Treatment and outcomes of ureter injuries due to ovariohysterectomy complications in cats and dogs.

OBJECTIVES: To describe the presentation, treatment and outcome of unilateral and bilateral ureter injuries resulting from ovariohysterectomy complications in cats and dogs. MATERIALS AND METHODS: Retrospective case series of cats and dogs with ureteric injuries resulting from an ovariohysterectomy complication. Patient signalment, history, presenting clinical signs, clinical pathology, imaging, diagnosis, treatment and outcome were obtained from the medical records and telephone contact with the owners. RESULTS: Fourteen female cats and five female dogs were included. Eleven (58%) exhibited clinical signs immediately after recovery from ovariohysterectomy, six (32%) had a median onset of clinical signs of 3 days (range 1 to 16 days), and two (10%) were referred immediately because of a known complication during surgery. Five of seven animals with bilateral ureter injury presented with anuria. Three animals died or were euthanased without definitive surgery. Surgical repair included ureteroneocystostomy (eight cats, one dog), ureteronephrectomy (four cats, two dogs), subcutaneous ureteral bypass placement (three cats) and ureteral stent (one cat). Of the 16 operated animals, seven (44%) that were discharged from the hospital experienced major complications requiring one or more additional surgeries. Overall outcome was excellent in 13 (68%), good in one (5%), fair in one (5%) and poor in four (22%) animals. CLINICAL SIGNIFICANCE: A key indicator of a ureteric injury is an animal failing to recover normally or becoming unwell shortly after ovariohysterectomy. Anuria is likely in animals with bilateral ureter injury. Excellent outcomes are possible following surgical treatment.

Determining the anatomical origin of canine hepatic masses by CT.

OBJECTIVES: To identify CT features of canine hepatic masses that could be used to determine their divisional or lobar origin. MATERIALS AND METHODS: Preoperative, postcontrast CT images of 57 surgically resected hepatic masses were reviewed with respect to their size, position relative to the midline, gallbladder and portal vein, nearest recognisable hepatic lobar vein or portal vein and point of contact with the diaphragm and displacement of adjacent organs. RESULTS: The most prevalent histological diagnoses were hepatocellular carcinoma (n=26; 46%) and adenoma (n=10; 18%). Based on surgical assessment, it was observed that masses originated in the left hepatic division in 30 (53%) instances, central division in seven (12%) and right division in 20 (35%). All masses to the left of midline were left divisional, but only 18/30 (60%) masses to the right of midline were right divisional. Most (26/31; 84%) masses to the left of the gallbladder were left divisional and 84% (16/19) masses to the right of the gallbladder were right divisional. Half (10/20; 50%) of the right-divisional masses were medial, lateral or dorsal to the portal vein, but all other hepatic masses were ventral to the portal vein. A hepatic lobar vein or portal vein branch adjacent to the mass was observed in 53 (93%) instances; this feature correlated with surgical assessment of the affected division in 53 (93%) hepatic masses and the affected lobe in 32 (56%). CLINICAL SIGNIFICANCE: Combining CT features of hepatic masses appears to be an accurate method for determining their divisional or lobar origin.

Intrahepatic congenital portosystemic shunts in dogs: short- and long-term outcome of suture attenuation.

