Use of pneumocystoplasty for overinflation of the swim bladder in a goldfish

A Ryukin goldfish was evaluated because of a 6-month history of progressive abdominal distention and positive buoyancy. Overinflation of the swim bladder was diagnosed, and the fish was anesthetized with tricaine methanesulfonate. Archimedes' principle was used to determine the volume of swim bladder that was removed surgically. The caudal swim bladder was exteriorized through an abdominal incision and 2 surgical clips were placed across it to limit its size. After surgery, the fish remained in a state of negative buoyancy in sternal and lateral recumbency on the bottom of the tank. Sutures were removed 15 days after surgery, but the fish died 24 days after surgery. A full necropsy could not be performed because of autolysis of the tissues, but the surgical clips and the swim bladder appeared unremarkable. Pneumocystoplasty may be a viable treatment for this condition.     

ULTRASONOGRAPHIC FEATURES OF GRASS AWNS IN THE URINARY BLADDER

Grass awns are a common cause of foreign body disease in animals, but little is known about their presence in the lower urinary tract. The ultrasonographic features of grass awns in vivo and in vitro have been described in detail. The purpose of this report is to describe the clinical and sonographic features of grass awns in the urinary bladder of dogs and cats. Three male Yorkshire terriers (one of which was examined twice) and one female domestic short‐haired cat were evaluated for signs of lower urinary tract disease, and an intravesicular grass awn was suspected based on ultrasound examination. The grass awn appeared ultrasonographically as a bladder stone (n=1) or a linear hyperechoic structure (n=4) with or without acoustic shadowing that was easy to identify due to contrast with surrounding urine. The presence of a grass awn within the urinary bladder was confirmed during exploratory surgery. In all patients, the route of entry of the grass awn was thought to have been retrograde migration from the urethral opening. The ultrasonographic appearance of grass awns in the bladder is consistent with that in other tissues.     

ASSESSMENT OF RESPIRATION‐INDUCED DISPLACEMENT OF CANINE ABDOMINAL ORGANS IN DORSAL AND VENTRAL RECUMBENCY USING MULTISLICE COMPUTED TOMOGRAPHY

Respiratory‐induced organ displacement during image acquisition can produce motion artifacts and variation in spatial localization of an organ in diagnostic computed tomography (CT) examinations. The purpose of this prospective study was to quantify respiratory‐induced abdominal organ displacement in dorsal and ventral recumbency using five normal dogs. All dogs underwent CT examinations using 64 multidetector row CT (64‐MDCT). A “3‐dimensional (3D) apneic CT exam” of the abdomen was acquired followed by a “4‐dimensional (4D) ventilated CT exam.” The liver, pancreas, both kidneys, both medial iliac lymph nodes, and urinary bladder were delineated on the 3D‐apneic examination and the organ outlines were compared to the maximum alteration in organ position in the 4D‐ventilated examination. Displacement was measured in dorsal‐to‐ventral (DV), right‐to‐left (RL), and cranial‐to‐caudal (CC) directions. Respiratory‐induced displacement of canine abdominal organs was not predictable and showed large variability in the three directions evaluated. For most canine abdominal organs, dorsal recumbency provided overall the least amount of displacement among all directions evaluated except for liver and urinary bladder. For liver, a large variability was found for all directions and a statistically significant difference was found only in the RL direction with ventral recumbency exhibiting less displacement (P = 0.0099). For the urinary bladder, ventral recumbency also provided less displacement but this was statistically significant only in the RL direction (P < 0.0001). Findings from this study indicated that dorsal recumbency may be preferred for minimizing respiratory motion artifacts in whole abdomen studies, but ventral recumbency may be preferred for liver and urinary bladder studies when respiration cannot be controlled.     

EVALUATION OF THE URETER AND URETEROVESICULAR JUNCTION USING HELICAL COMPUTED TOMOGRAPHIC EXCRETORY UROGRAPHY IN HEALTHY DOGS

Abdominal computed tomography (CT) using a protocol designed for evaluation of the ureters was performed on six normal purpose-bred research dogs. After noncontrast CT, a postcontrast scan was performed 3 min post midpoint of injection of 400 mgI/kg body weight of diatrizoate meglumine/sodium. Ureteral and ureterovesicular junction anatomy were readily assessed with minimal patient preparation. The ureters were similar in size to reported values and the renal pelvis, ureter, and ureterovesicular junction were easily identified on both noncontrast and contrast-enhanced scans. There was a significant relationship between bladder volume and interureterovesicular junction distance but not between bladder volume and ureterovesicular junction to internal urethral orifice distance. A reliable bony landmark for the identification of the internal urethral orifice could not be determined. The results of this preliminary study of normal anatomy should facilitate the clinical use of CT in the evaluation of ureteral disease (e.g., ureteral ectopia).     

