Background: The Liver is a well vascularized organ. Any pathology can impede its blood flow and this makes liver the most suitable organ for studying the Doppler indices and contrast enhanced perfusion parameters.

Methods: This clinical study enrolled 9 healthy dogs including 2 breeds each of beagle, German shepherd, Labrador Retriever, and one breed each of Crossbred, Pug and Pit bull. Spectral Doppler sonography and contrast enhanced ultrasonography (CEUS) of liver vasculature using a second generation contrast agent (Sonovue) was performed to standardize their normal pulsed-wave Doppler indices and contrast enhanced perfusion parameters.

Result: The mean &plusmn; SE values of Doppler indices of portal vein were PSV (27.68 &plusmn; 2.08 cm/s), EDV (15.32 &plusmn; 1.74 cm/s), MV (14.05 &plusmn; 1.94 cm/s), RI (0.44 &plusmn; 0.05) and PI (0.93 &plusmn; 0.11). Mean &plusmn; SE value of Doppler indices of hepatic artery were&nbsp; 53.78 &plusmn; 3.45 cm/s (PSV), 13.90 &plusmn; 1.82 cm/s (EDV), 21.63 &plusmn; 1.21 cm/s (MV), 0.73 &plusmn; 0.04 (RI), 1.93 &plusmn; 0.28 (PI) and for hepatic vein were 38.62 &plusmn; 4.62 cm/s (PSV), 11.92 &plusmn; 2.79 cm/s (EDV), 17.72 &plusmn; 2.95 cm/s (MV), 0.69 &plusmn; 0.06 (RI), 1.69 &plusmn; 0.23 (PI). CEUS of hepatic parenchyma showed three phases viz arterial, portal and late portal phase. Mean &plusmn; SE values of contrast enhanced hepatic perfusion parameters (in seconds) were 7.22 &plusmn;0.40 (Arrival time), 16.33 &plusmn;1.38 (Time to initial peak), 30.22 &plusmn;1.29 (Time to final peak), 54.55 &plusmn;2.93 (Decline time) and 160.78&plusmn;8.60 (Washout time).

&nbsp;

Quantification of Doppler Indices, Contrast Ultrasound Enhancement Phases and Perfusion Parameters of Hepatic Parenchyma in Healthy Dogs

Background: The spleen can be affected by a variety of vascular problems. Affected tissue neovascularization in these conditions can be effectively analysed using imaging modalities such as Doppler and contrast enhanced ultrasonography (CEUS). 
 
Methods: Nine healthy dogs were included in this clinical study comprising two breeds of Labrador Retrievers, German Shepherds, and Beagles and one breed each of Crossbred, Pug, and Pitbulls. Pulsed-wave Doppler indices and contrast-enhanced perfusion parameters of the splenic vasculature were obtained by performing spectral Doppler sonography and CEUS using a second-generation ultrasound contrast agent (Sonovue). 
 
Result: The mean &plusmn; SE value of splenic vein&rsquo;s Doppler indices were 10.94&plusmn;2.04 cm/s (PSV), 6.92&plusmn;1.28 cm/s (EDV), 6.44&plusmn;1.57 cm/s (MV), 0.35&plusmn;0.05 (RI) and 0.75&plusmn;0.17 (PI), while the indices of splenic artery were 31.21&plusmn;3.12 cm/s (PSV), 8.95&plusmn;1.63 cm/s (EDV), 13.98&plusmn;1.95 cm/s (MV), 0.71&plusmn;0.04 (RI), 1.75&plusmn; 0.24 (PI). Arterial and venous phases were visible on a CEUS of the splenic parenchyma. The mean &plusmn; SE value of the contrast enhanced splenic perfusion parameters (measured in seconds) were as follows: arrival time = 7.00 &plusmn; 0.33; time to initial peak = 15.05 &plusmn; 0.46; time to final peak = 28.92&plusmn;1.06; decline time = 97.89&plusmn;2.82; washout time = 152.22&plusmn; 9.10.

Quantification of Doppler Indices, Contrast Ultrasound Enhancement Phases and Perfusion Parameters of Splenic Parenchyma in Healthy Dogs

<div>Background: Embryonic mortality is one of the major factors leading to reproductive failure, decreased fertility and delayed pregnancy in cattle. 
 