OBJECTIVES: To report the short- and long-term outcomes of one- or two-staged suture attenuation for complete closure of intrahepatic congenital portosystemic shunts in dogs. MATERIALS AND METHODS: Retrospective cohort study of dogs surgically treated for intrahepatic congenital portosystemic shunts between February 2000 and March 2015. Long-term follow-up was conducted by telephone conversations with the referring veterinary surgeon, owner, or both. RESULTS: In total, 55 dogs had suture attenuation of their intrahepatic congenital portosystemic shunt; 10 dogs (18·2%) tolerated complete attenuation, whilst 45 dogs (81·8%) tolerated partial attenuation. Postoperative complications occurred in 24 dogs (43·6%), and six dogs (10·9%) died. Repeat surgery was performed in 33 of 39 dogs (84·6%) that had previously undergone partial attenuation, and 27 of these (84·9%) ultimately achieved complete shunt attenuation. One dog (3·0%) died following second surgery, resulting in an overall postoperative mortality of seven of 55 (12·7%). Detailed follow-up was available for 22 dogs that were still alive at a median of 29 months after surgery (7·4 to 103·1) with a subjectively good quality of life. Of 17 dogs (82·4%), 14 with complete attenuation in one or two surgeries had an excellent outcome compared with one of five dogs (20%) with persistent shunting. CLINICAL SIGNIFICANCE: Staged suture ligation resulted in a high proportion of complete attenuation and reduced persistent shunting compared with a single surgery. Repeat surgery was associated with fewer complications than the first surgery. The proportion of dogs with an excellent outcome was greater for those that had complete attenuation in one or two surgeries compared with those with persistent shunting.

Treatment of intrahepatic congenital portosystemic shunts in dogs: a systematic review.

The aim of this study was to establish the evidence base for the treatment of intrahepatic congenital portosystemic shunts in dogs through a systematic review of the pertinent literature. Studies were filtered for evidence to answer the question "Which of the treatment options for intrahepatic CPSS in dogs offers the best short- and long-term outcome?" Studies were assigned a level of evidence based on a system published by the Oxford Centre for Evidence-Based Medicine. Thirty-two studies were included in the review. Twenty-six provided level 4 evidence and six provided level 5 evidence. There were no level 1, 2 or 3 studies. One study compared surgical treatment with medical management and one study compared suture ligation with ameroid constrictor placement. The remaining studies were case series describing the outcome for one treatment method alone. Methods and timings of assessments of short- and long-term outcomes were highly varied, making direct comparisons challenging. The evidence regarding the treatment of intrahepatic congenital portosystemic shunts in dogs is weak, with only two studies directly comparing treatments. There is a lack of evidence regarding short- and long-term outcomes on which to base clinical decisions.

Lipopolysaccharide and toll-like receptor 4 in dogs with congenital portosystemic shunts.

Surgical attenuation of a congenital portosystemic shunt (CPSS) results in increased portal vein perfusion, liver growth and clinical improvement. Portal lipopolysaccharide (LPS) is implicated in liver regeneration via toll-like receptor (TLR) 4 mediated cytokine activation. The aim of this study was to investigate factors associated with LPS in dogs with CPSS. Plasma LPS concentrations were measured in the peripheral and portal blood using a limulus amoebocyte lysate (LAL) assay. LPS concentration was significantly greater in the portal blood compared to peripheral blood in dogs with CPSS (P = 0.046) and control dogs (P = 0.002). LPS concentrations in the peripheral (P = 0.012) and portal (P = 0.005) blood of dogs with CPSS were significantly greater than those of control dogs. The relative mRNA expression of cytokines and TLRs was measured in liver biopsies from dogs with CPSS using quantitative PCR. TLR4 expression significantly increased following partial CPSS attenuation (P = 0.020). TLR4 expression was significantly greater in dogs that tolerated complete CPSS attenuation (P = 0.011) and those with good portal blood flow on pre-attenuation (P = 0.004) and post-attenuation (P = 0.015) portovenography. Serum interleukin (IL)-6 concentration was measured using a canine specific ELISA and significantly increased 24 h following CPSS attenuation (P < 0.001). Portal LPS was increased in dogs with CPSS, consistent with decreased hepatic clearance. TLR4 mRNA expression was significantly associated with portal blood flow and increased following surgery. These findings support the concept that portal LPS delivery is important in the hepatic response to surgical attenuation. Serum IL-6 significantly increased following surgery, consistent with LPS stimulation via TLR4, although this increase might be non-specific.

Markers of angiogenesis associated with surgical attenuation of congenital portosystemic shunts in dogs.

