Prevalence and Prognostic Importance of Pulmonary Hypertension in Dogs with Myxomatous Mitral Valve Disease

Background

Pulmonary hypertension (PH) is common in dogs with myxomatous mitral valve disease (MMVD) but its effect on clinical outcome has not been investigated.

Hypothesis/objectives

The presence of PH worsens the outcome in dogs with MMVD. To compare survival times of dogs with MMVD and PH to those without PH.

Animals

Two hundred and twelve client‐owned dogs.

Methods

Case review study. Medical records of dogs diagnosed with ACVIM stage B2 and C MMVD between January 2010 and December 2011 were retrospectively reviewed. Long‐term outcome was determined by telephone interview or from the medical record. End of the observation period was March 2013. PH was identified if tricuspid regurgitation peak velocity was >3 m/s.

Results

Two hundred and twelve were identified. Eighty‐three dogs (39%) had PH. PH was more commonly identified in stage C compared to B2 (P < .0001). One hundred and five (49.5%) dogs died during the observation period. Median survival time for the entire study population was 567 days (95% CI 512–743). Stage C (P = .003), the presence of PH (P = .009), left atrial to aortic root ratio (LA/Ao) >1.7 (P = .0002), normalized left‐ventricular end‐diastolic diameter (LVEDn) >1.73 (P = .048), and tricuspid regurgitation pressure gradient (TRPG) >55 mmHg (P = .009) were associated with worse outcomes in the univariate analyses. The presence of TRPG >55 mmHg (HR 1.8 95% CI 1–2.9; P = .05) and LA/Ao > 1.7 (HR 2 95% CI 1.2–3.4; P = .01) remained significant predictors of worse outcome in the multivariate analysis.

Conclusions and Clinical Importance

In dogs with MMVD, moderate to severe PH worsens outcome.     

Glucocorticoid Receptor Density and Binding Affinity in Healthy Horses and Horses with Systemic Inflammatory Response Syndrome

Background

Dysregulation of the hypothalamic‐pituitary‐adrenal (HPA) axis occurs in horses with systemic inflammatory response syndrome (SIRS). Peripheral resistance to glucocorticoids has not been investigated in horses.

Objective

To determine if glucocorticoid receptor (GR) function in horses can be measured using flow cytometry, and to use this information to evaluate HPA axis dynamics.

Animals

Eleven healthy adult horses in parts 1 and 2. Ten horses with SIRS and 10 age and sex matched controls in part 3.

Methods

Flow cytometry was used to evaluate GR density and binding affinity (BA) in 3 healthy horses in part 1. In part 2, exogenous ACTH was administered to eight healthy horses. Their cortisol response and GR properties were measured. In part 3, CBC, serum biochemistry, cortisol and ACTH, and GR properties were compared between controls without SIRS (n = 10) and horses with SIRS (n = 10), and between survivors and nonsurvivors (n = 4 and n = 6 respectively).

Results

Flow cytometry can be used to measure GR properties in equine PBMCs. No correlation was observed between plasma cortisol concentration and GR density or BA in healthy horses (r = −0.145, P = .428 and r = 0.046, P = .802 respectively). Nonsurvivors with SIRS had significantly decreased GR BA (P = .008). Horses with triglyceride concentration > 28.5 mg/dL had increased odds of nonsurvival (OR=117; 95% CI, 1.94–7,060). GR BA <35.79% was associated with nonsurvival (OR = 30.33; 95% CI, 0.96–960.5).

Conclusions and Clinical Importance

Tissue resistance to glucocorticoids contributes to HPA axis dysfunction in adult horses with SIRS. These horses might benefit from treatment with exogenous glucocorticoids.     

Quantitative Contrast‐enhanced Ultrasonographic Assessment of Naturally Occurring Pancreatitis in Dogs

Background

Quantitative contrast‐enhanced ultrasonography (CEUS) can detect pancreatic perfusion changes in experimentally induced canine pancreatitis. However, its usefulness in detecting perfusion changes in naturally occurring pancreatitis is unclear.

Hypothesis/Objectives

To determine the feasibility of using CEUS to detect pancreatic and duodenal perfusion changes in naturally occurring canine pancreatitis.

Animals

Twenty‐three client‐owned dogs with pancreatitis, 12 healthy control dogs.

