Sudden deaths of horses in multiple equestrian disciplines have been attributed to acute and chronic respiratory and cardiovascular diseases. The aim of this study was to perform a review of aortic rupture in horses analyzing, case studies and assessing risk factors. The literature has reported a total of 137 cases of aortic rupture in horses for 28 years (1986-2014), with approximately five horses dying of aortic rupture per year. Histopathologically, there are observed discrete macroscopic degenerative changes in the intima layer only in the aorta. The histological evaluation in the beginning portion of the aorta of the heart evidenced degenerative changes with loss of continuity and distribution of elastic fibers. Risk factors for the rupture of the aorta are: spontaneous rupture associated with hypertension, preexisting vascular injury (aneurysm), dilated or hypertrophic cardiomyopathy, copper levels in the endothelium, genetic factors such as inbreeding, toxicology or pharmacological factors. Aortic rupture shows similarity with pulmonary hemorrhage induced by exercise especially under the locomotors induced trauma theory of exercise that can induce pulmonary hemorrhage. In conclusion, degenerative changes to discrete elastic fiber of the intima of the aorta in the emergence of the heart seem to predispose the aorta wall rupture at the time of maximum blood pressure during exercise and the consequent collapse and athletic horse’s death.

The aim of our study was to optimise an existing staining procedure: haematoxylin-eosin saffron (HES). The method follows the classical haematoxylin and eosin protocol with the addition of a staining step using natural saffron to better identify the collagen fibres. The saffron solution was obtained by dissolving ground saffron stigmas in absolute alcohol. In order to test the HES method for its staining ability on four main types of collagen (I, II, III, and IV), specific tissues (skin, tooth, cartilage, aorta, spleen, and penis) were chosen. The procedure showed a sharp differentiation between muscle, stained red or pink, and connective tissue, stained bright yellow or orange. HES allows the diagnosis of reticulin fibrosis undetected in HE and in previous saffron staining procedures. HES represents an advantageous alternative to HE staining giving highly reproducible results with high diagnostic value.

Objective: This study was conducted to assess the hazardous effects of high fructose administration on kidney, heart and aorta in rats. Materials and methods: Twenty adult healthy male albino rats weighing about 200-220 gm each were used in this study. The rats were divided into 2 duplicate groups; control group and fructose group. Fructose was administered to rats in fresh drinking water daily for 8 weeks (the whole experimental period). Serum urea, creatinine and sodium concentration were determined by using ready-made kits. Spectrophotometric and colorimetric methods were also used for the detection of other serum components. Histopathological examination of the tissues was done by staining with H&E, PAS and Masson trichrome stains.Results: Nephropathy was achieved in fructose group after one month as indicated by biochemical assay. Pathological observation showed that high fructose administration decreased size of cardio-myocytes, increased cardiac interstitial fibrosis score and aortic wall thickness. In kidneys, high fructose administration decreased glomerular tuft area and corpuscular area, increased percentage in the rats affected with interstitial renal fibrosis score 1 and percentage of rats had glomerular sclerosis score 2. Conclusion: High fructose in diet should be avoided because it can damage kidney, heart and aorta in rats. [J Adv Vet Anim Res 2017; 4(1.000): 71-79]

There is evidence that perfusing the heart with a heart and lung machine is less injurious than cross-clamping the aorta and administering cardioplegia during cardiac surgery. Although mitral valve replacement has been carried out without aortic cross-clamping and cardioplegia, it has been stated that cross-clamping is necessary in order to maintain visualization and a motionless surgical field for mitral valve repair. The purpose of this study was to determine the surgical feasibility of mitral valve repair without cross-clamping the aorta and using cardioplegia. Our hypothesis was that a completely bloodless and motion-free field would not be necessary to carry out mitral valve repair with annuloplasty and synthetic chordae tendineae sutures. Papillary muscles, chordae tendineae, annulus, and mitral valve leaflets were all readily visualized. Chordae tendineae sutures were used and annuloplasty was conducted without visual obstruction or motion interference. Our results show that mitral valve repair is feasible without cross-clamping the aorta and using cardioplegia.