Method: The study was aimed for investigating the incidence of embryonic mortality(EM), differentiate embryonic development and mortality based on color Doppler ultrasonographic characteristics. Different characteristics correlated were corpus luteum(CL) vascularity, embryonic development&nbsp;and EM features, monitored on day 21 post-insemination.&nbsp; 
 
Result: The overall incidence of EM was recorded to be 25%, with 15% and 10% mortality occurred between days 21-28 and 28-35 of gestation. Color Doppler analysis stated that, the CL in pregnant cows had a higher percentage of luteal tissue with positive Doppler signals on initial examination (day 21) differing significantly (P&lt;0.01) from non-pregnant and consistently increased till the end of the examination. However, cows with EM had a significantly lower CL vascularity than pregnant (P&lt;0.05) but significantly higher (P&lt;0.05) than non-pregnant cows on day 21. Embryos from pregnant cows (detected by 28 days) increased in size along the days of examination. However, cows diagnosed with EM showed signs (day 28), which included reduced intra-uterine allantoic fluid, absence of embryo proper with an embryonic heartbeat, hyperechoic free-floating embryonic debris in the uterus and distorted allanto-chorionic membrane. In conclusion, the present study firmly supports color Doppler ultrasonography in diagnosis of pregnant cows based on CL vascularity, visualizing the different characteristics signs of EM, and detecting non-pregnant animals undergoing EM as early as day 21.</div>

​Color Doppler Ultrasonographic Characteristics of Embryonic Development and Mortality in Dairy Cows

<div>Background: Pulsed-wave Doppler measures blood flow at specific point and provides information on velocity, direction and uniformity of blood flow throughout cardiac cycle. Till date, there is no published data on study of cardiac parameters using pulsed-wave Doppler echocardiography in Indian Spitz dogs. 
 
Methods: Twenty-four clinically normal Indian Spitz dogs were subjected to pulsed-wave Doppler echocardiography to determine the reference intervals for Doppler parameters of blood flow through mitral, tricuspid and aortic valves. Mitral peak E and A-wave velocities, E/A ratio, deceleration time, isovolumic relaxation time, E and A-wave velocity time integral, E duration and A duration were 0.69&plusmn;0.09 m/s, 0.43&plusmn;0.12 m/s, 1.69&plusmn;0.45, 111.25&plusmn;35.94 ms, 48.50&plusmn;24.77 ms, 0.07&plusmn;0.01 m and 0.04&plusmn;0.02 m, 196.88&plusmn;44.38 ms and 181.25&plusmn;64.89 ms, respectively. Tricuspid peak E and A-wave velocities, E/A ratio and E and A-wave velocity time integral were 0.57&plusmn;0.11 m/s, 0.38&plusmn;0.08 m/s, 1.56&plusmn;0.32 and 0.07&plusmn;0.02 m and 0.05&plusmn;0.01 m, respectively. Aortic peak velocity, velocity time integral and ejection time were 0.87&plusmn;0.07 m/s, 0.11&plusmn;0.02 m and 0.25&plusmn;0.04 s, respectively.&nbsp; 
 
Conclusion: The reference values of flow parameters across mitral, tricuspid and aortic valves using pulsed-wave Doppler echocardiography were determined. Mitral, tricuspid and aortic valve flow variables were unaffected by gender whereas isovolumic relaxation correlated positively with body weight.</div>

<div>Studies on Pulsed-wave Doppler Echocardiographic Parameters of Blood Flow through Mitral, Tricuspid and Aortic Valves in Healthy Indian Spitz Dogs</div>

<div style="text-align:justify">Background: Doppler ultrasonographic assessment of maternal and foetal blood flow/perfusion has become an indispensable diagnostic tool in veterinary obstetrics. Periodic Doppler examination of critical canine pregnancies to interpret vascular information such as blood velocity, flow direction/pattern and vascular pathologies would ensure safety of dam and survival chances of conceptuses. 
 
Methods: The present study included twenty apparently healthy bitches of different breeds presented at University Veterinary Hospital, Thrissur, Kerala for the management of breeding and pregnancy. Doppler examinations were conducted from fourth week of pregnancy at 10 d interval to evaluate blood flow in uteroplacental artery (UPA), umbilical artery (Uma) and foetal abdominal aorta by measuring pulsatility (PI) and resistive indices (RI).&nbsp; 
 