BACKGROUND: Dogs with congenital portosystemic shunts (CPSS) have hypoplasia of the intrahepatic portal veins. Surgical CPSS attenuation results in the development of the intrahepatic portal vasculature, the precise mechanism for which is unknown, although new vessel formation by angiogenesis is suspected. HYPOTHESIS: That the degree of portal vascular development and the increase in portal vascularization after CPSS attenuation is significantly associated with hepatic vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2) gene expression and serum VEGF concentration. ANIMALS: Client-owned dogs with CPSS undergoing surgical treatment. Forty-nine dogs were included in the gene expression data and 35 in the serum VEGF data. MATERIALS AND METHODS: Dogs surgically treated by partial or complete CPSS attenuation were prospectively recruited. Relative gene expression of VEGF and VEGFR2 was measured in liver biopsy samples taken at initial and follow-up surgery using quantitative polymerase chain reaction. Serum VEGF concentration was measured before and after CPSS attenuation using a canine specific ELISA. Statistical significance was set at the 5% level (P ≤ .05). RESULTS: There was a significant increase in the mRNA expression of VEGFR2 after partial attenuation (P = .006). Dogs that could tolerate complete attenuation had significantly greater VEGFR2 mRNA expression than those that only tolerated partial attenuation (P = .037). Serum VEGF concentration was significantly increased at 24 (P < .001) and 48 (P = .003) hours after attenuation. CONCLUSIONS AND CLINICAL IMPORTANCE: These findings suggest that intrahepatic angiogenesis is likely to occur after the surgical attenuation of CPSS in dogs, and contributes to the development of the intrahepatic vasculature postoperatively.

Hepatic hepcidin gene expression in dogs with a congenital portosystemic shunt.

BACKGROUND: Microcytic anemia is common in dogs with a congenital portosystemic shunt (cPSS) and typically resolves after surgical attenuation of the anomalous vessel. However, the pathophysiology of the microcytic anemia remains poorly understood. Hepcidin has been a key role in controlling iron transport in both humans and animals and in mediating anemia of inflammatory disease in humans. The role of hepcidin in the development of microcytic anemia in dogs with a cPSS has not been examined. HYPOTHESIS: To determine whether hepatic hepcidin mRNA expression decreases, while red blood cell count (RBC) and mean corpuscular volume (MCV) increase in dogs after surgical attenuation of a cPSS. ANIMALS: Eighteen client-owned dogs with confirmed cPSS undergoing surgical attenuation. METHOD: Prospective study. Red blood cell count (RBC) and mean corpuscular volume (MCV), together with hepatic gene expression of hepcidin, were measured in dogs before and after partial attenuation of a cPSS. RESULTS: There was a significant increase in both RBC (median pre 6.17 × 10(12) /L, median post 7.08 × 10(12) /L, P < .001) and MCV (median pre 61.5fl, median post 65.5fl, P = .006) after partial surgical attenuation of the cPSS. Despite the increase in both measured red blood cell parameters, hepatic gene expression of hepcidin remained unchanged. CONCLUSIONS AND CLINICAL IMPORTANCE: This study found no evidence that dysregulated production of hepcidin was associated with anemia in dogs with a cPSS.

Prevalence, outcome and risk factors for postoperative pyothorax in 232 dogs undergoing thoracic surgery.

