Increased splenic capacity in response to transdermal application of nitroglycerine in the dog

This study was conducted to determine if application of transdermal 2% nitroglycerine ointment (TDNG) to dogs anesthetized with alpha chloralose would produce splenic dilatation by relaxation of venous smooth muscle. Sonomicrometer crystals were applied to the spleen in each of 15 dogs, and a pressure-measuring catheter was inserted into a splenic vein. The sonomicrometer crystals permitted measurement of splenic dimension, which is known to correlate with splenic volume. Ten dogs were given 2.5 cm TDNG/10 kg, and 5 dogs (vehicle controls) were given only petrolatum, both applied to the inner surface of the auricular pinna. Splenic dimension in all dogs receiving TDNG increased significantly (P < .05) by 7.0 +/- 4.8%, whereas splenic dimension in dogs receiving petrolatum did not increase. Splenic venous pressures did not change significantly in either group. Spleens began to dilate 482 +/- 652 seconds after application of TDNG and achieved maximal dilatation at 861 +/- 632 seconds. Splenic dilatation occurred in the absence of elevation of splenic venous pressure, indicating that the dilatation probably resulted from relaxation of splenic smooth muscle. TDNG was absorbed transdermally and produced splenic dilatation in health dogs anesthetized with alpha chloralose. If the spleen is a sentinel for peripheral veins, then TDNG may increase venous capacity, retaining blood from the lungs and thereby functioning to reduce pulmonary congestion and edema in dogs with left-sided heart failure.     

Diagnosis and surgical treatment of a primary splenic torsion in a domestic ferret (Mustela putorius furo)

A 4-year-old female spayed domestic ferret (Mustela putorius furo) presented with a history of vomiting over 24 hours. On physical examination, a significantly enlarged, firm spleen was palpated. Abdominal radiographs and abdominal ultrasound were suggestive of a splenic torsion or splenic infarction. An exploratory laparotomy confirmed the initial diagnosis and splenectomy was performed using a vessel sealing device. Histologic evaluation and culture of the spleen were consistent with primary torsion without evidence of infection or neoplasia. The patient recovered from surgery without complications. Based on a literature search, this is the first report of the clinical diagnosis and successful surgical treatment of a primary splenic torsion in a ferret. Although it appears to be a rare and potentially life-threatening disease in ferrets, splenic torsion should be considered as a differential diagnosis in ferrets that present with non-specific signs and a palpably enlarged spleen.     

Anatomical variation of arterial supply to the rabbit spleen

The rabbit, which is widely used as an experimental animal and is also popular as a companion animal, has a flat and elongated spleen with the longitudinal hilus running along its visceral surface. The spleen receives via the hilus an arterial supply that is essential for splenic nutrition and normal functioning. However, the distribution and variation of the arteries to the spleen have not been studied in detail. This study investigated anatomical variations of splenic arterial supply in 33 New Zealand White rabbits with a colored latex injection into arteries. We also examined whether the length of the spleen correlated with the number of the splenic branches of the splenic artery. The splenic artery always arose as the first independent branch of the celiac artery and ran along the splenic hilus to usually provide 6 (range, 3 to 10) splenic branches to the spleen. There was a moderate correlation (R=0.6) between the number of splenic branches and the longitudinal length of the spleen. The splenic branches often arose as a trunk or trunks in common with short gastric arteries. The number of common trunk(s) was usually 1 (range, 0 to 4). The data showed that the pattern and number of arterial branches to the spleen varied according to the individual animal, suggesting that such variations should be considered when performing experimental and veterinary surgical treatments in rabbits.     

Diagnosis and treatment of a primary splenic lymphoma in a mule

The case reported here describes a transthoracic approach for removal of a splenic lymphoma from a 5‐year‐old mule. Nine months prior to presentation at Iowa State University College of Veterinary Medicine (ISUCVM), abdominal ultrasound was performed as part of a work‐up to investigate the cause of lethargy, anorexia and anaemia. Ultrasound examination identified a haemoabdomen and multiple splenic masses. Transabdominal biopsies were collected for histopathological evaluation and lymphoma diagnosed. Based on a number of clinical and laboratory examinations there was a lack of support for multicentric involvement and all results suggested solitary splenic involvement. Surgical removal of the spleen was accomplished via a transthoracic approach without complications. Histopathology of the splenic masses revealed a B cell lymphoma. Bone marrow was collected during surgery and submitted for cytology and was found to contain a normal lymphoid population with no evidence of neoplastic cells. The mule was discharged from the hospital 11 days after surgery.     

