Estimation of 24-h aldosterone secretion in the dog using the urine aldosterone:Creatinine ratio

ObjectivesOne potential method of evaluating renin–angiotensin–aldosterone system (RAAS) activation involves the quantification of urinary aldosterone excretion. While blood concentrations of aldosterone are easily obtained, results may be misleading because of minute-to-minute variation in aldosterone secretion and subsequent blood concentrations. Urinary aldosterone concentration measurement represents a more consistent “pooled” index of aldosterone secretion, but obtaining 24-h urine samples is time-consuming, difficult, and fraught with potential error. We postulated that the urinary aldosterone:creatinine ratio, measured from spot urine samples, would correlate well with 24-h urinary aldosterone excretion, and would provide a simple index of aldosterone excretion that would eliminate the need for 24-h urine collection.Animals, materials and methodsAfter validating an assay for aldosterone in canine urine, 24-h urinary aldosterone excretion was determined by radioimmunoassay from 8 normal, male beagle dogs under control conditions, after RAAS stimulation with amlodipine administration, and after RAAS attenuation with the addition of enalapril to amlodipine administration. Spot urine samples, each obtained at the same time of day, were used to determine the aldosterone:creatinine ratio during control conditions, RAAS stimulation, and RAAS attenuation.ResultsThe aldosterone:creatinine ratio from spot-checked urine samples correlated well with 24-h urinary aldosterone excretion (r = 0.77, P < 0.0001).ConclusionsA spot urinary aldosterone:creatinine ratio might be substituted for 24-h urinary aldosterone determination.     

Recurrence of Chlamydia suis infection in pigs after short-term antimicrobial treatment

The effect of short-term antimicrobial treatment on natural excretion of Chlamydia suis in rectal swabs and C. suis and Chlamydophila psittaci in nasal swabs was investigated in 47 clinically normal piglets by quantitative real-time PCR. Pigs were treated IM with 4 mg/kg enrofloxacin for 5 days (n = 22) or 2.5 mg/kg enrofloxacin for 3 days followed by 100 mg/mL tiamulin (n = 25). Antimicrobial treatment reduced the number of pigs positive for chlamydiae and the quantity of chlamydial DNA in positive swabs for a few days, but chlamydial excretion recurred in both groups. Short-term antimicrobial treatment at dosages recommended for treatment of other bacterial infections in pig herds was not effective in eliminating naturally occurring subclinical chlamydial infection in pigs.     

Influence of combined angiotensin-converting enzyme inhibitors and spironolactone on serum K, Mg, and Na concentrations in small dogs with degenerative mitral valve disease

ObjectiveTo determine if the administration of an angiotensin-converting enzyme inhibitor (ACEI) plus spironolactone caused hyperkalemia, hypermagnesemia, or hyponatremia in elderly small dogs with degenerative mitral valve disease (MVD).BackgroundACEIs and spironolactone can increase serum potassium and magnesium concentrations and lower serum sodium concentrations. It has been recommended to either not combine these drugs or to do so with caution.Animals, material and methodsFifty client-owned dogs with MVD, left atrial dilation, and without congestive heart failure or azotemia were evaluated retrospectively. Baseline data sets, followed by 1–9 (mean = 2.66) data sets, comprised of serum urea nitrogen (SUN), creatinine, sodium, potassium, and magnesium concentrations, were tabulated. Each dog received an ACEI plus spironolactone for a mean of 23.8 ± 26.6 weeks (range: 2–150) and a median of 15 weeks. No cardiac drugs other than an ACEI and spironolactone were administered during the study period.ResultsThere were no significant differences between baseline and follow-up serum sodium or potassium concentrations. Serum magnesium concentrations increased significantly (p = 0.02) with time >20 weeks compared to baseline.ConclusionsThe combination of an ACEI and spironolactone results in no significant difference between baseline and follow-up serum sodium or potassium concentrations. Although serum magnesium concentrations may increase significantly with time >20 weeks compared to baseline concentrations, hypermagnesemia appears to be rare, mild, and unlikely to be of clinical importance. The combination of an ACEI and spironolactone is safe in elderly small dogs with MVD with normal SUN and creatinine concentrations.     

