Improved owner quality of life following surgical repair of canine myxomatous mitral valve disease.

OBJECTIVE: To determine quality-of-life changes in owners of dogs undergoing mitral valve repair for myxomatous mitral valve disease, up to 12 months postoperatively. SAMPLE: Owners of 26 dogs undergoing mitral valve repair at a single UK veterinary referral hospital. METHODS: Dogs underwent mitral valve repair under cardiopulmonary bypass as previously described. Owner quality of life was assessed by self-completion of a previously validated questionnaire preoperatively and at 1, 3, 6, and 12 months postoperatively. RESULTS: There was a statistically significant improvement in quality-of-life scores from preoperatively up to 3 months postoperatively and a statistically significant improvement in individual question scores up to 6 months postoperatively. CLINICAL RELEVANCE: Results suggested that owner quality of life is significantly improved following surgical repair of their pet's myxomatous mitral valve disease, and this improvement continues beyond the immediate postoperative period. These results may be useful when counseling owners of surgical candidates and is another useful outcome measure.

Mitral Valve Repair-The Development and Rise of Options in the Veterinary World.

Both open surgical repair and a hybrid-interventional option are now available for mitral valve repair (MVR) at select veterinary centers worldwide, making the need for awareness of options and the intricacies around case selection of increasing importance. This article will overview both options currently available and their current stages of progress.

Immunohistochemical characteristics of local sites that trigger atrial arrhythmias in response to high-frequency stimulation.

AIMS: The response to high frequency stimulation (HFS) is used to locate putative sites of ganglionated plexuses (GPs), which are implicated in triggering atrial fibrillation (AF). To identify topological and immunohistochemical characteristics of presumed GP sites functionally identified by HFS. METHODS AND RESULTS: Sixty-three atrial sites were tested with HFS in four Langendorff-perfused porcine hearts. A 3.5 mm tip quadripolar ablation catheter was used to stimulate and deliver HFS to the left and right atrial epicardium, within the local atrial refractory period. Tissue samples from sites triggering atrial ectopy/AF (ET) sites and non-ET sites were stained with choline acetyltransferase (ChAT) and tyrosine hydroxylase (TH), for quantification of parasympathetic and sympathetic nerves, respectively. The average cross-sectional area (CSA) of nerves was also calculated. Histomorphometry of six ET sites (9.5%) identified by HFS evoking at least a single atrial ectopic was compared with non-ET sites. All ET sites contained ChAT-immunoreactive (ChAT-IR) and/or TH-immunoreactive nerves (TH-IR). Nerve density was greater in ET sites compared to non-ET sites (nerves/cm2: 162.3 ± 110.9 vs. 69.65 ± 72.48; P = 0.047). Overall, TH-IR nerves had a larger CSA than ChAT-IR nerves (µm2: 11 196 ± 35 141 vs. 2070 ± 5841; P < 0.0001), but in ET sites, TH-IR nerves were smaller than in non-ET sites (µm2: 6021 ± 14 586 vs. 25 254 ± 61 499; P < 0.001). CONCLUSIONS: ET sites identified by HFS contained a higher density of smaller nerves than non-ET sites. The majority of these nerves were within the atrial myocardium. This has important clinical implications for devising an effective therapeutic strategy for targeting autonomic triggers of AF.

Prospective evaluation of novel biomarkers of acute kidney injury in dogs following cardiac surgery under cardiopulmonary bypass.

