A Review of Central Venous Pressure and Its Reliability as a Hemodynamic Monitoring Tool in Veterinary Medicine.

OBJECTIVE: To review the current literature regarding central venous pressure (CVP) in veterinary patients pertaining to placement (of central line), measurement, interpretation, use in veterinary medicine, limitations, and controversies in human medicine. ETIOLOGY: CVP use in human medicine is a widely debated topic, as numerous sources have shown poor correlation of CVP measurements to the volume status of a patient. Owing to the ease of placement and monitoring in veterinary medicine, CVP remains a widely used modality for evaluating the hemodynamic status of a patient. A thorough evaluation of the veterinary and human literature should be performed to evaluate the role of CVP measurements in assessing volume status in veterinary patients. DIAGNOSIS: Veterinary patients that benefit from accurate CVP readings include those suffering from hypovolemic or septic shock, heart disease, or renal disease or all of these. Other patients that may benefit from CVP monitoring include high-risk anesthetic patients undergoing major surgery, trending of fluid volume status in critically ill patients, patients with continued shock, and patients that require rapid or large amounts of fluids. THERAPY: The goal of CVP use is to better understand a patient's intravascular volume status, which would allow early goal-directed therapy. PROGNOSIS: CVP would most likely continue to play an important role in the hemodynamic monitoring of the critically ill veterinary patient; however, when available, cardiac output methods should be considered the first choice for hemodynamic monitoring.

Platelet activation in a population of critically ill dogs as measured with whole blood flow cytometry and thromboelastography.

OBJECTIVE: To determine whether critically ill dogs had increased platelet activation and whether the proportion of activated platelets correlated with severity of illness. ANIMALS: 82 dogs in the intensive care unit of a veterinary teaching hospital and 24 healthy control dogs. PROCEDURES: Flow cytometry with monoclonal mouse anti-human CD61 and CD62 antibodies in resting and ADP-treated samples and kaolin-activated thromboelastography were used to compare platelet activation in blood samples of critically ill and control dogs. Serum antithrombin, von Willebrand factor, fibrinogen, and activated protein C concentrations; prothrombin time (PT); and activated partial thromboplastin time (aPTT) were measured. Revised survival prediction index, acute patient physiology and laboratory evaluation, systemic inflammatory response syndrome, and multiple organ dysfunction syndrome scores were used to estimate severity of illness. Severity of illness scores and platelet activation measurements were compared with survival time and duration and cost of hospitalization. RESULTS: Critically ill and control dogs had no differences in platelet activation for non-ADP-treated samples measured. Critically ill dogs had significantly increased platelet activation in response to 2, 6, and 10 µM ADP. Critically ill dogs had significantly increased maximum amplitude, α angle, and global clot strength and significantly decreased clot formation time. Critically ill dogs had significantly increased fibrinogen concentration, PT, and aPTT and significantly decreased antithrombin concentration. Survivors and nonsurvivors had similar flow cytometry and thromboelastography values. Three dogs developed macrothrombosis. CONCLUSIONS AND CLINICAL RELEVANCE: In this study, critically ill dogs had hyperreactive platelets, which may have contributed to a high incidence of hypercoagulability in this patient population.

Evaluation of the shock index in dogs presenting as emergencies.