Radial strain and strain rate by two-dimensional speckle tracking echocardiography and the tissue velocity based technique in the dog

ObjectivesTwo-dimensional (2D) speckle tracking echocardiography (STE) is a new angle-independent ultrasound technique based on tracking of speckles within the myocardium on 2D grayscale images. The aims of this prospective study were as follows: (1) to assess the variability of left ventricular peak systolic radial strain (St) and strain rate (SR) in awake dogs using STE (Protocol 1); and (2) to quantify these variables in a healthy canine population and compare them with tissue Doppler imaging (TDI)-based St and SR values (Protocol 2).BackgroundSt and SR may be assessed using TDI, which is limited by angle dependency.Animals, materials and methodsThirty-six STE examinations were performed on 6 healthy dogs for Protocol 1 and 37 healthy dogs were recruited for Protocol 2. In both studies, STE measurements were obtained offline from the right parasternal short-axis view by the same trained observer using automatic frame-to-frame tracking of grayscale speckle patterns.ResultsAll within- and between-day coefficients of variation were <10% (Protocol 1). In Protocol 2, St (46.7 ± 12.2%) and SR (2.7 ± 0.6 s⁻¹) measured by STE were correlated with heart rate (p < 0.01), but not with the ratio of early mitral inflow velocity to early mitral annular velocity. There was a good correlation between STE and TDI for both St and SR values (p < 0.001).ConclusionsSTE is a repeatable and reproducible non-Doppler method for assessing radial St and SR. The combination of these indices with conventional echo-Doppler variables could provide a new approach for accurately quantifying canine systolic function.     

Retrospective review of carvedilol administration in 38 dogs with preclinical chronic valvular heart disease

ObjectivesReport the effect of carvedilol administration on clinical and echocardiographic parameters and outcome in dogs with preclinical (ACVIM Stage B) chronic valvular heart disease (CVD).Animals, materials and methodsRetrospective case series of 38 client-owned dogs.Demographic, physical examination and diagnostic imaging findings, blood pressure (BP), administration details and outcome were obtained from medical records of dogs receiving carvedilol for preclinical CVD. When possible, additional follow-up information was obtained through telephone interviews with referring veterinarians and owners.ResultsBaseline data and follow-up were evaluated. Median and interquartile range (IQR) for age and weight were 8.6 (7.2–10.8) years and 8.5 (7.6–9.6) kg. 14/38 were male; 33/38 were Cavalier King Charles Spaniels; 33/38 had Stage B2 CVD. The initial dose of carvedilol was 0.31 (0.26–0.35) mg/kg PO twice daily. The carvedilol dose achieved following up titration was 1.11 (0.81–1.32) mg/kg twice daily. No adverse effects were recorded during up titration. Median survival for all dogs was 48.5 months with a 95% CI of 38.3–58.6.ConclusionsThis study suggests that carvedilol at the dose reported herein is well tolerated in small breed dogs with preclinical CVD. Prospective studies to evaluate efficacy are warranted.     

In vivo efficacy of tamarind (Tamarindus indica) fruit extract on experimental fluoride exposure in rats

The study was undertaken to determine the efficacy of hydro-methanolic (1:1) extract of tamarind (Tamarindus indica L.) fruit pulp in removing body fluoride burden. Thirty rats were divided into five groups. Keeping no fluoride group as the control, rats of no treatment, low dose, middle dose and high dose groups received sodium fluoride orally at the rate of 200 mg per kg body weight daily for 14 weeks. Rats of low dose, middle dose and high dose group simultaneously received tamarind fruit pulp extract at three doses, viz. 25 (low), 50 (medium) and 100 mg (high) per kg body weight orally, respectively. Fluoride concentration in blood, urine and long bone of experimental rats was monitored to assess the efficacy of the extract. Mean serum fluoride concentration in fluoride exposed rats was 0.145 ± 0.009 and 0.783 ± 0.042 μg/ml on days 0 and 98. In comparison, fluoride concentrations in tamarind treated rats were 0.179 ± 0.021 and 0.633 ± 0.015; 0.179 ± 0.021 and 0.502 ± 0.025 and 0.176 ± 0.021 and 0.498 ± 0.030 μg/ml in low, medium and high dose groups, respectively on day 0 and day 98 of the experiment. There was a significant (p ⩽ 0.01) increase in urinary fluoride excretion from day 28 onwards. The mean fluoride concentration in long bones of treated rats was significantly lower than the values recorded in fluoride exposed rats. These findings suggest that concomitant use of tamarind fruit pulp extract can reduce fluoride concentration in blood and bone and enhanced urinary excretion, indicating the ameliorative potential of fruits of tamarind in fluoride toxicity.     