OBJECTIVE: To assess the occurrence of acute kidney injury (AKI) in dogs undergoing cardiac surgery under cardiopulmonary bypass (CPB) and explore associations between traditional and novel serum and urinary biomarkers. DESIGN: Prospective cohort study conducted between July 2018 and April 2019. SETTING: University teaching hospital. ANIMALS: Nineteen dogs undergoing cardiac surgery under CPB with preoperative serum creatinine <140 µmol/L (<1.6 mg/dl). INTERVENTIONS: Blood and urine samples were obtained at 4 time points: preoperatively following general anesthesia induction, immediately postoperatively, and 2 and 4 days postoperatively (T1 , T2 , T3 , and T4 ). AKI was defined as an increase in serum creatinine ≥26.4 µmol/L (≥0.3 mg/dl) above baseline within 48 hours. Serum creatinine, C-reactive protein (CRP), symmetric dimethylarginine (SDMA), inosine, beta-aminoisobutyric acid (BAIB), urinary clusterin (uClus), and urinary cystatin B (uCysB) were measured. Data were log-transformed (log10 ) when appropriate and assessed using linear mixed-effects models. MEASUREMENTS AND MAIN RESULTS: AKI occurred in 3 of 19 dogs (15.8%, 95% confidence interval: 0.047-0.384). Inosine increased at T2 (adjusted mean ± standard error: 53 ± 5.6) in all dogs, and then gradually decreased. Log10 uCysB increased at T2 (2.3 ± 0.1) in all dogs and remained high. Log10 CRP and log10 uClus increased significantly at T3 (1.9 ± 0.1 and 3.6 ± 0.1, respectively) in all dogs and remained increased. There was a significant positive association between serum creatinine and SDMA (P < 0.001, estimate ± standard error: 0.06 ± 0.00), between log10 CRP and log10 uClus (P < 0.001, 0.35 ± 0.08), between SDMA and creatinine as well as between SDMA and BAIB (P < 0.001, 11.1 ± 0.83 and P < 0.001, 1.06 ± 0.22, respectively) for all dogs at all time points. CONCLUSIONS: Inosine and uCysB concentrations changed in all dogs immediately following a surgery under CPB and may indicate tubular injury. Further studies are required to ascertain the usefulness of those biomarkers in early detection of AKI.

Use of the Functional Evaluation of Cardiac Health questionnaire to assess health-related quality of life before and after mitral valve repair in dogs with myxomatous mitral valve disease.

OBJECTIVE: To determine changes in health-related quality of life up to 12 months after surgery in dogs with myxomatous mitral valve disease that undergo mitral valve repair. ANIMALS: 54 dogs that underwent mitral valve repair at a United Kingdom referral hospital. PROCEDURES: Health-related quality of life was assessed with a previously validated, owner-completed questionnaire before and 1, 3, 6, and 12 months after surgery. Results: There was a significant decrease in total score (corresponding to reduced negative impact of cardiac disease on quality of life) between the preoperative timepoint and all postoperative timepoints. A significant decrease in total score was also demonstrated between the 1- and 3-month timepoints, but no additional significant changes in total score between adjacent timepoints were identified beyond 3 months after surgery. Significant improvements in individual question scores were found up to 12 months after surgery. CLINICAL RELEVANCE: Health-related quality of life was significantly improved following mitral valve repair in dogs with myxomatous mitral valve disease and this improvement persisted for up to a year after surgery. These results may be useful when counseling owners of dogs considered candidates for this procedure.

Complications associated with and outcome of surgical intervention for treatment of esophageal foreign bodies in dogs.

OBJECTIVE: To identify complications associated with and short- and long-term outcomes of surgical intervention for treatment of esophageal foreign bodies (EFBs) in dogs. ANIMALS: 63 client-owned dogs. PROCEDURES: Patient records from 9 veterinary hospitals were reviewed to identify dogs that underwent surgery for removal of an EFB or treatment or an associated esophageal perforation between 2007 and 2019. Long-term follow-up data were obtained via a client questionnaire. RESULTS: 54 of the 63 (85.7%) dogs underwent surgery after an unsuccessful minimally invasive procedure or subsequent evidence of esophageal perforation was identified. Esophageal perforation was present at the time of surgery in 42 (66.7%) dogs. Most dogs underwent a left intercostal thoracotomy (37/63 [58.7%]). Intraoperative complications occurred in 18 (28.6%) dogs, and 28 (50%) dogs had a postoperative complication. Postoperative complications were minor in 14 of the 28 (50%) dogs. Dehiscence of the esophagotomy occurred in 3 dogs. Forty-seven (74.6%) dogs survived to discharge. Presence of esophageal perforation preoperatively, undergoing a thoracotomy, and whether a gastrostomy tube was placed were significantly associated with not surviving to discharge. Follow-up information was available for 38 of 47 dogs (80.9%; mean follow-up time, 46.5 months). Infrequent vomiting or regurgitation was reported by 5 of 20 (25%) owners, with 1 dog receiving medication. CLINICAL RELEVANCE: Results suggested that surgical management of EFBs can be associated with a high success rate. Surgery should be considered when an EFB cannot be removed safely with minimally invasive methods or esophageal perforation is present.

