Plasma and Tissue Amikacin Concentrations Following Regional Limb Perfusion of Chickens (Gallus gallus domesticus).

Intravenous regional limb perfusion (IVRLP) has been used in the treatment of pododermatitis and distal limb infections, which are significant causes of morbidity in avian species. This intravenous drug administration technique is designed to achieve high drug tissue concentrations while minimizing systemic toxic effects. Amikacin is commonly used for IVRLP in veterinary medicine, but dosing guidelines have not been established for its use in birds. The current study aimed to determine the tissue concentration of amikacin after a single IVRLP administration in healthy, euhydrated leghorn hen chickens (Gallus gallus domesticus). Chickens received a single IVRLP dose of 10 mg/kg amikacin and were euthanatized posttreatment at 1 hour (n = 6), 12 hours (n = 6), and 24 hours (n = 6) to assess tissue and synovial fluid concentrations of amikacin in the injected leg. Mean tissue concentrations were highest 1 hour post-IVRLP (synovial fluid = 153.0 µg/mL, metatarsal pad tissue = 26.05 µg/mL) before declining at the 12- and 24-hour time points. This indicates that administration of amikacin via IVRLP can reach minimum inhibitory concentrations of common bacterial isolates in tissues after a single treatment with 10 mg/kg amikacin. Regional limb perfusion every 24 hours is recommended, although the minimum days of treatment may be case dependent and vary based on response to therapy.

Faster perfusate instillation time results in more systemic leakage of amikacin sulfate when performing intravenous regional limb perfusion in horses.

OBJECTIVE: To evaluate if a difference in synovial amikacin concentrations exists in the radiocarpal joint (RCJ) following different durations of instillation of an IV regional limb perfusion (IVRLP) perfusate. ANIMALS: 7 healthy horses. METHODS: Horses received 2 IVRLPs with 2 g amikacin diluted to 60 mL with 0.9% NaCl via the cephalic vein in a crossover study design with a wash-out period between procedures. Instillation of the perfusate was administered over a 1-minute (technique 1) and 5-minute (technique 5) period. Concentrations of amikacin within the RCJ were measured at time (T) 5, 10, 15, 20, 25, and 30 minutes after instillation of the perfusate. Systemic concentrations of amikacin were measured at T0, 5, 10, 15, 20, 25, 29 minutes, and 1 minute after tourniquet removal (T31). Amikacin concentrations were determined by fluorescence polarization immunoassay. RESULTS: The median maximum concentration (CMAX) of amikacin within the RCJ for technique 1 was 338.4 µg/mL (range, 60 to 4,925 µg/mL), while the median CMAX for technique 5 was higher at 694.8 µg/mL (range, 169.2 to 3,410 µg/mL; P = .398). There was a higher amikacin blood concentration over time for technique 1 compared to technique 5 (P = .004). CLINICAL RELEVANCE: Administration of perfusate at different rates did not significantly affect synovial concentration of amikacin within the RCJ when performing IVRLP. However, increased systemic leakage was noted when the perfusate was administered over 1 minute, which might affect synovial concentrations in a larger group of horses.

Characterization of placentome vascular perfusion in relation to pregnancy associated glycoproteins throughout gestation in pregnant beef heifers.

During pregnancy, blood flow to the uterus changes to support fetal demand. Placentomes serve as vascular attachment sites on the placenta for exchange of gases, nutrients, and metabolic products. Non-invasive methods of ultrasonography and biomarkers have been described to assess placental health and fetal viability. Pregnancy associated glycoproteins (PAGs) are produced by the ruminant placenta and are detected in maternal circulation. In cattle, changes in circulating PAG concentrations are associated with embryonic and fetal outcomes. The objective of this study was to determine the association between placentome blood perfusion and circulating PAG concentrations as they relate to the health of the developing fetus. We hypothesized that placentome perfusion and PAG concentration will be positively correlated and associated with neonatal outcome. A prospective, observational study was designed using 26 pregnant, nulliparous, Angus heifers in which PAG concentration and placentome blood perfusion were assessed throughout gestation, with assessment of calving characteristics following parturition. Placentome blood perfusion was visualized at 30-day intervals via transrectal Doppler ultrasonography with power flow function. Ultrasound images were analyzed using ImageJ software to determine the percent area of perfusion and integrated pixel densities. Venous blood was collected and PAG concentrations were determined via serum PAG enzyme-linked immunoassay. Mean placentome blood perfusion increased as gestation advanced. PAG concentrations demonstrated the expected temporal trend, increasing with gestation length, and were positively linearly correlated with placentome perfusion (P < 0.0001). The relationship identified between circulating PAG concentration and placentome blood perfusion suggests the use of transrectal power flow Doppler ultrasonography as a noninvasive technique to determine placental blood flow morphometrics to assess conceptus wellbeing throughout pregnancy.

