BACKGROUND:

Information regarding acute kidney injury (AKI) in cats is limited, and there are no reliable tools to objectively assess disease severity and predict outcome.

OBJECTIVES:

To assess clinical signs, clinicopathologic abnormalities, etiology, and outcome of cats with AKI, and to develop models using clinical metrics and empirically derived scores to predict outcome.

ANIMALS:

One hundred and thirty-two client-owned cats.

METHODS:

Retrospective study. Bivariate logistic regression analyses were performed to identify variables predictive of 30-day survival. Continuous variables outside the reference range were divided into quartiles to yield quartile-specific odds ratios (OR) for survival. Models were developed incorporating weighting factors assigned to each quartile based on the OR. A predictive score for each model was calculated for each cat by summing all weighting factors. A second, multivariable logistic regression model was created from actual values of the same variables. Receiver operating characteristic curve analyses were performed to determine the models' performance. Models were further tested using a subset of cases not used in initial assessment.

RESULTS:

Fifty five of 132 cats (42%) remained dialysis-independent for at least 30 days after discharge, and the remaining 77 cats either died (n = 37, 28%) or were euthanized (n = 40, 30%). The most common etiology was ureteral obstruction (n = 46, 35%). Higher scores were associated with decreased probability of survival (P < .001). Models correctly classified outcomes in 75-77% of the cases and 84-89% of the cases in the subsequent evaluation.

CONCLUSIONS

AND CLINICAL IMPORTANCE: Models can provide objective guidance in assessing AKI prognosis and severity, but should be validated in other cohorts of cats.

BACKGROUND:

Boxer dogs are reported to be predisposed to arrhythmogenic right ventricular cardiomyopathy (ARVC), but the natural history has not been well characterized and inconsistent diagnostic criteria have been applied to identify affected dogs. Echocardiographic examination findings are unremarkable in many affected Boxer dogs, and in these dogs, 24-hour ambulatory ECG (Holter) monitoring often is used for diagnostic and prognostic purposes, despite limited information available relating Holter findings to outcome. HYPOTHESIS/

OBJECTIVES:

Boxers with complex ventricular arrhythmias at initial presentation will have shorter survival times. The objective was to investigate the prognostic value of Holter monitoring in Boxer dogs.

ANIMALS:

One hundred and twenty-two Boxer dogs seen at 3 university referral hospitals.

METHODS:

Retrospective study. Survival times were obtained for Boxer dogs evaluated by echocardiography and a 24-hour Holter ECG. Kaplan-Meier survival analysis was used to estimate the median survival time and Cox proportional hazards analysis was used to identify variables independently associated with cardiac mortality.

RESULTS:

Outcome data were obtained for 122/163 dogs meeting the inclusion criteria. Of the 70 dogs that had died, 45 were considered to have suffered cardiac-related deaths. Median survival was significantly longer in dogs with a left ventricular systolic diameter (LVIDs) ≤ 35 mm compared with those with LVIDs > 35 mm (P < .001). Multivariable analysis in dogs with LVIDs ≤ 35 mm showed that the presence of ventricular tachycardia, age >4.5 years, and male sex were independent predictors of cardiac mortality.

CONCLUSIONS

AND CLINICAL IMPORTANCE: Holter monitoring in Boxer dogs provides valuable prognostic information.

BACKGROUND:

In noncardiac critical disease in humans, myocardial injury as detected by cardiac troponin I and T (cTnI and cTnT) has been linked to high intensive care unit (ICU) death independent of prognostic composite scoring.

HYPOTHESIS:

Presence of myocardial injury predicts short-term death in critically ill dogs with systemic inflammation and provides additional prognostic information when combined with established canine prognostic composite scores.

ANIMALS:

Forty-two dogs admitted to the ICU with evidence of systemic inflammation and no primary cardiac disease.

METHODS:

Prospective cohort study. Blood samples were obtained at ICU admission for the measurement of cTnI and cTnT, C-reactive protein, and several cytokines. The acute patient physiologic and laboratory evaluation (APPLE) score and the survival prediction index were calculated within the first 24 hours of admission. Receiver operating characteristic (ROC) curves were used to examine the prognostic capacity of each biomarker and severity score. Multiple logistic regression analysis was performed to evaluate whether cardiac markers significantly contributed to severity scores.

RESULTS:

Twenty-eight day case fatality rate was 26% (11/42 dogs). cTnI concentrations were (median [range]) 0.416 [0.004-141.5] ng/mL and cTnT concentrations were 13.5 [<13-3,744] ng/L. cTnI, cTnT, and the APPLE score were all significant prognosticators with areas under the ROC curves [95% CI] of 0.801 [0.649; 0.907], 0.790 [0.637; 0.900], and 0.776 [0.621; 0.889], respectively. cTnI significantly contributed to the APPLE score in providing additional prognostic specificity (P = .025).

CONCLUSIONS

AND CLINICAL IMPORTANCE: Markers of myocardial injury predict short-term death in dogs with systemic inflammation and cTnI significantly contributes to the APPLE score.

