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.

Transvalvular pulmonic stent angioplasty: procedural outcomes and complications in 15 dogs with pulmonic stenosis.

INTRODUCTION: Balloon valvuloplasty is the treatment of choice for dogs with severe type A pulmonic stenosis (PS), but less successful for dogs with annular hypoplasia and unsuitable for supravalvular stenosis or cases with a circumpulmonary coronary malformation. We report outcomes and complications of the first 15 consecutive transvalvular pulmonic stent angioplasty procedures performed by a single center in dogs with PS. ANIMALS: Fifteen dogs with naturally occurring PS were included in the study. MATERIALS AND METHODS: Dogs underwent echocardiography before and four weeks after the procedure. Transvenous approaches were used to deploy a pre-mounted, balloon-expandable metallic stent in all cases. RESULTS: Of 15 dogs, all had annular hypoplasia, and in addition, supravalvular stenosis was diagnosed in 11 of 15 dogs, and three had R2A coronary malformation. All dogs survived to discharge. One dog died less than four weeks postoperatively (non-cardiac), but 14 of 15 dogs were re-examined at four weeks. Severity reduced in all cases; median pressure gradient reduced from 137 mmHg (range 81-202 mmHg) to 83 mmHg (range 31-155 mmHg). Clinical signs improved in all cases, and hematocrit reduced in all dogs with erythrocytosis. The median follow-up time was 280 days (range 95-896 days). Over one-year follow-up was available in six of fifteen dogs. Two dogs died because of refractory right-sided congestive heart failure signs: one at 10 months and one at 22 months postoperatively. CONCLUSIONS: Transvalvular pulmonic stent angioplasty technique was associated with an improvement in clinical signs and reduction in stenosis severity for all dogs in this population, including cases with supravalvular PS or circumpulmonary coronary malformation.

Long-term clinical outcomes following surgery for spontaneous pneumothorax caused by pulmonary blebs and bullae in dogs - a multicentre (AVSTS Research Cooperative) retrospective study.

OBJECTIVES: To report the clinical characteristics and recurrence rate of spontaneous pneumothorax secondary to pulmonary blebs and bullae following surgical management in a large cohort of dogs. To explore potential risk factors for recurrence and describe outcome. MATERIALS AND METHODS: Medical records were retrospectively reviewed for cases with spontaneous pneumothorax managed surgically between 2000 and 2017. Signalment, clinical presentation, diagnostic imaging, surgery, histopathology findings and patient outcomes were recorded. Follow-up was performed via patient records and telephone contact. RESULTS: Records of 120 dogs with surgically treated pneumothorax were identified and reviewed, with 99 cases appropriate for exploratory statistical analysis. Median follow-up was 850 days (range: 9-5105 days). Two- and 5-year survival rates were 88.4% and 83.5%, respectively. There was recurrence in 14 of 99 dogs (14.1%) with adequate follow-up, with a median time to recurrence of 25 days (1-1719 days). Univariable Cox regression analysis suggested increased risk for recurrence in giant breeds (hazard ratio = 11.05, 95% confidence interval: 2.82-43.35) and with increasing bodyweight (HR = 1.04, 95% confidence interval: 1.00-1.09). Of 14 dogs with recurrence, six were euthanased, two died of causes related to pneumothorax and six underwent further treatment, of which five were resolved. CLINICAL SIGNIFICANCE: Long-term survival for dogs with surgically managed spontaneous pneumothorax was good and associated with a low risk of recurrence. Giant breed dogs and increased bodyweight were the only variables identified as possible risk factors for recurrence. The outcome for dogs with recurrence undergoing a second intervention was also favourable.

Surgical management of impalement injuries to the trunk of dogs: a multicentre retrospective study.