Sedation with dexmedetomidine decreases skin perfusion in cats.

OBJECTIVE: To evaluate skin perfusion in cats receiving dexmedetomidine compared to a placebo. ANIMALS: 9 healthy adult research cats. METHODS: A randomized, blinded, placebo-controlled study design was used. Two sites, the dorsal metatarsus (site: limb) and lateral flank (site: flank), were evaluated with laser speckle contrast imaging (LSCI) at baseline and following administration of dexmedetomidine (1, 3, or 5 mcg/kg, IV) or a placebo (0.9% saline, IV). Mean speckle contrast (MSC), a surrogate for perfusion, was obtained from LSCI and compared between treatments. Heart rate, sedation score, and body temperature were recorded. Skin perfusion to the flank and limb, reported as MSC, was assessed via LSCI at baseline and at 5, 10, and 15 minutes posttreatment. RESULTS: There was a significant decrease in heart rate (P < .001) in cats receiving 1, 3, and 5 mcg/kg dexmedetomidine compared to placebo. There was a significant increase in median sedation score at all time points postsedation compared to baseline (P < .018). Changes in MSC for the metatarsus were not significantly different between treatments at any time point (P = .12). For the flank, MSC was significantly higher for cats treated with dexmedetomidine compared to baseline (P ≤ .01). Skin perfusion to the flank decreased as early as 5 minutes posttreatment with dexmedetomidine and persisted for at least 15 minutes, regardless of dexmedetomidine dose. CLINICAL RELEVANCE: Dexmedetomidine decreased skin perfusion in cats, even at low doses. Veterinarians may elect for an alternative sedative medication when decreased skin perfusion is a concern.

Morphine concentrations in distal thoracic limb synovial fluid following intravenous regional limb perfusion in horses.

Twelve adult horses were randomly assigned to 2 groups in a prospective experimental trial. A pneumatic tourniquet (425 mmHg) was placed, under sedation, proximal to the carpus on one randomly chosen thoracic limb. A cephalic vein catheter was placed distal to the tourniquet to establish an intravenous regional limb perfusion technique (IVRLP) with morphine (0.1 mg/kg) diluted with saline 0.9% to 0.1 mL/kg, and the tourniquet left in place for 30 minutes. Horses were euthanized at 1 h (Group I) or 6 h (Group II) following the IVRLP and synovial fluid from the radiocarpal, intercarpal, metacarpophalangeal, distal interphalangeal, and digital flexor tendon sheath was obtained from the injected and contralateral (control) limb immediately after. Morphine concentrations were determined using liquid chromatography-mass spectrometry. An unpaired t-test was used to compare morphine concentrations from both groups (P < 0.05). Synovial morphine concentrations were detected in the injected limb in all horses in Group I, except in one horse in the radiocarpal joint, and detected in 5 of 6 horses in Group II. Mean synovial concentrations ranged between 301.8 ± 192.3 and 608 ± 446.6 ng/mL in Group I and between 27.0 ± 17.7 and 136.8 ± 103.6 ng/mL in Group II and were significantly higher in Group I between paired anatomical sites of both groups for the radiocarpal and distal interphalangeal joints, and the digital flexor tendon sheath. In conclusion, concentrations of morphine after IVRLP can be detected in synovial fluid distal to the tourniquet at 1 and 6 hours in horses.

