CONTRAST HARMONIC ULTRASOUND OF SPONTANEOUS LIVER NODULES IN 32 DOGS

Thirty-two dogs with spontaneous hepatic nodules were given intravenous ultrasound contrast medium (Definity or Sonovue) and imaged with contrast harmonic software on a conventional ultrasound machine system. Digital video images were initially reviewed to describe the perfusion pattern of malignant nodules. The images were reviewed again to test this pattern against all individual nodules. Subjectively, there was improved conspicuity of malignant nodules after contrast enhancement compared with conventional imaging and increased numbers of malignant nodules were often noted. There was decreased conspicuity of benign nodules and no additional nodules were seen after contrast enhancement. There was a highly significant (P < 0.0001) association of malignancy with a hypoechoic nodule at surrounding normal liver peak contrast enhancement. Benign nodules were isoechoic to the surrounding normal liver at peak contrast enhancement. Only one benign nodule (hepatoma) had regions of hypoechogenicity compared with the surrounding normal liver at peak liver contrast enhancement. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were highly significant (P < 0.0001) (100%, 94.1%, 93.8%, 100%, and 96.9%, respectively). No complications or morbidity was noted throughout the course of the study. Contrast harmonic ultrasound appears to be accurate at discriminating between naturally occurring benign and malignant nodules in the liver of dogs.     

CHARACTERIZATION OF LYMPHOMATOUS LYMPH NODES IN DOGS USING CONTRAST HARMONIC AND POWER DOPPLER ULTRASOUND

Doppler ultrasound has been used in humans to determine angioarchitecture of lymph nodes as the criterion for the determination of malignancy. We hypothesized that the vascular and perfusion patterns of a canine malignant lymph node could be characterized with intravenous microbubble ultrasound contrast media and that contrast harmonic ultrasound could provide better conspicuity of the angioarchitecture when compared with Power Doppler ultrasound. In this study, 11 peripheral lymph nodes in dogs with histologically verified malignant lymphoma were imaged with fundamental ultrasound, Power Doppler ultrasound, and three contrast harmonic pulse sequences to characterize the vascular pattern and perfusion. Vascular imaging was greatly enhanced in these nodes with 2.13 times more vessels seen with contrast harmonic ultrasound compared with Power Doppler ultrasound (P < 0.01). The angioarchitecture of lymphomatous lymph nodes of dogs in this study were similar to those previously described in malignant superficial lymph nodes in human patients; 45.5% of the nodes had displacement of the central hilar vessel, 45.5% had aberrant vessels, 63.6% had pericapsular vessels, 36.4% had subcapsular vessels, and 81.8% had loss of the central hyperechoic band in fundamental sonography. Poor perfusion, indicated by a lower mean pixel intensity increase between pre- and postcontrast administration images, was seen in 36.4% of the lymph nodes while 63.6% had fair to good perfusion. The perfusion patterns in nine of the 11 lymph nodes were homogenous and two showed focal hypoperfused regions. We conclude that Power Doppler and contrast harmonic ultrasound are beneficial in accurately depicting angioarchitechture and can provide additional information in determining the presence of malignant vascular characteristics within lymphomatous nodes in dogs.     

Effects of urinary bladder distention on location of the urinary bladder and urethra of healthy dogs and cats

Evaluation of the anatomic location of the distended and empty urinary bladders and urethras of healthy adult male and female dogs and cats by retrograde urethrocystography revealed substantial variations. In 15 dogs in lateral recumbency with empty bladder lumens, the caudal portion of the urinary bladder was within the pelvic canal in 5 of 7 male and 5 of 8 female dogs. In female dogs examined in ventrodorsal recumbency, only 4 of 8 had the empty urinary bladders in part within the pelvic canal. After luminal distention, 3 of 7 male and 3 of 8 female dogs, while in lateral recumbency, had the urinary bladders in part intrapelvically. However, when female dogs were placed in ventrodorsal recumbency, only 1 of 7 urinary bladders was in part within the pelvis. The urinary bladders of 14 cats were consistently within the abdominal cavity, irrespective of whether the bladder lumen was distended or empty. Urethral flexures occurred in dogs with intrapelvic bladders that were distended or empty. Urethral flexures were not found in cats. The urethras of dogs and cats in lateral recumbency were generally closer to the floor of the pelvis after urinary bladder distention than when the bladder was empty. The urethra of the dogs and cats in ventrodorsal recumbency was to the left or right of or on the midsagittal plane, whether the urinary bladder was empty or distended. A greater degree of lateral displacement was encountered in ventrodorsal recumbency after urinary bladder distention.     