OBJECTIVES: To review a large series of dogs referred for treatment of traumatic impalement injuries to the thorax and/or abdomen and to report aetiologies, injury characteristics, management and long-term outcomes. MATERIALS AND METHODS: Previously collected data on dogs that were surgically treated for impalement injuries to the trunk at six veterinary specialist referral institutions in the UK over an 11-year period were reviewed. Data included patient signalment, physiological variables, injury-specific variables, diagnostic imaging reports, surgical procedures undertaken, duration of hospitalisation, antibiotic use, complications and outcomes. Data were reported with summary statistics. RESULTS: Fifty-four dogs were included. Impalement occurred most frequently on wooden objects (n=34), and the thoracic cavity was most commonly penetrated (n=37). Computed tomography was sensitive and specific to identifying wooden material in 64% and 88% of cases (n=11), respectively. Thoracotomy was performed in 56%, coeliotomy in 20% and a foreign body or its fragments were retrieved during surgery in 37% of the cases. Complications occurred in 19 dogs (35%), and of these, 68% were minor and 32% major. The survival rate for thoracotomy cases was 93% (n=30). Overall long-term survival was 90%. CLINICAL SIGNIFICANCE: Despite the often dramatic presentation of impalement injuries, the majority of patients treated in the specialist referral setting can achieve excellent outcomes. These injuries require thorough diagnostic imaging and interpretation before adequate surgical exploration and management, augmented by anaesthesia and critical care during the peri- and postoperative periods; therefore stable patients should be referred to centres able to provide this type of care.

Outcome of reconstruction of cutaneous limb defects in dogs using hygroscopic "self-inflating" tissue expanders.

OBJECTIVES: To describe the placement of self-inflating tissue expanders and clinical outcomes in 12 consecutive cases of reconstruction of distal cutaneous limb defects in dogs. MATERIALS AND METHODS: Cases of distal cutaneous limb defect were divided into three groups based on the location of the placement of the self-inflating tissue expanders: Group A (n=4): on, or proximal to, the elbow and stifle; Group B (n=4): distal to the elbow or stifle and proximal to the carpus or tarsus; and Group C (n=4): distal to the carpus or tarsus. Owner satisfaction and clinical outcome were documented. RESULTS: Thirteen cases were originally included, but one was excluded because of incomplete follow-up. In one case, the self-inflating tissue expanders were removed before expansion started. A mean of five expanders were implanted per dog (range 2 to 9). Devices were removed after a mean of 24 days (range 13 to 42 days). Primary closure was achieved in eight of 11 cases, including all cases from Group A and 75% and 33% of cases from Groups B and C, respectively. All incompletely reconstructed defects or areas of wound dehiscence healed by second intention. Eight of 12 owners were satisfied. CLINICAL SIGNIFICANCE: Self-inflating tissue expanders can be used as an alternative for the reconstruction of limb defects in dogs in which direct primary closure would otherwise not be achievable. Defects below the carpus and tarsus are more challenging to treat with this method.

Unilateral absence of the right pulmonary artery with associated aortopulmonary collaterals and bullous lung lesions in a dog.

This case report describes a combination of congenital cardiopulmonary abnormalities found in a 1-year-old Labrador Retriever. To the authors' knowledge this combination of cardiopulmonary abnormalities has not been previously reported in veterinary medicine. Unilateral absence of the right pulmonary artery associated with unilateral right-sided aortopulmonary collaterals was observed. These aortopulmonary collaterals preserved the blood supply to the right lung lobes but led to left ventricular volume overload. There was also evidence of severe bullous lung disease in the right lung, which was suspected to be secondary to pulmonary sequestration as a result of the anomalous hemi-pulmonary circulation. The diagnosis of left-sided volume overload was achieved by radiography and echocardiography while the remainder of the findings was diagnosed on computed tomography angiography. The owner refused surgery for occlusion of the shunting vessels and therapy at standard doses of benazepril, spironolactone and pimobendan was initiated. In spite of the severe volume overload, the dog remained stable with static non-progressive clinical signs and stable echocardiographic findings at 1-year follow-up. The case report also acts as a reminder of the possible occurrence of unusual extra-cardiac shunts in the presence of an unexplained left ventricular volume overload.

Outcome After Pneumonectomy in 17 Dogs and 10 Cats: A Veterinary Society of Surgical Oncology Case Series.