Douze chevaux adultes ont été assignés au hasard à deux groupes dans un essai expérimental prospectif. Un garrot pneumatique (425 mmHg) a été placé, sous sédation, à proximité du carpe sur un membre thoracique choisi au hasard. Un cathéter de la veine céphalique a été placé en aval du garrot pour établir une technique de perfusion intraveineuse régionale des membres (IVRLP) avec de la morphine (0,1 mg/kg) diluée avec une solution saline de 0,9 % à 0,1 mL/kg, et le garrot a été laissé en place pendant 30 minutes. Les chevaux ont été euthanasiés 1 h (groupe I) ou 6 h (groupe II) après l'IVRLP et le liquide articulaire de la gaine radiocarpienne, intercarpienne, métacarpo-phalangienne, interphalangienne distale et du tendon fléchisseur digital a été obtenu à partir du membre injecté et controlatéral (témoin) juste après. Les concentrations de morphine ont été déterminées par chromatographie liquide-spectrométrie de masse. Un test de t non apparié a été utilisé pour comparer les concentrations de morphine des deux groupes (P < 0,05). Des concentrations de morphine synoviale ont été détectées dans le membre injecté chez tous les chevaux du groupe I, sauf chez un cheval dans l'articulation radiocarpienne et détectées chez 5 des 6 chevaux du groupe II. Les concentrations synoviales moyennes variaient entre 301,8 ± 192,3 et 608 ± 446,6 ng/mL dans le groupe I et entre 27,0 ± 17,7 et 136,8 ± 103,6 ng/mL dans le groupe II et étaient significativement plus élevées dans le groupe I entre les sites anatomiques appariés des deux groupes pour le radiocarpien et les articulations interphalangiennes distales, et la gaine du tendon fléchisseur numérique. En conclusion, les concentrations de morphine après IVRLP peuvent être détectées dans le liquide synovial en aval du garrot à 1 et 6 heures chez les chevaux.(Traduit par Docteur Serge Messier).

Abdominal perfusion in canine patients with pyometra and sepsis evaluated by Doppler and contrast-enhanced ultrasound.

BACKGROUND: Sepsis is a condition characterized by organic dysfunction, leading to hemodynamic instability and high morbidity and mortality rates in humans and animals. Early identification of perfusion changes and appropriate management of sepsis are crucial for improving patient prognosis. Currently, the Systemic Inflammatory Response Syndrome (SIRS) and Sequential Organ Failure Assessment (SOFA) scores are widely studied for sepsis identification and evaluation of organ dysfunction. However, these scores do not assess gastrointestinal involvement, which is common in this condition. Contrast-enhanced ultrasound (CEUS) and Doppler have been considered promising diagnostic techniques for detecting changes in vascularization and microcirculation in a non-invasive and safe manner, particularly in the gastrointestinal system. This study aimed to evaluate duodenal perfusion using CEUS, as well as abdominal aortic and cranial mesenteric artery blood flow using Doppler ultrasound, and systolic arterial pressure (SAP) in 17 bitches with pyometra and in 10 healthy animals. RESULTS: The variables were compared between the pyometra and control groups, as well between patients with and without sepsis determined by the SOFA or SIRS scores. Pyometra was found to cause a reduction in abdominal aortic blood flow volume, aortic peak systolic velocity, and resistivity index as evaluated by Doppler ultrasound. Patients with sepsis according to the SOFA criteria only presented lower SAP. In contrast, sepsis animals identified by the SIRS score exhibited lower SAP, aortic peak systolic velocity, aortic blood flow volume, and aortic resistivity index and additionally, higher peak intensity of contrast in the duodenal wall. CONCLUSIONS: Pyometra causes a reduction in abdominal aortic blood flow, which is more pronounced in animals with sepsis identified by the SIRS criteria. These animals also exhibited a decrease in systolic blood pressure and an increase in duodenal perfusion, as evident by CEUS. However, these changes were not observed in patients with sepsis identified by the SOFA criteria. The alterations in intestinal perfusion observed in animals with sepsis indicate the presence of inflammation or dysfunction. In this regard, CEUS proves to be a valuable technique for detecting subtle changes in tissue hemodynamics that may not be apparent in conventional exams.

Computed tomographic evaluation of pancreatic perfusion in 10 dogs with acute pancreatitis.