Methods

Dogs diagnosed with pancreatitis were prospectively included. CEUS of the pancreas and duodenum were performed. Time‐intensity curves were created from regions of interest in the pancreas and duodenum. Five perfusion parameters were obtained for statistical analyses: time to initial up‐slope, peak time (Tp), time to wash‐out (TTW), peak intensity (PI), and area under the curve (AUC).

Results

For the pancreas, Tp of the pancreatitis group was prolonged when compared to controls (62 ± 11 seconds versus 39 ± 13 seconds; P < .001). TTW also was prolonged but not significantly (268 ± 69 seconds versus 228 ± 47 seconds; P = .47). PI and AUC were increased when compared to controls (95 ± 15 versus 78 ± 13 MPV; P = .009 and 14,900 ± 3,400 versus 11,000 ± 2,800 MPV*s; P = .013, respectively). For the duodenum, PI and AUC were significantly increased in the pancreatitis group when compared to controls.

Conclusions and Clinical Importance

Contrast‐enhanced ultrasonography can detect pancreatic perfusion changes in naturally occurring canine pancreatitis characterized by delayed peak with prolonged hyperechoic enhancement of the pancreas on CEUS. Additionally, duodenal perfusion changes secondary to pancreatitis were observed.     

Randomized Phase III Trial of Piroxicam in Combination with Mitoxantrone or Carboplatin for First‐Line Treatment of Urogenital Tract Transitional Cell Carcinoma in Dogs

Background

Reported response rates of transitional cell carcinoma (TCC) in dogs to piroxicam in combination with either mitoxantrone or carboplatin are similar; however, it is unknown whether either drug might provide superior duration of response.

Hypothesis/Objectives

To determine if the progression‐free interval (PFI) of dogs with TCC treated with mitoxantrone and piroxicam was different than that of dogs receiving carboplatin and piroxicam. The hypothesis was that the efficacy of mitoxantrone is no different from carboplatin.

Animals

Fifty dogs with TCC without azotemia.

Methods

Prospective open‐label phase III randomized study. Either mitoxantrone or carboplatin was administered every 3 weeks concurrently with piroxicam with restaging at 6‐week intervals. Twenty‐four dogs received carboplatin and 26 received mitoxantrone.

Results

Response was not different between groups (P = .56). None of the dogs showed complete response. In the mitoxantrone group, there were 2 (8%) partial responses (PR) and 18 (69%) dogs with stable disease (SD). In the carboplatin group, there were 3 PR (13%) and 13 (54%) dogs with SD. The PFI was not significantly different between groups (mitoxantrone = 106 days; carboplatin = 73.5 days; P = .62; hazard ratio 0.86; 95% confidence interval 0.47–1.56). Dogs with prostatic involvement experienced a shorter survival (median, 109 days) compared to dogs with urethral, trigonal, or apically located tumors; this difference was significant (median 300, 190, and 645 days, respectively; P = .005).

Conclusions and Clinical Importance

This study did not detect a different in outcome in dogs with TCC treated with either mitoxantrone or carboplatin in combination with piroxicam.     

Prognostic Value of Left Atrial Function in Dogs with Chronic Mitral Valvular Heart Disease

Background

A strong correlation between left atrial (LA) dysfunction and the severity of cardiac disease has been described in human patients with various cardiac diseases. The role of LA dysfunction in dogs with chronic mitral valvular heart disease (CMVHD) has not been addressed.

Objectives

To investigate the correlation between LA function and the prognosis of dogs with CMVHD.

Animals

Thirty‐eight client‐owned dogs with CMVHD.

Methods

Prospective clinical cohort study. Dogs were divided into 2 groups (survivors and nonsurvivors) based on the onset of cardiac‐related death within 1 year. Physical examination and echocardiographic variables were compared between the groups. For the assessment of the comparative accuracy in identifying patients with cardiac‐related death, receiver operating characteristic (ROC) curves and multivariate logistic analysis were used.

Results

The highest accuracy was obtained for the LA active fractional area change (LA‐FAC _act), with an area under the ROC curve (AUC) of 0.95, followed by the left atrial to aortic root ratio (LA/Ao), with an AUC of 0.94; peak early diastolic mitral inflow velocity (E), with an AUC of 0.85; and LA total fractional area change (LA‐FAC _total), with an AUC of 0.85. In the multivariate logistic regression analysis, LA‐FAC _act emerged as the only independent correlate of cardiac‐related death within 1 year (odds ratio = 1.401, P = .002).