Laparoscopic Cholecystectomy for Management of Uncomplicated Gall Bladder Mucocele in Six Dogs

Objectives— To describe a technique for, and outcome after, laparoscopic cholecystectomy (LC) for management of uncomplicated gall bladder mucocele (GBM) in dogs. Study Design— Case series. Animals— Dogs (n=6) with uncomplicated GBM. Methods— Dogs with ultrasonographic evidence of GBM but without imaging or laboratory signs of gall bladder rupture, peritonitis, or extra‐hepatic biliary tract rupture that had LC were included. A 4 portal technique was used. A fan retractor was used to retract the gall bladder to allow dissection around the cystic duct with 5 or 10 mm right‐angle dissecting forceps. The cystic duct was ligated using extracorporeally tied ligatures supplemented sometimes with hemostatic clips. A harmonic scalpel was used to dissect the gall bladder from its fossa. The gall bladder was placed into a specimen retrieval bag and after bile aspiration the bag was withdrawn through the 11 mm portal incision. Results— Five dogs had mild intermittent clinical signs including vomiting, inappetence, and lethargy. All dogs had successful LC without conversion to an open approach. All dogs with clinical signs had improvement or resolution of signs postoperatively. No important perioperative complications occurred and all dogs were alive at a median of 8 months postoperatively (range, 3–14 months). Conclusions— LC can be accomplished safely and effectively in dogs with uncomplicated GBM. Clinical Relevance— A minimally invasive approach for cholecystectomy can be used for the treatment of GBM in dogs.     

LYMPHOMA AFFECTING THE URINARY BLADDER IN THREE DOGS AND A CAT

Three dogs and one cat with lymphoma affecting the urinary bladder are reported and the findings on abdominal radiographs and ultrasound are described. Mural lesions representing lymphoma affecting the urinary bladder were identified ultrasonographically in all animals. The most common complications associated with urinary bladder lymphoma were hydronephrosis and hydroureter. In two patients contrast radiography was necessary to detect leakage of urine in the peritoneal and retroperitoneal space. The radiographic and ultrasonographic signs were similar to those reported with other urinary bladder neoplasms; hence urinary bladder lymphoma could not be distinguished from the more common urinary bladder neoplasms, such as transitional cell carcinoma. It is important to include lymphoma in the differential diagnosis of urinary bladder wall thickening and mural mass in dogs and cats.     

Tumors of the urogenital system in dogs and cats. Retrospective review of 138 cases

The aim of the study was to estimate the prevalence and localization of different tumors in the urogenital system in dogs and cats in relation to sex, age and breed of animals. The study was performed on tumors or tissue specimens from tumors of the urinary and genital system obtained during surgery from dogs and cats submitted to the Division of Pathological Anatomy, Department of Clinical Sciences Agricultural University of Warsaw from 1998 to 2005. Most tumors of the urogenital system recognized in the present study derived from dogs (94.20%, 130 cases), and only a few cases were obtained from cats (5.79%). Occurrence and localization of urogenital system tumors in present review is similar to findings reported by other authors. Testicular tumors in males, ovarian lesions in females and urinary bladder tumors in both sexes were most commonly recognized. Older dogs were most often affected, animals with nonmalignant tumors were a bit younger than those with malignant lesions. Any obvious breed predilections were found, but terriers were at increased risk for development of transitional cell carcinoma of the urinary bladder and mixed breed and German shepherd for development of testicular neoplasms.     