Severe canine acute pancreatitis can be fatal; imaging features that can predict the clinical course of disease are useful for clinicians. On computed tomography (CT), both pancreatic heterogeneous contrast enhancement and portal vein thrombosis have been correlated with poorer outcome. Perfusion CT is used in human medicine to evaluate pancreatic microcirculation to predict the future development of severe sequela to pancreatitis; this technology has yet to be explored in dogs with acute pancreatitis. The objective of this prospective, case-control study is to evaluate pancreatic perfusion using contrast-enhanced CT in dogs with acute pancreatitis and compare it with previously established values obtained in healthy dogs. Ten client-owned dogs preliminarily diagnosed with acute pancreatitis received a full abdominal ultrasound, specific canine pancreatic lipase (Spec cPL), and perfusion CT. Computer software calculated pancreatic perfusion, peak enhancement index, time to peak enhancement, and blood volume for 3-mm and reformatted 6-mm slices. The data was analyzed using Shapiro-Wilk test, linear mixed model, and Spearman's rho. Values for 3-mm slices were similar to 6-mm slices (all P < 0.05). Dogs with acute pancreatitis had a faster time to peak enhancement than healthy dogs (P = 0.04-0.06). Dogs with acute pancreatitis and homogeneous pancreatic enhancement had higher perfusion, faster time to peak enhancement, and greater blood volume compared to healthy dogs and dogs with acute pancreatitis and heterogeneous pancreatic enhancement (all P = / < 0.05). Pancreatic perfusion decreased with increased pancreatitis severity. No correlation was identified between Spec cPL and pancreatic perfusion (all P > 0.05). These findings preliminarily support perfusion CT in dogs with acute pancreatitis.

Effects of a 10% dimethyl sulfoxide solution on radiocarpal joint amikacin pharmacokinetics during intravenous regional limb perfusion in standing sedated horses.

OBJECTIVE: To determine the effect of a 10% dimethyl sulfoxide (DMSO) solution on the peak concentration (CMAX ) of amikacin in the radiocarpal joint (RCJ) during intravenous regional limb perfusion (IVRLP) compared with 0.9% NaCl. STUDY DESIGN: Randomized crossover study. ANIMALS: Seven healthy adult horses. METHODS: The horses underwent IVRLP with 2 g of amikacin sulfate diluted to 60 mL using a 10% DMSO or 0.9% NaCl solution. Synovial fluid was collected from the RCJ at 5, 10, 15, 20, 25, and 30 minutes after IVRLP. The wide rubber tourniquet placed on the antebrachium was removed after the 30 min sample. Amikacin concentrations were quantified by a fluorescence polarization immunoassay. The mean CMAX and time to peak concentration (TMAX ) of amikacin within the RCJ were determined. A one-sided paired t-test was used to determine the differences between treatments. The significance level was p < .05. RESULTS: The mean ± SD CMAX in the DMSO group was 1361.8 ± 593 µg/mL and in the 0.9% NaCl group it was 860 ± 481.6 µg/mL (p = .058). Mean TMAX using the 10% DMSO solution was 23 and 18 min using the 0.9% NaCl perfusate (p = .161). No adverse effects were associated with use of the 10% DMSO solution. CONCLUSION: Although there were higher mean peak synovial concentrations using the 10% DMSO solution no difference in synovial amikacin CMAX between perfusate type was detected (p = .058). CLINICAL SIGNIFICANCE: Use of a 10% DMSO solution in conjunction with amikacin during IVRLP is a feasible technique and does not negatively affect the synovial amikacin levels achieved. Further research is warranted to determine other effects of using DMSO during IVRLP.

Treatment of Septic Tenosynovitis and Osteoarthritis in an American White Pekin (Anas platyrhynchos domesticus) with Repeated Intravenous Regional Limb Perfusion and Antibiotic-Impregnated Calcium Sulfate Beads.