Failure to gulp surface air induces swim bladder adenomas in Japanese medaka (Oryzias latipes)

In order to elucidate the effects of swim bladder inflation failure on swim bladder carcinogenesis, we investigated the sequential histopathological changes of swim bladders at 13, 24, 35, and 53 days post-hatch (dph) in medakas with an uninflated swim bladder, which was experimentally induced by denying access to the air–water interface between 0 and 6 dph. The reactive oxygen species (ROS) levels were measured at 24 dph. An uninflated swim bladder was induced in 47.3% of the fish denied access to the air–water interface (the denied group). The total incidence of swim bladder adenoma was 54.1% in the denied group; however, these tumors were observed in all fish with an uninflated swim bladder. In fact, these tumors were observed from 13 dph and onwards. The TBARS levels of the juveniles showed a 2.6-fold increase in fish with an uninflated swim bladder in the denied group compared to that in the control group. It is speculated that swim bladder inflation failure has some effects on the gas gland to produce ROS, leading to DNA damage in the gas glandular epithelium, which develops into swim bladder adenomas. Consequently, it is concluded that denying access to the air-water interface between 0 and 6 dph in medaka is an easy method of inducing swim bladder tumors in a short-term period, and is a useful method for producing tumor-bearing fish.     

Original Study: Determination of normal intra‐abdominal pressure using urinary bladder catheterization in clinically healthy cats

Objective – To establish a reference interval for intra‐abdominal pressure (IAP) measured by urinary bladder catheterization in normal cats and determine if IAP is affected by observer variation, volume of saline instillation before measurement, or subject variables of gender, positioning, body condition score, and sedation. Design – Prospective experimental study. Setting – Private referral center. Animals – Twenty healthy adult cats. Interventions – Sedation with butorphanol, midazolam, and propofol for catheterization of the urinary bladder and measurement of IAP. Measurements and Main Results – A 5‐Fr red rubber urinary catheter was placed under sedation, and IAP was determined using a water manometer with the cats in right lateral and sternal recumbency. Three readings were taken in each position by 2 observers. The cats were allowed to recover with the urinary catheter in place, and IAP was measured in each cat while they were awake in right lateral and sternal recumbency. Conclusions – In this population of clinically healthy cats, median (interquartile range) IAP taken over all measurements was 7.00 cm H₂O (5.23–8.83 cm H₂O). There was no statistical difference between observers or subject gender. Factors associated with a statistically significant increase in IAP were right lateral compared with sternal recumbency (P=0.002), being awake compared with sedated (P<0.001), having a higher body condition score (P=0.01 and 0.001), instillation of a higher volume of saline into the bladder for measurement (P<0.001), and struggling during awake measurements (P<0.001).     

WHOLE BODY COMPUTED TOMOGRAPHIC CHARACTERISTICS OF SKELETAL AND CARDIAC MUSCULAR METASTATIC NEOPLASIA IN DOGS AND CATS

Muscular metastatic neoplasia has been reported to be rare in domestic animals, however previous studies were based primarily on necropsy findings. The purpose of this retrospective study was to describe whole body computed tomography (CT) characteristics of confirmed muscular metastases in a cohort of dogs and cats presented for oncology evaluation. Medical records of 1201 oncology patients were reviewed. Included animals underwent pre and postcontrast whole body CT, and CT‐guided tru‐cut biopsy or fine needle aspiration of one or more metastatic lesions. Twenty‐one dogs and six cats met inclusion criteria, representing 2.08% of all canine oncology patients and 3.1% of all feline oncology patients. Mean age was 9.6 years. Postcontrast CT characteristics included well‐demarcated, oval‐to‐round lesions with varying enhancement patterns: ring enhancing (n = 16), heterogeneously enhancing (n = 8), or homogeneously enhancing (n = 5). Five animals showed concurrent and varying nodular patterns. In seven cases (five dogs and two cats), one single muscular nodule was observed. In 20 cases, two or more lesions were observed. In two cases, cardiac hypodense nodules were observed in the postcontrast CT, while appearing isodense in the precontrast study. Necropsy confirmed neoplasia in both of them. Locations of muscular metastases included epaxial/paraspinal muscles of the cervical, thoracic, and lumbar spine (n = 18), superficial muscles of the thoracic wall (n = 13), scapular/shoulder region (n = 3), hind limb (n = 3), and abdominal wall muscles (n = 1). Findings supported the use of pre and postcontrast whole body CT for oncologic staging in dogs and cats, especially for primary tumors characterized by a high metastatic rate.     