OBJECTIVE: To determine the prevalence, outcome and risk factors for postoperative pyothorax in dogs undergoing thoracic surgery. METHODS: Case records were reviewed retrospectively to identify dogs with post thoracic surgery pyothorax, defined as septic neutrophilic inflammation within the pleural space based on cytology and/or a positive bacterial culture of pleural fluid. Those identified were reviewed for potential risk factors for postoperative pyothorax based on biological plausibility and previously published data. These potential risk factors were explored by multivariable logistic regression. RESULTS: Of 232 dogs undergoing thoracic surgery, 15 (6.5%) dogs developed pyothorax. Bacteria cultured included methicillin-resistant Staphylococcus aureus and multi-resistant Escherichia coli. Of these dogs, six died, four were euthanased and five were treated successfully. A diagnosis of idiopathic chylothorax [Odds Ratio (OR)=12.5, 95% Confidence Interval (CI)=2.7-58.5, P=0.001], preoperative intrathoracic biopsy (OR=14.3, 95% CI=1.7-118.7, P=0.014) and preoperative thoracocentesis (OR=11.2, 95% CI=1.6-78.2, P=0.015) were identified as independent risk factors for development of postoperative pyothorax. CLINICAL SIGNIFICANCE: Idiopathic chylothorax, intrathoracic biopsy and prior thoracocentesis are independent risk factors for postoperative pyothorax, which was associated with a 67% mortality rate.

Histopathological findings in the livers of cats with a congenital portosystemic shunt before and after surgical attenuation.

Histopathological changes are reported in the livers of cats with congenital portosystemic shunts (CPSS) before and after surgical attenuation. Medical records, portovenograms and liver biopsies from cats treated surgically for CPSS were reviewed. Biopsies were graded for histopathological features characteristic of CPSS. Of 40 cats with CPSS included in the study, all had portal vein hypoplasia and arteriolar hyperplasia at initial surgery, 20 (50 per cent) had hepatocyte swelling with microvesicular vacuolar change, 17 (42.5 per cent) had fibrosis, 12 (30 per cent) had hepatocyte swelling with macrovesicular vacuolar change, 8 (20 per cent) had biliary hyperplasia and 2 (5 per cent) had haemosiderin within Küpffer cells. Cats with macrovesicular vacuolar change were significantly older than cats without (P = 0.001), with median ages of 18.5 months and 8.5 months, respectively. Twenty-five cats had partial attenuation of the CPSS at initial surgery, and 16 of these had follow-up biopsy samples. There were no significant differences in the histopathological features of biopsies before and after partial attenuation. From first to second surgery, there was a significant improvement in intrahepatic vasculature on portovenography both before (P = 0.001) and after (P = 0.039) temporary complete attenuation. Following partial CPSS attenuation, there was no significant change in histopathological features despite an improvement in intrahepatic vasculature on portovenography.

Vascular endothelial growth factor (VEGF) and VEGF receptor expression in biopsy samples of liver from dogs with congenital portosystemic shunts.

Surgical attenuation of a congenital portosystemic shunt (CPSS) results in increased liver mass, development of intrahepatic portal vasculature and improved liver function. Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis. The aim of this study was to investigate the role of VEGF and its receptor in the hepatic response to CPSS surgery. The study included 99 dogs with CPSS treated with either partial or complete suture attenuation. Forty-four dogs with partial attenuation underwent a second surgery for complete attenuation. The expression of VEGF and VEGF receptor 2 (VEGFR2) in biopsy samples of liver was assessed by immunohistochemistry with rabbit anti-human VEGF polyclonal antibody and mouse anti-human VEGFR2 monoclonal antibody. Expression of these molecules was graded. The proportion of samples expressing VEGF was significantly greater in samples from dogs with CPSS compared with control samples (P=0.04) and the proportion of samples expressing VEGFR2 was significantly greater in control samples compared with samples from dogs with CPSS (P=0.04). VEGF labelling grade decreased significantly (P=0.038) and VEGFR2 increased significantly (P=0.046) between first and second surgery. The decrease in VEGF may reflect transient expression, preferential expression of other factors, reperfusion of existing vessels and/or increased angiogenesis before surgery in the form of arterialization and subsequent reduction due to improved portal blood flow. Partial suture attenuation was associated with a degree of 'normalization' of VEGF and VEGFR2 expression when compared with the control samples. Further investigation is needed to provide more information on the hepatic response to CPSS surgery.

Treatment of extrahepatic congenital portosystemic shunts in dogs - what is the evidence base?