A 2-year-old female American white pekin (Anas platyrhynchos domesticus) was assessed for a 2-month history of chronic lameness and swelling involving the left leg. Radiographic images of the left leg showed soft tissue swelling of the digits and tarsometatarsus with osteolysis of the tarsometatarsal-phalangeal joint. A complete blood count revealed marked leukocytosis and hyperproteinemia. A Streptococcus species was isolated from a bacterial culture of fluid obtained from the left tarsometatarsal-phalangeal joint. Biweekly intravenous regional limb perfusions of the left leg with ampicillin-sulbactam and amikacin were performed on the patient. Despite initial improvement in left leg lameness and swelling, follow-up radiographic images showed progressive osteolysis of the tarsometatarsal-phalangeal joint and associated digits. Surgical placement of antibiotic-impregnated calcium sulfate beads into the left tarsometatarsal-phalangeal joint was next performed with concurrent, repeated intravenous regional limb perfusion using the same antibiotic. Following the placement of antibiotic-impregnated beads and continued intravenous regional limb perfusion, the duck had decreased lameness and swelling of the left leg. Repeated antibiotic treatment through intravenous regional limb perfusion and concurrent placement of antibiotic-impregnated calcium sulfate beads is a practical treatment option for complicated distal limb infections in avian species. This therapeutic protocol has great potential in treating aggressive distal leg infections in many avian species because regional limb perfusion alone may not penetrate the joint adequately to achieve complete resolution of infection.

Differences in Outflow Facility Between Angiographically Identified High- Versus Low-Flow Regions of the Conventional Outflow Pathways in Porcine Eyes.

Purpose: To investigate differences in outflow facility between angiographically determined high- and low-flow segments of the conventional outflow pathway in porcine eyes. Methods: Porcine anterior segments (n = 14) were mounted in a perfusion chamber and perfused using Dulbecco's phosphate buffered solution with glucose. Fluorescein angiography was performed to determine high- and low-flow regions of the conventional outflow pathways. The trabecular meshwork (TM) was occluded using cyanoacrylate glue, except for residual 5-mm TM areas that were either high or low flow at baseline, designating these eyes as "residual high-flow" or "residual low-flow" eyes. Subsequently, outflow was quantitatively reassessed and compared between residual high-flow and residual low-flow eyes followed by indocyanine green angiography. Results: Fluorescein aqueous angiography demonstrated high-flow and low-flow regions. Baseline outflow facilities were 0.320 ± 0.08 and 0.328 ± 0.10 µL/min/mmHg (P = 0.676) in residual high-flow and residual low-flow eyes before TM occlusion, respectively. After partial trabecular meshwork occlusion, outflow facility decreased to 0.209 ± 0.07 µL/min/mmHg (-32.66% ± 19.53%) and 0.114 ± 0.08 µL/min/mmHg (-66.57% ± 23.08%) in residual high- and low-flow eyes (P = 0.035), respectively. There was a significant difference in the resulting IOP increase (P = 0.034). Conclusions: Angiographically determined high- and low-flow regions in the conventional outflow pathways differ in their segmental outflow facility; thus, there is an uneven distribution of local outflow facility across different parts of the TM.

Optimal injection rate and catheter size for brain perfusion computed tomography using non-ionic contrast medium in clinically normal Beagles.

OBJECTIVE: To evaluate the effects of contrast medium injection rates and intravenous injection catheter sizes on the time-density curve (TDC) of brain perfusion computed tomography (PCT) images in clinically normal Beagles and provide a reference range for the perfusion parameters for clinical application of PCT in veterinary medicine. ANIMALS: 5 healthy, sexually intact male Beagles. PROCEDURES: All dogs underwent general anesthesia for PCT. Contrast medium (350 mg I/kg) was injected at 3 different injection rates (2, 3, and 4 mL/second) and with 2 sizes of an intravenous catheter (20-gauge and 24-gauge). The rostral cerebral artery and dorsal sagittal sinus were selected as the regions of interest of the TDC. Initiation time of arterial inflow (ta), venous outflow (tv), peak time of arterial enhancement (Tap), and the peak time of venous enhancement (Tvp), were measured, and the difference between Tap and tv (Tap-tv) and between Tap and ta (Tap-ta) was calculated. RESULTS: Both Tap-tv and Tap-ta were significantly (P < .05) shorter at the rate of 3 mL/second than at 2 mL/second with the 24-gauge catheter. However, there was no significant difference according to catheter sizes. Particularly, a 4 mL/second injection rate using a 24-gauge catheter mostly resulted in contrast medium leakage and catheter rupture. CLINICAL RELEVANCE: CONTRAST MEDIUM INJECTION: At a rate of 3 mL/second and with a 24-gauge catheter ensures optimal image acquisition and stable contrast medium injection in brain PCT for small dogs. PCT may be useful for diagnosing cerebrovascular events and hemodynamic changes in small dogs.