Chronic splenic torsion in a dog with an accessory spleen

A 4-year-old, neutered male, mixed breed Old English sheepdog was presented for evaluation and treatment of anorexia, vomiting, and diarrhea. Presumptive severe pancreatitis was diagnosed based on the referral bloodwork. Abdominal ultrasonography identified a suspected liver lobe torsion based on the presence of a normal spleen. However, an exploratory laparotomy identified a splenic torsion in addition to a grossly normal spleen.Key clinical message:This case demonstrates that a second, potentially large area of splenic tissue (ectopic or accessory) can be present in the dog; therefore, the presence of a normal appearing spleen on abdominal ultrasonography does not rule out splenic torsion.     

Canine and feline emphysematous gastritis may be differentiated from gastric emphysema based on clinical and imaging characteristics: Five cases

Gastric pneumatosis is an imaging finding defined as the presence of gas foci in the gastric wall. In humans, this imaging feature can result from one of two separate clinical entities: life‐threatening emphysematous gastritis or clinically benign gastric emphysema. This retrospective case series study describes the clinical and imaging features in five animals diagnosed with spontaneous gastric pneumatosis without gastric dilatation‐volvulus. Three canine and two feline cases of spontaneous gastric pneumatosis were identified on radiographic and ultrasonographic examinations. In addition to gastric pneumatosis, one dog and two cats presented concomitant systemic signs such as lethargy, hematemesis, anemia, or leukocytosis. Two dogs remained asymptomatic or presented mild gastrointestinal signs. Portal gas was described in two dogs and one cat, and pneumoperitoneum in one dog. These features were not considered clinically significant. The dog and two cats with systemic signs were euthanized due to clinical deterioration and diagnosed with emphysematous gastritis. The gastric pneumatosis of both dogs without systemic signs resolved while on medical management without antibiotic therapy. These latter cases were interpreted as consistent with gastric emphysema. Findings from the current study indicated that gastric pneumatosis can occur without gastric dilatation‐volvulus in cats and dogs and that a combination of clinical and imaging characteristics may help to differentiate between potentially life‐threatening emphysematous gastritis and relatively benign gastric emphysema. More studies are needed to determine the etiology and risk factors associated with these conditions.     

Chronic primary splenic torsion with peritoneal adhesions in a dog: case report and literature review

Primary splenic torsion in dogs is uncommon and can occur in acute or chronic form. The chronic form is difficult to diagnose because the clinical signs are vague and sometimes intermittent. A dog with a history of diaphragmatic hernia repair two years previously presented with chronic, vague clinical signs and an abdominal mass. The mass was revealed to be spleen on ultrasonography. On exploratory laparotomy, the dog was found to have a splenic torsion of approximately 180 degrees with mature, fibrous adhesions retaining the spleen in a torsed position. A splenectomy was performed, and the dog recovered uneventfully with complete resolution of prior clinical signs. Prognosis for dogs with splenic torsion is good, although complications are relatively common.     

Diagnosis of a large splenic tumor in a dog: computed tomography versus magnetic resonance imaging

This study demonstrated magnetic resonance imaging (MRI) and computed tomography for large-sized splenic hemangiosarcoma. Radiography and ultrasonography revealed the presence of a large-sized soft-tissue mass in the cranial abdomen. Computed tomography showed hypoattenuating mass. The mass was located in contact with liver, spleen and stomach, and the origin of the mass remained ambiguous. The mass was T2-hyperintense and T1-hypointense with mild contrast enhancement. MRI allowed a differentiation between large-sized tumor and neighboring normal structure, and the mass was consequently identified as arising from spleen. These results suggested that MRI might be a useful tool to visualize large-sized splenic tumors and improve the accuracy of diagnosis.     