OBJECTIVES: To (1) determine a reference interval for shock index (SI) [defined as heart rate (HR)/systolic blood pressure (SBP)], in a group of healthy dogs, and (2) compare SI in healthy dogs with dogs presenting to the emergency room (ER) deemed to be in or not in a state of shock. DESIGN: Prospective study. ANIMALS: Sixty-eight clinically normal dogs, 18 dogs that were presented to the ER deemed to be in shock and 19 dogs presenting to the ER not deemed to be in shock. SETTING: University teaching hospital. INTERVENTIONS: Peripheral or central venous blood sampling. MEASUREMENTS AND MAIN RESULTS: Heart rate and SBP were recorded on simulated presentation (healthy dogs), and emergency presentations for both dogs deemed to be in shock and dogs not deemed in shock. Dogs in shock had a median SI of 1.37 (0.87-3.13), which was significantly higher than both other groups; dogs not deemed in shock had median SI 0.73 (0.56-1.20), P < 0.0001 and healthy dogs had median SI 0.78 (0.37-1.30) P < 0.0001), respectively. Receiver operator characteristic curve analysis suggested a SI cut-off of 1.0, yielding an area under the receiver operator characteristic (AUROC) of 0.89 (Specificity (Sp) 89, Sensitivity (Sn) 90) when comparing dogs deemed in shock with healthy dogs, and 0.92 (Sp 95, Sn 89) when comparing dogs in shock with to dogs not deemed in shock. CONCLUSIONS: The SI is an easy and noninvasive patient parameter that is higher in dogs that are deemed to be in shock than both healthy dogs and dogs presented as emergencies but not deemed to be in a state of shock. The measurement of SI may have some benefit in clinical assessment of emergency patients.

Seizures and severe nutrient deficiencies in a puppy fed a homemade diet.

CASE DESCRIPTION: An 8-month-old male Saint Bernard developed tetanic seizures and hyperthermia during evaluation of bilateral osteochondritis dissecans of the shoulder joints. Further investigation revealed that the dog was receiving an unbalanced homemade diet. CLINICAL FINDINGS: Preliminary evaluation of the dog revealed bilateral signs of pain and mild muscle wasting in the shoulder joint areas. Serum biochemical analysis revealed severe hypocalcemia, hyponatremia, hypochloremia, hyperphosphatemia, vitamin D deficiency, and taurine deficiency. Diffuse osteopenia was identified on radiographs of the mandible and long bones, confirming bone demineralization. Analysis of the homemade diet revealed that the dog's diet was severely deficient in a variety of nutrients. TREATMENT AND OUTCOME: The dog responded positively to treatment for hypocalcemia, hyperthermia, and seizures. The dog's diet was changed to a complete and balanced canine diet formulated for growth. Body weight and body condition were monitored, and dietary intake was adjusted to achieve optimal body condition during growth. After initial evaluation, serial monitoring of serum calcium and taurine concentrations revealed that values were within reference limits and the dog had no further clinical signs associated with dietary deficiency. CLINICAL RELEVANCE: Findings in this puppy highlight the risks associated with feeding an unbalanced homemade diet during growth and the importance of obtaining a thorough dietary history from all patients. For owners who elect to feed a homemade diet, it is critical to have the homemade diet carefully formulated by a veterinary nutritionist to avoid severe nutrient imbalances, especially in young, growing dogs.

Kaolin-activated thromboelastography in echocardiographically normal cats.

OBJECTIVE: To determine reference values for kaolin-activated thromboelastography in echocardiographically normal cats. ANIMALS: 30 healthy cats without evidence of cardiomyopathy on echocardiographic examination. PROCEDURES: All cats underwent echocardiographic examination, the findings of which were reviewed by a board-certified cardiologist. Cats that struggled (n = 10) received mild sedation with butorphanol and midazolam IM to permit phlebotomy without interruption in jugular venous blood flow. Blood samples were collected for analysis of thromboelastography variables, PCV, total solids concentration, platelet count, activated partial thromboplastin time, prothrombin time, fibrinogen concentration, and antithrombin concentration. RESULTS: All 4 thromboelastography variables had < 5% mean intra-assay variability. Mean values were as follows: reaction time, 4.3 minutes; clotting time, 1.6 minutes; α angle, 66.5°; and maximum amplitude, 56.4 mm. Compared with nonsedated cats, cats that required sedation had a significantly shorter clotting time and greater α angle, whereas reaction time and maximum amplitude were not significantly different. CONCLUSIONS AND CLINICAL RELEVANCE: Kaolin-activated thromboelastography was a reliable test with unremarkable intra-assay variability in echocardiographically normal cats. Sedation may affect certain thromboelastography variables, but the effect is unlikely to be clinically important. It remains unknown whether subclinical cardiomyopathy has a significant effect on thromboelastography variables in cats.