Result: Throughout the study the UPA showed biphasic wave. Up to 40 days of gestation the UPA showed diastolic notch and from 41-50 days it disappeared completely. The PI and RI decreased significantly at 5 per cent level between each 10 d interval. Similarly, the PI and RI of Uma decreased significantly at 5 per cent level between each 10 d interval. The PI of foetal abdominal aorta increased significantly at 5 per cent level from &pound; 30 d to 31-40 d of gestation and thereafter it decreased significantly up to whelping. During early pregnancy the diastolic wave form was absent for Uma and abdominal aorta although at later stages both these vessels showed biphasic wave forms. The study also included the early diagnosis of two abnormal pregnancies, viz., a complete foetal resorption in a Labrador bitch and an incomplete abortion in a Rottweiler bitch by Doppler ultrasound. The incomplete abortion was critically managed and the bitch whelped five healthy puppies fourteen days from the date of the incomplete abortion of three puppies. Thus, the study demonstrated the potential applicability of Doppler Ultrasound in the management of normal and abnormal pregnancies and predicting survival chances of neonates after whelping.&nbsp;</div>

<div style="text-align:justify">Doppler Ultrasonographic Assessment of Maternal and Foetal Blood Flow in Canine Pregnancy and Its Application in the Critical Management of Gestation#</div>

<div style="text-align: justify;">Ultrasonography has been considered as one of the most valuable diagnostic tools in veterinary medicine. The study standardizes the Doppler ultrasonographic hepato biliary biometric features in six leopards (Panthera pardus). The hepato biliary ultrasonographic examination was performed under general anaesthesia while lateral recumbency using a 3.5 MHz convex array transducer. The hepatobiliary images obtained at area covered the periphery just behind the sternum and last ribs of thorax on left and right side of abdomen. Gall bladder was visualized at a moderate pressure below the level of sternum. The hepato biliary measurements were recorded and it can be concluded that Doppler ultrasonography as valuable technique for measuring hepato biliary biometric features and could be used as reference values for diagnosis of hepato biliary diseases and disorders in leopards.</div>

Doppler ultrasound evaluation of heptobiliary system in leopards (Panthera pardus)

<div>Background: The Ultrasonograph of spleen in live goats were studied using a convex probe 2.5 to 5 MHz Colour Doppler Mylab onevet (e-saote) German Ultrasound Scanner in Veterinary Clinical Complex, Veterinary College and Research Institute, Namakkal. 
 
Methods: The extent of spleen in live goats when examined by USG revealed differences from the usual gross anatomical observations made in the embalmed or exsanguinated goats. The parietal surface of spleen was in direct contact with the pulmonary diaphragm while the ventral visceral surface lay over the cranial part of dorsal sac of the rumen. 
 
Result: The capsule was highly echogenic while the parenchyma consisted of numerous weak echoes distributed homogenously. The splenic vessels were anechoic with hyperechoic walls and appeared as longitudinal or cross sections. The greatest length was found at 11th intercostal space during the post-natal age of three to five months which was about 6 cm. The greatest length was found at 10th intercostal space during the post-natal age of eight to twelve months which was about 7 cm. The greatest length was found at 9th intercostal space during the post-natal age above one year which was about 9 to 15 cm. During the post-natal age above one year the smallest length was found to be behind the last rib which was about 4 cm in adult goats.</div>

<div>Doppler Ultrasonographic Study of the Spleen in Live Post Natal Goats</div>

Background: Physical activity alters the cardiovascular system of dogs depending on the exercise characteristics and the animal&rsquo;s physical conditioning. Little is known about the cardiovascular changes in working police dogs. This study evaluated the cardiovascular responses of working Labradors to regular exercise and various workload.&nbsp; 
 
Methods: Twelve working Labradors of Tamil Nadu police department that were regularly trained and exercised 30 minutes morning and evening and twelve normal household pet Labradors brought for regular checkup to Madras Veterinary College Teaching hospital were taken for the study. All the animals were subjected to physical, clinical, hematobiochemical, electrocardiographic examinations and cardiac auscultation before performing echocardiography. Those animals which showed normal recordings in all the above tests were further subjected to M-mode, Pulsed wave and Tissue Doppler echocardiography. In this study, the resting heart rate values of working groups were lesser than that of normal pet dogs.&nbsp; 
 
Result: The results of echocardiography showed significant increase in Interventricular septal diameter during diastole, left atrial diameter, aortic artery diameter and the left atrium to aortic diameter ratio without impairing systolic and diastolic cardiac functions in working dogs. The present study indicated that there were few changes in the echocardiographic parameters which might be a response to physiological adaptation and regular exercise.

