Clinical findings, surgical treatment and long-term outcome of dogs and cats with double aortic arch: four cases (2005-2022).

OBJECTIVE: To describe the clinical presentation, diagnostic findings, treatment and long-term outcome following surgery of dogs and cats undergoing surgical treatment for a double aortic arch. MATERIALS AND METHODS: Medical records of dogs and cats diagnosed with a double aortic arch between 2005 and 2022 at three small animal referral hospitals were retrospectively reviewed. Long-term outcome was assessed by a clinical examination and/or by contacting the owners or referring veterinarians. RESULTS: Two dogs and two cats were included. Regurgitation after eating, stunted growth and poor weight gain were the predominant clinical features. All animals had thoracic radiography and oesophagography; a dilation of the cranial thoracic oesophagus cranial to the heart base, was described in all animals. CT angiography confirmed double aortic arch in three of these and the right aortic arch was larger and appeared more well developed compared with the left aortic arch in all based on CT or surgical findings. Surgery was performed via a left fourth intercostal thoracotomy; ligation and transection of the lesser left aortic arch was performed. Follow-up time ranged from 360 to 1563 days. All animals showed a marked improvement during the postoperative period, and all gained weight gradually. Owners' perception of the surgical procedure outcome and quality of life was described as excellent for all animals. CLINICAL SIGNIFICANCE: Surgical ligation of the lesser aortic arch in dogs and cats with double aortic arch is associated with a favourable prognosis for recovery, resolution of clinical signs, and quality of life with only minor feeding modifications.

Surgical valvulotomy for tricuspid valve stenosis in a dog.

A 2-year, 4-month-old neutered female Labrador retriever was brought for evaluation of right-sided congestive heart failure. Echocardiographic examination revealed tricuspid valve dysplasia with only two small orifices in the valve resulting in severe tricuspid stenosis. The dog underwent a right fifth lateral intercostal thoracotomy and surgical tricuspid valvulotomy, under cardiopulmonary bypass. The stenosis was relieved by dividing the valve leaflets between the two orifices with continuation to the commissures, creating a 'bileaflet' valve. The dog made a good recovery initially, with echocardiography at 48 h after surgery showing a reduction in tricuspid valve E and A wave velocities and pressure half-time (from 230 ms to 65 ms). She was discharged five days after surgery, and spironolactone, benazepril, pimobendan, and clopidogrel were prescribed. The dog was re-presented two days later having collapsed, with pyrexia, facial swelling, and pitting edema on the ventral neck and intermandibular region. Investigations did not reveal an underlying cause, and the clinical signs resolved with supportive therapy. Two years after surgery, the dog was free of clinical signs with normal exercise tolerance and only mild tricuspid regurgitation on echocardiography, with discontinuation of all medications.

Surgical management of chronic otitis secondary to craniomandibular osteopathy in three West Highland white terriers.

Three West Highland white terriers were presented for investigation of left-sided para-aural abscessation. CT revealed chronic otitis media with extensive osseous proliferation surrounding the horizontal and vertical ear canals contiguous with the expanded temporal bone, consistent with a unilateral variant of craniomandibular osteopathy. A left total ear canal ablation with lateral bulla osteotomy was performed in all dogs. An ultrasonic bone curette (Sonopet; Stryker) proved useful when removing the osseous proliferation in two dogs. Histopathological examination of the ear canals was consistent with craniomandibular osteopathy and the treatment led to resolution of the presenting clinical signs in all dogs. To our knowledge, this is the first report of craniomandibular osteopathy engulfing the external ear canal, presumably leading to chronic otitis media and para-aural abscess formation. This is also the first reported use of an ultrasonic bone curette in canine otic surgery.

Surgical management of a cat with hepatic arterioportal fistula.

A 9-month-old domestic short-haired cat presented with stunted growth and chronic gastrointestinal signs. Tachypnoea, a heart murmur and cranial abdominal bruit were detected on physical examination. Echocardiography revealed volume overload in all heart chambers. CT angiography identified an abnormal communication between the hepatic arterial circulation and the portal vein, along with multiple acquired shunts. The abnormal vascular communication was surgically ligated. Echocardiography documented improvement in cardiac parameters following surgery and the cat continues to have no clinical signs 39 months after surgery. This report describes successful surgical management of feline hepatic arterioportal fistula for the first time.

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.

Surgical treatment of pulmonic stenosis in dogs under cardiopulmonary bypass: outcome in nine dogs.