Choledochotomy and primary repair of extrahepatic biliary duct rupture in seven dogs and two cats

Objective : To report clinical findings and outcome in dogs and cats undergoing choledochotomy or primary repair of extrahepatic biliary duct rupture. Methods : Retrospective study of dogs (n=7) and cats (n=2) that had choledochotomy or primary bile duct repair. Results : Extrahepatic biliary obstruction was confirmed at surgery in all cases. The underlying cause in four dogs and both cats was choledocholithiasis, two dogs had gall bladder mucocoeles with associated bile duct rupture, and one dog had inspissated bile obstructing the bile duct secondary to gall bladder carcinoid tumour. Three dogs and both cats had choledochotomies performed to relieve extrahepatic biliary obstruction, and four dogs with bile duct rupture underwent primary repair of the defect. One dog with a bile duct rupture was re‐explored four days postoperatively and had suffered dehiscence of the repair; this rupture was re‐repaired. All animals were discharged from the hospital, and did not have clinical recurrence of extrahepatic biliary obstruction. Clinical Significance : Choledochotomy and primary repair of extrahepatic biliary duct rupture were associated with low perioperative morbidity and no mortality in this small cohort of cases. These techniques are reasonable options either alone or in conjunction with other procedures when bile duct patency cannot be re‐established by catheterisation or bile duct discontinuity exists.     

Ultrasonic diagnosis in dogs and cats. 1. Manner of function, instruments, biological effects

Ultrasonography utilizes high frequency sound waves between 2 and 10 MHz. Returning echos from reflecting surfaces in the body are displayed as two-dimensional images on a CRT screen. Ultrasonography is particularly useful for analysis of internal structures of parenchymal organs such as liver, spleen, kidneys, prostate and uterus, as well as fluid filled organs such as heart, urinary bladder, gallbladder, and pregnant uterus. The clinical examination is safe. Sector transducers with frequencies between 5 and 10 MHz are useful for dogs and cats.     

ULTRASOUND IMAGING OF THE COELOMIC STRUCTURES IN THE BOA CONSTRICTOR (BOA CONSTRICTOR)

Transverse ultrasound images from three live boa constrictors ( Boa constrictor ) were compared to the corresponding gross sections of a euthanized boa constrictor. The snakes were anesthetized, placed into dorsal recumbency, and imaged through the ventral scutes. Ultrasound images were produced with a real time, B-mode scanner and a linear 7.5-MHz transducer. The heart, liver, stomach, gall bladder, pancreas, kidneys, and fat body were the coelomic structures most consistently recognized ultrasonographically. Results of this study indicate that ultrasound is a useful imaging technique in snakes.     

ASSOCIATIONS BETWEEN ULTRASOUND AND CLINICAL FINDINGS IN 87 CATS WITH URETHRAL OBSTRUCTION

Urethral obstruction is a life‐threatening form of feline lower urinary tract disease. Ultrasonographic risk factors for reobstruction have not been previously reported. Purposes of this retrospective cross‐sectional study were to describe urinary tract ultrasound findings in cats following acute urethral obstruction and determine whether ultrasound findings were associated with reobstruction. Inclusion criteria were a physical examination and history consistent with urethral obstruction, an abdominal ultrasound including a full evaluation of the urinary system within 24 h of hospitalization, and no cystocentesis prior to ultrasound examination. Medical records for included cats were reviewed and presence of azotemia, hyperkalemia, positive urine culture, and duration of hospitalization were recorded. For medically treated cats with available outcome data, presence of reobstruction was also recorded. Ultrasound images were reviewed and urinary tract characteristics were recorded. A total of 87 cats met inclusion criteria. Common ultrasound findings for the bladder included echogenic urine sediment, bladder wall thickening, pericystic effusion, hyperechoic pericystic fat, and increased urinary echoes; and for the kidneys/ureters included pyelectasia, renomegaly, perirenal effusion, hyperechoic perirenal fat, and ureteral dilation. Six‐month postdischarge outcomes were available for 61 medically treated cats and 21 of these cats had reobstruction. No findings were associated with an increased risk of reobstruction. Ultrasonographic perirenal effusion was associated with severe hyperkalemia (P = 0.009, relative risk 5.75, 95% confidence interval [1.54–21.51]). Findings supported the use of ultrasound as an adjunct for treatment planning in cats presented with urethral obstruction but not as a method for predicting risk of reobstruction.     