Canine heartworm (Dirofilaria immitis) in Fresno and Madera Counties, California: prevalence differences between foothill and valley habitats

The aim of this study was to assess the prevalence of heartworm in domestic dogs in Madera and Fresno Counties, California, dependent on habitat and other host and environmental factors. Dogs were screened for presence of heartworm antigen using the PetChek^® ELISA on blood samples (N = 519) collected at seven sites during April-July 2009. Eighteen dogs were heartworm antigen positive. Pearson Chi-square analyses were conducted testing the presence of heartworm antigen against the following independent variables: elevation range, percentage of time spent outdoors during the day, percentage of time spent outdoors during the night, pet coat length, weight class, prevention status, and sex. Dogs that spent at least 50% of their time outdoors during the day were significantly more likely to have heartworm that those who spent less time outside (N = 519, df = 1, p = 0.031). Overall prevalence (3.47%) was lower than expected, with Madera County having 3.8% positive samples and Fresno County 3.5%; this prevalence is lower than in many previous studies. The effect of time spent outdoors on heartworm prevalence was similar to previous studies. The impact of elevation on infection, though not significant, requires further investigation, as does the prevalence and viability of larval stages in mosquitoes.     

Weekly variability of plasma and serum NT-proBNP measurements in normal dogs

ObjectivesTo determine the weekly variability of serum and plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations in healthy dogs.Animals, materials and methodsFifty-three normal dogs were examined prospectively. Serum (n = 25) or plasma (n = 28) samples were obtained for NT-proBNP assay at one week interval for 3 consecutive weeks.ResultsMedian serum or plasma NT-proBNP concentration did not change over 3 consecutive weeks. Twenty-two of 53 dogs (42%) had at least one NT-proBNP value >500 pmol/L, including 14 dogs with at least one serum NT-proBNP concentration >500 pmol/L and 8 dogs with at least one plasma NT-proBNP concentration >500 pmol/L during the 3-week sampling period. The difference between the maximum and minimum NT-proBNP value obtained over the 3-week sampling period was <100 pmol/L in 40% of dogs, between 100 and 200 pmol/L in 40% of dogs, and >200 pmol/L in 20% of dogs. Of the 19 dogs with a value >500 pmol/L on either week 1 or 2, 11 dogs (58%) had a subsequent NT-proBNP value <500 pmol/L on either week 2 or 3.ConclusionsThere is a high degree of variability in weekly serum and plasma NT-proBNP values in healthy dogs. Individual variability should be considered when interpreting NT-proBNP results in dogs.     

Fluoxetine combined with clorazepate dipotassium and behaviour modification for treatment of anxiety-related disorders in dogs

The effectiveness of clorazepate dipotassium combined with fluoxetine and a behaviour modification programme for the treatment of anxiety disorders in dogs was investigated. Forty dogs with anxiety disorders were initially enrolled and 36 dogs completed the trial. Dogs were classified into two behavioural categories (anxious dogs with aggression and anxious dogs without aggression) according to their presenting complaints, and were also subdivided into males, females, juveniles and adults. The dog owners were provided with a behaviour modification plan for their dogs to be commenced in the first week of therapy. Clorazepate dipotassium was administered PO at 1.0 mg/kg every 24 h for 4 weeks, and fluoxetine was administered PO at 1.0 mg/kg every 24 h for 10 weeks. Therapy with both drugs was initiated simultaneously. Improvement was reported in 25/36 dogs. Significant differences in treatment effects were observed between anxious dogs with aggression and anxious dogs without aggression (P < 0.05). Positive correlations between owner compliance with the treatment plan and reported improvement achieved during three periods of study were also noted.     

