Aortic catheterization in cattle via the costoabdominal artery and validation for progesterone and estradiol-17 beta sample collection

The abdominal portion of the aorta was catheterized in 27 cows. Local analgesia was achieved by infiltration of anesthetic agents. A 10-cm skin incision was made caudal and parallel to the 13th rib at the lateral border of the epaxial muscles. The dorsal costoabdominal artery was exposed at its first lateral cutaneous branch by careful dissection through fascial layers. A sterile polyvinyl catheter (1.52 mm OD) was inserted into the artery and was advanced 35 to 40 cm to the abdominal portion of the aorta. Catheter patency was maintained for up to 5 weeks. Concentrations of plasma progesterone and estradiol-17 beta in samples obtained from the abdominal portion of the aorta were similar to simultaneously obtained concentrations in samples from the jugular vein before and after parturition.     

Comparison between tail and jugular venipuncture techniques for blood sample collection in common chameleons (Chamaeleo chamaeleon)

The most common technique used for collecting blood samples from chameleons, ventral tail caudal venipuncture (Reptile care. An Atlas of Diseases and Treatments, Vol. II, T.F.H. Publication, New Jersey, 1991) sometimes presents undesired effects. Here we compared tail versus jugular vein venipuncture techniques in the common chameleon. In the first experiment, we collected 0.25% of the chameleon's body mass in blood from either tail or jugular sites in size-matched pairs of animals to check for secondary effects. In a second experiment, we measured white blood cells (WBC), red blood cells (RBC), total plasma protein and uric acid in blood samples collected from both sites in the same individual. We found few secondary effects following the use of either venipuncture site although skin darkening was observed in few specimens when using the ventral tail vein. Blood profiles were similar between samples. The repeatability of measurements was similar in RBC and WBC counts and remarkably low (<0.90). Despite the few differences recorded, we recommend jugular venipunction in chameleons as skin darkening is unlikely, blood volumes are easily obtained and collection time is shorter.     

Avian clinical pathology. General considerations

Summary

General aspects of avian clinical pathology are reviewed. It is concluded that in a clinical setting a volume of blood equivalent to 1 per cent of body weight can be collected safely from avian species for laboratory examinations. The anticoagulant of choice for most laboratory investigations is lithium heparin. In most bird species the right jugular vein is the preferred site for routine blood sampling. The use of a vacuum system greatly facilitates the procedure. The importance of immediately processing blood samples is explained. The many variables that may influence haematological or biochemical parameters are discussed and the reasons for determining blood chemical reference values by non‐parametric methods are emphasised.     

A model for the preferential delivery of isoflurane to the spinal cord of the goat

To identify the blood supply of the caprine central nervous system, six anaesthetised goats were perfused with coloured suspension into the brachiocephalic artery, the aorta, the iliac artery and the femoral artery. The subsequent distribution indicated that the brain and the main segments of the spinal cord were supplied by the brachiocephalic artery and aorta, respectively. Ten similarly anaesthetised goats then received emulsified isoflurane randomly via either the proximal part of the descending aorta (arterial group) or an ear vein (venous group). In the arterial group, the isoflurane partial pressure (P_iso) in femoral arterial blood was almost double the P_iso in jugular venous blood. The model showed that preferential delivery of isoflurane to the goat spinal cord in situ was possible and could be used for further research into the mechanisms of anaesthetic action, particularly factors affecting immobility.     

The Mammary Blood Flow in the Cow as Measured by the Antipyrine Absorption Method