Effects of urinary bladder distension on the length of the dog and cat urethra

Urethral lengths were determined in male and female cats and in female dogs from positive contrast retrograde urethrocystograms at 2 levels of urinary bladder distension. Urethral lengths were longer on urethrograms obtained after urinary bladder distension in female cats and in 7 of 8 female dogs. The intrapelvic and penile urethra were longer after bladder distension in 4 of 6 male cats. In female cats, urethral lengths significantly increased (P less than 0.05) after urinary bladder distension.     

Estimation of the volume of the gall bladder of 32 dogs from linear ultrasonographic measurements

The maximum length and depth of the longitudinal section, and the maximum width and depth of the transverse section of the gall bladders of 32 dog cadavers were measured ultrasonographically; the contents of the gall bladder were then aspirated and its actual volume measured. The volume of the gall bladder was estimated from the ultrasonographic measurements by using formulae suggested for assessment of the volumes of the urinary bladder in human beings and the gall bladder of dogs, and these formulae were compared with a formula derived from the measurements made in this study. In 21 of the dogs, the measurements were repeated twice so that their reproducibility could be evaluated. All the formulae gave good estimations of the volume of the dogs' gall bladders, but the formula for the human urinary bladder volume was better than the other two. The actual volume of the gall bladder was related to the dogs' bodyweight. There were no significant differences between the repeated measurements of the maximum length and depth of the longitudinal section or the width of the transverse section of the gall bladder, but there were significant variations in the depth of the transverse section.     

Minimally Invasive Inguinal Approach for Tube Cystostomy

Objective— To report a technique for tube cystostomy placement via a minimally invasive inguinal approach and outcome in 9 dogs and 6 cats with urinary tract obstruction or detrusor atony.
Study Design— Case series.
Animals— Dogs (n=9) and cats (6).
Methods— Medical records (January 2004–January 2008) of dogs and cats that had tube cystostomy via an inguinal approach were reviewed. Retrieved data included signalment, diagnosis, surgical technique, and complications. Access to the bladder was through a muscle splitting approach in the inguinal region with the cystostomy tube placed through a skin incision made several centimeters proximal to this incision and secured in the bladder by a purse string suture. Cystopexy during closure of the muscle layers ensured secure closure and minimized the likelihood of uroabdomen if tube dislodgment occurred.
Results— Cystostomy tubes were placed in 5 cats as an emergency procedure for treatment of acute urinary tract obstruction or urethral rupture, and as an elective procedure in 9 dogs and 1 cat. No complications occurred during cystostomy tube placement. Postprocedural complications were minor (peristomal irritation in 2 dogs with latex catheters, catheter laceration, premature removal) and only occurred when tubes were retained for >4 weeks. Urinary tract infection at catheter removal in 6 dogs resolved with antibiotic administration.
Conclusions— An inguinal approach for cystostomy tube placement facilitated rapid catheter placement into the bladder with minimal soft tissue dissection. Cystopexy during abdominal wall closure provided peritoneal protection should premature dislodgement of the cystostomy tube occur.
Clinical Relevance— An inguinal approach should be considered for rapid tube cystostomy particularly in metabolically compromised animals.     

EFFECTS OF CORN OIL ADMINISTERED ORALLY ON CONSPICUITY OF ULTRASONOGRAPHIC SMALL INTESTINAL LESIONS IN DOGS WITH LYMPHANGIECTASIA