Pharmacokinetics of oral gabapentin in greyhound dogs

The purpose of this study was to assess the pharmacokinetics of gabapentin in healthy greyhound dogs after single oral doses targeted at 10 and 20 mg/kg PO. Six healthy greyhounds were enrolled (3 males, 3 females). Blood was obtained at predetermined times for the measurement of gabapentin plasma concentrations by liquid chromatography/mass spectrometry. Pharmacokinetic parameters were determined with computer software.The actual mean (and range) doses administered were 10.2 (9.1–12.0) mg/kg and 20.5 (18.2–24) mg/kg for the 10 mg/kg and 20 mg/kg targeted dose groups. The mean C_MAX for the 10 and 20 mg/kg groups were 8.54 and 13.22 μg/mL at 1.3 and 1.5 h, and the terminal half-lives were 3.3 and 3.4 h, respectively. The relative bioavailability of the 10 mg/kg group was 1.13 compared to the 20 mg/kg group. Gabapentin was rapidly absorbed and eliminated in dogs, indicating that frequent dosing is needed to maintain minimum targeted plasma concentrations.     

Gastrointestinal parasitism reduces the plasma availability of doramectin in lambs

A study was undertaken to investigate the effect of parasitism on plasma availability and pharmacokinetic behaviour of doramectin (DRM) in lambs. Fourteen parasitised grey face Suffolk lambs (26.9 ± 1.5 kg bodyweight) were selected for the study. Seven pairs of lambs were allocated to two groups to obtain an approximately even weight distribution. Group I (non-parasitised) was pre-treated with three repeated administrations of 5 mg/kg fenbendazole to maintain a parasite free condition. In group II (parasitised), the lambs did not receive any anthelmintic treatment. After the 85-day pre-treatment period, both groups of animals were treated with DRM by subcutaneous (SC) injection in the shoulder area at 200 μg/kg. Throughout the experimental period, both groups were maintained together under similar feeding and management conditions. Blood samples were collected by jugular venepuncture at different set times between 0.5 h and 60 days post-treatment. After plasma extraction and derivatisation, samples were analysed by high performance liquid chromatography (HPLC) with fluorescence detection. A computerised kinetic analysis was performed and the data were compared using the Student’s paired t test.The parent molecule was detected in plasma between 30 min and either day 20 (parasitised) or day 35 (non-parasitised) post-DRM treatment. The AUC values of the parasitised group (143.0 ± 18 ng d/mL) were significantly lower (P < 0.05) than those observed in the parasitically naïve animals (229.6 ± 21.7 ng d/mL). The mean residence time (MRT) in the parasitised group (3.4 ± 0.3 days) was significantly shorter (P < 0.05) than in the healthy group (6.6 ± 0.6 days). Study results have shown that parasitic disease, through alteration in the body condition, can produce significant changes in the plasma disposition of DRM when administered SC to parasitised lambs.     

Azotemia in cats with feline hypertrophic cardiomyopathy: Prevalence and relationships with echocardiographic variables

ObjectivesThe prevalence of renal azotemia in cats with acquired heart disease is not well documented. The aims of this study were therefore (1) to determine the prevalence of azotemia within a hospital population of cats with hypertrophic cardiomyopathy (HCM), and (2) to evaluate the relationship between echocardiographic variables and plasma urea and creatinine.Animals, materials and methods134 client-owned cats were retrospectively studied including 102 cats with HCM and 32 control cats. A complete physical examination, electrocardiography, systolic arterial blood pressure measurement, thoracic radiographs, and echocardiography were performed. Plasma creatinine and urea were determined in all cats. The animal was considered azotemic if plasma creatinine was >1.8 mg/dL and/or urea >65 mg/dL (i.e. BUN> 30 mg/dL).ResultsThe prevalence of azotemia was lower in control cats (25.0%) than in cats with HCM (58.8%) (P = 0.003). No significant differences in plasma urea and creatinine were observed between the HCM and control cats. There was no effect of plasma creatinine and urea on conventional echocardiographic variables in cats with HCM.ConclusionsAzotemia is a frequent finding in cats with HCM but is not dependent on echocardiographic variables.     