After intramammary application of 3 g antipyrine dissolved in 30 ml distilled water into each quarter the absorption of antipyrine from the udder proceeds as a first order reaction. As the injected amount is known as well as the amount of antipyrine milked out about 1 hour later can be determined, it is possible to calculate the amount absorbed at any time between injection and emptying.It is shown, that the concentrations of antipyrine in the blood from the jugular vein and external pudic artery are identical after intramammary application of antipyrine. In experiments on lateral recumbent cows it is shown that the venous blood returns from the udder via both the subcutaneous abdominal and the external pudic veins. In the standing cows blood samples were drawn from the jugular and the subcutaneous abdominal veins. The blood samples from the subcutaneous abdominal veins were drawn during manual compression of the external pudic veins to get representative concentrations of antipyrine in the total venous blood from the udder. On account of the amount of antipyrine absorbed and the difference in antipyrine concentrations between the subcutaneous abdominal veins and the jugular vein the mammary blood flow in lactating cows was found to vary between 22–101 ml/min. per 100 g gland tissue.The possibility of calculating the mammary blood flow after injection in two glands only — while the two remaining glands might be used for other studies — is shown and discussed. The influence of the individual differences in the venous anastomoses on the results is discussed, and a procedure is described to select cows suitable for experiments on mammary blood flow.     

Comparison of three different techniques for subcutaneous relocation of the carotid artery in small ruminants

Three surgical techniques for subcutaneous relocation of the carotid artery in small ruminants are compared. A total of 25 sheep and seven goats were used and randomly assigned to three groups. In group A (technique A), the carotid artery was moved subcutaneously and kept there by suturing the tissues on both sides of the jugular vein beneath the relocated artery and the skin above it. In the other two groups the relocated artery was secured into a skin strip (technique B) or a skin fold (technique C). The animals were used for repeated blood sampling over a period of several months. Technique A did not provide good immobilization whilst among the three, technique B provided the least protection of the relocated artery and was the most difficult to perform. It was concluded that technique C was superior to the other two methods in providing better conditions for long-term blood sampling.     

Catheterization of the caudal vena cava via the lateral saphenous vein in the ewe, cow, and gilt: an alternative to utero-ovarian and medial coccygeal vein catheters

Current methods for obtaining venous blood from the reproductive organs of livestock often have a low rate of success or involve intensive surgical procedures that may impair ovarian function. Therefore, the caudal vena cava was catheterized via the lateral saphenous vein to determine the feasibility of using this method for chronic sampling of blood draining from the reproductive organs of ewes (n = 6), cows (n = 6), and gilts (n = 7). Blood samples were collected at 2-cm (ewes and gilts) or 5-cm (cows) intervals during insertion of catheters. Correct placement, defined as the position at which plasma concentrations of progesterone or estrogen were at least threefold greater than in jugular venous plasma, varied among species and among animals within species. It seemed, however, that a majority of catheters would be placed correctly if secured at 48 to 52 cm in ewes, 52 cm in gilts, and 90 to 100 cm in cows. Saphenous vein catheters were secured for sequential sampling of vena caval blood during the follicular phase of ewes (n = 25), cows (n = 4), and gilts (n = 5). Catheters remained patent for the duration of sampling in all individuals. Concentrations of estrogen in jugular and vena caval plasma were correlated (ewe P less than .0003; cow P less than .0001; gilt P less than .0001). Profiles of progesterone and estrogen revealed an episodic pattern of secretion in vena caval but not jugular plasma. Catheterization of the vena cava via the saphenous vein is a relatively simple and noninvasive method for obtaining blood containing uterine and ovarian hormones before their metabolism.     

A method for chronically quantifying net absorption of nutrients and gut metabolites into hepatic portal vein in conscious swine

Surgical procedures are described for chronic cannulation of portal vein, ileal vein, abdominal aorta, and carotid artery in pigs. Silastic or Micro-Renathane tubing was used for cannulating portal vein and ileal vein, while carotid artery was cannulated with Micro-Renathane tubing. The lumen of Micro-Renathane tubing was coated with tri-dodecylmethyl ammonium chloride (TDMAC)-heparin complex. The abdominal aorta was cannulated via saphenous artery with vinyl tubing. This allows simultaneous collection of blood samples from hepatic portal vein and systemic artery (carotid or abdominal aorta) and continuous infusion of p-aminohippuric acid (PAH) into ileal vein. The constant PAH infusion provided an indicator-dilution method for estimating the blood flow rate in portal vein. In 13 pigs weighing 54 +/- 2.8 kg, the mean portal vein blood flow rate during the 8-h postprandial period was estimated to be 1,979 ml X min-1 X pig-1 or 37.8 ml X min-1 X kg-1 body weight. By simultaneously measuring the concentration of nutrients and metabolites in the portal and systemic arterial blood and multiplying porto-arterial differences by the estimated portal vein blood flow rate, the net absorption of nutrients (except long-chain fatty acids) and metabolites into hepatic portal system in conscious swine can be quantified.     