Normal M-mode, Pulsed Wave and Tissue Doppler Echocardiographic Studies in Healthy Working Police Dogs

Background: Ultrasonography is a second most commonly used diagnostic imaging technique in veterinary practice after radiography. The ultrasonographic examination of clinically healthy animals provides relevant information about anatomical location, echo texture, size and shape of organs. In the present study, the echo-structural pattern of urinary system of adult female goats were evaluated to find the normal structural pattern of various constituents of urinary system.&nbsp; 
 
Methods: B-mode ultrasonographic study of urinary system was performed in 20 healthy adult female Jamunapari goats. Mean&plusmn;S.E. values of body weight and age of selected animals were 27.49&plusmn;0.79 kg and 2.77&plusmn;0.10 years, respectively. All twenty animals were subjected to sonographic examination after clipping the hairs from desired sites to scan the various organs of urinary system in standing position under physical restraint without using any anesthetic agent. The values of various clinico-physiological parameters including rectal temperature, heart rate, respiration rate, colour of mucous membranes were recorded to examine the health status prior to sonography. The left and right kidneys were scanned from right dorsal flank by paravertebral approach using a transcutaneous micro-convex probe at 5 MHz and a convex probe at 2.8-6 MHz frequency. A dual frequency (5-9 MHz) micro-curved array cavity probe was used to scan bladder and urethra per rectally. The renal parenchyma in healthy goats was distinctly divided into hypoechoic outer cortex and anechoic inner medulla. The hyperechoic renal sinus complex was present in center of the kidney and renal pelvis was anechoic. The renal capsule was seen as hyperechoic fine line surrounding the renal parenchyma. Pulsed wave renal color doppler ultrasound was performed in 3 healthy goats with the aim to generate reference images of renal vasculature.&nbsp; 
 
Result: The Mean&plusmn;SE values of renal length, renal height, horizontal diameter of renal sinus, vertical diameter of renal sinus and diameter of renal pelvis for right kidney were 6.11&plusmn;0.09, 3.26&plusmn;0.08, 3.01&plusmn;0.11, 1.32&plusmn;0.03, 1.05&plusmn;0.03, respectively while for left kidney these values were 6.02&plusmn;0.09 and 3.35&plusmn;0.07, 2.67&plusmn;0.12, 1.14&plusmn;0.06, 1.10&plusmn;0.07 cm. The ureters could not be visualized in any of the goats. The distended bladder was seen as anechoic circular structure surrounded by a smooth echogenic wall with a mean thickness of 1.65&plusmn;0.06 mm. No significant difference was observed in the measurements of both kidneys except in dimensions of renal sinus. Positive correlation was found between renal size and body weight of goats. It was concluded that ultrasound is an easy, rapid and non-invasive method to evaluate echotexture and morphometry of structures of urinary system.

Studies on Echostructural Pattern of Urinary System in Adult Female Goats

Background: Fatty liver is a major metabolic disorder of dairy cows with a high morbidity rate during early lactation. Diagnosis of mild and moderate fatty liver is difficult because affected cows often do not differ clinically from cows with normal liver. The need for the early identification of fatty liver cannot be overemphasized as it appears to be the root cause for occurrence of many post-partum metabolic diseases. A precise diagnosis of the different categories of fatty liver is possible by liver biopsies which entail a minor surgery. Spectral doppler is yet another milestone in identification of fatty infiltration of liver, without causing any trauma to the liver. With this backdrop this research study was carried out to document the ultrasonographic pattern of liver, to evaluate the Spectral Doppler derived indices of portal blood flow in fatty liver syndrome in cattle. 
 
Methods: The study was conducted in clinical cases, presented to Large Animal Medicine Outpatient Unit of Madras Veterinary College Teaching Hospital over a period of 24 months. Dairy cows, with the history of recent calving, postpartum inappetance and brought for other routine check-ups were included for the study. Suspected cases were subjected to further examination. Concurrent diseases presented with Fatty liver syndrome were recorded. Animals were grouped into four categories based on the above investigations as group I, II, III and IV as control, mild fatty liver, moderate fatty liver and severe fatty liver respectively.&nbsp; 
 
Result: B-Mode Ultrasonography was superior in grading the fatty liver, compared to spectral doppler. Spectral Doppler derived indices of portal blood flow in fatty liver syndrome revealed significant reduction in venous pulsatility index in severe cases. But grading the fatty liver was not possible with spectral doppler. Among clinical manifestations, Postparturient inappetance (98.3 per cent), reduced milk yield and weight loss were the prominent in fatty liver syndrome. Major concurrent diseases in fatty liver syndrome were ketosis, haemoprotozoan diseases, repeat breeder and mastitis. The present study will be helpful in field level diagnosis of fatty liver in cattle and supplements the knowledge on concurrent diseases that could influence the prognosis of individual animal. The study also opens gateway to do further research in considering alternates to the liver biopsy and histopathological studies.