Cranial Vena Cava Research Articles

Blood flow changes in the rabbit cranial and caudal venae cavae during postural loads after propranolol, bisoprolol and methyldopa pretreatment

To treat the hyperadrenergic form of postural orthostatic tachycardia syndrome, the β1,2-adrenergic receptor blocker propranolol, the β1-blocker bisoprolol and the central agonist of inhibitory presynaptic α2-adrenergic receptors, methyldopa, are used in clinical practice. There is no data in the literature concerning the effects of these drugs on venae cavae flows during postural tests. In acute experiments on anesthetized rabbits, we studied changes of cranial and caudal venae cavae flows during orthostatic (head up tilt by 25°) and antiorthostatic (head down tilt by −25°) tests for 20 s after preliminary pretreatment with propranolol, bisoprolol and methyldopa. Before administration of these drugs, in response to orthostasis at 4 and 20 s, a decrease of the cranial and caudal venae cavae flows was noted. During antiorthostasis, caudal venae cavae flow increased for 4 s, and by 20 s it decreased to the initial value; cranial venae cavae flow decreased by 4 s, and by 20 s it was greater than the initial one. After propranolol pretreatment, caudal venae cavae flow decreased to a greater extent compared with intravenous administration of bisoprolol and methyldopa. After methyldopa administration during orthostasis, by 20 s, the cranial venae cavae flow decreased more pronouncedly than in the caudal venae, while after propranolol and bisoprolol pretreatment under conditions of orthostasis, both cranial and caudal venae cavae flows decreased approximately to the same extent. During antiorthostasis by 20 s after pretreatment with propranolol caudal venae cavae flow increased more than cranial venae cavae flow. In case of pretreatment with bisoprolol and methyldopa, in response to antiorthostasis, cranial venae cavae flow increased not only to a greater extent than caudal venae cavae flow, but also more pronouncedly compared with its increase in rabbits initially. Thus, we concluded, that in case of postural loads after pretreatment with indicated above drugs, there are differences in the mechanisms of blood flows redistribution in the basins of the cranial and caudal venae cavae.

Use of cardiac gated computed tomography in the diagnosis of a rare congenital cardiovascular anomaly in an adult alpaca.

A 5-year-old female alpaca was presented with respiratory distress and lethargy. Thoracic radiographs revealed a cranioventrally distributed alveolar pattern, caudodorsal bronchial pattern, cardiomegaly, increased soft tissue opaque content in the ventral thorax, and rounded soft tissue opaque structures craniodorsal to the carina. Cardiac gated CT demonstrated a patent ductus arteriosus, ventricular septal defect, complete left atrioventricular valve atresia, partial anomalous venous connections from the cranial pulmonary veins to the azygous and cranial vena cava, severe right-sided cardiomegaly, pleural and peritoneal fluid, and severe hepatic congestion. These findings were confirmed with necropsy.

Computed tomographic findings in canine and feline heart base tumors (25 cases).

Tumors located at the heart base are rare in dogs and cats and aortic body tumors (chemodectoma/paraganglioma), hemangiosarcoma, ectopic thyroid carcinoma, lymphoma, and other uncommon neoplasia can be found at that location. The objective of this retrospective case series was to describe the CT characteristics of canine and feline heart base tumors. CT studies of 21 dogs and four cats with histologically or cytologically confirmed heart base tumors were reviewed for size, location, shape, margination, contrast enhancement, adjacent neovascularization, invasion, mass effect, cavitary effusions, and metastasis. Neuroendocrine tumors (15 aortic body tumors, three ectopic thyroid carcinoma, and three nonspecific neuroendocrine) were more commonly observed than hemangiosarcoma (4) and were frequently located between the cranial vena cava and aortic arch (12/21; 57%) and or dorsal to the pulmonary trunk bifurcation/pulmonary arteries (10/21; 48%). Hemangiosarcoma was more commonly found cranioventral to the aortic arch and cranial to the right auricular appendage (3/4; 75%). Mediastinal and peritumoral neovascularization was associated with 16/21 (76%) neuroendocrine tumors but none of the hemangiosarcoma. Median postcontrast attenuation in Hounsfield units (HU) was higher in neuroendocrine (110 HU) than in hemangiosarcoma (51 HU). Pericardial effusion was frequently observed with hemangiosarcoma (3/4; 75%) and infrequently in neuroendocrine (3/21; 14%). In four cases (all neuroendocrine), concurrent cranial mediastinal masses were present. CT provides useful information regarding the characteristics of heart base tumors, indicating differences between the appearance of neuroendocrine tumors and hemangiosarcoma. However, no differences were found between aortic body tumors and ectopic thyroid carcinoma.