Unilateral absence of an external jugular vein in two English bulldogs with pulmonary valve stenosis

Two English bulldogs referred for interventional palliation of severe pulmonary valve stenosis were incidentally diagnosed with unilateral absence of an external jugular vein (left in one case, right in the other) by computed tomography and Doppler ultrasound. The right internal jugular vein also could not be visualized in the dog with absence of the left external jugular vein. Cervical venous anomalies can impact diagnostic or interventional venous catheterization procedures such as balloon pulmonary valvuloplasty. Additionally, absence of an external jugular vein may impact central venous catheter placement. Absence of an external jugular vein should be considered in dogs when the external jugular vein cannot be easily palpated. Ultrasound or computed tomography may help identify jugular venous anatomy and confirm anomalies.     

Aortic to caudal vena cava ratio measurements using abdominal ultrasound are increased in dogs with confirmed systemic hypertension

Chronically sustained systemic hypertension in dogs can damage the kidneys, eye, brain, heart, and vessels. In human medicine, systemic hypertension has been implicated as the most common risk factor for aorta dilation, which can progress to an aneurysm. Abdominal ultrasound has been commonly used to monitor the size of the abdominal aorta in people with systemic hypertension. In this retrospective cross‐sectional abdominal ultrasound study, evaluation of the size of the abdominal aorta relative to the caudal vena cava was performed in 18 control dogs and 128 dogs with confirmed systemic hypertension. Preexisting conditions contributing to systemic hypertension in these dogs were renal disease, hyperadrenocorticism, diabetes mellitus, adrenal tumors, and previous administration of phenylpropanolamine or palladia. The abdominal aorta and caudal vena cava were assessed from longitudinal images cranial to the trifurcation with measurements made from outer border to outer border of the walls, being careful not to compress the caudal vena cava that would alter its size. Our hypothesis was the ratio of the diameter of the abdominal aorta to caudal vena cava would be higher in dogs with systemic hypertension compared to dogs with normal blood pressure. The mean abdominal aorta‐caudal vena cava ratio was 1.028 in control dogs with a normal blood pressure and 1.515 in dogs with systemic hypertension. In dogs with confirmed systemic hypertension, the abdominal aorta was dilated compared to the caudal vena cava in the caudal abdomen. An increase in the abdominal aorta‐caudal vena cava ratio in a dog should raise suspicion for the presence of systemic hypertension and prompt evaluation of blood pressure.     

Catheters: a review of the selection, utilisation and complications of catheters for peripheral venous access

Intravenous catheters are used for the administration of medications and fluids and are an integral part of veterinary practice. The aim of catheter use is to optimise administration of medication and minimise complications such as thrombus formation, thrombophlebitis and sepsis. Catheters made from teflon are less flexible, less durable and stimulate more tissue reaction than polyurethane or silicon. However silicon catheters are more expensive and complicated to insert. Generally, for veterinary practice, the biostability and cost of polyurethane catheters make them preferable for short and long-term use. The smallest diameter catheter should be selected to minimise internal vessel wall contact and irritation without compromising medication delivery. The site of insertion varies with individual preference, vessel access and patient compliance. The jugular, cephalic, saphenous, ear, lateral thoracic and subcutaneous abdominal veins are accessible. Hair removal and a thorough aseptic skin preparation should be performed prior to catheter insertion. Daily maintenance is required to detect complications and maximise catheter longevity. Potential complications include thrombus formation, thromboembolism, bacterial colonisation and septicaemia, blood loss and air embolism. Permanent or transient skin dwelling bacteria are commonly isolated if sepsis occurs. The development of novel antiseptic and antibiotic impregnated catheters may reduce the complications associated with catheter infection in the future.     