OBJECTIVE To evaluate the correlation coefficient of the ratio between diameter of the caudal vena cava (CVC) and diameter of the aorta (Ao) in dogs as determined ultrasonographically with systolic pressure variation (SPV). ANIMALS 14 client-owned dogs (9 females and 5 males; mean ± SD age, 73 ± 40 months; mean body weight, 22 ± 7 kg) that underwent anesthesia for repair of skin wounds. PROCEDURES Anesthesia was induced. Controlled mechanical ventilation with a peak inspiratory pressure of 8 cm H2O was immediately started, and SPV was measured. During a brief period of suspension of ventilation, CVC-to-Ao ratio was measured on a transverse right-lateral intercostal ultrasonographic image obtained at the level of the porta hepatis. When the SPV was ≥ 4 mm Hg, at least 1 bolus (3 to 4 mL/kg) of Hartmann solution was administered IV during a 1-minute period. Bolus administration was stopped and the CVC-to-Ao ratio measured when SPV was < 4 mm Hg. Correlation coefficient analysis was performed. RESULTS 28 measurements were obtained. The correlation coefficient was 0.86 (95% confidence interval, 0.72 to 0.93). Mean ± SD SPV and CVC-to-Ao ratio before bolus administration were 7 ± 2 mm Hg and 0.52 ± 0.16, respectively. Mean ± SD SPV and CVC-to-Ao ratio after bolus administration were 2 ± 0.6 mm Hg and 0.91 ± 0.13, respectively. CONCLUSIONS AND CLINICAL RELEVANCE In this study, the CVC-to-Ao ratio was a feasible, noninvasive ultrasonographically determined value that correlated well with SPV.

OBJECTIVE To determine the scan delay for use in performing cardiac CT angiography in dogs. ANIMALS 4 clinically normal adult Beagles. PROCEDURES In a crossover study, 12 formulations of iohexol solutions differing in iodine dose (300, 400, and 800 mg/kg) and concentration (undiluted and diluted 1:1, 1:2, and 1:3 with saline [0.9% NaCl] solution) were administered IV to each dog. Dynamic CT angiography was performed to evaluate enhancement characteristics of each formulation, with the region of interest set over the aorta. Time-attenuation curves (TACs) were obtained and analyzed. RESULTS Peak arc–type TACs were obtained after administration of all undiluted formulations. Curve shape changed from peak arc type to plateau type as the total volume of the contrast solution (ie, dilution) increased. Prolonged peaks characteristic of plateau-type TACs suggested that a sufficient period of homogeneous attenuation could be achieved for CT scanning with administration of higher iohexol dilutions (1:2 or 1:3) containing higher iodine doses (400 or 800 mg/kg). In particular, attenuation values for plateau-type TACs remained between 200 and 300 Hounsfield units for > 16 seconds after the plateau endpoint was reached for 1:2 and 1:3 dilutions containing an iodine dose of 800 mg/kg. Scan delays of 13 to 17 seconds were computed for those 2 formulations. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that for clinically normal dogs, a scan delay of 13 to 17 seconds could be used to perform cardiac CT angiography with iohexol solutions containing an iodine dose of 800 mg/kg at dilutions of 1:2 or 1:3.

Objective: To obtain quantitative variables of the abdominal aorta and both kidneys on the basis of time-attenuation curves (TACs) and to measure glomerular filtration rate (GFR) for each kidney and the global GFR in clinically normal cats by use of dynamic computed tomography (CT) and Patlak analysis. Animals: 9 healthy cats. Procedures: All the cats were anesthetized with propofol. Anesthesia was maintained by administration of isoflurane, and CT examination was performed in the anesthetized cats. The TACs and renal volume were measured by use of the baseline precontrast and single-slice dynamic scans. The CT-GFR of each kidney and the global CT-GFRs were calculated via Patlak plot analysis. Results: CT-GFR results from 7 cats were valid. Peak aortic enhancement was detected between 9.0 and 14.0 seconds after iohexol injection, and the initial peak time of renal parenchymal enhancement was 15 to 24 seconds after iohexol injection. Mean ± SD global GFR was 2.06 ± 0.62 mL/min/kg. Mean ± SD CT-GFR of the right and left kidneys was 0.97 ± 0.32 mL/min/kg and 1.05 ± 0.31 mL/min/kg, respectively. Conclusions and Clinical Relevance: The CT-GFR method can be rapidly and conveniently performed in clinically normal cats. This combined structural-functional approach provided physiologic and morphological information on the kidneys of cats.