OBJECTIVE: To report the signalment, presenting clinical signs, surgical complications, histologic diagnosis, postoperative complications, and outcome of dogs and cats undergoing pneumonectomy. STUDY DESIGN: Retrospective case series; multicenter study. ANIMALS: Client-owned dogs (n=17) and cats (n=10). METHODS: Signalment, clinical signs, side affected, surgical data, preoperative diagnostic tests (including complete blood count, serum biochemistry, cytologic diagnosis, chest radiographs, and computed tomography), histologic diagnosis, surgical complications, adjunctive therapy, and date and cause of death were collected from records of dogs and cats that underwent pneumonectomy. Survival estimates and complication were assessed. RESULTS: Seventeen animals had a left-sided pneumonectomy performed (12 dogs, 5 cats) and 10 animals had a right-sided pneumonectomy (5 dogs, 5 cats). Fourteen animals were diagnosed with neoplasia (52%). The overall incidence of complications for dogs and cats were 76 and 80%, respectively, with major complications in 41 and 50%, respectively. Respiratory complications (persistent pleural effusion, oxygen dependence, persistent increased respiratory rate, or coughing) were the most frequent complications. No animals died or were euthanatized intraoperative or within the first 24 hours postoperative. One dog (6%) and 2 cats (20%) died, or were euthanatized in the first 2 weeks postoperative. CONCLUSION: Based on this case series, right and left pneumonectomy can be performed with low perioperative mortality in dogs and cats, with some animals experiencing prolonged survival.

Comparison of postoperative complications in healthy dogs undergoing open and closed orchidectomy.

OBJECTIVE: To compare closed and open orchidectomy in dogs and the associated complications. METHODS: A randomised controlled blinded prospective clinical study of 73 cases was undertaken involving the recording of all complications during and in the 10 days following orchidectomy of dogs fulfilling the standardised inclusion criteria. The active variable was the surgical technique of either open or closed orchidectomy. RESULTS: Dogs undergoing open orchidectomy experienced significantly more complication events than the dogs undergoing closed orchidectomy [24 of 34 (70%) versus 18 of 39 (46%), P = 0 · 04]. Dogs undergoing open orchidectomy were statistically more likely to develop scrotal complications (21 of 34, 61%) compared with dogs undergoing closed orchidectomy (13 of 39, 33%; P = 0 · 02). CLINICAL SIGNIFICANCE: Open orchidectomy is associated with a higher overall complication rate in the first 10 days after surgery than closed orchidectomy. Open orchidectomy is also associated with increased scrotal complications including swelling, bruising and pain compared with closed orchidectomy.

Use of negative contrast computed tomography for diagnosis of a colonic duplication in a dog.

A 24-week-old dog was presented with recurrent rectal prolapse because of colonic duplication. Colonic duplication is an extremely uncommon congenital abnormality, with only six cases reported in veterinary medicine, one diagnosed at necropsy and five after barium enema, colonoscopy, abdominal ultrasound, exploratory laparotomy either alone or in combination. In this case, these techniques failed to identify the abnormality and diagnosis was ultimately achieved via negative contrast computed tomography. The evaluation generated by the computed tomography images allowed a refined surgical approach. To the authors' knowledge, negative contrast computed tomography has not yet been reported in the veterinary literature to diagnose gastrointestinal pathologies. Colonic duplication in this case was treated by removal of the intercolonic septum via colotomy.

Static hydraulic urethral sphincter for treatment of urethral sphincter mechanism incompetence in 11 dogs.

OBJECTIVE: To review the postoperative results and complications associated with urethral sphincter mechanism incompetence managed with a static hydraulic urethral sphincter. METHODS: Case records and a telephone owner questionnaire were retrospectively used to assess postoperative urinary continence scores (1 - dripping constantly to 10 - completely dry) and presence and frequency of complications. RESULTS: Eleven spayed females were included. Median continence score/10 (range) awarded preoperatively was 3 (2 to 6), and scores at two weeks, three and six months were 8 (4 to 10), 9 (4 to 10) and 8 (4 to 10), respectively. At the last survey, the median continence score of 9 (5 to 10) was significantly better (P=0·004) than before surgery. Complete continence was achieved in 36·4% of dogs. The median (range) follow-up time was 412 (118 to 749) days. Complications occurred in 9 of 11 dogs and included dysuria (n=7), bacterial cystitis (n=7), longer urination time (n=8), urinary retention (n=3), haematuria (n=1), pain (n=3) and incisional seroma (n=3). CLINICAL SIGNIFICANCE: Static hydraulic urethral sphincter was frequently associated with minor complications but no major complications (i.e. those requiring further surgery). Continence scores were significantly improved compared with those before surgery, with the possibility of further improvement following inflation of the sphincter.