Regional antibiotic perfusion through the lateral saphenous vein in two horses with septic calcaneal osteitis.

In this case report, two horses with chronic refractory infections in the tuber calcanei were successfully managed via intravenous antibiotic regional limb perfusion through the lateral saphenous vein after failure of conventional treatment approaches, including surgery and intravenous regional limb perfusion using the cranial branch of the medial saphenous vein. Surgical delay in these cases may have allowed the development of chronic infection, which prevented the conventional regional perfusion from working effectively. The spatial difference of the vessels relative to the tuber calcanei possibly contributed to the treatment outcome in these horses. This report describes a novel approach for regional antimicrobial perfusion to the equine plantar hock region using the lateral saphenous vein.

Assessment of the microvascular perfusion using sidestream dark-field imaging in healthy newborn foals.

BACKGROUND: Different methods to measure tissue perfusion are available in equine neonatology, but they are not representative of microvascular derangements. OBJECTIVE: To evaluate the feasibility of the sidestream dark-field (SDF) capillaroscopy to visualize the capillary microvasculature in conscious newborn foals, the differences between two imaging sites and times of measurements, and the measurements' reproducibility. METHODS: Seventeen healthy newborn foals were enrolled. Three sites at the upper and lower lip mucosa were assessed by SDF, using a hand-held capiscope, at 24 h and at 4-5 days after birth. Videos were assessed independently by two observers for quality and for semiquantitative calculation of microvascular parameters, including vascular density (VD), microvascular flow index (MFI), proportion of perfused vessels (PPV), and functional capillary density (FCD). Data were analyzed using unpaired and paired Student's T-tests to assess differences between sites and time-points. Bland-Altman plots and intraclass correlation coefficient (ICC) were used to assess measurement reproducibility. RESULTS: Differences were found between the upper and the lower lip for VD at both 24 h and 4-5 days, and for FCD at 24 h, and between the two time-points for PPV at the lower lip. ICC for measurement reproducibility was good for all parameters (0.64-0.79) for the lower lip, and was good for VD and FCD (0,76-0,79) and fair to moderate for MFI and PPV (0.31-0.41) for the upper lip. CONCLUSIONS: Measurement of the capillary microvasculature is feasible in the conscious newborn foal. The lower lip has the best measurement reproducibility. Further investigations are warranted in cardiovascularly compromised cases, particularly in septic foals.

Contrast-enhanced ultrasonography for evaluation of the blood perfusion of sciatic nerves in healthy dogs.

Blood supply to the peripheral nerves is essential for fulfilling their structural and functional requirements. This prospective, experimental, exploratory study aimed to assess the feasibility of contrast-enhanced ultrasonography (CEUS) for evaluating blood perfusion of the sciatic nerve in normal dogs. Contrast-enhanced ultrasonography examinations were performed on the bilateral sciatic nerves after bolus injection of Sonazoid™ (0.015 mL/kg) in 12 healthy Beagles for 150 s. Then, qualitative assessment of the wash-in timing, degree and enhancement patterns, and quantitative measurement of the peak intensity and time to peak intensity were performed from the sciatic nerve. The results were compared to those obtained from the adductor muscle around the nerve and caudal gluteal artery. After contrast agent injection, the sciatic nerve was enhanced at approximately 13-14 s, immediately after wash-in of the caudal gluteal artery. The peak intensity of the sciatic nerve was significantly lower than that of the caudal gluteal artery and higher than that of the adductor muscle. The time to peak intensity was significantly slower than that of the caudal gluteal artery; but was not significantly different from that of the adductor muscle. There were no significant differences in the peak intensity and time to peak intensity between the left and right sciatic nerves. These results demonstrate the feasibility of CEUS to assess blood perfusion of the sciatic nerve in healthy dogs qualitatively and quantitatively. This result from healthy dogs could serve as a reference for further studies that evaluate the sciatic nerve under pathological conditions.

The effects of aging and gestational month on uteroplacental vascular perfusion, and umbilical artery hemodynamics in pregnant jennies.