Central corneal thickness in koi fish: effects of age, sex, body length, and corneal diameter

OBJECTIVE: To establish the central corneal thickness (CCT) of normal koi fish by ultrasonic pachymetry, and its relationship to age, sex, body length and corneal diameter. METHODS: Age, sex and body length of 33 koi fish (17 male and 16 female fish) were recorded. Horizontal and vertical corneal diameters of each eye were obtained using Jameson calipers. Central corneal thickness of all eyes was measured by ultrasonic pachymetry. Intraocular pressure (IOP) by rebound tonometry was obtained for a subgroup of nine koi (18 eyes). RESULTS: Mean central corneal thickness was 325.9 microm. Central corneal thickness of female koi was greater than CCT of male fish (P < 0.01). Central corneal thickness increased with increasing age overall and within both sexes (P < 0.01). Central corneal thickness increased with increasing body length (P < 0.001). For male and female fish, CCT increased with increasing horizontal and vertical corneal diameters (P < 0.01). Mean horizontal corneal diameter (HCD) was 8.05 mm, mean vertical corneal diameter (VCD) was 7.38 mm, and HCD was consistently greater than VCD. Mean IOP of a subgroup of these koi was 4.9 mmHg by rebound tonometry. CONCLUSIONS: Koi CCT increases with increasing age, body length and corneal diameter.     

CT AND MRI FEATURES OF CAROTID BODY PARAGANGLIOMAS IN 16 DOGS

Carotid body tumors (paragangliomas) arise from chemoreceptors located at the carotid bifurcation. In imaging studies, this neoplasm may be confused with other neck neoplasms such as thyroid carcinoma. The purpose of this retrospective, cross‐sectional study was to describe computed tomographic (CT) and magnetic resonance imaging (MRI) characteristics of confirmed carotid body tumors in a multi‐institutional sample of dogs. A total of 16 dogs met inclusion criteria (14 examined using CT and two with MRI). The most common reason for imaging was a palpable cervical mass or respiratory signs (i.e., dyspnea or increased respiratory noises). The most commonly affected breed was Boston terrier (n = 5). Dogs were predominantly male castrated (n = 10) and the median age was 9 years [range 3–14.5]. Most tumors appeared as a large mass centered at the carotid bifurcation, with poor margination in six dogs and discrete margins in ten dogs. Masses were iso‐ to hypoattenuating to adjacent muscles in CT images and hyperintense to muscles in T1‐ and T2‐weighted MRI. For both CT and MRI, masses typically showed strong and heterogeneous contrast enhancement. There was invasion into the adjacent structures in 9/16 dogs. In six of these nine dogs, the basilar portion of the skull was affected. The external carotid artery was entrapped in seven dogs. There was invasion into the internal jugular vein in three dogs, and into the external jugular, maxillary, and linguo‐facial veins in one dog. Imaging characteristics helped explain some clinical presentations such as breathing difficulties, Horner's syndrome, head tilt, or facial nerve paralysis.     

Evaluation of Emamectin Benzoate for the Control of Experimentally Induced Infestations of Argulus sp. in Goldfish and Koi Carp

Abstract

The effect of 0.2% emamectin benzoate (SLICE; Intervet/ Schering-Plough Animal Health, Roseland, New Jersey) administered in top-dressed, pelleted commercial fish feed was evaluated for control of freshwater Argulus sp. in goldfish Carassius auratus and koi carp, a variant of common carp Cyprinus carpio, in freshwater aquaria at 24–25°C. Sixteen individually housed goldfish were each exposed to 37 Argulus. The number of fish lice attached to each fish at the start of the experiment was not determined; however, the total number of motile fish lice in each aquarium (on fish and in the water) was determined at the start and end of each experiment. Eight goldfish were fed the control diet (0 μg · kg fish biomass^?1 · d^?1) and eight were fed the medicated diet (50 μg · kg fish biomass^?1 · d^?1) for seven consecutive days. After treatment, fish louse infestation in controls was 20.5 ± 1.5 (mean ± SE) lice per fish. No Argulus were found on fish in the treated group. In a separate experiment, 10 individually housed koi were each exposed to 128 Argulus. Five koi were fed the control diet and five were fed a low-dose medicated diet (5 μg · kg fish biomass^?1 · d^?1) for 7 d. After treatment, fish louse infestation among the controls was 14.6 ± 3.8 lice per koi. No Argulus were found on koi in the treated group. Hence, a 7-d regimen of oral emamectin benzoate controlled experimental infestation of Argulus when administered to goldfish at 50 μg · kg fish biomass^?1 · d^?1 and to koi at 5 μg · kg fish biomass^?1 · d^?1.