Mechanical comparison of median sternotomy closure in dogs using polydioxanone and wire sutures.

OBJECTIVES: To compare the mechanical properties of two different materials for canine median sternotomy closure. STUDY DESIGN: In vitro biomechanical study. SAMPLE POPULATION: Twelve canine cadaveric entire sternum and portion of associated ribs and musculature. METHODS: Median sternotomy leaving the manubrium intact was closed using polydioxanone and stainless steel wire in a figure of eight pattern. Constructs were loaded in a servohydraulic material testing system and displacement was compared at loads of 125, 150, 200, 250, 300, 350 and 400 N, and at failure. RESULTS: Displacement at loads up to 400 N and failure did not show any statistical difference between the polydioxanone and the stainless steel wire. However, the loading forces to create failure of the construct were superior for the stainless steel. Polydioxanone and stainless steel wire had the same response to distractive forces for loads applied up to 400 N. CLINICAL SIGNIFICANCE: This study cannot recommend the use of polydioxanone over wires but suggests that polydioxanone can potentially be an alternative for primary median sternotomy closure in selected patients.

Complex extrahepatic portocaval shunt with unusual caval features in a cat: computed tomographic characterisation.

A two-year-old, neutered male domestic shorthair cat was evaluated for a history of urate calculi, and neurologic signs. Diagnostic imaging revealed an elongated and tortuous single extrahepatic portosystemic shunt which appeared to receive normal tributaries of the caudal vena cava. Surgical correction of the shunt was carried out using cellophane banding. Eight months following surgery, clinical signs had resolved. Computed tomographic angiography allows thorough, rapid imaging of complex vascular anomalies to aid proper surgical correction. Errors in the formation of the portal vein and caudal vena cava can produce complex anomalies of the abdominal vasculature. Persistence of the embryologic left subcardinal vein is proposed to account for the lesion.

Transient tricuspid valve regurgitation following surgical treatment of cor triatriatum dexter in a dog.

Echocardiographically documented tricuspid valve regurgitation appeared immediately after surgical treatment of cor triatriatum dexter in a two-month-old rottweiler. Medical treatment was instituted with benazepril, spironolactone and furosemide. Pimobendan was added after five months, and all treatment was discontinued two months later when clinical signs of ascites and hepatomegaly had resolved and tricuspid valve regurgitation was markedly reduced on echocardiography. To the authors' knowledge, this is the first report describing the development and spontaneous improvement of haemodynamically significant tricuspid valve regurgitation following surgical treatment of cor triatriatum dexter in a dog. It is hypothesised that the increase in right atrial volume and pressure following cor triatriatum dexter repair and transient ischaemia of papillary muscles led to dilatation of the right atrioventricular annulus and subsequent severe tricuspid valve regurgitation in the face of an anatomically normal valve. Time and pharmacological preload reduction as well as normalisation of right atrial inflow and subsequent cardiac remodelling substantially reduced tricuspid valve regurgitation and eliminated clinical signs of heart failure. It is also possible that heart recovery has been spontaneous.

Influence of anaesthesia on canine hip dysplasia score.

Hip dysplasia (HD) scores, based on the five grades, as defined by the Fédération Cynologique Internationale, were compared between anaesthetized (group 1, n = 3839) and non-sedated non-anaesthetized dogs (group 2, n = 1517). Each dog was radiographed in the standard ventro-dorsal hip joint extended position. Each radiograph was evaluated by the same reader blinded regarding the dog's status of anaesthesia. Results showed that there was a significant difference in hip dysplasia prevalence between group 1 (22%) compared with group 2 (9%) (P < 0.005). This difference was the result of a lower rate of hip-joint laxity assessment and the measurement of Norberg-Olsson angle <105 degrees in group 2 compared with group 1. The acetabular and femoral morphologies were not significantly different between the groups. The data confirm that the scoring of dogs for HD on standard radiographs with the hip joints extended is influenced by anaesthesia.

Bilothorax following cholecystectomy in a dog.

A 10-year-old, entire female Pyrenean shepherd dog was presented for acute onset of gastroenteritis. An abdominal ultrasound examination showed the presence of a suspected gall bladder mucocele. After surgery for cholecystectomy, the dog showed signs of an acute onset of respiratory distress due to bilothorax. The bilothorax responded well to medical treatment that comprised of thoracocentesis and oral steroids.