OBJECTIVES: To describe the outcome for nine dogs with pulmonic stenosis treated by open patch grafting using expanded polytetrafluoroethylene under cardiopulmonary bypass. MATERIALS AND METHODS: Data were collected from the hospital records of all dogs that had undergone right ventricular outflow tract grafting with an expanded polytetrafluoroethylene patch under cardiopulmonary bypass between 2006 and 2012 for the treatment of pulmonic stenosis. Echocardiographic images were reviewed and the pressure gradient across the right ventricular outflow tract re-measured. Owners of dogs still alive at the time of writing were invited to return to the hospital for reassessment. RESULTS: Nine dogs met the inclusion criteria. Median pressure gradient preoperatively was 118 mmHg, (range 102 to 259 mmHg) reducing to a median of 20 mmHg (range 7 to 53 mmHg) at 48 hours postoperatively and 14 mmHg (range 10 to 70 mmHg), with a median percentage reduction of 89% (range 41 to 94%) at long-term follow-up. Eight of nine dogs survived surgery, with six of nine surviving to hospital discharge. Two dogs were still alive over 6 and 8 years postoperatively. No long-term deaths were believed to be attributable to pulmonic stenosis. CLINICAL SIGNIFICANCE: Expanded polytetrafluoroethylene patch grafting of the right ventricular outflow tract for treatment of severe pulmonic stenosis in dogs is feasible and can be an effective method to reduce the severity of right ventricular outflow tract obstruction.

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.

Long-term serum bile acid concentrations in 51 dogs after complete extrahepatic congenital portosystemic shunt ligation.

OBJECTIVES: To report the long-term bile acid stimulation test results for dogs that have undergone complete suture ligation of a single congenital extrahepatic portosystemic shunt. MATERIALS AND METHODS: Data were collected from the hospital records of all dogs that had undergone a complete suture ligation of a single congenital extrahepatic portosystemic shunt. Owners were invited to return to the referral centre or their local veterinarian for repeat serum bile acid measurement. Dogs diagnosed with idiopathic epilepsy and undergoing bile acid stimulation tests were used as a comparison population. RESULTS: Fifty-one study dogs were included, with a mean follow-up time of 62 months. 48 dogs had no evidence of multiple acquired shunts and a significant reduction in the pre- and post-prandial serum bile acid concentrations at long-term follow-up compared with pre-operative measurements. Pre- and post-prandial serum bile acids were statistically significantly greater for dogs that had undergone a full ligation (with no evidence of multiple acquired shunts) at all time points compared to the control dogs (P<0·001 for all comparisons). CLINICAL SIGNIFICANCE: The results suggest that in dogs treated with complete suture ligation mild increases in serum bile acids are not clinically relevant if there are no physical examination abnormalities, a normal body condition score and no relapse in clinical signs.

Outcome of bioprosthetic valve replacement in dogs with tricuspid valve dysplasia.

OBJECTIVES: To describe the short-term and long-term outcome in dogs with tricuspid valve dysplasia undergoing tricuspid valve replacement under cardiopulmonary bypass. METHODS: Data were collected from the hospital records of all dogs that had undergone tricuspid valve replacement under cardiopulmonary bypass between 2006 and 2012. Dogs were considered candidates for tricuspid valve replacement if they had severe tricuspid valve regurgitation associated with clinical signs of cardiac compromise. RESULTS: Nine dogs of six different breeds were presented. Median age was 13 months (range 7 to 61 months), median weight 26·5 kg (range 9·7 to 59 kg). Eight bovine pericardial valves and one porcine aortic valve were used. One non-fatal intraoperative complication occurred. Complications during hospitalisation occurred in six dogs, four of which were fatal. Of the five dogs discharged, one presented dead due to haemothorax after minor trauma seven days later. The four remaining dogs survived a median of 533 days; all of these dogs received a bovine pericardial valve. CLINICAL SIGNIFICANCE: Based on our results, tricuspid valve replacement with bovine or porcine prosthetic valves is associated with a high incidence of complications.

Successful treatment of intra-abdominal eumycotic mycetoma caused by Penicillium duponti in a dog.

A 2-year-old female neutered golden retriever was presented for investigation of an intra-abdominal mass. Computed tomography revealed a mass associated with the caudal pole of the right kidney. Incisional biopsy findings were consistent with eumycotic mycetoma. The mass was subsequently removed in conjunction with right ureteronephrectomy. Two years later, the dog re-presented with a splenic mass and fungal plaques located throughout the peritoneum. Splenectomy was performed and the mass was diagnosed as eumycotic mycetoma caused by Penicillium duponti. Indefinite systemic treatment with 10 mg/kg itraconazole orally once a day was initiated. Thirty-two months after the last surgery, there were no clinical signs apart from mild polydipsia. Haematology and biochemistry results were unremarkable. To the authors' knowledge, this is the first report of successful treatment of intra-abdominal eumycotic mycetoma with a combination of surgery and systemic antifungal therapy in the dog. Penicillium duponti has not apparently been reported to cause disease in animals or humans.