Blood Flow Changes in the Rabbit Cranial and Caudal Venae Cavae during Postural Loads after Propranolol, Bisoprolol and Methyldopa Pretreatment

Blood Flow Changes in the Rabbit Cranial and Caudal Venae Cavae during Postural Loads after Propranolol, Bisoprolol and Methyldopa Pretreatment

Positive correlation between echocardiographic tricuspid E peak velocity and central venous pressure in dogs: A preliminary study.

In the absence of vascular obstruction, central venous pressure (CVP) is a hydrostatic pressure in the cranial and caudal vena cava, providing valuable information about cardiac function and intravascular volume status. It is also a component in evaluating volume resuscitation in patients with septic shock and monitoring patients with right heart disease, pericardial disease, or volume depletion. Central venous pressure is calculated in dogs by invasive central venous catheterization, which is considered high-risk and impractical in critically ill patients. This study aimed to investigate the feasibility of using echocardiographic tricuspid E/E' as a noninvasive method to estimate CVP in anesthetized healthy dogs under controlled hypovolemic conditions. Ten male mixed-breed dogs were included in the study after a thorough health assessment. For hypovolemia induction, blood withdrawal was performed, and echocardiographic factors of the tricuspid valve, including peak E and E' velocities, were measured during CVP reduction. Repeated measures analysis of variance and Bonferroni post hoc tests were employed to compare the average difference between measured echocardiographic indices and CVP values derived from catheterization and intermittent measurement methods. Spearman's ρ correlation coefficient was used to evaluate the correlation between echocardiographic indices and CVP. E peak velocity had a significant negative correlation with venous blood pressure phases (r=-0.44, P=.001), indicating a decrease in peak E velocity with progressive CVP reduction. However, tricuspid valve E' peak velocity and E/E' did not correlate with CVP, suggesting that these parameters are not reliable for CVP estimation in dogs.

Morphological evidence of a potential arrhythmogenic substrate in the caudal and cranial vena cava in horses.

Three-dimensional electro-anatomical mapping, previously performed in horses with atrial arrhythmias, has demonstrated the medial region of the caudal vena cava (CaVC), 1-8 cm caudal to the fossa ovalis, as an anatomical predilection site for atrial tachycardia associated with areas of slow conduction and conduction block. Slow conduction has also been recorded in the cranial vena cava (CrVC). To investigate the morphological characteristics of the myocardial sleeves (MS) in the CaVC and CrVC, in order to identify a potential substrate of right sided atrial arrhythmias. Cross sectional. Post-mortem dissection of 37 hearts from adult warmblood horses without known cardiovascular disease. Macroscopic examination of the myocardial distribution, evaluated the MS area, length, width, and shape in the CaVC and the CrVC. At least 2 samples from each vena cava MS were histologically examined using Masson's trichrome staining. Myocardial sleeves into the medial CaVC and into the CrVC were observed in all horses and showed variations in distribution, shape, and size between horses. Their mean ± standard deviation length from the limbus into the CaVC reached 5.7 ± 1.0 cm (maximum 8.3 cm), and from the azygos vein into the CrVC 5.3 ± 1.6 cm (maximum 8.6 cm). Myocardium-free islands were observed in the CaVC and CrVC in 30% and 6% of horses, respectively. Histologically, MS showed a non-uniform myocardial fibre arrangement, with presence of fibroadipose tissue, features known to result in slow conduction and pro-arrhythmia. Study only included horses without history of atrial arrhythmia. Myocardial sleeves are present in both CaVC and CrVC, showing anatomical variations between horses. Tissue characteristics known to favour re-entry were identified indicating that these venae cavae MS are a potential substrate for atrial tachyarrhythmias and a target for treatment by ablation.