Conclusions and Clinical Importance

Regarding both the size and function, the LA has a strong correlation with the prognosis of dogs with CMVHD. The most significant independent predictor of mortality in this study was LA‐FAC _act.     

Relationship between lean body mass and serum renal biomarkers in healthy dogs

Background

Symmetric dimethylarginine (SDMA) is an accurate and precise biomarker for estimating glomerular filtration rate (GFR) in humans and cats. Serum creatinine (sCr) also correlates with GFR, but has limitations as a biomarker of renal function because nonrenal factors can influence its concentration.

Hypothesis

Differences in lean body mass (LBM) influence sCr, but not serum SDMA concentrations.

Animals

Forty‐one healthy Beagles, mean age 9.9 years (range: 3.1–14.8 years), were studied over a 6 month period.

Methods

Serum biomarkers of renal function were measured prospectively at baseline, and 1, 3, and 6 months. SDMA concentrations were measured by liquid chromatography‐mass spectroscopy and sCr concentrations by enzymatic colorimetry. Body composition was determined by dual energy x‐ray absorptiometry.

Results

LBM (P < .001) and age (P = .006) were significant explanatory variables for sCr concentration (R ²  = 0.38), but not SDMA concentration. Time on food was the only significant explanatory variable for SDMA concentration (R ²  = 0.49). SDMA concentrations decreased across time (P < .001). LBM was affected by sex (males > females; P = .02). Mature adult dogs (<8 years) had greater LBM compared with geriatric dogs (≥8 years; P < .001).

Conclusion and Clinical Importance

sCr concentrations, but not SDMA concentrations, are influenced by LBM, which limits sCr utility as a biomarker for monitoring renal function in dogs with decreased LBM. Reductions in LBM can lower sCr concentration and overestimate GFR. SDMA concentrations, but not sCr concentrations were influenced by time on food. SDMA could have clinical advantages over sCr in monitoring response to nutritional interventions.     

The Clinical and Serological Effect of a Gluten‐Free Diet in Border Terriers with Epileptoid Cramping Syndrome

Background

Canine epileptoid cramping syndrome (CECS) is a paroxysmal movement disorder of Border Terriers (BTs). These dogs might respond to a gluten‐free diet.

Objectives

The objective of this study was to examine the clinical and serological effect of a gluten‐free diet in BTs with CECS.

Animals

Six client‐owned BTs with clinically confirmed CECS.

Methods

Dogs were prospectively recruited that had at least a 6‐month history of CECS based on the observed phenomenology (using video) and had exhibited at least 2 separate episodes on different days. Dogs were tested for anti‐transglutaminase 2 (TG2 IgA) and anti‐gliadin (AGA IgG) antibodies in the serum at presentation, and 3, 6, and 9 months after the introduction of a gluten‐free diet. Duodenal biopsies were performed in 1 dog.

Results

Serum TG2 IgA titers were increased in 6/6 BTs (P = .006) and AGA IgG titers were increased in 5/6 BTs at presentation compared to those of controls (P = .018). After 9 months, there was clinical and serological improvement in all BTs with CECS strictly adhering to a gluten‐free diet (5/5). One dog had persistently increased antibody titers. This dog scavenged horse manure. On the strict introduction of a gluten‐free diet this dog also had an improved clinical and serological response. The diet‐associated improvement was reversible in 2 dogs on completion of the study, both of which suffered a relapse of CECS on the re‐introduction of gluten.

Conclusions

Canine epileptoid cramping syndrome in BTs is a gluten‐sensitive movement disorder triggered and perpetuated by gluten and thus responsive to a gluten‐free diet.     

Clinical Severity Score System in Dogs with Degenerative Mitral Valve Disease

Background

Several risk factors already have been determined for dogs with degenerative mitral valve disease (DMVD). Risk factors often have been considered in isolation and have not always taken into account additional information provided by the history and physical examination (PE).

Hypothesis/Objectives

Data obtained from history and PE of dogs with DMVD provide prognostic information and can be used for risk stratification.

Animals

Client‐owned dogs (n = 244) with DMVD recruited from first opinion practice.