Lymphangiectasia is one of the causes of protein‐losing enteropathy in dogs and characteristic ultrasonographic small intestinal lesions have been previously described. The purpose of this study was to determine whether corn oil administered orally (COAO) would result in increased conspicuity of these characteristic small intestinal ultrasonographic lesions in dogs with lymphangiectasia. Affected dogs were included if they underwent corn oil administered orally and had a surgical full‐thickness intestinal biopsy diagnosis of lymphangiectasia. Control dogs had normal clinical examination and standard laboratory test findings. Ultrasound images of duodenum, jejunum, and ileum were obtained prior to and 30, 60, 90, and 120 min after corn oil administered orally for all dogs. Parameters recorded for each ultrasound study were intestinal wall thickness, mucosal echogenicity, and presence or absence of hyperechoic mucosal striations (HMS) and a parallel hyperechoic mucosal line (PHML). Nine affected and five controls dogs were included in the study. Seven of the nine dogs with lymphangiectasia had hyperechoic mucosal striations prior to corn oil administered orally. Jejunal hyperechoic mucosal striations were significantly associated with lymphangiectasia at multiple time points (P < 0.05) and were best identified in dogs with lymphangiectasia 60 or 90 min after corn oil administered orally. Increased mucosal echogenicity was observed in all dogs at multiple time points after corn oil administered orally. A parallel hyperechoic mucosal line was present in the jejunum in 4/5 healthy and 6/9 dogs with lymphangiectasia at one or more time points after corn oil administered orally. Findings indicated that corn oil administered orally improves conspicuity of characteristic ultrasonographic lesions in dogs with lymphangiectasia, however some of these lesions may also be present in healthy dogs that recently received a fatty meal.     

Comparison of biopsy samples obtained using standard endoscopic instruments and the harmonic scalpel during laparoscopic and laparoscopic-assisted surgery in normal dogs

Objectives— To compare tissue specimens of canine abdominal organs collected by standard techniques (ST) and harmonic scalpel (HS) and to determine the effect of each technique on wound healing.
Study Design— Experimental.
Animals— Twelve dogs.
Methods— Paired biopsy samples (ST, HS) were collected from liver, spleen, adrenal gland, pancreas, stomach, jejunum, and bladder using laparoscopic or laparoscopic-assisted methods. Hemorrhage at biopsy sites was assessed (present or absent). Specimens were evaluated for diagnostic quality and histologic changes. Dogs were necropsied at 4 or 14 days postoperatively.
Results— HS incision caused less frequent hemorrhage of all organs except spleen. HS specimens had more coagulation necrosis than ST specimens, but both techniques yielded specimens that were sized similarly and were of diagnostic quality. At necropsy, HS biopsy sites of the stomach, jejunum, bladder, adrenal gland, and pancreas were more hyperemic than ST sites. There were more adhesions at jejunal and pancreatic ST biopsy sites. HS biopsy sites had more coagulation necrosis at days 4 and 14 postoperatively. Differences in fibrin deposition, inflammation, and fibrosis were present at biopsy sites of some organs at days 4 or 14 and in comparisons between days 4 and 14.
Conclusions— Diagnostic quality biopsy specimens were obtained with HS and ST. Although HS-induced gross and histologic changes during the first 2 postoperative weeks, no clinical complications were observed.
Clinical Relevance— Both HS and ST can yield specimens with minimal hemorrhage and HS resulted in no apparent postoperative problems in normal dogs. Although HS caused more inflammation and adhesions at biopsy sites of the pancreas, adrenal gland, and jejunum, no clinical complications occurred.     

Presumptive migrating gall bladder mucocoele in two dogs with gall bladder rupture

A 10‐year‐old neutered female soft‐coated wheaten terrier and a 10‐year‐old, entire female Pomeranian were presented for vomiting and anorexia. Using ultrasound, an oval structure with a stellate, kiwifruit‐like appearance typical of a gall bladder mucocoele was observed in the caudal abdomen of the soft‐coated wheaten terrier and adjacent to the liver in the Pomeranian. There was also a moderate volume of abdominal effusion in both dogs. Cytology of the peritoneal fluid indicated a sterile exudative process but varied between the two dogs, with an absence of bile pigment in the soft‐coated wheaten terrier and marked bile peritonitis in the Pomeranian. An entire free‐floating ectopic mucocoele was confirmed via exploratory laparotomy with concomitant gall bladder rupture and common bile duct obstruction. Both dogs recovered completely after surgery. This is the first report of cases of gall bladder rupture with entire free‐floating gall bladder mucocoeles in dogs.