Biochemical and hematological characteristics of blood indicators, productivi-ty of piglets under the influence of additional feed “Activo”

The article discusses the issue of the condition of the piglets' bodies before and after weaning after feeding the additional feed “Activo.” The object of the study was piglets born from sows of the large white breed of ADN genetics. Piglets were divided into control (n = 111) and experimental (n = 110). From the 5th to the 43rd day of life, the piglets were given pre-starter compound feed in loose form. In the research group's pre-starter compound feed, “Activo,” was introduced in the amount of 0.2 kg/t of finished compound feed. Blood was collected from the cranial vena cava of the piglets of the control and experimental groups for biochemical and hematological parameters on the 28th and 43rd days of the piglets' life. Productivity control was carried out by weighing animals on the day of birth, at weaning, and on the 43rd day of life. Feed consumption was monitored, and average daily gains and feed conversion were determined. According to the results of the research on piglets before weaning, we can see an increase in the total protein level in the experimental group's blood by 2.85 % compared to the control group. The albumin concentration in the control group's piglets was 47.33 %, and the experimental group was 48.00 %, which is 1.42 % more than the control group. There was also an increase in α-, β-, and γ-globulins in the experimental group. After piglets were weaned, a probable increase in total protein and albumin was noted in the experimental group by 3.96 % and 1.85 %, respectively, in the control group. At the beginning of the experiment, the piglets of the control and experimental groups had a slight difference in live weight, which was 3.35 % in favor of the control group. Already on the 28th day of life, the piglets of the research group had a live weight statistically higher by 6.58 % (P < 0.001) concerning the control. Thus, for 14 days of the experiment after weaning, the increase in live weight of piglets of the experimental group probably increased by 11.9 % (Р < 0.01), and the difference in the weight of piglets between the control and experimental groups was 0.88 kg, or 8.15 % (P < 0.001). The average daily growth rate of piglets in the experimental group also increased by 11.8 % (Р < 0.01). The difference in feed conversion between the control and experimental groups is 0.19 kg or 10.8 %.

Hemoglobin Scavenging Proteins Reduce Free Hemoglobin during Venovenous Extracorporeal Circulation and Reduce Markers of Organ Damage and Inflammation

Introduction Extracorporeal circulation (ECC) procedures circulate blood outside the body, either to apply a process or to take over an organ's function. The circuits used for these procedures often utilize a pump to drive blood flow. These pumps subject red blood cells to excessively high shear stresses, leading to hemolysis and release of hemoglobin (Hb) into the plasma. Acellular free hemoglobin is detrimental, increasing nitric oxide (NO) scavenging and leading to hypertension and vasoconstriction, as well as increasing oxidative stress, endothelial dysfunction, and tissue damage. The goal of the present study was to determine whether natural and synthetic protein solutions that sequester heme and Hb can reduce the inflammation and organ damage in a small rodent model of venovenous ECC (VVECC). The present study investigates two different scavenging solutions: i) a solution containing native proteins such as haptoglobin, hemopexin, and transferrin (Protein Cocktail) and ii) a solution containing the apohemoglobin-haptoglobin (ApoHb-Hp) complex, which is a synthetic heme and Hb scavenger. Methods Male Golden Syrian hamsters were instrumented with a dorsal window chamber prior to the day of the experiment. On the day of the experiment, animals were anesthetized using inhaled isoflurane and prepped for cannulation surgery. A drainage cannula was inserted into the right jugular vein, advanced past the heart, and positioned in the inferior vena cava. A reinfusion cannula was inserted into the left jugular vein and advanced into the left cranial vena cava to return blood to the right atrium. An arterial catheter was inserted into the left carotid artery for arterial blood access. After surgery, the animal was transferred to the VVECC setup, where the cannulas were spliced into the ECC circuit. The circuit consisted of a peristaltic pump and bubble trap and was primed with one of three solutions: i) 5% human serum albumin (HSA, control), ii) ApoHb-Hp, or iii) Protein Cocktail. The animal was situated on a motorized stage below a hyperspectral camera, which took images of the microvasculature contained in the window chamber every 5 minutes to assess Hb oxygen saturation (HbsO2) within individual arterioles and venules. VVECC was broken up into 7 different stages based on blood flow through the circuit, as shown in Figure 1. After 2 hrs of VVECC, the animal was euthanized, and tissue samples were taken for biomarker analysis. In half the animals, the right kidney was excised for histology and stained for iron. Plasma samples taken after draining the circuit were analyzed using size exclusion chromatography (SEC) to quantify the amount of free or bound Hb. Results The two scavenging solutions showed significant increase in the percentage of bound Hb compared to the HSA control ( Figure 2). The ApoHb-Hp scavenged significantly more Hb than the Protein Cocktail. Urinary creatinine, u-NGAL, BUN, KIM-1 (markers of renal damage) all showed a significant reduction in ApoHb-Hp compared to the HSA control. Additionally, staining of kidney sections revealed a reduction in iron deposits in the ApoHb-Hp group compared to the HSA control. Next, we evaluated AST and ALT, which are markers of liver function, to identify any differences in hepatic damage. We found that AST levels significantly decreased in both scavenging solutions compared to the HSA control. On the other hand, ALT showed a significant decrease only in the ApoHb-Hp group when compared to the HSA control. Conclusion This study aimed to evaluate the effectiveness of two different heme and Hb scavenging solutions when used to prime an ECC circuit. The primary focus was on their ability to reduce organ damage, inflammation, and iron accumulation, which are significant concerns in patients undergoing procedures like cardiopulmonary bypass and extracorporeal membrane oxygenation (ECMO). The results showed a substantial reduction in damage and inflammatory markers in the group treated with ApoHb-Hp compared to the HSA control. The ApoHb-Hp has the potential to significantly minimize the harmful effects of hemolysis during ECC procedures, thereby safeguarding patients from organ damage and inflammation. These findings suggest that these scavenging solutions can be used as a proactive measure to mitigate the adverse consequences of hemolysis in patients undergoing ECC therapies.

