL [130 g/L], 8.9% when Hgb 13-20 g/dL [130-200 g/L], and 6.5% when Hgb>20 g/dL [200 g/L]. The coefficient of variability among the 4 individual POC readings was 3.4%. CONCLUSIONS: A smartphone-based photometric method for measuring Hgb represents a clinically useful POC alternative to a standard laboratory Hgb measurement. There was excellent intrasample reproducibility, and the standard deviation of percent errors was relatively constant across CBC ranges. Additional sampling of patients with a greater range of diseases and biochemical abnormalities that may influence spectrophotometric assays (ie, abnormal bilirubin, icterus, lipemia, hemolysis) is warranted to extend the findings of this study.