Splenosis in a dog

A 6-year-old male Rhodesian Ridgeback dog developed splenosis following splenectomy for a rupture of the spleen. The dog did well for 4 years following splenectomy but then developed progressive hepatomegaly, leading to the death of the animal. Grossly the abdomen was filled with masses of tissue arising from the liver. Multiple nodules of various sizes were seen in the remainder of the liver and attached to the mesentery, diaphragm and peritoneal wall. Histologically, the lesions contained splenic tissue consisting of both red and white pulp, and were characterized by all the normal cell elements of the spleen, including erythropoietic tissue. The proportion of red to white pulp was, however, abnormal, and the fibromuscular septae and sheath arteries were not obvious. In the smaller lesions, and in the margins of the large lesions, splenic tissue replaced the hepatic tissue except for the bile ducts. The multiple, intrahepatic nodules indicated splenic vein embolism.     

ENDOSCOPIC ULTRASOUND OF THE CANINE ABDOMEN

The aim of this study was to develop a standardized procedure for examination of the canine abdomen using endoscopic ultrasound and to describe the organs and structures that could be identified transgastrically. The abdomen of four healthy dogs and two cadavers were examined with endoscopic ultrasound. Five anatomic landmarks were used for standardized imaging of the cranial abdomen. These were the portal vein, splenic head and body, duodenum, left kidney, and aorta. High-resolution images of the following organs and structures could be made: distal esophagus, gastric wall from the cardia to the pylorus, liver, caudal vena cava, hepatic lymph nodes, liver hilus, and associated vessels, trifurcation of the celiac artery as well as the path of its branches and the left pancreatic limb and body. Structures that were more difficult to image were the distal duodenum and right pancreatic limb, the entire jejunum, ileum, and cecum as well as the tail of the spleen. Endoscopic ultrasound allowed excellent visualization of the gastric wall and regional structures without interference with gas artefacts. Centrally located organs such as the pancreas could be well examined transgastrically with endoscopic ultrasound without interference by overlying intestinal segments as is common with transabdominal ultrasound.     

CORRELATION OF ULTRASOUND FINDINGS,LIVER AND SPLEEN CYTOLOGY,AND PROGNOSIS IN THE CLINICAL STAGING OF HIGH METASTATIC RISK CANINE MAST CELL TUMORS

Cytologic sampling of the ultrasonographically normal spleen and liver is not implemented routinely in the clinical staging of canine cutaneous mast cell tumors and normal ultrasound findings are often accepted as sufficient evidence for ruling out splenic or liver metastasis. Our objective was to define the specificity and sensitivity of ultrasound findings for diagnosis of mast cell infiltration when verified with cytologic evaluation, and to define the prognostic role of cytologic evaluation of liver and splenic aspirates. Dogs with a diagnosis of clinically aggressive grade II, or grade III mast cell tumor treated with a combination vinblastine/CCNU chemotherapy protocol, were selected retrospectively based on availability of cytologic evaluation of spleen plus or minus liver for staging. Out of 19 dogs, 10 dogs had a grade II tumor and nine a grade III tumor. Seven dogs had mast cell infiltration of the spleen, liver, or both. The sensitivity of ultrasound for detecting mast cell infiltration was 43% for the spleen and 0% for the liver. Dogs with positive cytologic evidence of mast cell infiltration to spleen, liver, or both had significantly shorter survival (100 vs. 291 days) than dogs without evidence of mast cell infiltration (P<0.0001). Routine splenic aspiration should be performed regardless of ultrasonographic appearance in dogs with a clinically aggressive mast cell tumor.     