Arteriovenous Malformation of the Tongue Resulting in Recurrent Severe Hemorrhage in a Young Dog.

An 8 mo old male entire beagle was presented to the emergency and critical care service following several severe bleeding episodes from the oral cavity. Oral examination revealed a purple, spongy, pulsatile lesion on the rostral two-thirds of the tongue. Computed tomography angiography revealed a severely distended right linguofacial vein with numerous, tortuous branching vessels within the tongue, consistent with an arteriovenous (AV) malformation. A cervical surgical approach was performed, and the right lingual artery was isolated and catheterized. A direct arteriogram confirmed this was the main feeder artery to the lesion, and it was ligated. Although the bleeding episodes initially resolved, a moderate bleeding episode occurred 6 days postoperatively, and a partial glossectomy was performed. Histopathology was consistent with an AV malformation. The dog had a good recovery from surgery and remains free of clinical signs 13 mo later. Following extensive review of the veterinary literature, this is the only reported case of a lingual AV malformation in the dog. Partial glossectomy resulted in resolution of the clinical signs and was well tolerated. Although rare, AV malformations should be considered as a differential diagnosis for spontaneous oropharyngeal bleeding.

Development of a pro-arrhythmic ex vivo intact human and porcine model: cardiac electrophysiological changes associated with cellular uncoupling.

We describe a human and large animal Langendorff experimental apparatus for live electrophysiological studies and measure the electrophysiological changes due to gap junction uncoupling in human and porcine hearts. The resultant ex vivo intact human and porcine model can bridge the translational gap between smaller simple laboratory models and clinical research. In particular, electrophysiological models would benefit from the greater myocardial mass of a large heart due to its effects on far-field signal, electrode contact issues and motion artefacts, consequently more closely mimicking the clinical setting. Porcine (n = 9) and human (n = 4) donor hearts were perfused on a custom-designed Langendorff apparatus. Epicardial electrograms were collected at 16 sites across the left atrium and left ventricle. A total of 1 mM of carbenoxolone was administered at 5 ml/min to induce cellular uncoupling, and then recordings were repeated at the same sites. Changes in electrogram characteristics were analysed. We demonstrate the viability of a controlled ex vivo model of intact porcine and human hearts for electrophysiology with pharmacological modulation. Carbenoxolone reduces cellular coupling and changes contact electrogram features. The time from stimulus artefact to (-dV/dt)max increased between baseline and carbenoxolone (47.9 ± 4.1-67.2 ± 2.7 ms) indicating conduction slowing. The features with the largest percentage change between baseline and carbenoxolone were fractionation + 185.3%, endpoint amplitude - 106.9%, S-endpoint gradient + 54.9%, S point - 39.4%, RS ratio + 38.6% and (-dV/dt)max - 20.9%. The physiological relevance of this methodological tool is that it provides a model to further investigate pharmacologically induced pro-arrhythmic substrates.

Heterozygosity for P2Y12 receptor gene mutation associated with postoperative hemorrhage in a Greater Swiss Mountain dog.