SPECIFICS OF ANTIBODY GENESIS IN NOVOSIBIRSK BREED SM-1 PIGS IN THE PROCESS OF PHYLOGENESIS

The article presents data reflecting the features of the synthesis of IgM and IgG in pigs of the SM-1 breed of Novosibirsk selection in phylogenesis. The studies were conducted on pigs on the 30th, 60th, 90th and 240th days of life in 1990, 1996 and 2006. birth. Each group of animals included 66 animals. Groups of animals were formed according to the method of analogues, taking into account age, body weight, sex and health. Pigs were bled from the cranial vena cava. The concentration of IgM and IgG in the blood serum of animals was determined by simple radial immunodiffusion. The study results showed that pigs born in 1990 differ from their peers born in 1996 and 2006 in statistically significant high levels of IgM at 30, 60, and 240 days of age and increased activity of IgG synthesis at three months of age. So, at 30 days of age, piglets born in 1990 exceeded the IgM content in the blood serum of sucklings born in 1996 by 15.5% (P<0.001) and piglets born in 2006 - by 20.0% (P<0.001). On the 60th day of life, the differences between pigs born in 1990 and 1996 and between 1990 and 2006 were, respectively, 26.2 (P<0.01) and 32.5% (P<0.01). In pigs on the 240th day of life, born in 1990, the concentration of IgM in the blood serum was 44.6% (P<0.001) higher than in pigs born in 1996 and 48.0% (P<0.001) higher than in pigs 2006 year of birth. At two months, piglets born in 1990 were inferior in IgG level to piglets born in 1996 by 24.4% and too young animals born in 2006 by 24.7% (P<0.01). A month after weaning, pigs born in 1990 demonstrated the best rehabilitation qualities of the immune system. As a result, piglets born in 1990 were ahead of their counterparts in 1996 and 2006. births by 26.1% (P<0.001) and 26.0% (P<0.001), respectively. Pigs 1996 and 2006 birth throughout the study showed a stable level of antibody genesis.

Persistent left cranial vena cava in an alpaca cria incidentally identified with computed tomography

AbstractA 12‐week‐old alpaca cria, that had been managed conservatively for a subluxation of the third and fourth cervical vertebrae (C) and possible C6–C7 subluxation identified several weeks previously following trauma at birth, was presented for investigations of acute onset tetraparesis. During investigations with computed tomography, a persistent left cranial vena cava, with an unusual phenotype, was incidentally identified with concurrent absence of the right cranial vena cava. The azygous vein could be seen crossing over the mediastinum to join the persistent left cranial vena cava, which continued caudally, passing left lateral to the heart and emptying into the caudal vena cava at the level of the diaphragm.

Giant right atrial aneurysm associated with persistent left cranial vena cava in a cat

A 10-month-old female spayed Scottish Fold was referred to cardiology for incidental radiographic cardiomegaly. Echocardiography was suspicious for a right atrial or right auricular aneurysm. The differential diagnosis also included peritoneal–pericardial diaphragmatic hernia, mass lesion (cyst, granuloma, or neoplasia), or cardiac malformation. A giant right atrial aneurysm associated with a persistent left cranial vena cava was subsequently confirmed with computed tomography.