This study aimed to correlate the pulsed wave spectral indices of the middle uterine artery at both sides with placental development in jenny within mid-late pregnancies, and establish umbilical Doppler values for different ages and different gestational months. Twenty Equus Asinus pregnant jennies 260-450 kg (average, 320 ± 10 kg) were examined from 5 to 9 months of pregnancy with different ages (4-14 years). Monthly B-mode ultrasound examination was performed on both the combined thickness of the uterus and placenta (CTUP; mm) and umbilical artery cross-sectional diameter, and Doppler mode examination was performed on both the middle uterine (MUA at right [R] and left [L] sides) and umbilical arteries to measure both Doppler indices that expressed by resistance (RI) and pulsatility indices (PI), and blood flow rate. CTUP was elevated within pregnancy time at different ages (P < 0.05). L. PI was significantly declined throughout different ages (P < 0.05), but this declining trend was not observed in L. RI. The L. blood flow rate (R; bpm) was elevated among different ages and different months (P < 0.05). Both RI and PI were significantly decreased from 5 to 9 month of gestation period in jennies (P < 0.05).. The umbilical arteries cross-sectional diameter (Umb A; mm), was elevated among different ages and different months, while both Doppler indices were declined. A positive correlation was found (between both Doppler indices of both umbilical and uterine arteries P < 0.001). There was elevated vascular perfusion in uterine and umbilical arteries associated with reduced both Doppler indices along the course of pregnancy at different ages.

Evaluation of the relationship between placentome perfusion, echotexture, and endocrine changes in cows at the end of pregnancy.

Although Doppler ultrasonography (USG) is frequently used in human medicine to evaluate placental function and fetal well-being, studies in veterinary medicine are limited. Thus, this study aimed to determine the relationship between placentome perfusion and echotexture and endocrine changes during the last stages of pregnancy in cows using B-mode/Doppler USG and reveal the effects of hormonal changes on placentome and uterine artery hemodynamics. The animals consisted of 12 pregnant Swiss Brown cows 3.8 ± 0.34 years old with at least one birth. Imaging with USG was continued for 1 month, thrice weekly, until delivery. To determine serum progesterone (P4), total estrogen, and cortisol levels, blood was drawn from the tail vein immediately after USG examinations. Contrast (CON), homogeneity (HOM), and mean gray value (MGV) were determined by placentome echotexture analysis. Color Doppler perfusion areas (A mix) and power Doppler perfusion areas (A red) of the placentome, pulse rate (PR), pulsatility index (PI), resistance index (RI), blood flow velocity (BFVe), blood flow volume (BFVo), and diameter (DM) in the spectral analysis of uterine artery values were collected. ImageJ was used to analyze the B-mode images, and PixelFlux (Chameleon® Software, Münster, Germany) was used to calculate the placentome perfusion values and hemodynamic parameters of the uterine artery in Doppler images. In the last month of pregnancy, there was no statistical difference in the placentome echotexture values CON and HOM. However, MGV increased close to birth (P < 0.001). Placentome perfusion level and area did not change significantly but were found to decrease numerically 2 days before delivery (P > 0.05). Uterine artery PR increased from 62.36 bpm on day 25 prepartum to 81.42 bpm at birth (P < 0.05). The P4 concentration decreased in the last month of pregnancy, whereas an increase was detected in estrogen and cortisol during this period (P < 0.05). In the uterine artery of pregnant cornu, RI and PI were negatively correlated with BFVe (P < 0.01). Based on this study, echotextural differences were observed in placentomes in the last stage of pregnancy in cows, and there were significant changes in placental and uterine artery blood flow. These changes may be related to placental maturation, especially on the days close to birth.

Evaluation of the impact of blood donation on tissue perfusion and sublingual microcirculation in dogs: A pilot study.

The objective was to assess the feasibility of the sublingual microcirculation evaluation in dogs by using Sidestream Dark Field (SDF) imaging device and to evaluate the impact of blood donation on sublingual microcirculation and tissue perfusion. Before and after blood sampling, macrocirculatory parameters and tissue perfusion parameters were collected. After quality assessment, four videos per individual and per period were retained for analysis. Data were presented as median (1st quartile - 3rd quartile). The evaluation of the sublingual microcirculation with SDF was feasible in sedated dogs: good quality videos could be recorded in 10/12 dogs (83%). The median blood donation volume was 14 mL/kg (13-15). A significant association between the volume of blood collected and the increase in heart rate was observed: for each milliliter of blood drawn, heart rate increased by 1 bpm (CI95% = [0.2, 2], P = 0.03). Blood collection was associated with a significant increase of shock index (estimate = 0.17, CI95% = [0.02, 0.32], P = 0.04). After blood donation, lactate concentration significantly decreased (before: 2.1 (1.7-2.8), after: 1.1 (0.8-1.7) mmol/l, P = 0.009). No significant variation of the microcirculatory parameters was observed. In conclusion, sublingual evaluation of the microcirculation with SDF technology is feasible in dogs. In the present condition, blood donation did not significantly alter microcirculation. These results need to be confirmed in a larger population.