Investigating hypercoagulability during treatment for immune-mediated thrombocytopenia: a pilot study.

BACKGROUND: Thromboembolism has recently been described as a complication following treatment for idiopathic thrombocytopenic purpura (ITP). This pilot study was undertaken to determine whether dogs suffering from ITP experience hypercoagulability during treatment and recovery. STUDY DESIGN: Thromboelastograms (TEG) were performed on dogs with ITP within 24 hours of admission to the hospital, the first day the platelet count exceeded 40 × 10(9) /L (Day 1), and on Days 4, 7, and 14. KEY FINDINGS: All dogs had hypocoagulable TEG tracings on initial admission to the hospital, but developed TEG tracings suggestive of hypercoagulability during the study period as indicated by increased maximum amplitude. SIGNIFICANCE: Dogs with ITP developed changes on TEG consistent with hypercoagulability during the study period. Many factors are likely to contribute to these changes. The clinical risk of thrombosis in these patients is unknown.

Treatment and predictors of outcome in dogs with immune-mediated thrombocytopenia.

OBJECTIVE: To characterize the clinical course of disease and identify prognostic indicators for immune-mediated thrombocytopenia in dogs. DESIGN: Retrospective cohort study. ANIMALS: 73 dogs treated for immune-mediated thrombocytopenia at the Foster Hospital for Small Animals at the Tufts Cummings School of Veterinary Medicine and the Tufts Veterinary Emergency Treatment and Specialties Hospital. PROCEDURES: Medical records from the period of January 2002 through June 2008 were reviewed to identify dogs with a diagnosis of immune-mediated thrombocytopenia. Data collected included signalment, clinical signs, results of initial diagnostic tests, treatment, complications, and survival duration. RESULTS: Dog ages ranged from 5 months to 15 years (median, 8.1 years). Cocker Spaniels were overrepresented, compared with their distribution in the entire hospital population during the same period. Sixty-one of the 73 (84%) dogs survived to discharge. Seven (11 %) of those dogs were lost to follow-up. Five of the remaining 54 (9%) dogs had a relapse of the disease. The presence of melena or high BUN concentration at admission to the hospital was significantly correlated with a decreased probability of survival. CONCLUSIONS AND CLINICAL RELEVANCE: Immune-mediated thrombocytopenia is a serious yet treatable disease, which may have a lower rate of recurrence than previously reported. The presence of melena or high BUN concentration in the study suggested a poor prognosis for affected dogs.

The use of deep oral swabs as a surrogate for transoral tracheal wash to obtain bacterial cultures in dogs with pneumonia.

OBJECTIVE: To determine agreement in bacterial culture and susceptibility (BC&S) between deep oral swab (DOS) and routine transoral tracheal wash (TOTW) in dogs with pneumonia. DESIGN: Prospective study, performed between 2008 and 2010 with no follow-up period. SETTING: University teaching hospital. ANIMALS: Five puppies and 5 adult dogs with community or hospital-acquired pneumonia. MEASUREMENTS AND MAIN RESULTS: A DOS was collected from each patient; dogs were then briefly anesthetized with propofol(a) for a routine TOTW. Routine microbiology techniques were used for culture. Positive culture results were obtained from all 20 swabs. Results of BC&S were compared between the 2 sites. In all puppies, there was no agreement between DOS and TOTW. In adult dogs, 2 patients with hospital-acquired infection (HAI) had complete agreement between the BC&S results from DOS and TOTW. Two adult dogs had some similarity in BC&S results, and the final dog had no relationship between cultures. CONCLUSIONS: DOS is not an appropriate alternative to TOTW to obtain samples for BC&S in puppies with pneumonia. In adult dogs, traditional TOTW remains the gold standard, but DOS may be considered in dogs with suspected HAI. Further work is needed to confirm this preliminary finding.