Techniques for venous blood sampling from the white pekin duck

Common sites for blood sampling in the pekin duck and other avian species include the basilic vein, jugular vein, superficial plantar metatarsal vein, heart, and occipital sinus. The use of each of these sites is described and/or illustrated. In the present study using the pekin duck, the superficial plantar metatarsal vein proved most satisfactory for collecting repeated samples (every 5 minutes for 30 minutes) with minimal trauma to the duck.     

Variations in blood flow to and from the bovine mammary gland measured using transit time ultrasound and dye dilution.

Blood flow across the lactating bovine mammary gland was measured by two techniques. The use of transit time flow probes appeared to give flows which correlated well with dye dilution in only one of five cows, although the relative changes in flow were similar between the techniques in four of the cows. Further studies were made on the effect of posture on mammary blood flow using both techniques. The crossover of venous blood from one side of the mammary gland was also studied using the dye dilution technique, and revealed large differences between animals and also with posture. These observations suggest that particular care should be taken when sampling blood from the milk vein of cows, if a representative sample is required. Changes in blood flow with posture may be indicative of a repartitioning of flow within the body, and the physiology of such a mechanism would be of interest in itself. The control of this mechanism may be useful in modifying blood flow to the mammary gland and thus milk yield, since blood flow is related to the level of milk production.     

Critical care surgical techniques

A veterinarian dealing with critical and trauma patients must be proficient with techniques for tracheostomy, thoracostomy tube placement for chest drainage, diagnostic peritoneal lavage, and autotransfusion. The utilization of these techniques may be life-saving in the critical patient. A tracheostomy is indicated in any patient with upper airway obstruction that cannot be managed with supplemental oxygen and/or orotracheal intubation. A tracheostomy tube with an inner cannula is preferred. Tracheostomy tubes should be cleaned at 3- to 4-h intervals, and methods should be employed to decrease thick tracheal secretions and to remove them from the trachea. A patient with a tracheostomy tube should be monitored continuously. A thoracostomy tube is indicated in any patient with large and/or continuous accumulation of air, blood, fluid, or chyle in the pleural space. The thoracostomy tube should be at least the same size as the patient's main stem bronchus. The thoracostomy tube is placed aseptically at the seventh intercostal space at the junction of the upper one third and lower two thirds of the lateral chest wall. Fluid or air may be removed from the chest intermittently with a three-way stopcock attached to the thoracostomy tube and a 60-ml syringe. If continuous drainage is needed, a continuous underwater seal and suction system should be used. Diagnostic abdominal paracentesis and peritoneal lavage are useful techniques in the determination of abdominal trauma, hollow viscus rupture, peritonitis, hepatic trauma, and urinary system trauma. When a multiholed catheter and lavage are used, the accuracy of detecting abdominal trauma is 95 per cent. When only needle paracentesis is used, the accuracy drops to 47 per cent. Abdominal lavage fluid can be analyzed for bacteria, whole blood, white blood cells, free bilirubin, creatinine, blood urea nitrogen, amylase, alkaline phosphatase, and alanine aminotransferase. Large volumes of whole blood recovered from abdominal or thoracic paracentesis can be reinfused into the patient if needed, providing it is not contaminated or markedly hemolyzed. The blood should be collected aseptically into blood bottles or bags. If the bleeding is ongoing or the blood only a few hours old, anticoagulants should be used. If the hemorrhage is several hours old, then clotting and defibrination has already occurred and the blood can be collected into "dry" bags or bottles. Before use, abdominal blood should be analyzed for urine, bile or fecal contamination. Blood collected from the thoracic cavity is much less likely to be contaminated. Autotransfused blood is administered through a standard blood administration set.     