Clinicopathologic Findings in Chickens (Gallus gallus domesticus) Administered Amikacin Through Intravenous Regional Limb Perfusion.

Regional limb perfusion (RLP) has been used to treat cases of distal limb infections in avian species. Potentially nephrotoxic drugs, such as amikacin, may increase the risk of nephrotoxicity with RLP because of the presence of the renal portal system and direct venous blood flow from the pelvic limbs to the kidneys. In a randomized, blinded, placebo-controlled study, the safety of repeated amikacin administration (20 mg/kg q24h for 3 doses) via RLP was evaluated in healthy female chickens (Gallus gallus domesticus; n = 8 treatment, n = 8 saline control group). Plasma uric acid concentrations were not significantly elevated in treated birds compared with the control group at any time point following RLP. One week following the final RLP, birds were necropsied and the kidneys evaluated grossly and histologically. There was no significant difference in renal pathology scores between treated and control birds or between kidneys ipsilateral to the perfused limb and contralateral kidneys. This study concludes that RLP of amikacin at high doses produced no discernable renal pathology in healthy euhydrated chickens.

Exogenous L-arginine administration improves uterine vascular perfusion, uteroplacental thickness, steroid concentrations and nitric oxide levels in pregnant buffaloes under subtropical conditions.

Heat stress (HS) during pregnancy adversely affects uterine vascular perfusion and foetal development. L-arginine (L-Arg), a nitric oxide (NO) precursor, has been proven to enhance an organ's vascular perfusion. Therefore, this study aimed to examine the effect of L-Arg administration on the pregnant buffaloes' uterine haemodynamics and uteroplacental thickness under environmental HS conditions. For this purpose, pluriparous (n = 12) HS-pregnant buffaloes (mid-gestation, 180-190 days; temperature humidity index >85) were haphazardly assigned into two groups, either administered a single intravenous (IV) bolus of 5 mg/kg BW of L-Arg Hcl (n = 6; ARG) or received normal saline (0.9%; IV; 25 ml) that served as a control group (n = 6; CON). Combined uteroplacental thickness (CUPT, mm), middle uterine arteries' (MUA) diameter (mm) and uterine Doppler haemodynamics (ipsilateral and contralateral to the pregnant horn) were examined utilizing B-mode and colour Doppler ultrasonography, respectively. The serum levels of progesterone (P4), estradiol 17ß (E2), nitric oxide (NO) and total antioxidant capacity (TAC) were assayed using commercial kits. The experimental time points were - 1, 0, 2, 4, 24, 48, 72, 96 and 120 h post-L-Arg administration. The ARG group showed higher (p < .05) CUPT and MUA diameter values starting at 24 h post-treatment and onward than the control buffalo cows. In addition, there were improvements (p < .05) in the blood flow parameters in the ipsilateral MUA after L-Arg treatment evidenced by lower values of pulsatility and resistive indices starting at 48 and 4 h, respectively and onward, and higher values of peak systolic velocity, coloured areas towards the pregnant uterine horn (both 24-72 h). Increases in the NO levels were found during the period between 4 and 120 h in the ARG group compared to the CON group. Moreover, significant increases in the E2 and P4 means were noted in the ARG group, especially at 24 h onward, respectively compared to the CON group. Concerning the TAC status, neither the administration nor the hours affected serum TAC levels in the HS pregnant buffaloes (CON and ARG). In conclusion, L-Arg administration improved uteroplacental thickness and enhanced uterine haemodynamics, NO levels, and steroids production in mid-pregnant buffalo cows under environmental heat stress conditions which could improve foetal growth and development.