Methods and normal values for echocardiography in adult dairy cattle

ObjectiveThe objective of the study was to report normal ultrasonographic appearance and intra-cardiac dimensions in two dairy breeds and to calculate cardiac output (CO) using echocardiography.BackgroundIntra-cardiac dimensions, time indices and CO estimation have not previously been reported in adult cattle.Animals, materials and methodsEchocardiograms were obtained from healthy adult dairy cows (10 Jersey (J) and 12 Holstein Friesians (HF)) in the body weight range of 400 to 700 kg. Standard echocardiographic images were obtained from the left and right hemithoraces. Velocity time integrals were obtained in order to calculate CO using pulsed wave Doppler of aortic flow in the J cows. Measurements obtained included pulmonary artery and aortic diameters, left and right ventricular diameters (and calculated fractional shortening and left ventricular ejection fraction), left atrial size and time indices assessing valve function.ResultsHF cows had significantly (p < 0.05) larger pulmonary artery and aortic diameters, larger left atrial diameters and left ventricular internal diameters during diastole, but these were not different when corrected for body weight. Left and right ventricular dimensions, adjusted for body weight, were significantly larger (p = 0.02 and p = 0.035 respectively) in J cows when compared to HF cows. No differences were noted in the time indices between the two groups. No significant differences were noted in intra-operator variability and the only significant difference in inter-operator variability was in measurement of the pulmonary artery (p = 0.03; ICC = 0.63).ConclusionsIt is possible to obtain repeatable, reliable echocardiograms in order that meaningful intra-cardiac dimensions can be obtained in adult dairy cattle.     

Assessment of the combination of spinosad and milbemycin oxime in preventing the development of canine Angiostrongylus vasorum infections

Angiostrongylus vasorum is an increasingly reported parasite in Europe that develops in dogs after ingestion of infective third stage larvae (L3) that reside in gastropod molluscs which are needed to complete the parasite's life-cycle. Infection can produce a diversity of clinical signs, determined by involvement of the respiratory, neurological, and/or coagulation system, with a likely fatal outcome in the absence of treatment. Few drugs have been shown to reliably prevent infection, and data on treatment of infections is limited. A controlled, randomized, partially blinded laboratory study was therefore executed to evaluate the efficacy and safety of a combination tablet of spinosad/milbemycin oxime in dogs inoculated with approximately 250 A. vasorum L3. Sixteen healthy nematode free adult dogs were randomly allocated to two study groups of 8 dogs each. Thirty days post inoculation (dpi) all dogs in the fed state were treated: dogs in group B were treated with spinosad and milbemycin oxime at the dose rates of 45–60 mg/kg and 0.75–1.0 mg/kg bodyweight, respectively, approximately the lower half portion of the expected full unit dose range; dogs in group A were treated with placebo tablets. All dogs were euthanized and necropsied 56–58 dpi. The heart and lungs were examined to determine the presence of A. vasorum. All placebo group dogs were infected at necropsy with counts ranging from 22 to 98 adult worms and a geometric mean worm count of 55.2. In contrast, the geometric mean worm count in the spinosad/milbemycin oxime group was 0.7 with worm numbers ranging from 0 to 8. The results of this study demonstrate that a single treatment with the tablet combination of spinosad and milbemycin oxime administered 30 dpi provided 98.8% preventive efficacy against development of adult A. vasorum infections. Monthly treatments with spinosad and milbemycin oxime have the potential to prevent the establishment of infections with A. vasorum in dogs.     