Methods

Prospective longitudinal follow‐up of dogs with DMVD. History and PE data were obtained at 6‐month intervals and analyzed with time‐dependent Cox models to derive relative risk of cardiac death. Independent hazard ratios were used to derive a clinical severity score (CSS), the prognostic value of which was evaluated by analyzing the median survival times for different risk groups and ROC analysis. Analysis of the progression of CSS over time also was undertaken.

Results

History of cough, exercise intolerance, decreased appetite, breathlessness (difficulty breathing) and syncope with PE findings of heart murmur intensity louder than III/VI and absence of respiratory sinus arrhythmia were independently associated with outcome and allowed development of the CSS. Clinical severity score distinguished groups of dogs with significantly different outcomes.

Conclusions and Clinical Importance

Routinely obtained clinical findings allow risk stratification of dogs with DMVD. Results of ancillary diagnostic tests may be complementary to history and PE findings and always should be interpreted in conjunction with these findings.     

Early Tumor Response to Intraarterial or Intravenous Administration of Carboplatin to Treat Naturally Occurring Lower Urinary Tract Carcinoma in Dogs

Background

Survival times and tumor responses associated with malignant neoplasia of the lower urinary tract are poor despite the vast array of current treatments. Therefore, the evaluation of alternative treatments, such as intraarterial administration of chemotherapy (IAC) should be considered.

Objective

To describe a technique for superselective catheterization for IAC and to evaluate initial tumor response by ultrasonography after both IAC and intravenous administration of chemotherapy (IVC).

Animals

Client‐owned dogs with lower urinary tract neoplasia treated with either IVC (n = 15) or IAC (n = 11).

Methods

Retrospective study. An arterial approach via the carotid or femoral artery was utilized to obtain superselective access and administer chemotherapy in the IAC cases. Medical record review was performed, data were recorded, and recorded variables were evaluated statistically.

Results

Intraarterial chemotherapy was successfully administered in all cases. There was a significantly greater decrease in longest unidimensional measurement in the IAC group as compared to the IVC group (P = .013). The IAC group was also significantly more likely to have a tumor response as assessed by modified RECIST guidelines (P = .049). Dogs in the IAC group were significantly less likely to develop anemia (P = .001), lethargy (P = .010) and anorexia (P = .024).

Conclusion and Clinical Importance

This study demonstrated the feasibility and efficacy of performing IAC for lower urinary tract neoplasia. Further investigation is necessary as the follow‐up time was short and the impact on long‐term outcome and survival was not determined.     

Longitudinal Electrocardiographic Evaluation of Dogs with Degenerative Mitral Valve Disease

Background

Increased heart rate (HR) and decreased heart rate variability (HRV) are evident in some dogs with degenerative mitral valve disease (DMVD).

Objectives

Evaluation of the factors influencing HR and HRV (assessed by the vasovagal tonus index; VVTI) and their change over time in dogs with DMVD.

Animals

Client‐owned dogs (n = 257) with DMVD recruited from first opinion practice.

Methods

Prospective longitudinal follow‐up at six‐monthly intervals of dogs with DMVD. Dogs followed up for at least 18 months (n = 102) were grouped according to their outcome as dogs dying/euthanized because of cardiac disease (n = 28; Group 1), noncardiac disease (n = 40; Group 2) and dogs alive (n = 34; Group 3). HR and VVTI were measured on 1‐minute ECG recordings. Repeated measures linear models were constructed to investigate the factors that influence HR and VVTI and their changes over time.

Results

Heart rate and VVTI were affected by disease severity and were different in Cavaliers compared to other breeds. Group 1 and Group 2 dogs underwent an increase in HR and decrease in VVTI, evident at least 18 months before death. Group 1 had a further decrease in VVTI followed by an increase in HR approximately 1 year and 6 months before death, respectively.

Conclusions and Clinical Importance

Dogs with DMVD have an increase in HR and decrease in HRV over a year before death, with greater changes in those dogs dying/euthanized because of cardiac disease. Both HR and VVTI can potentially be regarded as biomarkers for all‐cause mortality.     

Relationship of Body Size to Metabolic Markers and Left Ventricular Hypertrophy in Cats

Background

Cats with hypertrophic cardiomyopathy (HCM) are larger and have higher insulin‐like growth factor‐1 (IGF‐1) concentrations than cats without HCM.

Hypothesis/Objectives

The aim of this study was to assess echocardiographic findings in a colony of adult cats to determine the relationship between early growth and left ventricular hypertrophy (LVH).