Received March 24, 2010; accepted January 17, 2011     

COMPUTED TOMOGRAPHIC CHARACTERISTICS OF THE THYROID GLANDS IN EIGHT HYPERTHYROID CATS PRE‐ AND POSTMETHIMAZOLE TREATMENT COMPARED WITH SEVEN EUTHYROID CATS

Hyperthyroidism is the most common feline endocrinopathy; thyroid computed tomography (CT) may improve disease detection and methimazole dose selection. Objectives of this experimental pre‐post with historical case‐control study were to perform thyroid CT imaging in awake or mildly sedated hyperthyroid cats, compare thyroid gland CT appearance in euthyroid and hyperthyroid cats pre‐ and postmethimazole treatment, and determine whether thyroid size or attenuation correlate with methimazole dose needed for euthyroidism. Premethimazole treatment, eight hyperthyroid cats received CT scans from the head to heart, which were compared to CT of seven euthyroid cats. Total thyroxine levels were monitored every 3–4 weeks. Postmethimazole CT was performed 30 days after achieving euthyroid status. Computed tomography parameters recorded included thyroid length, width, height, attenuation, and heterogeneity. Median time between CT was 70 days (53–213 days). Mild sedation was needed in five hyperthyroid cats premethimazole, and none postmethimazole. Thyroid volume was significantly larger in hyperthyroid cats compared to euthyroid cats (785.0 mm³ vs. 154.9 mm³; P = 0.002) and remained unchanged by methimazole treatment (?4.5 mm3; P = 0.50). Thyroid attenuation and heterogeneity decreased with methimazole treatment (96.1 HU vs. 85.9 HU; P = 0.02. 12.4 HU vs. 8.1 HU; P = 0.009). Methimazole dose ranged from 2.5 to 10 mg daily with a positive correlation between pretreatment thyroid gland volume and dose needed to achieve euthyroidism (P = 0.03). Euthyroid and hyperthyroid cats are easily imaged awake or mildly sedated with CT. Methimazole in hyperthyroid cats significantly lowers thyroid attenuation and heterogeneity, but not size.     

Triple phase computed tomography of the pancreas in healthy cats

While the availability and use of computed tomography (CT) continues to grow, no study has described the size and multiphase CT appearance of the normal feline pancreas. This information is important to not only allow more accurate identification and differentiation of disease, but it may also be useful in assessing pancreatic function. In this prospective analytical study, we described a triple phase CT protocol of the pancreas for use in sedated cats and the attenuation, enhancement pattern, size, and volume of the pancreas for a group of healthy cats. Fifteen healthy cats were enrolled in the study and a standardized protocol for acquiring arterial, portal, and delayed phase CT images of the pancreas was developed and described. The pancreas was hypo to isoattenuating to both the liver and spleen in all phases in the majority of cats with a homogenous enhancement pattern noted in all 15. Mean pancreatic attenuation was 48, 79, 166, and 126 Hounsfield units (HU) respectively on precontrast, arterial, portal, and delayed phase images. In addition, mean height, length, and width of the left lobe of the pancreas were larger than the right lobe in all 15 cats. There were no associations between volume and volume: body weight ratio with age (P = 0.6518, P = 0.6968) or sex (P = 0.7013, P = 0.2043). This baseline information may be beneficial for use in future studies characterizing pancreatic disease in cats as well as future research studies evaluating pancreatic endocrine function.     