Use of two point-of-care analyzers provides reference intervals of prothrombin time and activated partial prothrombin time in nonanesthetized healthy ferrets (Mustela putorius furo)

Coagulation tests are an essential tool in the diagnosis and management of coagulopathies in mammals. The aim of the current study was to establish reference intervals for prothrombin time (PT) and activated partial PT (aPTT) in healthy ferrets using 2 different point-of-care analyzers (Idexx Coag DX and MS QuickVet Coag Combo). 86 clinically healthy ferrets under 3 years of age (47 females and 39 males) from 4 breeders and 2 private practices. Blood samples were collected from the cranial vena cava in all ferrets without anesthesia and placed in trisodium 3.2% citrated plastic tubes. Sixty-six blood samples from the 4 ferret breeding farms and 1 private practice were analyzed using the Idexx Coag DX and 21 from the other private practice using the MS QuickVet Coag Combo. Reference intervals for the Idexx Coag DX were as follows: aPTT (n = 65), 69.84 to 105.99 seconds; PT (65), 14.44 to 21.98 seconds. Reference intervals for the MS QuickVet Coag Combo were as follows: aPTT (n = 21), 74.90 to 115.50 seconds; PT (21), 18.31 to 23.05 seconds. With both types of analyzers, there was no significant age effect on aPTT and PT. This study provided coagulation times for 2 point-of-care analyzers in healthy ferrets as a tool for the diagnosis of coagulopathies.

Effect of Reduced Crude Protein Level on Fecal Nitrogen Excretion and Blood Profile in Finishing Pigs

The purpose of this experiment was to evaluate the effects of a low-protein diet on the selected variables of protein and energy metabolism in the blood serum as well as on the indicators of fermentation in the faeces (fecal crude protein, ammonia, pH, volatile fatty acids, and dry matter). Twelve finishing pigs (initial body weight: 64.6 ± 3.35 kg) were randomly divided into two groups and fed basal diets with crude protein (CP) levels of 13.6% and 15.4%, respectively. The Lysine, Methionine, Threonine, and Tryptophan levels in the 13.6% CP group were the same as those in the 15.4% CP group after the addition of four crystalline amino acids—Lysine, Methionine, Threonine, and Tryptophan to the diet. The blood and faeces samples were taken from the cranial vena cava and from the rectum at the end of the study period (44 days). The results showed that with the decrease in dietary CP level from 15.4% to 13.6% (a decrease of 1.8%), the fecal crude protein, the fecal ammonia, as well as the blood urea level decreased in the experimental group compared to the control group (P< 0.05 and 0.01, respectively).

Double vena cava cranialis in a female Pug – a case report

The purpose of the present case report was to describe an extremely rare variation of vena cava cranialis in a Pug dog observed during routine dissection. The right cranial vena cava was normally represented, while the left cranial vein was described as an exception and very rarely in mammalian orders with an asymmetric cranial hollow vein, while there are animal classes and orders in which the double, symmetrical cranial hollow vein is normally present. The different end in the right atrium of this extra vein, visualised by imaging methods, can be misinterpreted as pathology of the heart. The left cranial vena cava is an important finding during radiological examination, as well as for specialists dealing with breeding and hereditary anomalies.

Acupuncture Treatment Improves Transport Stress in Microminipigs Through the Acupoint in Ears.

This study aimed to investigate the effects of acupuncture treatment through the ear acupoints on transport stress in experimental microminipigs. Experiment 1: Six animals were equally divided into two groups (Control and Treatment). In the treatment group, before transportation (6 h; vehicle and plane), short, ultrathin circular transdermal needles were applied to locations corresponding to the acupoints on the apical area of both ears. Peripheral blood samples were collected from the cranial vena cava 2 days before and immediately after transportation. Blood stress markers, biochemistry indicators, and oxidative stress levels were examined. Experiment 2 (follow-up study: diarrhea incidence after transportation): Diarrhea incidence after transportation in the control and treatment groups was investigated. Experiment 1: Transport stress induced an increase in blood cortisol, serum amyloid A (SAA), glucose, non-esterified fatty acid, and derivatives of reactive oxygen metabolites (d-ROMs) and decreased the biological antioxidant potential (BAP)/d-ROMs ratio yet did not affect BAP. Acupuncture suppressed the increases in SAA and d-ROMs values and the decrease in BAP/d-ROMs ratio. Experiment 2: The total diarrhea incidence was 25% in the control group, whereas diarrhea was not observed in the treatment group. Acupuncture treatment suppresses hypothalamic-pituitary-adrenal function and, as a result, reduces transport stress without affecting the suppression of the central catecholaminergic system. Acupuncture treatment for transport stress can improve animal welfare.