ULTRASONOGRAPHIC APPEARANCE OF HISTOPLASMOSIS IDENTIFIED IN THE SPLEEN IN 15 CATS

Histoplasmosis is the second most common fungal infection reported in the cat. The disseminated form involving lung, liver, lymph nodes, spleen, and bone marrow is a frequent manifestation of the disease. Limited information is available in the literature regarding the ultrasonographic appearance of the spleen in cats with disseminated or splenic histoplasmosis. A retrospective review of splenic ultrasound images from 15 cats confirmed to have histoplasmosis by splenic aspirates was performed. Size, echotexture, echogenicity, margin appearance, presence of nodules, and the overall shape of the spleen were reported in each case. Splenomegaly was documented in all cases (15/15) and a hypoechoic appearance of the spleen was documented in 14/15 of cases. The spleen was diffusely and uniformly affected in 14/15 (six homogenous and eight with a subtle mottled appearance) and had discrete nodules in 1/15 cats. Histoplasmosis should be included in the differential list for an enlarged and hypoechoic spleen in cats with consistent clinical findings. Additionally, ultrasound guided splenic aspirate may be a useful method to obtain a cytology sample for diagnosis.     

Effect of acute gastric dilatation on gastric myoelectic and motor activity in dogs.

OBJECTIVE: To investigate the effects of experimentally induced acute gastric dilatation on electrical and mechanical activities of the stomach in dogs. ANIMALS: 7 healthy dogs. PROCEDURE: Electrodes and strain-gauge force transducers were implanted on the serosal surface of the antrum and pylorus. Eight days later, baseline gastric electrical and contractile activities were recorded. The dogs were anesthetized and mechanically ventilated to maintain normocapnia while the stomach was distended (intragastric pressure, 30 mm Hg) for 180 minutes, using a thin compliant bag. Gastric electrical and contractile activities were recorded again on days 1 and 10 after dilatation. Recordings were analyzed to determine gastric slow-wave frequency, slow-wave dysrhythmia, propagation velocity of slow-waves, coupling of contractions to slow waves, motility index on the basis of relative contractile amplitudes, and onset of contractions after a standardized meal. RESULTS: Electrical or contractile activities were not significantly different 18 hours after acute gastric dilatation (day 1). Arrhythmias were evident before and after gastric dilatation in dogs from which food was withheld and in dogs after consumption of a meal. CONCLUSIONS: Variables for assessing gastric electrical and contractile activities were unaffected 18 hours after acute gastric dilatation. CLINICAL RELEVANCE: Analysis of results of this study indicated that altered electrical and contractile activities in dogs with short-term gastric dilatation are not likely to be secondary to the process of acute gastric dilatation.     

Intermittent gastric dilatation after gastropexy in a dog.

Gastroperitoneal adhesions, which developed after tube gastrostomy in a 3-year-old dog, caused an inverted L configuration of the pyloric antrum and duodenum, resulting in periodic episodes of gastric dilatation. The dog had undergone tube gastrostomy for treatment of gastric dilatation/volvulus, but gastropexy adhesions broke down 27 months later, necessitating a second pexy procedure. Adhesions then developed, constricting gastric outflow and trapping gas in the stomach and proximal duodenum. When the ventral row of adhesions was surgically dissected, the angle between the pyloric antrum and the duodenum was straightened, facilitating flow of digesta. Gastropexy rarely causes the degree of adhesion formation and the complications reported in this dog.     

Ultrasonography of the spleen in 50 healthy cows

This paper describes the ultrasonographic appearance, location and size of the spleen in 50 healthy commercial milk cows destined for slaughter. The intercostal spaces of the left thoracic wall were scanned with a 3.5 MHz linear transducer. In each intercostal space, the appearance of the splenic parenchyma, the dorsal and ventral margins and the distance between them, and the diameter of the splenic vessels were recorded. The spleen was seen in intercostal spaces 7-12. It was 2.0-5.0 cm thick, and tapered ventrally. The splenic capsule appeared as an echogenic line. The splenic parenchyma consisted of numerous small regularly spaced echoes, and vessels within the parenchyma appeared as anechoic round to oval or elongated images. The long axis was oblique, running caudodorsal to cranioventral. The distance from the dorsal margin of the spleen to the midline of the back was greatest in the 7th intercostal space (60.9+/-6.81) and smallest in the 12th intercostal space (12.7+/-2.85 cm). The extent of the spleen was greatest in the 8th intercostal space (24.9+/-10.77 cm) and smallest in the 12th intercostal space (9.5+/-5.38 cm). The mean diameter of the splenic vessels ranged from 0.66+/-0.28 to 0.90+/-0.65 cm, depending on the intercostal space scanned. Ultrasonography of the spleen in healthy cows provides information that can be used as a reference when examining cattle with suspected splenic disease.     