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.

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.

Cavitary pulmonary lesion associated with Aspergillus fumigatus infection in a German shepherd dog.

A two-year-old female German shepherd dog was presented with chronic cough and haemoptysis. Thoracic radiographs revealed a thin-walled cavitary lesion within a consolidated left cranial lung lobe. Bronchoalveolar lavage confirmed a concurrent bacterial infection; however, despite antibiotic and anthelmintic therapy the clinical signs failed to resolve. A left cranial lung lobectomy was performed. Histopathology and fungal culture confirmed the presence of Aspergillus fumigatus. The necrotic cavity had features compatible with a bronchial origin, possibly a form of cystic bronchiectasis, arising either as a congenital anomaly or acquired secondary to infection. Surgery provided resolution of clinical signs for just over a year before the dog deteriorated again and was subsequently euthanised. Necropsy was declined by the owners. This case report presents a unique presentation in which the predominant clinical sign was coughing due to pulmonary involvement. Aspergillus fumigatus was isolated from the left cranial lung lobe.

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.

Congenital oesophageal stricture in a Japanese shiba inu.

An 11-week-old, female, Japanese shiba inu, weighing 1.3 kg, was presented with a history of intermittent regurgitation since birth. An oesophagram showed a partial obstruction of the caudal cervical oesophagus associated with a narrow, transverse tissue band. Following surgical resection, the regurgitation resolved and the dog attained a normal bodyweight. Histological examination revealed focally hyperplastic epithelium with dense fibrous underlying connective tissue forming the band. The diagnosis was a congenital oesophageal stricture.

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.

Double chambered right ventricle in 9 cats.

BACKGROUND: Double-chambered right ventricle (DCRV) is a frequently recognized cardiac congenital abnormality in humans. It has been described in dogs and in 1 cat. However systemic description of clinical and echocardiographic features of the disease in cats is currently lacking from the veterinary literature. ANIMALS: Nine cats with DCRV are described. RESULTS: The cats ranged from 4 months to 10 years of age. Eight cats at presentation were asymptomatic and 1 cat had chylothorax. In all cases echocardiography revealed abnormal fibromuscular bundles obstructing the mid-right ventricle, dividing the chamber into 2 compartments. The proximal right ventricular compartment was markedly hypertrophied, and right atrial dilation was usually present. The mean pressure gradient measured across the stenotic area was 130 +/- 50 mm Hg. Concurrent abnormalities included a ventricular septal defect (n = 2); aortic malalignment, aortic insufficiency (n = 1); and congenital peritoneal-pericardial diaphragmatic hernia (n = 1). Two cats had systolic anterior motion of the mitral valve, one of which had concurrent left ventricular hypertrophy. Five cats have remained asymptomatic for a median period of 3.6 years (range, 3.3-5 years) and 3 cats have developed clinical signs associated with congestive heart failure (at 2, 3.3, and 9 years). One cat showed progressive lethargy and exercise intolerance and underwent partial ventriculectomy at the age of 2 years. This cat died during the operation with electromechanical dissociation. CONCLUSIONS: DCRV is a congenital cardiac abnormality that may be more common than previously recognized.

Post-Translational Modifications of the P2X(4) purinergic receptor subtype in the human placenta are altered in preeclampsia.

P2X(4) receptors are activated by extracellular ATP to raise intracellular calcium, thus altering cell signalling. ATP release occurs under pathophysiological, stress and adverse cell conditions; these are all increased in preeclampsia. Although P2X(4) is abundantly expressed in normal placenta neither the differences in the amount of protein nor its post-translational modifications have been studied in placentae from pregnancies complicated by preeclampsia. Thus we examined P2X(4) protein expression, localization and post-translational modifications in normotensive controls, term and preterm preeclamptic placentae. Densitometric analysis of Western blots showed a significant increase in P2X(4) protein expression in both term (p=0.002) and preterm preeclamptic (p=0.0008) placental samples compared to normotensive controls however the tissue localization of this receptor subtype was unaltered across the groups. Our data showed that P2X(4) is a nitrated protein in the placenta and this nitration is upregulated in preterm preeclamptic placenta compared to normotensive controls (p=0.03). We also demonstrated that P2X(4) is heavily glycosylated in the placenta by deglycosylation with PNGase F which reduced the protein product size by 23 kDa. We propose that P2X(4) acts within the syncytiotrophoblast to alter intracellular calcium and subsequent signalling pathways thereby restoring placental cell homeostasis following ATP-induced changes during pathophysiological conditions such as preeclampsia. We also propose that the post-translational modifications of nitration and glycosylation are required for the normal functioning of P2X(4).