Echocardiographic values in healthy Pugs: Effect of body weight, age, and sex.

Transthoracic echocardiography represents the main noninvasive technique for evaluating cardiac morphology and function in dogs. In dogs with particular somatotypes, such as brachymorphic dogs, breed-specific echocardiographic values are needed for a proper echocardiographic interpretation. Nowadays, the Pug represents one of the most popular brachymorphic canine breeds worldwide. However, data on echocardiographic measurements in this breed are currently limited. We aimed to determine echocardiographic values in a population of apparently healthy Pugs, and to assess the possible effects of body weight (BW), age, and sex on selected echocardiographic variables, with particular emphasis on those related to the left-sided cardiac chambers. Apparently healthy Pugs underwent a full physical examination, a 1-minute six-lead electrocardiogram, and a complete transthoracic echocardiography. Twenty-four echocardiographic variables were measured by combining M-mode, two-dimensional and Doppler modalities, and relative values were determined by applying the statistical procedures recommended by the Clinical and Laboratory Standards Institute. Moreover, the effect of selected demographic variables on echocardiographic measurements was tested using a linear mixed model. The investigation included 86 Pugs. Echocardiographic values were provided for each variable and compared with previous veterinary literature. A statistically significant effect of BW, age, and sex was documented for several of the tested variables. Doppler examination demonstrated a trivial pulmonary regurgitation in 24/86 (27.9%) Pugs. Moreover, a persistent left cranial vena cava was suspected in 4/86 (4.7%) dogs. Echocardiographic features of the Pug were addressed and echocardiographic values were made available for clinical use. Because our findings were obtained using a standardized echocardiographic analysis in a population of 86 healthy Pugs, they may act as a reliable guide for an accurate echocardiographic interpretation in this breed.

A morphological study on sinus and atrioventricular nodes in saanen goats*

In mammals, the sinus node and atrioventricular node are defined as the heart's specific stimulus and conduction systems. The electrical stimulation that starts in the sinus node continues with the atrioventricular node, and the rhythmic stimulation occurs in this way. There are differences in the sinus and atrioventricular nodes' location, size, and cell structures between species. In this study, which was carried out to determine the morphological structures and locations of the sinus and atrioventricular nodes in Saanen goat hearts, nine hearts from healthy goats were used. After performing the routine tissue follow-up procedure for histological examinations, 5 μm-thick serial sections taken from paraffin-blocked samples were stained with Crossman Trichrome and Periodic Acid Schiff (PAS) and photographed. It was determined that the sinus node was in a subepicardial position near where the cranial vena cava opens up to the right atrium. The sinus node, with an average length of 8-10 mm was crescent-shaped. The atrioventricular node was located in the subendocardium layer in the right half of the interatrial and the interventricular septum, where the coronary sinus opened into the right atrium. An atrioventricular node with an average length of 4.5-5 mm was observed to be roughly oval. Two types of cells were identified in both nodes: cells with small, rounded with empty cytoplasm and rather large nuclei, and cells with thin, elongated structures and darker staining.

Some cardiopulmonary effects of capnoperitoneum in anesthetized guinea pigs (Cavia porcellus): spontaneous ventilation versus intubation and mechanical ventilation

