Bilateral choanal atresia in a cat

A 7-month-old female spayed domestic shorthair cat was presented for investigation of stertor, open mouth breathing without apparent distress, and chronic bilateral nasal discharge that was unresponsive to antibiotics. Complete bilateral bony choanal atresia was diagnosed with computed tomography and nasopharyngoscopy. Choanal atresia is an uncommon congenital condition where the choana (nasal passage into the nasopharynx) is blocked by abnormal bone or soft tissue uni- or bilaterally. The cat's clinical signs improved dramatically immediately after trans-palatal surgical correction. Post-surgical complications included the development of nasopharyngeal scar tissue and subsequent stenosis, persistent right-sided nasal discharge, and permanent damage to the right eye (blindness and cataract formation). Nasopharyngeal stenosis was managed with repeated balloon dilatations and temporary stenting, and the owner reported an excellent quality of life at 8-month follow-up. Bilateral bony choanal atresia has not been previously reported in cats. Uni- or bilateral choanal atresia should be considered in young cats presenting with refractory stertor, chronic nasal discharge, and/or open mouth breathing.     

Pharmacokinetics and pharmacodynamics of intravenous medetomidine in the horse

ObjectiveTo describe the pharmacodynamics and pharmacokinetics following an intravenous (IV) bolus dose of medetomidine in the horse.Study designProspective experimental trial.AnimalsEight, mature healthy horses age 11.7 ± 4.6 (mean ± SD) years, weighing 557 ± 54 kg.MethodsMedetomidine (10 μg kg^?1) was administered IV. Blood was sampled at fixed time points from before drug administration to 48 hours post administration. Behavioral, physiological and biochemical data were obtained at predetermined time points from 0 minutes to 24 hours post administration. An algometer was also used to measure threshold responses to noxious stimuli. Medetomidine concentrations were determined by liquid chromatography-Mass Spectrometry and used for calculation of pharmacokinetic parameters using noncompartmental and compartmental analysis.ResultsPharmacokinetic analysis estimated that medetomidine peaked (8.86 ± 3.87 ng mL^?1) at 6.4 ± 2.7 minutes following administration and was last detected at 165 ± 77 minutes post administration. Medetomidine had a clearance of 39.6 ± 14.6 mL kg^?1 minute^?1 and a volume of distribution of 1854 ± 565 mL kg^?1. The elimination half-life was 29.1 ± 12.5 minutes. Glucose concentration reached a maximum of 176 ± 46 mg dL^?1 approximately 1 hour post administration. Decreased heart rate, respiratory rate, borborygmi, packed cell volume, and total protein concentration were observed following administration. Horses lowered their heads from 107 ± 12 to 20 ± 10 cm within 10 minutes of drug administration and gradually returned to normal. Horse mobility decreased after drug administration. An increased mechanical threshold was present from 10 to 45 minutes and horses were less responsive to sound.Conclusion and clinical relevance Behavioral and physiological effects following intravenous administration positively correlate with pharmacokinetic profiles from plasma medetomidine concentrations. Glucose concentration gradually transiently increased following medetomidine administration. The analgesic effect of the drug appeared to have a very short duration.     

Iron-source preference of Staphylococcus aureus infections

Although bacteria use different iron compounds in vitGro, the possibility that microbes distinguish between these iron sources during infection has hitherto not been examined. We applied stable isotope labeling to detect source-specific iron by mass spectrometry and show that Staphylococcus aureus preferentially imports heme iron over transferrin iron. By combining this approach with computational genome analysis, we identified hts (heme transport system), a gene cluster that promotes preferred heme iron import by S. aureus. Heme iron scavenging by means of hts is required for staphylococcal pathogenesis in animal hosts, indicating that heme iron is the preferred iron source during the initiation of infection.     

Brain natriuretic peptide concentration in dogs with heart disease and congestive heart failure

Plasma brain natriuretic peptide concentration ([BNP]) is high in humans with cardiac disease and is further increased with congestive heart failure (CHF). The hypotheses of this study were that dogs with moderate to severe mitral regurgitation due to myxomatous mitral valve disease (MVD) would have increased plasma [BNP] compared to normal dogs, that plasma [BNP] would be higher in dogs with CHP, and that plasma [BNP] would predict premature death from cardiovascular disease. The study population consisted of 34 dogs: 9 normal dogs and 25 dogs with MVD. Patients were divided into 4 groups: group 1-10 dogs with moderate to severe MVD and no radiographic evidence of CHF; group II--6 dogs with severe MVD and mild CHF; group III--7 dogs with severe MVD and moderate CHF; and group IV--2 dogs with severe MVD and severe CHF. Diagnostic tests included thoracic radiographs, an echocardiogram, a serum chemistry profile, and the measurement of plasma [BNP] by a canine-specific radioimmunoassay. There was a significant positive correlation between the plasma [BNP] and heart disease/failure groups (P = .0036). Plasma [BNP] increased with progressively increasing severity of MVD and CHE Group I dogs had higher plasma [BNP] than did control dogs (P < .0001), and plasma [BNP] was higher in dogs with CHF (groups II-IV versus group I; P = .012). Plasma [BNP] was also weakly positively correlated with left atrial size (r = 0.43, P = .04). For every 10-pg/mL increase in plasma [BNP], the mortality rate over 4 months' time increased approximately 44%.     