A variety of surgical treatments and medical therapies are recommended for dogs with extrahepatic congenital portosystemic shunts (CPSS). The objective of this review was to assess the evidence base for the management of extrahepatic CPSS in dogs. An online bibliographic search was performed in November 2010 to identify articles relating to the question "Which of the treatment options for extrahepatic CPSS in dogs offers the best short- and long-term outcomes?" Articles were assigned a level of evidence based on a modified grading system. Thirty-eight articles were included in the review. Thirty-six articles were classified as grade 4 and two as grade 5. The timings and methods of assessment of short- and long-term outcomes varied widely between studies. One prospective study (grade 4a) showed that surgically treated dogs survived significantly longer than medically treated dogs. Four retrospective studies (grade 4b) compared the outcome of two surgical techniques but there were no statistically significant differences between treatment groups in terms of complications or outcome. The review found that the evidence base for the treatment of extrahepatic CPSS is weak. There is a lack of evidence of short- and long-term outcomes to recommend one treatment over another.

Spontaneous gastroduodenal perforations in dogs: a retrospective study of 15 cases.

The clinical findings and outcomes following surgical management of spontaneous gastroduodenal perforations in 15 dogs were reviewed in a retrospective study to identify related risk factors. Clinical and clinicopathological findings were diverse. Use of multiple diagnostic procedures yielded a strong index of suspicion for gastrointestinal perforation. There was a trend towards improved survival for animals with perforation of the gastric fundus/body compared to pyloric or duodenal perforation, although the difference was not statistically significant. Five dogs were euthanased at surgery; two dogs died within two days after surgery. Seven of the eight surviving dogs had a favourable long-term outcome. Previous administration of NSAIDs was the only identified predisposing factor in ten of 10 of the dogs.

Plasma lactate concentrations and blood gas values in dogs undergoing surgical attenuation of a single congenital portosystemic shunt.

Plasma concentration of lactate and the values of pH, pO(2) and pCO(2) were measured in the portal, systemic venous and, when possible, systemic arterial blood of 31 dogs with a single congenital portosystemic shunt, before and shortly after the temporary complete occlusion of the shunt, and at the end of surgery. At completion of the surgery, the shunt in 16 of the dogs had been occluded completely whereas in the other 15 it had been occluded only partially. There were no significant differences between any of the measurements of these variables in the portal venous, systemic venous or arterial plasma of any of the dogs, or between the values measured in the groups in which the shunts had been occluded completely or partially. Furthermore, there were no significant differences between the two groups of dogs in the arteriovenous gradients calculated at any of the sampling sites or sampling times. None of the variables was associated with the development of postoperative complications.

Indications, outcomes and complications following lateral thoracotomy in dogs and cats.

OBJECTIVES: Lateral thoracotomy is widely used for surgical management of thoracic diseases in small animals. The purpose of this paper is to describe the indications for lateral thoracotomy in dogs and cats and the associated outcomes and complications. METHODS: Medical records of animals undergoing lateral thoracotomy were reviewed and owners contacted regarding complications and survival. Relationships between signalment and treatment variables and outcome variables were investigated. RESULTS: Seventy dogs and 13 cats underwent lateral thoracotomy. Sixty-two per cent of cats and 91 per cent of dogs survived to discharge. Survival to discharge was significantly lower in cats than dogs, for neoplastic than non-neoplastic disease and in older animals. Survival to discharge was higher in animals undergoing patent ductus arteriosus ligation than in those undergoing lung lobectomy or oesophageal surgery. Survival to discharge was not related to surgeon experience. The incidence of complications was not related to species, age, disease, duration of surgery, surgeon experience or duration of thoracostomy tube placement. A low complication rate (5 per cent) was associated with thoracostomy tubes. CLINICAL SIGNIFICANCE: The approach of lateral thoracotomy has a minimal complication rate and animals with a disease requiring this approach have a high survival rate.

Complications and long-term outcomes of the ligation of congenital portosystemic shunts in 49 cats.