A 3-year-old, female Greater Swiss Mountain dog developed a hemoperitoneum following an exploratory laparotomy and ovariohysterectomy. Platelet count, PT, APTT, and plasma von Willebrand factor antigen concentration were within RIs. A buccal mucosal bleeding time (BMBT) was prolonged. Given the probability of a hereditary thrombopathia, the dog was administered desmopressin, fresh platelet transfusions, and aminocaproic acid to control hemorrhage. Subsequently, DNA testing for the P2Y12 receptor gene mutation identified the dog as being a heterozygote (carrier). Further platelet function testing was performed following complete recovery. Results of a repeat BMBT and a point-of-care screening test using the Platelet Function Analyzer-100 (collagen/adenosine-diphosphate [ADP] test cartridge) were within RIs. Flow cytometric studies demonstrated a marked reduction in fibrinogen binding to the dog's platelets in response to ADP - adenosine diphosphate activation. Likewise, turbidimetric aggregometry revealed a complete absence of platelet aggregation in response to ADP. However, there were a normal aggregation response to the platelet agonist convulxin and a mild reduction in amplitude in response to γ-thrombin. This is the first report of a dog heterozygous for the P2Y12 receptor gene mutation exhibiting a bleeding tendency and having evidence of impaired platelet function in vitro in response to ADP activation. Given that the mutant allele for the P2Y12 thrombopathia appears to be widespread in the Greater Swiss Mountain dog breed, veterinarians need to be aware that both homozygotes and heterozygotes for this platelet receptor mutation are at risk of developing life-threatening bleeding following trauma or surgery.

Clinical comparison of the hybrid dynamic compression plate and the castless plate for pancarpal arthrodesis in 219 dogs.

OBJECTIVE: To describe and compare a large population of dogs that had pancarpal arthrodesis (PCA) using either a hybrid dynamic compression plate (HDCP) or a CastLess Plate (CLP). STUDY DESIGN: Multicenter, retrospective, cohort study. ANIMALS: Dogs (n = 240; 261 PCA). METHODS: Medical records (2000-2012) from 12 UK orthopedic centers were reviewed for dogs that had PCA to document signalment, diagnosis, arthrodesis method, and complication rates. Follow-up data were used to compare outcome (lameness evaluation and radiographic healing) after use of HDCP and CLP plates. RESULTS: PCA was performed with HDCP in 125 cases, CLP in 105, and by other techniques in 31. Carpal hyperextension injury was the most common diagnosis in HDCP and CLP groups. Surgical site infection (18.3%) was the most common postoperative complication. There was no difference in intra- (11% HDCP, 21% CLP) or postoperative (34% HDCP, 41% CLP) complication rates. Use of external coaptation did not affect postoperative complication rates or outcome. External coaptation related complications occurred in 32% HDCP and 18% CLP (P = .02). At median follow-up, most dogs were classified as having no or mild lameness (73% HDCP, 83% CLP) and there was radiographic healing in 40% HDCP and 46% CLP (P = .8) cases. CONCLUSIONS: CLP and HDCP may both be used successfully to achieve pancarpal arthrodesis. Adjunctive external coaptation does not appear to have a measurable clinical benefit but is associated with morbidity.

Use of vacuum-assisted closure to maintain viability of a skin flap in a dog.

CASE DESCRIPTION: A 4-year-old sexually intact male Labrador Retriever-Poodle mix was admitted to the hospital for treatment of a wound in the left thoracic region. The wound had been debrided and primary closure had been performed by the referring veterinarian 4 days previously. CLINICAL FINDINGS: The dog had a 20-cm-long wound covered by a large flap of skin that extended caudally from the scapula over the left side of the thorax. A 3-cm defect was evident at the cranioventral aspect of the wound, from which purulent material was being discharged. The skin flap was necrotic, and the skin surrounding the flap was bruised. Signs of pain were elicited when the wound and surrounding region were palpated. Other findings, including those of thoracic radiography, were unremarkable. TREATMENT AND OUTCOME: The wound was debrided, and vacuum-assisted closure (VAC) was initiated for 3 days until a healthy bed of granulation tissue developed. A reconstructive procedure was performed with a rotation flap 3 days after VAC dressing removal. The VAC process was reinitiated 2 days following reconstruction because of an apparent failing of the skin flap viability. After 5 days of VAC, the flap had markedly improved in color and consistency and VAC was discontinued. Successful healing of the flap occurred without the need for debridement or additional intervention. CLINICAL RELEVANCE: Use of VAC led to a good overall outcome for the dog, with complete healing achieved. Additional evaluation of this technique for salvaging failing skin flaps is warranted in dogs, particularly considering that no reliable method for flap salvage in veterinary species has been reported to date.