ObjectiveTo compare cardiopulmonary variables and blood gas analytes in guinea pigs (Cavia porcellus) during anesthesia with and without abdominal carbon dioxide (CO2) insufflation at intra-abdominal pressures (IAPs) 4 and 6 mmHg, with and without endotracheal intubation. Study designProspective experimental trial. AnimalsA total of six intact female Hartley guinea pigs. MethodsA crossover study with sequence randomization for IAP and intubation status was used. The animals were sedated with intramuscular midazolam (1.5 mg kg–1) and buprenorphine (0.2 mg kg–1) and anesthetized with isoflurane, and an abdominal catheter was inserted for CO2 insufflation. Animals with endotracheal intubation were mechanically ventilated and animals maintained using a facemask breathed spontaneously. After 15 minutes of insufflation, the following variables were obtained at each IAP: pulse rate, respiratory rate, rectal temperature, oxygen saturation, end-tidal CO2 (intubated only), peak inspiratory pressure (intubated only), noninvasive blood pressure and blood gas and electrolyte values, with a rest period of 5 minutes between consecutive IAPs. After 4 weeks, the procedure was repeated with the guinea pigs assigned the opposite intubation status. ResultsIntubated guinea pigs had significantly higher pH and lower partial pressure of CO2 in cranial vena cava blood (PvCO2) than nonintubated guinea pigs. An IAP of 6 mmHg resulted in a significantly higher PvCO2 (65.9 ± 19.0 mmHg; 8.8 ± 2.5 kPa) than at 0 (53.2 ± 17.2 mmHg; 7.1 ± 2.3 kPa) and 4 mmHg (52.6 ± 10.8 mmHg; 7.01 ± 1.4 kPa), mean ± standard deviation, with intubated and nonintubated animals combined. Conclusions and clinical relevanceAlthough the oral anatomy of guinea pigs makes endotracheal intubation difficult, capnoperitoneum during anesthesia induces marked hypercapnia in the absence of mechanical ventilation. An IAP of 4 mmHg should be further evaluated for laparoscopic procedures in guinea pigs because hypercapnia may be less severe than with 6 mmHg.

Abnormalities of External Jugular Veins in Bulldogs with Pulmonary Valve Stenosis

Simple SummaryThis case series is about two French bulldogs and one English bulldog affected by pulmonary valve stenosis that were diagnosed with different abnormalities of the external jugular veins (EJV) before a pulmonary balloon valvuloplasty. The EJV abnormalities encountered were severe hypoplasia of both external jugular veins and right external jugular vein absence, associated with persistent left cranial vena cava. All cases were diagnosed through computed tomography and vascular ultrasound. The aim of this case series is to describe external jugular veins abnormalities that can affect the decision-making process regarding central venous catheterization needed to perform procedures such as pulmonary balloon valvuloplasty or central catheter placement. Based on the results of the present case series, anomalies of the external jugular veins should be considered in French and English bulldogs when the external jugular veins cannot be clinically identified or when echocardiography shows coronary sinus dilation. Vascular ultrasound or computed tomography may help identify jugular venous anomalies and should be considered in the preoperative evaluation of bulldogs that need to undergo interventional procedures requiring transjugular catheterization.Two French bulldogs and one English bulldog affected by pulmonary valve stenosis and referred for pulmonary balloon valvuloplasty were diagnosed with different abnormalities of the external jugular veins. The diagnosis included unilateral absence of the right external jugular vein and bilateral hypoplasia of the external jugular veins, associated with persistent left cranial vena cava. Vascular ultrasound and computed tomography were used for the diagnosis. Jugular vein anomalies can affect decision-making regarding the central venous catheterization needed to perform procedures such as pulmonary balloon valvuloplasty or central catheter placement. Based on the results of the present case series, anomalies of external jugular veins should be considered in French and English bulldogs when the external jugular veins cannot be palpated or when echocardiography shows coronary sinus dilation. Vascular ultrasound or computed tomography may help identify jugular venous anomalies and should be considered in the preoperative evaluation of bulldogs that need to undergo interventional procedures requiring transjugular catheterization.

Venous drainage of the heart of the red fox (Vulpes vulpes)

This study was carried out to reveal the coronary venous system of the red fox (Vulpes vulpes) heart. The hearts used in the study were obtained from six red foxes that were brought to the Kafkas University Wildlife Rescue and Rehabilitation Centre after serious injuries due to firearms or traffic accidents and could not be saved despite all interventions. Latex was injected from the cranial vena cava and caudal vena cava to expose the coronary vasculature. Hearts were photographed after dissection. It was determined that venous drainage of the red fox heart was provided by the great cardiac vein, middle cardiac vein, right cardiac veins, and the smallest cardiac veins. The strongest of these veins was determined to be the paraconal interventricular vein with a diameter of 3.03 ± 0.44 mm. It was determined that the paraconal interventricular vein was accompanied by a strong vein with a diameter of 2.09 ± 0.43 mm in five of six fox hearts examined. It was observed that left atrial oblique vein participated in the formation of the coronary sinus in four hearts, and the great cardiac vein, middle cardiac vein, and the left marginal ventricular vein were seen to be drained into the coronary sinus in the other two hearts. It was determined that the paraconal interventricular vein and middle cardiac vein collected the venous blood of septum interventriculare via septal veins in all hearts. In this study, the smallest cardiac veins were clearly identified for the first time, and the myocardial bridge was revealed in a wild animal for the first time.