Association between outcome and changes in plasma lactate concentration during presurgical treatment in dogs with gastric dilatation-volvulus: 64 cases (2002-2008).

OBJECTIVE: To determine whether changes in presurgical plasma lactate concentration (before and after initial fluid resuscitation and gastric decompression) were associated with short-term outcome for dogs with gastric dilatation-volvulus (GDV). DESIGN: Retrospective case series. ANIMALS: 64 dogs. PROCEDURES: Medical records were reviewed, and signalment, history, resuscitative treatments, serial presurgical lactate concentrations, surgical findings, and short-term outcome were obtained for dogs with confirmed GDV. RESULTS: 36 of 40 (90%) dogs with an initial lactate concentration 9.0 mmol/L). Within HIL dogs, there was no difference in mean +/- SD initial lactate concentration between survivors and nonsurvivors (10.6 +/- 2.3 mmol/L vs 11.2 +/- 2.3 mmol/L, respectively); however, there were significant differences in post-treatment lactate concentration, absolute change in lactate concentration, and percentage change in lactate concentration following resuscitative treatment. By use of optimal cutoff values within HIL dogs, survival rates for dogs with final lactate concentration > 6.4 mmol/L (23%), absolute change in lactate concentration 4 mmol/L (86%), or percentage change in lactate concentration > 42.5% (100%). CONCLUSIONS AND CLINICAL RELEVANCE: Calculating changes in plasma lactate concentration following initial treatment in dogs with GDV may assist in determining prognosis and identifying patients that require more aggressive treatment.

Association between outcome and organ system dysfunction in dogs with sepsis: 114 cases (2003-2007).

OBJECTIVE: To determine whether multiple organ dysfunction syndrome (MODS) could be identified in dogs with sepsis secondary to gastrointestinal tract leakage, and whether the number of affected organ systems was significantly associated with mortality rate. DESIGN: Multicenter retrospective case series. ANIMALS: 114 dogs. PROCEDURES: Medical records for dogs treated surgically because of sepsis secondary to gastrointestinal tract leakage between 2003 and 2007 were reviewed. Sepsis was diagnosed on the basis of results of bacterial culture of peritoneal fluid, gross evidence of gastrointestinal tract leakage at surgery, or both. Renal dysfunction was defined as a > or = 0.5 mg/dL increase in serum creatinine concentration after surgery. Cardiovascular dysfunction was defined as hypotension requiring vasopressor treatment. Respiratory dysfunction was defined as a need for supplemental oxygen administration or mechanical ventilation. Hepatic dysfunction was defined as a serum bilirubin concentration > 0.5 mg/dL. Dysfunction of coagulation was defined as prolonged prothrombin time, prolonged partial thromboplastin time, or platelet count < or = 100,000/microL. RESULTS: 89 (78%) dogs had dysfunction of 1 or more organ systems, and 57 (50%) dogs had MODS. Mortality rate increased as the number of dysfunctional organ systems increased. Mortality rate was 70% (40/57) for dogs with MODS and 25% (14/57) for dogs without. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that MODS, defined as dysfunction of at least 2 organ systems, can be identified in dogs with sepsis and that organ system dysfunction increased the odds of death.

Effect of National Football League games on small animal emergency room caseload.