Animals

Twenty‐eight neutered adult cats (20 males, 8 females) from a colony ≥3 years of age for which growth curves were available.

Methods

Case–control study. Physical examination and echocardiography were performed, and body weight, body condition score (BCS), and head length and width were measured. Circulating glucose, insulin, N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP), and IGF‐1 concentrations were measured and growth data were collected. Stepwise multivariate analyses were performed.

Results

Mean age was 5.2 ± 1.1 years. Current BCSs ranged from 4 to 9 (median, 6) and mean body weight was 4.88 ± 1.29 kg. Variation in body weight was apparent by 6 (mean = 3.26 ± 0.80 kg) and 12 months of age (mean = 4.02 ± 1.02 kg). Cardiac abnormalities included a cardiac murmur (n = 7; 24%), gallop (n = 3; 10%), and arrhythmia (n = 1; 4%). Fourteen of 28 cats (50%) had echocardiographic evidence of LVH. Head width (P = .017), body weight (P < .001), NT‐proBNP (P = .023), and IGF‐1 (P = .013–.022) were significantly associated with selected measures of LVH.

Conclusions and Clinical Importance

Potential associations between body size, IGF‐1, LVH, and HCM warrant future prospective studies.     

Estimating the Sensitivity and Specificity of Real‐Time Quantitative PCR of Fecal Samples for Diagnosis of Rhodococcus equi Pneumonia in Foals

Background

Real‐time, quantitative PCR (qPCR) methods for detecting Rhodococcus equi in feces have been developed as a noninvasive, rapid diagnostic test for R. equi pneumonia, but have not been evaluated in a large population of foals.

Objective

The objective of this study was to evaluate the clinical utility of fecal PCR as a diagnostic test for R. equi pneumonia in foals using receiver operating characteristic (ROC) methods.

Animals

186 foals born in 2011 at an R. equi‐endemic ranch in Texas.

Methods

Fecal samples were collected at the time of onset of clinical signs for pneumonic foals (n = 31). Foals with pneumonia were matched by age and birth date to healthy (n = 31) and subclinical (n = 124) control foals; fecal samples were collected from these controls. DNA was extracted from feces using commercial kits and concentration of virulent R. equi in feces was determined by qPCR.

Results

Concentration of R. equi in feces differed significantly (P < .05) among groups. The area under the ROC curve for fecal qPCR for diagnosis of R. equi pneumonia was 89% (95% CI, 83–99), with a sensitivity of 94% and specificity of 72%.

Conclusions and Clinical Importance

qPCR of feces can be useful as an alternative to tracheobronchial aspiration for the diagnosis of R. equi in foals with clinical signs of pneumonia. Caution should be used in extrapolating results of this study to other populations because fecal concentration of R. equi might vary by geographic location or management practices.     

Discrepancies in Identification of Left Atrial Enlargement Using Left Atrial Volume versus Left Atrial‐to‐Aortic Root Ratio in Dogs

Background

Left atrial size is prognostically important in dogs with myxomatous mitral valve disease (MMVD).

Hypothesis/Objectives

To compare the level of agreement in identification of left atrial enlargement (LAE) between the left atrial‐to‐aortic root ratio (LA : Ao) and left atrial volume using the biplane area‐length method indexed to body weight (LA Vol/BW).

Animals

Sixty dogs with MMVD and 22 normal dogs were prospectively studied with 2‐dimensional echocardiography.

Methods

The upper limit of normal for LA Vol/BW was defined as 1.1 mL/kg. LA : Ao was deemed normal if ≤1.5. To define overall disease severity, each dog was assigned a mitral regurgitation severity score (MRSS) based on echocardiographic parameters that did not include left atrial size. ACVIM staging also was utilized.

Results

Of 60 affected dogs, 20 were ACVIM Stage B1, 25 were Stage B2, and 15 were Stage C. LA Vol/BW identified LAE in 12 cases in which LA : Ao was normal; 7 of these were Stage B1 and 5 were Stage B2. This diagnostic disagreement was significant (P = .00012). Of the 12 cases in which diagnostic discrepancies were identified, 5/5 of the B2 dogs and 3/7 B1 dogs had a moderate MRSS, whereas 4/7 B1 dogs had a mild MRSS. No diagnostic discrepancies between LA : Ao and LA Vol/BW were apparent in dogs with a severe MRSS.