BACKGROUND:

In humans, fresh frozen plasma (FFP) loses factor V and VIII activities after 1 year. It then becomes frozen plasma (FP), and theoretically is unsuitable for use in patients with coagulopathies. These findings have not been reported for dogs.

HYPOTHESIS:

Canine FP is hemostatically active after 5 years of storage.

ANIMALS:

Fresh plasma (Group FsP; n = 15) and 5-year-old FP (Group FzP; n = 10) from blood bank donors.

METHODS:

Group FsP and Group FzP samples were evaluated by thromboelastography (TEG), one-stage prothrombin time (OSPT), activated partial thromboplastin time (APTT), fibrinogen, and antithrombin. Fresh plasma (n = 6) and a subset of Group FzP (n = 8) were evaluated for clotting factor activities (V, VIII, IX, X). A 2nd experiment using short-term storage of thawed FP under suboptimal conditions (refrigerated [4°C] or refrozen [-20°C]) by TEG was performed to simulate general practice storage capabilities.

RESULTS:

Group FzP had shorter reaction time (P = .0007) and larger angle (P = .0004) compared with Group FsP by TEG, suggesting hypercoaguability. Factor VIII and X activities were lower in Group FzP (P = .02 and .005, respectively). Fibrinogen, OSPT, and APTT were significantly lower or longer for Group FzP than Group FsP (P < .05), but most values remained within reference intervals for dogs.

CONCLUSIONS

AND CLINICAL IMPORTANCE: Five-year-old canine FP stored at -30°C is hemostatically active and should be clinically evaluated in patients with coagulopathies. If active, the monetary savings of using older plasma will be substantial.

BACKGROUND:

The detailed pathological phenotype of diet-responsive chronic enteropathy (CE) and its modulation with dietary therapy remain poorly characterized. HYPOTHESIS/

OBJECTIVES:

Key mucosal lesions of diet-responsive CE resolve with dietary therapy.

METHODS:

This was a prospective observational study of 20 dogs with diet-responsive CE. Endoscopic duodenal biopsies collected before and 6 weeks after the start of a dietary trial were assessed by means of qualitative and quantitative histopathological, immunohistochemical, and ultrastructural criteria. Control duodenal biopsies were obtained from 10 healthy Beagle dogs on 1 occasion.

RESULTS:

Compared with control dogs, the CE dogs had higher villus stunting scores and higher overall WSAVA scores, a lower villus height-to-width ratio, and higher lamina propria density of eosinophils. The CE dogs also had ultrastructural lesions of the mitochondria and brush border. In common with other studies in which the disease and control populations are not matched for breed, age, sex, and environment, these comparisons should be interpreted with caution. Comparing biopsies collected at presentation and 6 weeks after starting the dietary trial, mean lamina propria mononuclear cell score and lamina propria densities of eosinophils and mononuclear cells decreased. Dietary therapy also improved ultrastructural lesions of the mitochondria and brush border, eliciting a decrease in intermicrovillar space and an increase in microvillus height.

CONCLUSIONS

AND CLINICAL IMPORTANCE: In dogs with diet-responsive CE, the remission of clinical signs with dietary therapy is associated with subtle decreases in lamina propria density of eosinophils and mononuclear cells, and resolution of ultrastructural lesions of the enterocyte.

BACKGROUND:

Food and Drug Administration Center for Veterinary Medicine (FDA/CVM) cited concern regarding failure of heartworm prophylaxis. The positive and negative predictive value of the heartworm antigen test is an estimate of the probability of adult heartworm infection. HYPOTHESIS/

OBJECTIVES:

Assess the sensitivity, specificity, and predictive value of heartworm antigen tests. Explore the role of heartworm test accuracy and treatment with immiticide to generate reports of suspected failure of heartworm prophylaxis.

METHODS:

Literature searches for published information on the accuracy of heartworm antigen tests and efficacy of immiticide for treatment of the adult heartworm.

RESULTS:

Weighted averages for heartworm antigen test sensitivity and specificity were 78.2 and 97.3%, respectively. Efficacy of immiticide by 2-injection or alternate dose protocols were 88.3 and 89.1%, respectively. Depending on prevalence, the positive predictive value of the heartworm antigen test ranged from 15 to 54% and negative predictive value from 99 to 99.9%. For a hospital testing 1,000 dogs per year, false-positive test results may vary from 24 to 27 dogs. If these dogs were on heartworm preventive, they may undergo treatment and be classified as prophylaxis failures. Ten percent of dogs who were treated and continued or placed on prophylaxis at the time of treatment may have adult heartworms when tested 1 year later and be presumed to represent failure of prophylaxis.

CONCLUSIONS:

When interpreting heartworm antigen test results, clinical signs, history, and regional prevalence of heartworm disease should be considered in estimating the predictive value of the test result. Limitations of test and treatment should be discussed with clients as part of the decision-making process.

BACKGROUND:

The stoic nature of alpacas and limitations of current diagnostic tests make early recognition of inflammatory diseases in this species challenging.