Gastric ulceration subsequent to partial invagination of the stomach in a dog with gastric dilatation-volvulus

CASE DESCRIPTION-An 8-year-old castrated male German Shepherd Dog was evaluated because of abdominal distension, retching, and vomiting. CLINICAL FINDINGS-Gastric dilatation-volvulus was suspected on the basis of the dog's signalment, history, clinical signs, and results of clinicopathologic analyses and abdominal radiography. Celiotomy was performed, and gastric dilatation-volvulus was confirmed along with splenomegaly. Gastric invagination was performed over an area of gastric necrosis. The dog was reevaluated 21 days later after an episode of collapse. Findings of physical examination and clinicopathologic analyses were suggestive of internal hemorrhage. Abdominal ultrasonography and subsequent celiotomy revealed severe gastric ulceration at the gastric invagination site, splenic torsion, and a focal splenic infarct. TREATMENT AND OUTCOME-Splenectomy and gastrectomy of the necrotic tissue were performed. The dog was discharged from the hospital, and the owner was instructed to administer gastroprotectants and feed the dog a bland diet. The dog was reported to be healthy 3.25 years after surgery. CLINICAL RELEVANCE-Findings suggest that complications associated with the gastric invagination procedure include severe gastric ulceration that may require subsequent surgery. Prolonged treatment with gastroprotectants following gastric invagination surgery may be necessary to avoid gastric ulceration in dogs.     

Ultrasonographic-anatomic correlation and imaging protocol for the spleen in anesthetized dogs

Sonographic and/or anatomic observations were made of the spleen in 27 dogs. Anatomic studies were used to establish precise correlations between the gross anatomic features of the organ and its ultrasonographic image. In 8 anesthetized dogs, ultrasonographic images of the spleen were made in dorsal, transverse, and sagittal planes. When it was incident to the ultrasonic beam, the splenic capsule was represented by a fine echogenic line that defined the boundaries of the organ. The splenic substance had a uniformly mottled echogenicity apart from the anechoic lumen of the splenic venous rami, which were detected at and near the hilus of the spleen. Less regularly, splenic arterial rami were detected at the hilus, but not within the splenic substance. Dorsal and transverse images were made with the ultrasonic transducer perpendicular to the left thoracic and abdominal wall at the 11th intercostal space and caudoventrad to it. Sagittal images were produced with the transducer's face directed craniad, placed parallel to the left lateral abdominal wall, and pushed under the costal arch. The adoption of such an ultrasonographic imaging protocol ensures that all of the spleen is inspected. A definitive opinion can then be given as to whether the spleen is normal or abnormal. Pathologic changes in the spleen must also be differentiated from changes in adjacent organs or structures.     

Hammondia heydorni oocysts in the faeces of a greyhound in New Zealand

AIMS: To identify oocysts found in faecal material of a greyhound. METHODS: Polymerase chain reaction (PCR) and DNA sequencing were used to study genomic DNA isolated from oocysts purified from faeces of a greyhound. RESULTS: Database searches with the DNA sequences obtained showed they were derived from Hammondia heydorni. A species-specific PCR was developed to detect H. heydorni DNA. CONCLUSIONS: Light microscopy in conjunction with PCR and DNA sequencing definitively identified the presence of H. heydorni oocysts in faeces of a greyhound. CLINICAL RELEVANCE: This study confirms the presence of H. heydorni in New Zealand and indicates the need to correctly identify similar oocysts from dogs, rather than assume they are Neospora caninum.     

Gastric dilatation and torsion in small or miniature breeds of dogs—three case reports

Three cases of gastric dilatation with or without torsion are described in small or miniature breeds of dog. Gastric neoplasia in the form of leiomyomata was present in two cases.