Conclusions and Clinical Importance

This study shows evidence of diagnostic disagreement between LA : Ao and LA Vol/BW for assessment of LAE. LA Vol/BW may be superior to LA : Ao for identification of mild LAE.     

Serum Cortisol Concentrations in Dogs with Pituitary‐Dependent Hyperadrenocorticism and Atypical Hyperadrenocorticism

Background

Atypical hyperadrenocorticism (AHAC) is considered when dogs have clinical signs of hypercortisolemia with normal hyperadrenocorticism screening tests.

Hypothesis/Objectives

To compare cortisol concentrations and adrenal gland size among dogs with pituitary‐dependent hyperadrenocorticism (PDH), atypical hyperadrenocorticism (AHAC), and healthy controls.

Animals

Ten healthy dogs, 7 dogs with PDH, and 8 dogs with AHAC.

Method

Dogs were prospectively enrolled between November 2011 and January 2013. Dogs were diagnosed with PDH or AHAC based on clinical signs and positive screening test results (PDH) or abnormal extended adrenal hormone panel results (AHAC). Transverse adrenal gland measurements were obtained by abdominal ultrasound. Hourly mean cortisol (9 samplings), sum of hourly cortisol measurements and adrenal gland sizes were compared among the 3 groups.

Results

Hourly (control, 1.4 ± 0.6 μg/dL; AHAC, 2.9 ± 1.3; PDH, 4.3 ± 1.5) (mean, SD) and sum (control, 11.3 ± 3.3; AHAC, 23.2 ± 7.7; PDH, 34.7 ± 9.9) cortisol concentrations differed significantly between the controls and AHAC (P < .01) and PDH (P < .01) groups. Hourly (P < .01) but not sum (P = .27) cortisol concentrations differed between AHAC and PDH dogs. Average transverse adrenal gland diameter of control dogs (5.3 ± 1.2 mm) was significantly less than dogs with PDH (6.4 ± 1.4; P = .02) and AHAC (7.2 ± 1.5; P < .01); adrenal gland diameter did not differ (P = .18) between dogs with AHAC and PDH.

Conclusions and Clinical Importance

Serum cortisol concentrations in dogs with AHAC were increased compared to controls but less than dogs with PDH, while adrenal gland diameter was similar between dogs with AHAC and PDH. These findings suggest cortisol excess could contribute to the pathophysiology of AHAC.     

Dorsal Compressive Atlantoaxial Bands and the Craniocervical Junction Syndrome: Association with Clinical Signs and Syringomyelia in Mature Cavalier King Charles Spaniels

Background

Dorsal compressive lesions at the atlantoaxial junction (ie, AA bands) occur in dogs with Chiari‐like malformations (CMs), but their clinical relevance is unclear.

Objective

Investigate the influence of AA bands on clinical status and syringomyelia (SM) in mature cavalier King Charles spaniels (CKCS).

Animals

Thirty‐six CKCS, 5–12 years of age, including 20 dogs with neuropathic pain.

Methods

Dogs were examined and assigned a neurologic grade. Magnetic resonance imaging (MRI) of the craniocervical junction was performed with the craniocervical junction extended and flexed (ie, normal standing position). Imaging studies were assessed for the presence of an AA band, CM, SM or some combination of these findings. Band and SM severity were quantified using an objective compression index and ordinal grading scale, respectively.

Results

Of 36 CKCS imaged, 34 had CM. Atlantoaxial bands were present in 31 dogs and were more prominent in extended than flexed positions. Syringomyelia was found in 26 dogs, 23 of which also had AA bands. Bands were associated with both the presence (P = .0031) and severity (P = .008) of clinical signs and SM (P = .0147, P = .0311, respectively). Higher compression indices were associated with more severe SM (P = .0137).

Conclusions

Prevalence of AA bands in older CKCS is high. Positioning of dogs in extension during MRI enhances the sensitivity of the study for detecting this important abnormality. There were significant associations among AA bands, clinical signs, and SM in dogs with CM; additional work is needed to understand whether or not this relationship is causal.     

Association of Vitamin D Status and Clinical Outcome in Dogs with a Chronic Enteropathy

Background

Dogs with a chronic enteropathy (CE) have a lower vitamin D status, than do healthy dogs. Vitamin D status has been associated with a negative clinical outcome in humans with inflammatory bowel disease.