Only two of 49 cats undergoing surgical ligation of congenital extra- and intrahepatic portosystemic shunts died perioperatively, a mortality rate comparable with the mortality rates of dogs undergoing surgical attenuation of congenital portosystemic shunts and cats in which the shunts are attenuated with an ameroid ring constrictor. Thirty (83 per cent) of the 36 cats for which long-term information was available were still alive at a median follow-up period of 47 months (range six to 105 months); the outcome was excellent (no clinical signs) in 20 of them (median follow-up 37 months, range six to 105 months) and good (minimal clinical signs) in seven (median follow-up 39 months, range 10 to 73 months) and none of these 27 cats was on any long-term medication or special diet. The only major cause of morbidity was the development of neurological signs in 18 (37 per cent) of the cats. These included seizures and a wide variety of other neurological signs, and their development and persistence was not affected by the presence of preoperative seizures, the type of shunt, the degree of shunt attenuation or the age of the cat. The serum concentrations of ammonia and preprandial bile acids were normal or significantly below normal in the cats with neurological signs. Liver histopathology was similar in the cats with and without neurological signs. Ten (56 per cent) of the 18 cats that developed neurological signs recovered normal neurological function long term.

Torsion and volvulus of the transverse and descending colon in a German shepherd dog.

A German shepherd dog was presented two months after surgery for correction of acute gastric dilatation volvulus. The dog had been diagnosed with exocrine pancreatic insufficiency. Radiographs revealed marked gaseous distension of one loop of intestine with a generalised increase in intestinal gas content. A 360 degrees anticlockwise rotation of the descending and transverse colon, around the longitudinal axis of the mesocolon, was diagnosed at exploratory coeliotomy. The transverse and descending colon appeared uniformly necrotic and an end-to-end colo-colic resection and anastomosis was performed. The dog initially made satisfactory postoperative progress but was euthanased on the third postoperative day after it developed an intestinal intussusception.

Clinical efficacy and pharmacokinetics of carprofen in the treatment of dogs with osteoarthritis.

Six medium to large breed dogs with osteoarthritis were treated with 2 mg/kg of racemic carprofen, mixed with their morning feed, daily for 28 days. The treatment significantly (P < 0.01) reduced their mean lameness score, measured on a visual analogue scale, and there was a trend (P = 0.11) for the peak vertical forces exerted on a forceplate to be increased in the most severely affected limb. The plasma concentration-time relationships of the S(+) and R(-) enantiomers were studied for 24 hours after the first dose and after seven days and 28 days. There were no significant differences between the mean pharmacokinetic parameters measured on the three occasions, suggesting that carprofen was not accumulated and that tolerance to the drug did not develop. Although the pharmacokinetic parameters of the S(+) and R(-) enantiomers were generally very similar, there were wide variations both between and within dogs.

Asymmetric densitometric and mechanical adaptation of the left fifth metacarpal bone in racing greyhounds.

The densitometric and mechanical structural properties of the left and right fifth metacarpal bones of 10 racing greyhounds with a fracture of the central tarsal bone and 10 without a fracture were investigated by dual energy x-ray absorptiometry and a servo-hydraulic materials testing machine. In all the greyhounds the bone mineral density of the left fifth metacarpal bone was significantly greater than that of the right (P<0.001), but there was no significant difference between the degree of asymmetry in bone mineral density in the two groups. The ultimate torque and energy-to-failure of the left fifth metacarpal bone of the greyhounds with a fracture of the right central tarsal bone were significantly higher than in the right fifth metacarpal bone and higher than in both the left and right fifth metacarpal bones of the greyhounds with no fracture (P<0.05). The ultimate torque and energy-to-failure were significantly related to bone mineral density (P<0.005), and 22 per cent of the variation in these structural properties could be explained by variations in bone mineral density. Fifth metacarpal remodelling in response to asymmetric cyclic loading is bone-specific, and structural properties are enhanced in the left fifth metacarpal of greyhounds with a fracture of the right central tarsal bone.