Contrast echocardiography in Boxer dogs with and without aortic stenosis

ObjectivesThe aim of this study was to investigate whether contrast echocardiography could enhance the subcostal Doppler signal for aortic flow measurements and achieve myocardial opacification, in Boxer dogs with and without AS.BackgroundIn evaluating dogs for aortic stenosis (AS) subcostal Doppler echocardiography was used for measurement of the aortic flow velocity, a measurement that can sometimes be difficult to perform in Boxer dogs.Animals, materials, and methodsCardiac auscultation, phonocardiographic and echocardiographic examinations, including a contrast study with Optison, were performed on 29 Boxer dogs selected based on previous examinations.ResultsThe initial subcostal Doppler signal was weak in 66% of the dogs and a marked improvement was seen in all dogs after contrast injection. The peak aortic flow velocity increased 5% from 2.58 ± 1.42 m/s before contrast to 2.71 ± 1.54 m/s after contrast (p = 0.003). This corresponds to a 2.8 mmHg increase in the pressure gradient from 26.6 mmHg before to 29.4 mmHg after contrast. A dose of 0.05–0.1 mL of Optison administered intravenously resulted in approximately 4 min of Doppler signal enhancement. With the present technique contrast echocardiography did not achieve myocardial opacification.ConclusionsSingle use of the contrast agent Optison can be recommended for enhancement of the subcostal Doppler signal in dogs, in which plain Doppler signals are difficult to obtain. Albeit statistically significant, the mild increase in peak aortic flow velocity after contrast was not considered biologically or clinically significant.     

Effect of dexmedetomidine vs. acepromazine–methadone premedication on limb to lung circulation time in dogs

The study compared limb-to-lung circulation times (CT) in dogs under general anaesthesia after premedication with dexmedetomidine (DEX) or acepromazine–methadone (ACE–M). Healthy male and female dogs (n = 20) were randomly assigned to receive acepromazine 0.04 mg/kg and methadone 0.2 mg/kg intramuscularly (IM), or DEX 0.01 mg/kg IM. Anesthesia was induced with propofol and maintained with isoflurane at similar concentration in both groups. Mechanical ventilation was started immediately (20 breaths/min; inspiratory to expiratory ratio 1:2) and tidal volume was adjusted to achieve an end-tidal CO₂ concentration (PE’CO₂) of between 3.9 and 5.3 kPa. Ten minutes later arterial blood gas was analyzed and baseline data recorded for 3 minutes. A single dose of sodium bicarbonate 0,5 mEq/kg was administered intravenously over 10 s starting with inspiration. Limb-to-lung CT was defined as the time interval between the start of bicarbonate injection and the recording of the highest PE’CO₂.Following bicarbonate administration, PE’CO2 increased, and then rapidly decreased to baseline in both groups. CT was shorter in the ACE–M group (20 ± 2.3 vs. 27 ± 5.1 s). Bodyweight was higher in the ACE–M group (30.6 ± 3.9 vs. 23.3 ± 6.8 kg). Mean arterial blood pressure was higher in the DEX group (92 ± 9 vs. 73 ± 7 mm Hg) but premedication with DEX significantly prolonged CT compared to premedication with ACE–M.     

Pharmacokinetics and effects of cetirizine in horses with insect bite hypersensitivity

Horses with insect bite hypersensitivity (IBH) have difficulty in completely avoiding allergens, so effective treatment options are required. A randomised, placebo controlled and double blinded field study was conducted to determine the pharmacokinetics and efficacy in reducing dermatitis of the antihistamine cetirizine given orally at 0.4 mg/kg twice daily for 3 weeks. The influence of protection blankets and stabling were also investigated.The estimated maximum plasma concentration (C_max) and trough plasma concentration of cetirizine were 135 ng/mL and 18 ng/mL, respectively. There was no difference in dermatitis reduction between the treatment and placebo groups (P = 0.77). The findings indicated that cetirizine was of no apparent benefit in treating IBH at the dose rate tested. The use of blankets and stabling were shown to have favourable influence on the dermatitis (P < 0.05) and may be the preferred options to prevent this condition.     