Ninety-one equine aortic and cranial mesenteric arterial segments were evaluated ultrasonographically in a water bath. On the basis of pathologic evidence of verminous arteritis, arterial segments were classified into 4 categories, and the ultrasonographic characteristics of each group were evaluated. Normal arteries (class 1) were ultrasonographically characterized by a smooth luminal surface layer and uniform wall thickness and echogenicity. Arteries with only histopathologic evidence of verminous arteritis (class 2) were ultrasonographically characterized by a smooth luminal surface layer, uniform thickness, uniform echogenicity, and the presence of a hyperechoic luminal layer. Arteries with both gross and histopathologic evidence of verminous arterities (class 3) were characterized ultrasonographically by an irregular luminal surface layer, varying wall thickness, varying wall echogenicity, and the presence of a hyperechoic luminal layer. The ultrasonographic characteristics of arteries with luminal thrombosis (class 4) were an irregular luminal surface, varying wall thickness, and nonuniform echogenicity.

Hemodynamic effects of spontaneous ventilation, intermittent positive-pressure ventilation (IPPV), and high-frequency oscillatory ventilation (HFOV) were compared in 6 dogs during halothane anesthesia. Anesthesia was induced with IV thiamylal Na and was maintained with halothane (end-tidal concentration, 1.09%). During placement of catheters, dogs breathed spontaneously through a conventional semiclosed anesthesia circuit. Data were collected, and dogs were mechanically ventilated, using IPPV or HFOV in random order. Ventilation was adjusted to maintain PaCO2 between 38 and 43 mm of Hg during IPPV and HFOV. Cardiac index, aortic blood pressure, and maximum rate of increase of left ventricular pressure were significantly (P less than 0.05) less during HFOV than during spontaneous ventilation, whereas right atrial and pulmonary artery pressure were significantly greater during HFOV than during spontaneous ventilation. During IPPV, only the maximum rate of increase of left ventricular pressure was significantly less than that during spontaneous ventilation.

OBJECTIVE To estimate the left atrium–to–aorta ratio (LA:Ao) and establish 95% prediction intervals for left ventricular M-mode transthoracic echocardiographic measurements in clinically normal adult Dachshunds. ANIMALS 40 healthy Dachshunds. PROCEDURES For each dog, 3 standard 2-D echocardiographic methods (diameter, circumference, and cross-sectional area) were used to measure the left atrium and aorta and calculate the LA:Ao from right parasternal short axis (RPSA) images obtained at the level of the aortic valve cusps. Left ventricular M-mode measurements were acquired from RPSA images obtained at the chordal level immediately below the mitral valve. Descriptive data were generated, and the 95% prediction intervals were calculated by use of an allometric scaling equation and linear regression and compared with those calculated on the basis of data obtained from dogs of multiple breeds in a previous study.RESULTS The mean (SD) LA:Ao was 1.40 (0.13), 2.09 (0.17), and 2.85 (0.48) for the diameter, circumference, and cross-sectional area methods, respectively. The 95% prediction intervals for the left ventricular M-mode measurements determined by an allometric scaling equation on the basis of Dachshund-specific data were narrower than those determined on the basis of data obtained from dogs of multiple breeds. For that allometric equation, scaling exponents on the basis of Dachshund-specific data ranged from 0.129 to 0.397 and did not absolutely conform to the presumed index for linear measurements (ie, body weight0.333). CONCLUSIONS AND CLINICAL RELEVANCE The LA:Aos and 95% prediction intervals calculated in this study can be used as preliminary guidelines for echocardiographic measurements of clinically normal Dachshunds.