Objectives

To examine the relationship between serum 25 hydroxyvitamin D (25(OH)D) concentrations at diagnosis and clinical outcome in dogs with a CE.

Animals

Forty‐one dogs diagnosed with CE admitted to the Royal Dick School of Veterinary Studies, Hospital for Small Animals between 2007 and 2013.

Methods

Retrospective review. Serum 25(OH)D concentrations were compared between dogs which were alive at follow up or had died because of non‐CE‐related reasons (survivors) and dogs which died or were euthanized due to their CE (non‐survivors). A binary logistic regression analysis was performed to determine significant predictors of death in dogs with CE.

Results

Serum concentrations of 25(OH)D at the time a CE was diagnosed were significantly lower in nonsurvivors (n = 15) (median nonsurvivors 4.36 ng/mL, interquartile range 1.6–17.0 ng/mL), median survivors (n = 26) (24.9 ng/mL interquartile range 15.63–39.45 ng/mL, P < .001). Serum 25(OH)D concentration was a significant predictor of death in dogs with CE (odds ratio 1.08 [95% CI 1.02–1.18)]).

Conclusions

Serum 25(OH)D concentrations at diagnosis are predictive of outcome in dogs with CE. The role of vitamin D in the initiation and outcome of chronic enteropathies in dogs is deserving of further study.     

Usefulness of Conventional and Tissue Doppler Echocardiography to Predict Congestive Heart Failure in Dogs with Myxomatous Mitral Valve Disease

Background

Systolic and diastolic functions have been evaluated to predict outcome in congestive heart failure (CHF). Recently, tissue Doppler imaging (TDI) has become useful for the estimation of myocardial function in cardiac diseases of humans and animals.

Objective

This study was designed to assess whether myocardial function as assessed by TDI is associated with the occurrence of CHF in dogs with myxomatous mitral valve disease (MMVD) and whether additional information is gained over conventional Doppler variables.

Animals

Forty‐one privately owned dogs (15 healthy dogs and 26 dogs with MMVD) were included. Dogs with MMVD were divided into non‐CHF (n = 10) and CHF groups (n = 16).

Methods

Conventional echocardiographic examinations were performed. In addition, TDI‐derived variables, including radial and longitudinal velocities, strain, and strain rate were assessed.

Results

Several (12 of 47, 26%) conventional and tissue Doppler echocardiography variables were significant predictors of CHF in a univariate analysis (P < .05). However, TDI‐derived E/E _{m sept} was the only load‐independent significant predictor of CHF (P < .05) after multivariate logistic regression analysis. The E/E _{m sept} cut‐off value of >18.7 had a sensitivity of 56% and specificity of 90% in predicting CHF in dogs with MMVD.

Conclusions and Clinical Importance

The combination of TDI of the mitral annulus and mitral inflow velocity provided better estimates of diastolic dysfunction in dogs with MMVD and CHF. Additional study is warranted to assess TDI‐derived E/E _{m sept}, an index of diastolic function that could contribute to the management of dogs with MMVD and CHF.     

Reliability of the i‐STAT for the determination of blood electrolyte (K+, Na+, and CI−) concentrations in cattle

Background

Rapid determination of blood electrolyte concentrations can help determine electrolyte status and delivery of effective volume of electrolyte solutions in field conditions.

Objective

To evaluate reliability of the i‐STAT, a point‐of‐care (POC) device, in measuring blood K⁺, Na⁺, and CI ⁻ concentrations in cattle.

Animals

Ninety‐eight cattle with various diseases.

Methods

In this prospective study, blood samples collected from the jugular vein were processed for determination of K⁺, Na⁺, and CI ⁻ concentrations in blood and plasma using the i‐STAT and auto‐analyzer (Cobas C501), respectively. Blood and plasma electrolyte data were subjected to student t‐test for comparison, the concordance analysis for agreement, accuracy, and precision, the Passing‐Bablok regression and the Bland‐Altman plot for reliability, and receiver operating characteristics curves for sensitivity (Se) and specificity (Sp).