Swim bladder tumor in the young adult scoliotic medaka (Oryzias latipes)

A swim bladder tumor was detected in one scoliotic medaka aged 22 weeks. The tumor was located in the dorsal abdominal cavity, with maximum dimension of 1,850 × 1,500 µm. No swim bladder lumen was identified, and the region where the swim bladder lumen would have been located, was replaced with adipose tissues. The tumor was a non-invasive, expansile, and encapsulated solid mass with a few cysts, and comprised a homogenous population of well-differentiated, densely packed, gas glandular epithelium-like cells. The tumor mass was connected to a rete mirabile that showed a hyperplastic capillary plexus; however, the tumor cells did not invade the rete mirabile, thereby revealing that the tumor was an adenoma originating from the gas glandular epithelium of the swim bladder. Since proliferative lesions in the swim bladder have been reported in some teleosts with skeletal deformations, including medaka, the occurrence of a spontaneous swim bladder tumor in teleosts is considered to be closely associated with various types of skeletal deformation, and spinal curvature in particular.     

THORACIC COMPUTED TOMOGRAPHY IN FELINE PATIENTS WITHOUT USE OF CHEMICAL RESTRAINT

Computed tomography (CT) and thoracic radiography were performed in nonsedated, nonanesthetized, cats with thoracic disease. The final diagnosis was obtained with echocardiography, cytology, histopathology, necropsy, or response to therapy. For CT imaging, cats were in a positioning device using a 16 multislice helical CT system. Fifty‐four cats had CT imaging of which 50 had thoracic radiography. The most common diagnoses were lung neoplasia, lower airway disease, and cardiomyopathy (nine each). Other disease groups included mediastinal mass (eight), infection (seven), trauma (four), and hernia (three). CT provided additional correct diagnoses in 28% (14/50) and additional information in 74% (37/50) of the cats. Additional correct diagnoses achieved only with CT were most common for cats with lower airway disease. The most common additional findings with CT were lung nodules (n=4), lung masses (n=4), bronchiectasis (n=4), and mediastinal lymphadenopathy (n=3). Survey CT led to a significant different diagnosis or different prognosis in 20 of the 50 cats that were imaged both modalities. Contrast CT was performed in 19 cats, most commonly in cats with lung neoplasia (n=6), a mediastinal mass (n=4) or an infection (n=3), and provided additional correct diagnosis in two cats not achieved with survey CT. Thoracic CT using a positioning device in diseased awake cats is feasible, safe, and clinically useful.     

COMPARISON BETWEEN COMPUTED TOMOGRAPHIC CHARACTERISTICS OF THE MIDDLE EAR IN NONBRACHYCEPHALIC AND BRACHYCEPHALIC DOGS WITH OBSTRUCTIVE AIRWAY SYNDROME

Prevalence of subclinical middle ear lesions in dogs that undergo computed tomography (CT) and magnetic resonance imaging of the head has been reported up to 41%. A predisposition in brachycephalics has been suggested, however evidence‐based studies are lacking. Aims of this retrospective cross‐sectional study were to compare CT characteristics of the middle ear in groups of nonbrachycephalic and brachycephalic dogs that underwent CT of the head for conditions unrelated to ear disease, and test associations between thickness of the soft palate and presence of subclinical middle ear lesions. One observer recorded CT findings for each dog without knowledge of group status. A total of 65 dogs met inclusion criteria (25 brachycephalic, 40 nonbrachycephalic). Brachycephalic dogs had a significantly thicker bulla wall (P = 2.38 × 10^?26) and smaller luminal volume (P = 5.74 × 10^?20), when compared to nonbrachycephalic dogs. Soft palate thickness was significantly greater in the brachycephalic group (P = 2.76 × 10^?9). Nine of 25 brachycephalic dogs had material in the lumen of the tympanic cavity, compared to zero of 45 of nonbrachycephalics. Within the brachycephalic group, a significant difference in mean soft palate thickness was identified for dogs with material in the middle ear (12.2 mm) vs. air‐filled bullae (9 mm; P = 0.016). Findings from the current study supported previous theories that brachycephalic dogs have a greater prevalence of subclinical middle ear effusion and smaller bulla luminal size than nonbrachycephalic dogs. Authors recommend that the bulla lumen volume formula previously developed for mesaticephalic dogs, (?0.612 + 0.757 [lnBW]) be adjusted to 1/3(?0.612 + 0.757 [lnBW]) for brachycephalic breeds.     