Wide range of Chlamydiales types detected in native Australian mammals

The Chlamydiales are a unique order of intracellular bacterial pathogens that cause significant disease of birds and animals, including humans. The recent development of a Chlamydiales-specific 16S rDNA polymerase chain reaction (PCR) assay has enabled the identification of Chlamydiales DNA from an increasing range of hosts and environmental sources. Whereas the Australian marsupial, the koala, has previously been shown to harbour several Chlamydiales types, no other Australian marsupials have been analysed. We therefore used a 16S rDNA PCR assay combined with direct sequencing to determine the presence and genotype of Chlamydiales in five wild Australian mammals (gliders, possums, bilbies, bandicoots, potoroos). We detected eight previously observed Chlamydiales genotypes as well as 10 new Chlamydiales sequences from these five Australian mammals. In addition to PCR analysis we used antigen specific staining and in vitro culture in HEp-2 cell monolayers to confirm some of the identifications. A strong association between ocular PCR positivity and the presence of clinical disease (conjunctivitis, proliferation of the eyelid) was observed in two of the species studied, gliders and bandicoots, whereas little clinical disease was observed in the other animals studied. These findings provide further evidence that novel Chlamydiales infections occur in a wide range of hosts and that, in some of these, the chlamydial infections may contribute to clinical disease.     

Tremorgenic mycotoxin intoxication with penitrem A and roquefortine in two dogs

In this report, we describe the natural intoxication of 2 dogs that consumed moldy dairy products found in the household garbage and the procedures used to identify and quantify the tremorgenic mycotoxins, roquefortine and penitrem A, in the remaining portions of ingested materials. Following the ingestion of mycotoxins, the dogs of our report developed muscle tremors or seizures that resembled clinical signs of strychnine poisoning. Roquefortine was the predominant mycotoxin in a moldy cream cheese wrapper that was found among scattered garbage consumed by the first dog. Penitrem A was the only mycotoxin detected in discarded moldy macaroni and cheese that was consumed by the second dog. Treatment of dogs with tremorgenic mycotoxin intoxication involves supportive care. Close monitoring is important because the development of aspiration pneumonia is common and has been reported as the cause of death. Clinical signs of intoxication gradually resolve within 24 to 48 hours.     

QUANTIFICATION OF LEFT VENTRICULAR MASS USING CARDIAC MAGNETIC RESONANCE IMAGING COMPARED WITH ECHOCARDIOGRAPHY IN DOMESTIC CATS

The hypotheses were that cardiac magnetic resonance imaging (cMRI) would accurately determine LV mass in domestic cats and would do so more accurately than echocardiography (ECHO). ECHO was performed on seven sedated cats. LV mass was calculated using the truncated ellipse formula from a right parasternal long-axis view. T1 weighted gradient echo cMRI was acquired from anesthetized cats during multiple phases of the cardiac cycle. Short-axis images were obtained by acquiring 3 mm thick contiguous slices perpendicular to the cardiac long axis. LV mass was determined using Simpson's rule. Endocardial and epicardial borders were traced on each slice at end-systole, end-diastole, and mid-cycle and the difference in areas was myocardial area. Myocardial area was multiplied by slice thickness to calculate myocardial volume. Total (summated) myocardial volume was multiplied by myocardial density (1.05) to obtain LV mass at three measured phases of the cardiac cycle. Cats were euthanized and the LV was dissected and weighed to determine true mass. CMRI at end-systole most accurately quantified LV mass and was more accurate than echocardiography (P = 0.0078). Actual LV mass ranged from 6.5 to 10.5 g (mean = 8.5 g, SD = 1.6 g) compared with MRI LV mass at end-systole, which ranged from 6.7 to 11.1 g (mean = 8.7 g, SD = 1.7 g) and echocardiographic LV mass at enddiastole, which ranged from 5.2 to 9.1 g (mean= 7.1 g, SD = 1.8 g). Inter- and intraobserver variability for cMRI was 2%. CMRI obtained at end-systole accurately and reliably quantifies LV mass in domestic cats. It is more accurate than the echocardiographic method used in this study.     

Clinical chemistry values and tissue enzyme activities in western barred bandicoots (Perameles bougainville)

BACKGROUND: The western barred bandicoot, Perameles bougainville, is an endangered Australian marsupial species whose survival is threatened by a papillomatosis and carcinomatosis syndrome. Investigations to characterize this syndrome would benefit from species-specific clinical chemistry data. OBJECTIVES: The purpose of this study was to determine plasma biochemical reference values and to determine enzyme activities in various tissues of P. bougainville. METHODS: Heparinized blood samples were collected by jugular venipuncture from 53 clinically healthy bandicoots of both sexes and at 3 geographic locations. Plasma was analyzed for routine clinical chemistry variables using an automated biochemistry analyzer. Tissues obtained following humane euthanasia of 3 bandicoots were analyzed for alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), creatine kinase (CK), alpha-amylase (AML), and gamma-glutamyltransferase (GGT) activities. RESULTS: Significant differences in the results were found for animals based on geographic location and sex; hence, results were expressed as minimum and maximum values. A population reference interval was calculated for AST activity (20-283 U/L). ALT was found mainly in the liver, with lower levels in cardiac and skeletal muscle and kidneys. AST was detectable in many tissues, including the heart, liver, kidneys, and central nervous system; CK was found in skeletal and cardiac muscle and central nervous system; AML was found in the pancreas; and GGT was found mainly in kidneys with lower levels in the intestines and pancreas. CONCLUSIONS: These findings will facilitate the interpretation of clinical chemistry results from P. bougainville and thereby inform population management and clinical decision-making.