Estimation of daily urinary potassium excretion using urinary creatinine as an index substance in prepartum dairy cows

In the present study, the daily excretion of potassium (K) in urine (urinary K(UK)) was estimated from a 6 h urine sample using urinary creatinine (UC) as the index substance. All urine was collected from six pregnant Holstein cows at 6 h intervals for 24 h on 3 days of the 4th, 2nd and final week before the expected date of parturition. In total, 72 6 h urine samples were obtained. Daily UC excretion (mg/day per kg bodyweight (BW)) was almost the same for the three sampling days. Daily UC excretion varied among cows from 22.1 to 24.3 mg/day per kg BW with a mean of 22.8 mg/day per kg BW with no significant difference. Thus, daily UC excretion was confirmed to be constant throughout the prepartum period with no differences among individuals. The concentration ratios of K to creatinine ((UK mg/dL)/(UC mg/dL) (UK/UC)) correlated strongly to the hourly K excretions (mg/h per kg BW) (r = 0.952, P < 0.01) in the 6 h urine samples. The differences in the UK/UC ratio between sampling periods were not significant within each cow. Therefore, daily UK excretion (mg/day) can be estimated using the equation: daily UK excretion (mg/day) = daily UC excretion (mg/day per kg BW) × BW (kg) × 6 h urine sample UK/UC, where daily UC excretion can be a given value.     

Quadricuspid aortic valve and associated abnormalities in the dog: Report of six cases

ObjectivesTo describe the clinical and echocardiographic findings in dogs with quadricuspid aortic valve (QAV).BackgroundQAV is a rare canine congenital heart disease which has been reported only three times in the young dog.Animals, materials and methodsSix dogs (0.3- to 13-year-old) with QAV diagnosed by two-dimensional echocardiography were retrospectively evaluated. Medical records, echocardiograms, and follow-ups were reviewed.ResultsAccording to aortic cusp morphology, QAV was classified as type A (n = 1), type B (n = 4) or type C (n = 1). QAV was associated with at least one other heart disease in all of the dogs including, ventricular septal defect (n = 1), enlarged left coronary ostium (n = 4), degenerative mitral valve disease (MVD, n = 1) and patent ductus arteriosus (PDA, n = 3). Mild to moderate aortic regurgitation was also detected in all dogs by continuous-wave and color-flow Doppler echocardiography. QAV was diagnosed in four asymptomatic dogs referred for evaluation of a heart murmur. The remaining two dogs had QAV and PDA with evidence of mild exercise intolerance and moderately retarded growth. The PDA was surgically corrected in both dogs and at the time of writing, 1–2.5 years after the initial diagnosis, none of the six animals shows evidence of clinical signs.ConclusionQAV is a cause of aortic insufficiency. It may incidentally be found by two-dimensional echocardiography in dogs of various ages in association with other congenital or acquired cardiac abnormalities.     

IL-6 and TNF-alpha production during active canine visceral leishmaniasis

We investigated the production of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) during canine visceral leishmaniasis (VL) to gain a better understanding of the role of such multi-functional cytokines in parasite resistance. IL-6 and TNF-α levels were measured by capture ELISA in sera from 8 healthy dogs from a non-endemic area (control group) and in sera from 16 dogs from Araçatuba, SP, Brazil, an area endemic for leishmaniosis. The dogs from the endemic area were selected by positive ELISA serology against total Leishmania chagasi antigen, positive spleen imprints for Leishmania, and the presence of at least three clinical signs associated with active visceral leishmaniasis (fever, dermatitis, lymphoadenopathy, onychogryphosis, weight loss, cachexia, locomotory difficulty, conjunctivitis, epistaxis, hepatosplenomegaly, edema, and apathy).Enhanced systemic IL-6 production was found in sera from dogs with the active disease compared to healthy dogs (t-test, P < 0.05). In contrast, TNF-α did not differ between the two groups studied. There was no correlation between IL-6 production and anti-leishmanial antibody titers in the sera. Our findings suggest that IL-6 is a good marker of active disease during leishmaniasis, and that other cytokines may be involved in the hypergammaglobulinemia characteristic of canine visceral leishmaniasis.