EFFECT OF CONTRAST MEDIUM INJECTION DURATION ON PEAK ENHANCEMENT AND TIME TO PEAK ENHANCEMENT OF CANINE PULMONARY ARTERIES

Our goal was to investigate the effect of contrast medium injection duration on pulmonary artery peak enhancement and time to peak enhancement. Fourteen dogs were allocated into one of seven predefined weight categories, each category contained two dogs. Dogs in each weight category were assigned to group A or B. Animals in each group received a different contrast medium injection protocol. In group A, a fixed injection rate of 5 ml/s was used. In group B, the contrast injection rate was calculated as follows: flow rate=contrast volume/scan duration+10 s. Time to peak enhancement and peak enhancement of the main left and right pulmonary arteries were measured on single‐level, dynamic CT images for a fixed time of 30 s. Rank correlation (Spearman's) coefficients between injection duration and time to peak enhancement and between body weight and peak enhancement were calculated. For group A, there was a significant negative correlation between peak enhancement and weight (r=?0.94; P=0.005), while for group B, there was no significant correlation (r=?0.64 and P=0.18). There was a significant correlation between time to peak enhancement and injection duration in both groups (group A: r=0.99; P=0.006 and group B: r=0.85; P=0.02). In conclusion, injection duration is a key feature in a CT angiography injection protocol. A protocol with an injection duration adjusted to the scan duration seems to be particularly suitable for veterinary applications where a population with great weight variability is studied.     

Cystosonographic measurements of canine bladder tumours

The purpose of this study was to evaluate the variability of cystosonographic bladder tumor measurements with both operator and bladder volume changes. Ten dogs with bladder tumors were included. In each dog, three operators determined tumor dimensions for three different bladder volumes. Intraclass correlation coefficient was used to assess operator reliability. Response Evaluation Criteria in Solid Tumors (RECIST) and greater than or equal to 50% differences in tumor measurements were used as guidelines. Poor to fair correlations between operators were found for the different tumor dimensions (r_I = 0.4 – 0.7). The percent differences in tumor dimensions with operator and bladder volume changes were significant enough to misclassify the tumors into the categories of partial response (PR) or progressive disease (PD). These results suggest that cystosonographic measurements of bladder tumors are affected by both changes in operator and bladder volume, and the discrepancies are significant enough to change response classification.     

THE VETMOUSETRAP™: A DEVICE FOR COMPUTED TOMOGRAPHIC IMAGING OF THE THORAX OF AWAKE CATS

The VetMousetrap^?, a novel device that allows computed tomography (CT) of awake cats and provides a clinically supportive environment, is described. Ten normal cats were used to test the device for ambient internal oxygen, carbon dioxide levels, and temperature. Twenty‐two awake normal cats were imaged using a 16‐multi‐slice helical CT unit to evaluate dose‐equivalent protocols. Two different X‐ray tube potentials (kV), 80 and 120, and two different helical pitches, 0.562 and 1.75, were evaluated. The signal intensity of the pulmonary parenchyma (SI_lung), signal intensity of background (SI_backgr), contrast, noise, signal‐to‐noise ratio (SNR), and contrast‐to‐noise ratio (CNR) were calculated. Three evaluators ranked the images for sharpness of liver margins, motion, helical, and windmill artifacts. CT was successfully completed in 20 of 22 cats. No artifacts directly related to the device were detected. Overall, 75 of 80 (94%) examinations were judged to have absent or minimal motion artifact. A statistically significant difference was found for SNR (P=0.001) and CNR (P=0.001) between all protocols. The higher pitch protocols had significantly lower noise and higher SNR and CNR, lower motion artifact but greater helical artifacts. A protocol using 80 kV, 130 mA, 0.5 s, and 0.562 pitch with 1.25 mm slice thickness, and 0.625 mm slice reconstruction interval is recommended. The VetMousetrap^? appears to provide the opportunity for diagnostic CT imaging of the thorax of awake cats.     

COMPUTED TOMOGRAPHIC CHARACTERISTICS OF INTRAPELVIC MASSES IN DOGS

In people, the computed tomography (CT) characteristics of intrapelvic masses can be used to distinguish a malignant from a benign mass. As prognosis varies greatly between malignant and benign intrapelvic masses, knowledge of their biological behavior can aid treatment planning before surgery. The purpose of this study was to determine if CT characteristics exist to help differentiate benign from malignant intrapelvic masses in dogs. The CT images of 14 dogs with a histopathologically confirmed intrapelvic mass were evaluated. Postcontrast internal heterogeneity of the mass was the only characteristic significantly associated with malignancy (P=0.005). Preoperative CT examination of intrapelvic masses in dogs can provide prognostic information before invasive surgical treatment.