OBJECTIVE: To evaluate whether games of popular professional football teams have an effect on small animal emergency room caseload and percentage of dogs and cats that subsequently are hospitalized, are euthanatized, or die following admission to veterinary emergency rooms located within a dedicated fan base. DESIGN: Prospective study. ANIMALS: 818 dogs and cats admitted to the emergency room. PROCEDURES: During the 2007 New England Patriots (NEP) football season, small animal emergency room caseload was recorded for Sunday (4-hour blocks, 8:00 AM until 12:00 midnight) and Monday night (7:00 PM to 11:00 PM). Number of dogs and cats that subsequently were hospitalized, died, or were euthanatized was recorded. Mean game importance rating (GIR) was determined for NEP games (scale, 1 [mild] to 3 [great]). RESULTS: Percentage of dogs and cats admitted from 12:00 noon to 4:00 PM on Sundays during NEP games (mean GIR, 1.7) versus non-NEP games was not different. Mean +/- SD percentage of dogs and cats admitted from 4:00 PM to 8:00 PM on Sundays during NEP games (mean GIR, 2.4) versus non-NEP games was significantly different (18 +/- 5% and 25 +/- 7% of daily caseload, respectively). Percentage of dogs and cats admitted from 8:00 PM to 12:00 midnight on Sundays during NEP games (mean GIR, 2.1) versus non-NEP games was not different. Game type (NEP vs non-NEP) during emergency room admission did not influence whether dogs and cats subsequently were hospitalized, died, or were euthanatized. CONCLUSIONS AND CLINICAL RELEVANCE: Professional sporting events may influence veterinary emergency room caseloads.

Aplastic anemia in two kittens following a prescription error.

A medication error resulted in two kittens being treated with azathioprine (12 and 12.5 mg/kg) instead of azithromycin for 2 weeks. On clinical examination, the kittens were febrile, weak, and had oronasal hemorrhage. Complete blood cell counts indicated severe bone marrow suppression. Treatment consisted of multiple transfusions, antibiotics, and granulocyte colony-stimulating factor. One of the kittens responded to therapy and had a complete recovery. The other kitten was treated for 40 days with no clinical response before dying. Both kittens also contracted Mycoplasma hemofelis infection from a contaminated blood transfusion.

Canine pericardial effusion: pathophysiology and cause.

Pericardial effusion is the abnormal accumulation of fluid in the pericardial space. As the fluid volume and intrapericardial pressure increase, cardiac tamponade can develop. The most common causes of pericardial effusion include cardiac hemangiosarcoma, idiopathic pericardial effusion, and chemodectoma. Understanding the underlying cause is important in providing treatment recommendations and an accurate prognosis.

Canine pericardial effusion: diagnosis,treatment, and prognosis.

Most cases of pericardial effusion can be diagnosed with a thorough physical examination. Physical examination findings may include muffled heart sounds, pulsus paradoxus, and jugular venous distention. Radiographs may show a globoid cardiac silhouette. Echocardiography is reliable in diagnosing pericardial effusion. Pericardiocentesis is indicated for the emergency treatment of pericardial tamponade. Pericardiectomy may improve survival in some dogs. The prognosis varies greatly, depending on the underlying cause.

Advances in respiratory therapy.

Effective respiratory therapy depends on obtaining a definitive diagnosis and following established recommendations for treatment. Unfortunately, many respiratory conditions are idiopathic in origin or are attributable to nonspecific inflammation. In some situations, disorders are controlled rather than cured. Recent advances in pulmonary therapeutics include the use of new agents to treat common diseases and application of local delivery of drugs to enhance drug effect and minimize side effects.

Retrospective study of tetanus in 20 dogs: 1988-2004.

The case records of 20 dogs that were treated for tetanus between 1988 and 2004 were reviewed. Young, large-breed dogs were most commonly affected. Twelve dogs had a likely source of infection identified. All dogs were treated with intravenous antibiotics and supportive care, such as muscle relaxants and sedation for muscle tremors and rigidity. Sixteen dogs received tetanus antitoxin. The mortality rate was 50%. Complete recovery in survivors required approximately 1 month.

Evaluation of a focused assessment with sonography for trauma protocol to detect free abdominal fluid in dogs involved in motor vehicle accidents.