Nutrient uptake by viscera drained by the portal vein in neonatal calves during intravenous infusion of glutamine

OBJECTIVE: To quantify glutamine use by viscera drained by the portal vein in neonatal calves and to determine whether uptake could be stimulated by long-term IV infusion or long-term use of oral supplements. ANIMALS: 4 healthy neonatal calves. PROCEDURE: A femoral artery, jugular vein, and the portal vein were surgically cannulated in each calf. Blood flow in the portal vein was measured, using an ultrasonic transit-time flow probe. Calves were given an IV infusion of glutamine on days 6, 8, and 10 after surgery. Before the first infusion, calves were fed a diet of milk only. The diet was supplemented with glutamine for the second and third infusions. Glutamine was administered via the jugular vein during a 5-hour period. Venous and arterial blood samples were collected every hour for 5 hours. RESULTS: During glutamine infusion, uptake of glutamine by viscera drained by the portal vein increased in association with increased production of ammonia. Glutamine supplementation of the diet did not alter glutamine uptake. Glutamine infusion did not increase viscera uptake of indispensable amino acids. Long-term use of glutamine supplements or infusion of glutamine for periods of more than 1 hour increased glutamine uptake by viscera. Arterial leucine concentration and uptake of leucine by the viscera decreased during glutamine infusion, indicating that leucine became the limiting factor. CONCLUSION: Glutamine administration (supplements or infusions) to calves may require that a mixture of amino acids be provided to improve effectiveness. CLINICAL RELEVANCE: Glutamine may be beneficial in treatments designed to promote intestinal healing in diarrheic calves.     

Colic in the horse. A clinical and clinical chemical study of 42 cases

42 horses were examined. The physical signs with relation to circulatory insufficiency and the abdominal disease were registered following a two-phased examination procedure. Great prognostic value was found in the degree of circulatory insufficiency judged by pulse rate and character, filling of the jugular vein, skin temperature, colour of mucous membranes, capillary refill time, sweating, depression, skin turgor and degree of enophthalmus. In making a causal diagnosis the abdomen was examined for shape, tenderness, peristaltic sounds, gastric dilation by siphoning, abnormal rectal findings and macroscopic changes in peritoneal fluid. Greatest diagnostic difficulties were encountered in cases of intestinal atonia, acute enteritis and torsion of the colon. In selected (severe) cases laboratory tests were obtained. Blood samples were examined for packed cell volume, hemoglobin, red and white blood cell counts, differential white blood cell count, blood gases and acid-base status, lactate, serum total protein and albumin, plasma sodium, potassium, chloride, calcium, magnesium, inorganic phosphorus, glucose, creatinine, BUN, total bilirubin, ASAT, CK, BASP and GGT. Peritoneal fluid was examined for red blood and white cell counts, total protein, specific gravity, pH and lactate, and enzymes as in blood. Laboratory results generally confirmed the clinical signs of shock, and packed cell volume and blood lactate were regarded to be of greatest prognostic interest. Although the performed laboratory information, macroscopic evaluation was thought to reveal sufficient information in most cases. It was concluded that supervening shock is of decisive importance in severe forms of colic, and that a careful and repeated evaluation of the circulatory insufficiency often provides one with a tentative prognosis although the final diagnosis is not obtained. In spite of therapy fatal outcome was found in all seriously shocked horses.     

Partial aneurysmectomy and autologous patch venoplasty in a horse diagnosed with pseudoaneurysm of the jugular vein

Experience with vascular pathology and vascular surgery, especially with the use of grafts, is limited in horses. Only one case of a venous aneurysm has been described in the horse, but without successful surgical correction. This case report describes the treatment of a 3-year-old female pony presented with an intermittent localised swelling of the left jugular vein after a previous thrombophlebitis. Ultrasonographic examination revealed a large jugular vein pseudoaneurysm. Treatment consisted of a partial aneurysmectomy preserving the healthy medial wall of the jugular vein. An autologous saphenous vein patch technique was used to reconstruct the vein with the largest possible lumen to minimise thrombus formation. Anticoagulants, antimicrobial and anti-inflammatory drugs were administered pre- and post-operatively. Follow-up ultrasound examinations initially showed local narrowing of the graft. At 2 and 8 months post-operatively, no external deformation of the jugular vein was visible and ultrasonography revealed patent blood flow with only a slight difference in lumen diameter. The patch venoplasty proved a viable surgical technique for jugular vein reconstruction resulting in a sufficient lumen, no thrombus formation and a good cosmetic and functional outcome.     