Exercise does not induce major changes in plasma muscle enzymes, creatinine, glucose and total proteins concentrations in untrained beagle dogs.

Changes in plasma creatinine (Pl-Creat), glucose, total proteins (Pl-TP), creatine kinase (Pl-CK), lactate dehydrogenase, aspartate aminotransferase and packed cell volume were evaluated in untrained Beagle dogs before, during and after a 60 min race at an average speed of 9 km/h. There was no major effect of exercise on those parameters except, when phases are compared, a slight increase of Pl-TP during exercise (max. + 6.4%), a moderate but after exercise (delayed increase of Pl-CK max. + 245%) and a slight decrease of Pl-Creat after exercise (max. -9.6%). It was therefore concluded that strenuous exercise in sedentary dogs did not induce major variations in any of routine plasma variables measured and would not lead to clinically relevant misinterpretation. However, for Pl-CK, the interpretation of repeated measures may be misleading if two samples are collected in the same animal before and after exercise.

Comparison of ultrasonography and pharmacokinetic analysis of creatine kinase release for quantitative assessment of postinjection muscle damage in sheep.

OBJECTIVES: To investigate and validate noninvasive methods for the quantitative evaluation of postinjection muscle damage. ANIMALS: 5 adult sheep. PROCEDURES: Muscle lesions were induced twice in the lumbar region of the longissimus dorsi muscles (2 sides) by IM administration of a 20% formulation of long-acting oxytetracycline (20 mg/kg of body weight). Clinical signs and local cutaneous temperature above the injection site were recorded. Muscle lesions were quantitatively evaluated by ultrasonography and by use of pharmacokinetic analysis of plasma creatine kinase activity, and both were compared with a comprehensive planimetric computer-assisted analysis of the injection sites after euthanasia. RESULTS: Transient cutaneous hypothermia (temperature change, -3.9+/-0.62 C) and subsequent persistent hyperthermia (3.1+/-1.35 C) were observed after the administrations. Despite coefficient of variation < 10% for precision of ultrasonographic measurement of normal muscle, measurements of the lesions, with coefficient of variation > 60% for precision, were systematically underestimated. Quantitative evaluation of muscle damage by use of pharmacokinetic analysis of creatine kinase (12.1+/-4.96 g) was in agreement with results of macroscopic planimetric evaluation (10.8+/-3.64 g). CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasonography cannot be used for quantitative assessment of postinjection muscle damage. Pharmacokinetic analysis of creatine kinase provides an accurate quantitative evaluation of macroscopic muscle damage after IM administration of drugs.

Use of plasma creatine kinase pharmacokinetics to estimate the amount of excercise-induced muscle damage in Beagles.

OBJECTIVE: To assess the effects of moderate exercise on plasma creatine kinase (CK) pharmacokinetics and to estimate exercise-induced muscle damage in dogs. ANIMALS: 6 untrained adult Beagles. PROCEDURE: The study was divided into 3 phases. In phase 1, dogs ran for 1 hour at a speed of 9 km/h, and samples were used to determine the area under the plasma CK activity versus time curve (AUC) induced by exercise. In phases 2 and 3, pharmacokinetics of CK were calculated in dogs during exercise and at rest, respectively. Values for AUC and plasma clearance (CI) were used to estimate muscle damage. RESULTS: At rest, values for Cl, steady-state volume of distribution (Vdss), and mean retention time (MRT) were 0.32+/-0.02 ml/kg of body weight/min, 57+/-173 ml/kg, and 3.0+/-0.57 h, respectively. During exercise, Cl decreased significantly (0.26+/-0.03 ml/kg/min), MRT increased significantly, (4.4+/-0.97 h), and Vdss remained unchanged. Peak of plasma CK activity (151+/-58.8 U/L) was observed 3 hours after completion of exercise. Estimated equivalent amount of muscle corresponding to the quantity of CK released was 41+/-29.3 mg/kg. CONCLUSION AND CLINICAL RELEVANCE: These results revealed that exercise had a minor effect on CK disposition and that the equivalent amount of muscle damaged by moderate exercise was negligible. This study illustrates the relevance for use of the minimally invasive and quantitative pharmacokinetic approach when estimating muscle damage.