OBJECTIVE: To establish a focused assessment with sonography for trauma (FAST) protocol in dogs, determine whether FAST can be performed by veterinary clinicians without extensive ultrasonographic experience, and assess the frequency of free fluid (as determined via FAST) in the abdominal cavity of dogs following motor vehicle accidents (MVAs). DESIGN: Prospective study. ANIMALS: 100 client-owned dogs evaluated within 24 hours of an MVA. PROCEDURE: Dogs were placed in lateral recumbency for the FAST examination. To detect fluid in the abdomen, 2 ultrasonographic views (transverse and longitudinal) were obtained at each of 4 sites (just caudal to the xiphoid process, on the midline over the urinary bladder, and at the left and right flank regions). RESULTS: In the 100 dogs evaluated via FAST, free abdominal fluid was detected in 45 dogs. In 40 of those 45 dogs, abdominocentesis was performed; hemoperitoneum and uroperitoneum were diagnosed in 38 and 2 dogs, respectively. Compared with dogs that had no free abdominal fluid detected via FAST, dogs that had free abdominal fluid detected via FAST had significantly higher heart rates and serum lactate concentrations and significantly lower PCVs and total solid concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that FAST is a simple and rapid technique that can be performed on dogs in an emergency setting to detect intra-abdominal free fluid and can be performed by veterinary clinicians with minimal previous ultrasonographic experience.

Cardiac troponins I and T in dogs with pericardial effusion.

Cardiac troponin I (cTnI) and cardiac troponin T (cTnT) are sensitive and specific markers for myocardial ischemia and necrosis. Dogs with pericardial effusion frequently have myocardial ischemia and necrosis, and these changes are more severe in dogs with hemangiosarcoma (HSA). We investigated the utility of using serum cTnI and cTnT concentrations to identify the idiopathic pericardial effusion from that associated with HSA. Blood samples for measurement of cTnI and cTnT concentrations were collected before pericardiocentesis in 37 dogs with pericardial effusion. Eighteen dogs had a mass consistent with HSA, 6 dogs had idiopathic pericardial effusion, 1 dog had mesothelioma, and 1 dog had a heart base tumor. No final diagnosis was achieved for 11 dogs. Dogs with pericardial effusion had significantly higher serum concentrations of cTnI (P < .001) but not cTnT (P = .16) than did normal dogs. Dogs with HSA had significantly higher concentrations of cTnI (2.77 ng/dL; range: 0.09-47.18 ng/dL) than did dogs with idiopathic pericardial effusion (0.05 ng/dL; range: 0.03-0.09 ng/dL) (P < .001). There was no difference in the concentration of cTnT between dogs with HSA and those with idiopathic pericardial effusion (P = .08). Measurement of cTnI may be useful in helping to distinguish between idiopathic pericardial effusion and pericardial effusion caused by HSA.

Hemostatic changes in dogs with naturally occurring sepsis.

Sepsis is a frequent source of morbidity and mortality in critically ill patients. The goal of this case control study was to measure hemostatic changes in dogs with naturally occurring sepsis. Blood was collected within 24 hours of admission from 20 dogs that fulfilled the criteria for sepsis. Sepsis was defined as histologic or microbiological confirmation of infection and 2 or more of the following criteria: hypo- or hyperthermia, tachycardia, tachypnea, or leukopenia, leukocytosis, or > 3% bands. Culture and sensitivities were performed on appropriate samples from all septic dogs. Twenty-eight control dogs were enrolled on the basis of normal results of physical examination, CBC, serum biochemistry, and coagulation profile. Plasma samples were analyzed for prothrombin time (PT), partial thromboplastin time (PTT), fibrin(ogen) degradation products (FDP), D-dimer (DD) concentrations, antithrombin (AT) activity, and protein C (PC) activity. Data were compared between groups by chi-square or independent t-tests. PC (P < .001) and AT (P < .001) activities were significantly lower in dogs with sepsis compared to controls. Dogs with sepsis had significantly higher PT (P = .007), PTT (P = .005), D-dimer (P = .005), and FDP (P = .001) compared to controls. Platelet counts were not significantly different between groups. Ten of the 20 septic dogs (50%) died, but no association was identified between any of the measured variables and outcome. These findings are consistent with previous studies in animals with experimentally induced disease and in clinical studies of humans. On the basis of these results, further investigation of the role of AT and PC in canine sepsis is warranted.