Development of the Equine Venous Sinuses of the Dura Mater

The equine dorsal sinus system of the dura mater develops from the dural venous plexuses. In early development, venous blood from these plexuses is drained into the primary head vein, which together with the stem of the caudal dural plexus joins the primitive internal jugular vein. After involution of the primary head vein new channels, the transverse and sigmoid sinuses, develop which empty into the internal jugular vein. The temporal sinus develops secondarily and coexists with the sigmoid sinus. After regression of the sigmoid sinus and internal jugular vein, the temporal sinus represents the sole channel in the equine fetuses, by which venous blood from the brain is drained through the emissary vein of the retroarticular foramen into the external jugular system.     

Hypertonic saline.

A key feature in the successful resuscitation of dehydrated or endotoxemic ruminants is the total amount of sodium administered. Administration of small volumes of HS and HSD offer major advantages over large volumes of isotonic saline because HS and HSD do not require intravenous catheterization or periodic monitoring, and are therefore suitable for use in the field. Hypertonic saline and HSD exert their beneficial effect by rapidly increasing preload and transiently decreasing afterload. Contrary to early reports, HS and HSD decrease cardiac contractility and do not activate a pulmonary reflex. The osmolality of HS and HSD should be 2400 mOsm/L (7.2% NaCl solution, 8 times normal plasma osmolality). Use of HS and HSD solutions of different osmolality to 2400 mOsm/L should be avoided at all costs, as too low a tonicity removes the main advantages of HS (low cost, decreased infusion time), whereas too high a tonicity may cause rapid vasodilation and decreased cardiac contractility, resulting in death. Rapid administration (> 1 mL/kg-1/min-1) of HS (2400 mOsm/L) should be avoided, as the induced hypotension may be fatal when coupled with a transient decrease in cardiac contractility. For treating dehydrated adult ruminants, HS (2400 mOsm/L, 4-5 mL/kg i.v. over 4-5 minutes) should be administered through the jugular vein and the cow allowed to drink water. This means that 2 L of HS should be administered to adult cattle. HSD should be administered in conjunction with isotonic oral electrolyte solutions to all calves 8% or more dehydrated (eyes recessed > or = 4 mm into the orbit, cervical skin tent duration > 6 seconds) or calves with reduced cardiac output (fetlock temperature < 29 degrees C when housed at 10-24 degrees C). For treating dehydrated calves, HSD (2400 mOsm/L NaCl in 6% dextran-70, 4-5 mL/kg i.v. over 4-5 minutes) should be administered through the jugular vein and the calf allowed to suckle an isotonic oral electrolyte solution. This means that 120-200 mL of HSD of HSD should be administered to a calf. HSD should be routinely administered to severely depressed or comatose calves, as HSD provides the fastest method of resuscitation while rapidly reversing the effects of hyperkalemia.     

Comparison of a new device for blood sampling in cats with a vacuum tube collection system - plasma biochemistry, haematology and practical usage assessment

Using paediatric devices to collect venous blood from a cephalic vein in cats offers numerous practical advantages over traditional jugular venepuncture and vacuum closed systems: minimal restraint is required; there is minimal risk of serious injury to the cat; the discomfort associated with venepuncture is reduced by the use of small diameter (25 gauge) needles; very small volumes (200 microl) of blood are extracted; and the risk of vein collapse or haematoma is low. The aim of this study was to compare the haematological and plasma chemistry results obtained from six healthy cats using the two sampling techniques. Five plasma biochemical analytes were measured and a complete haematological examination was performed on each specimen. No clinically relevant difference between the two blood sampling techniques was observed for any variable, indicating that paediatric devices provide a useful alternative to vacuum tubes for venous blood collection in the cat.