OBJECTIVES:

In a model of mild systemic inflammation, this study evaluated the utility of different clinical and clinicopathologic variables as accurate predictors of inflammation in alpacas.

ANIMALS:

Twelve clinically healthy alpacas were randomly assigned to equal-sized treatment (TG) and control (CG) groups. After collection of initial blood samples (0 hour), lipopolysaccharide (LPS; 20 μg/kg/24 h) or saline was administered by SC osmotic mini-pumps (OMP) for 96 hours. Additional blood samples were collected at 12, 18, 24, 36, 48, 72, 96, 120, 144, and 240 hours and differential leukocyte counts and concentrations of globulin, albumin, iron, haptoglobin, and serum amyloid A were measured.

RESULTS:

Mild swelling was observed at OMP implantation sites in both groups. Other clinical signs of systemic inflammation were not observed. Total leukocytes, neutrophils, albumin, and globulin concentrations were not significantly different between groups. Compared with CG-alpacas, TG-alpacas had fewer lymphocytes (P = .0322), more band neutrophils (P = .0087), and higher neutrophil/lymphocyte ratios (P = .0295) during the first 96 hours of the study. During LPS administration, serum iron concentrations were significantly decreased in TG-alpacas (P < .0001). Haptoglobin concentrations of TG-animals exceeded those of CG-animals after removal of OMP (P = .0056). Serum amyloid A was not detectable in alpacas in this study.

CONCLUSION

AND CLINICAL IMPORTANCE: These results indicated that neutrophil/lymphocyte ratios and serum iron concentrations are early indicators of inflammation in alpacas. Additional research is needed to evaluate the acute phase protein responses of alpacas.

BACKGROUND:

Vinorelbine (VRL) has been investigated in dogs, but its use in cats has not been studied. HYPOTHESIS/

OBJECTIVES:

To determine the maximal tolerated dose (MTD) and dose-limiting toxicity (DLT) of VRL in tumor-bearing cats.

ANIMALS:

Cats were included in this prospective phase I trial if they had confirmed malignancy, received ≥1 VRL treatment, and had adequate follow-up. Previous treatment was acceptable, but concurrent chemotherapy or radiotherapy was not permitted.

METHODS:

Using a modified phase I design, cats were enrolled in cohorts of 3 at a starting dosage of 9 mg/m(2) . Cats tolerating the first treatment well were eligible to receive additional VRL treatments at escalating dosages; escalations beyond the perceived MTD were permitted based on individual tolerance. Intended treatment interval was 7 days. Patient histories, physical examinations, and complete blood counts were performed weekly.

RESULTS:

Nineteen cats were included. Sixty-one VRL treatments were administered. Median number of treatments was 2 (range, 1-9). Starting dosages were 9-12 mg/m(2) . Maximal dosage administered was 15.5 mg/m(2) . The MTD was 11.5 mg/m(2) . Acute DLTs were neutropenia, vomiting, and nephrotoxicity. Other notable toxicities were weight loss and anemia.

CONCLUSIONS

AND CLINICAL IMPORTANCE: Vinorelbine is tolerated in cats at a weekly interval. Recommended starting dosage is 11.5 mg/m(2) . Neutropenia was transient, lasting <7 days; vomiting was self-limiting in most cases. Although VRL-associated nephrotoxicity has not been reported, potential attribution of this toxicity to VRL must not be discounted. Further investigation of the efficacy of VRL in feline malignancies is warranted.

BACKGROUND:

Chagas disease (Trypanosomiasis) is a cause of myocarditis in the southern United States causing cardiac conduction abnormalities, arrhythmias, and heart failure.

OBJECTIVES:

To report clinical findings and outcome in Chagas positive (CP) dogs requiring pacemaker implantation for bradyarrhythmias.

ANIMALS:

One hundred and forty-four client-owned dogs requiring pacemaker implantation.

METHODS:

Retrospective case series. Information regarding history, physical exam, laboratory and diagnostic imaging findings, treatment, and survival were obtained from medical records, with additional follow-up information obtained by contacting referring veterinarians and owners.

RESULTS:

Of the 144 dogs requiring pacemaker implantation from January 2001 to May 2010, 83 (57.6%) had a Chagas titer performed and 9 (10%) were CP. Concurrent ventricular arrhythmias (odds ratio 1.61, P = .005) or atrioventricular (AV) block (odds ratio 4.18, P < .001) increased the likelihood that a Chagas titer was submitted. Median age for CP dogs was 6.2 years (range, 0.3-10); 7 were male. Bradyarrhythmias included high-grade 2nd or 3rd degree AV block (n = 8) and sinus bradycardia with 1st degree AV block (n = 1); 5 had concurrent ventricular arrhythmias. A positive Chagas titer had a negative impact on survival (hazard ratio 4.04; 95% CI 1.36-12.1, P = .012) with a reported median survival time of 365 days (interquartile range, 84-973 days).

CONCLUSIONS

AND CLINICAL IMPORTANCE: Bradyarrhythmias can result in clinical signs requiring pacemaker implantation in CP dogs, and although the diagnosis negatively impacts survival, pacemaker therapy is a viable treatment option.