Results

Plasma concentrations of K⁺ (4.39 versus 4.2 mmol/L; P < .0001) and CI ⁻ (100.30 versus 99.4 mmol/L; P < .04) were greater than their concentrations in blood. Plasma and blood Na⁺ concentrations were similar (136.95 versus 136.8 mmol/L). The i‐STAT results were highly correlated with the Cobas C501 results (r = 0.970, 0.922, and 0.866 for K⁺, Na⁺, and CI ⁻, respectively). Regression equations fitting blood (Y) and plasma (X) concentration did not deviate from the identity line for K⁺ (Y = −0.10 + 0.98 × X), Na⁺ (Y = X), and CI ⁻ (Y = 3.04 + 0.96 × X). The mean bias (blood concentration ‐ plasma concentration) was −0.20 for K⁺ (P = .03), −0.16 for Na⁺ (P = .12), and −0.87 for CI ⁻ (P = .93). The i‐STAT had 76–100% Se and 87.7–100% Sp for assessing electrolyte statuses.

Conclusions and Clinical Importance

The i‐STAT yielded results that were in agreement with the auto‐analyzer, with negligible biases in measurement of plasma K⁺, Na⁺, and CI ⁻ concentrations. The i‐STAT is a reliable POC device and can be used in field condition to assess electrolyte status in cattle.     

Incidence,Timing, and Risk Factors of Azathioprine Hepatotoxicosis in Dogs

Background

The use of azathioprine (AZA) in dogs is limited by the development of hepatotoxicosis and cytopenias.

Hypothesis and Objectives

To characterize the observed incidence, timing, and risk factors for AZA hepatotoxicosis in dogs treated clinically, and to determine the relationship between the development of hepatotoxicosis and cytopenias.

Animals

Fifty‐two dogs treated with AZA with clinical and biochemical follow‐up, with a subset of 34 dogs available for determination of changes in liver enzyme activities in serum.

Methods

Retrospective medical record review, from January 2009 through December 2013.

Results

Hepatotoxicosis (as defined by a >2‐fold increase in serum ALT) was observed in 5 of 34 dogs (15%) within a median onset of 14 days (range, 13–22 days). Dogs had a median 9‐fold increase in ALT and 8‐fold increase in ALP, which stabilized or resolved with drug discontinuation or dose reduction. German shepherds were significantly over‐represented (3 of 5 dogs with hepatotoxicosis; P = .0017). Thrombocytopenia or neutropenia were seen in 4 of 48 dogs with CBC follow‐up (8% of dogs), but occurred significantly later in treatment (median onset, 53 days; range 45–196 days) compared to hepatotoxicosis (P = .016).

Conclusions and Clinical Importance

These results support the routine monitoring of liver enzymes during the first 1–4 weeks of AZA treatment in dogs, with continued monitoring of the CBC. Additional studies are warranted to characterize the apparently higher risk of AZA hepatotoxicosis in German shepherds.     

Changes in Systolic Blood Pressure over Time in Healthy Cats and Cats with Chronic Kidney Disease

Background

Hypertension is a common problem in older cats, most often associated with chronic kidney disease (CKD). Cross‐sectional studies have suggested that blood pressure in cats increases with age.

Hypothesis/Objectives

To determine whether blood pressure in cats increases with age and whether this occurs independently of the presence of CKD. To investigate risk factors for developing hypertension.

Animals/Subjects

Two hundred and sixty‐five cats with CKD and 133 healthy cats ≥9 years were retrospectively identified.

Methods

Four groups were created according to status at initial evaluation (CKD or healthy) and blood pressure at the last included visit (normotensive [NT] or developed hypertension [DH]): Healthy‐NT, Healthy‐DH, CKD‐NT and CKD‐DH. Systolic blood pressure (SBP) over time slopes were compared with 0 and between groups. Risk factors for the development of hypertension were investigated, and associations of biochemical and clinical variables with SBP were examined.

Results

Cats that were hypertensive at CKD diagnosis (n = 105) were not included in further analyses. Twenty‐seven cats with CKD and 9 healthy cats developed hypertension ≥3 months after diagnosis of CKD or their first visit. Systolic blood pressure significantly increased with age in all cats (P < .001). Healthy cats were at less risk than cats with CKD to become hypertensive (hazard ratio 0.2, P < .001), with creatinine being an independent risk factor for the development of hypertension.

Conclusions and Clinical Importance

The high prevalence of hypertension in azotemic cats in this study shows the importance of monitoring of SBP in elderly cats, and in particular in cats with CKD.