The generation of the first chromosome-level de novo genome assembly and the development and validation of a 50K SNP array for the St. John River aquaculture strain of North American Atlantic salmon.

Atlantic salmon (Salmo salar) in Northeastern US and Eastern Canada has high economic value for the sport fishing and aquaculture industries. Large differences exist between the genomes of Atlantic salmon of European origin and North American (N.A.) origin. Given the genetic and genomic differences between the 2 lineages, it is crucial to develop unique genomic resources for N.A. Atlantic salmon. Here, we describe the resources that we recently developed for genomic and genetic research in N.A. Atlantic salmon aquaculture. Firstly, a new single nucleotide polymorphism (SNP) database for N.A. Atlantic salmon consisting of 3.1 million putative SNPs was generated using data from whole-genome resequencing of 80 N.A. Atlantic salmon individuals. Secondly, a high-density 50K SNP array enriched for the genic regions of the genome and containing 3 sex determination and 61 putative continent of origin markers was developed and validated. Thirdly, a genetic map composed of 27 linkage groups with 36K SNP markers was generated from 2,512 individuals in 141 full-sib families. Finally, a chromosome-level de novo genome assembly from a male N.A. Atlantic salmon from the St. John River aquaculture strain was generated using PacBio long reads. Information from Hi-C proximity ligation sequences and Bionano optical mapping was used to concatenate the contigs into scaffolds. The assembly contains 1,755 scaffolds and only 1,253 gaps, with a total length of 2.83 Gb and N50 of 17.2 Mb. A BUSCO analysis detected 96.2% of the conserved Actinopterygii genes in the assembly, and the genetic linkage information was used to guide the formation of 27 chromosome sequences. Comparative analysis with the reference genome assembly of the European Atlantic salmon confirmed that the karyotype differences between the 2 lineages are caused by a fission in chromosome Ssa01 and 3 chromosome fusions including the p arm of chromosome Ssa01 with Ssa23, Ssa08 with Ssa29, and Ssa26 with Ssa28. The genomic resources we have generated for Atlantic salmon provide a crucial boost for genetic research and for management of farmed and wild populations in this highly valued species.

Decortication, thoracic omentalization, and pericardiectomy for treatment of severe fibrosing pleuritis in a cat.

CASE DESCRIPTION: A 5-year-old spayed female domestic shorthair cat was evaluated because of an acute onset of dyspnea and open-mouthed breathing. CLINICAL FINDINGS: Thoracic radiography revealed pleural effusion and signs consistent with restrictive pleuritis, and results of preoperative CT were consistent with diffuse, severe restrictive pleuritis, bilateral pleural effusion, and pulmonary atelectasis. Thoracocentesis yielded a red, turbid fluid that was identified as chylous effusion with chronic inflammation. TREATMENT AND OUTCOME: Exploratory thoracotomy revealed diffuse, severe fibrous adhesions between the mediastinum, heart, lung lobes, and thoracic wall, with a thick fibrous capsule enveloping all lung lobes. Surgical treatment consisted of complete pleural decortication, pericardiectomy, and thoracic omentalization. The cat remained hospitalized for 6 days, receiving oxygen supplementation, multimodal analgesia, and supportive care. Long-term home care consisted of prednisolone administration, rutin supplementation, and provision of a low-fat diet. At recheck examinations 3-, 7-, and 20-weeks postoperatively, the cat remained tachypneic, but was otherwise clinically normal without dyspnea or respiratory distress. Follow-up thoracic radiography revealed improved pulmonary expansion, decreased pleural effusion, and resolved pneumothorax. CLINICAL RELEVANCE: Surgical management of fibrosing pleuritis secondary to idiopathic chylothorax in cats has historically resulted in poor outcomes. This report details the first successful use of complete decortication in the surgical management of severe fibrosing pleuritis in a cat.

Medical and Interventional Management of Upper Urinary Tract Uroliths.

Nephroliths are often clinically silent. When non-obstructive and of an amenable stone type, dissolution should be attempted. When problematic, nephrolithotomy can be considered. Depending on stone type, size, and species, extracorporeal shockwave lithotripsy or endoscopic nephrolithotomy are preferred techniques. Obstructive ureterolithiasis should be addressed immediately to preserve kidney function. Because of decreased morbidity and mortality and versatility for all causes, interventional techniques for kidney decompression are preferred by the authors. Proper training and expertise in these interventional techniques should be acquired before performing them on clinical patients for the best possible outcomes.

The effect of lidocaine on postoperative jejunal motility in normal horses.

OBJECTIVE: To measure the effect of lidocaine on the duration of the migrating myoelectric complex (MMC) and Phases I, II, and III of the MMC, spiking activity of the jejunum, and number of Phase III events when administered postoperatively to normal horses. STUDY DESIGN: Nonrandomized cross-over design. METHODS: Horses were anesthetized and via flank laparotomy 4 silver-silver chloride bipolar electrodes were sutured to the proximal jejunum. Electrical activity was recorded for 6 hours during 3 recording sessions beginning 24, 48, and 72 hours postoperatively. Saline (0.9% NaCl) solution was administered for 3 hours followed by lidocaine administration for 3 hours (1.3 mg/kg bolus intravenously [IV], 0.05 mg/kg/min IV constant rate infusion). RESULTS: Duration of MMC was unchanged during lidocaine administration (77 minutes-saline versus 105 minutes-lidocaine, P=.16). Durations of Phase I and II were unchanged during lidocaine administration (P=.19 and .056, respectively). Phase III was shorter during lidocaine administration (P=.002). Spiking activity was unchanged at all time periods during lidocaine administration (24 hours-P=.10; 48 hours-P=.95; and 72 hours-P=.12). The number of Phase III events was unchanged over all time periods during lidocaine administration (P=.053). CONCLUSIONS: Duration of MMC, spiking activity, and number of Phase III events was unchanged during lidocaine administration. CLINICAL RELEVANCE: Use of lidocaine as a prokinetic agent cannot be supported by this study in normal horses; however, results may differ in clinically affected horses.