Search Results

Abstract

Objective—To assess the outcome of extrahepatic portosystemic shunt (EHPSS) treatment in dogs aged 5 years and older.

Design—Retrospective case series.

Animals—17 client-owned dogs.

Procedures—Medical records for dogs (≥ 5 years old) that underwent surgical attenuation of an EHPSS (1992 through 2005) were evaluated; data, including clinical signs, clinicopathologic findings, surgical procedure, and outcome, were recorded. Follow-up information was obtained via patient examination or telephone interview with veterinarians and owners.

Results—Dogs (5 to 9 years old [median age, 6.6 years]) had neurologic (n = 12), urinary tract (8), and gastrointestinal tract (6) EHPSS-associated clinical signs. Serum bile acids and ammonia concentrations were abnormal in all evaluated dogs. Treatment of EHPSSs included complete (n = 6 dogs) or partial (2) suture attenuation or ameroid constrictor placement (9). Two dogs died following surgery. Follow-up information (6 to 120 months) was available for 13 dogs. Deaths were attributable to heart failure (n = 1), bacterial hepatitis (2; with pyelonephritis in 1 dog), and unknown causes (3). At a median of 23 and 25 months, serum bile acids concentrations had almost normalized in 5 of 8 dogs and ammonia concentrations were within reference limits in 3 of 5 dogs, respectively; dogs with abnormal liver function test results had no associated clinical signs. Median long-term survival time was 72 months.

Conclusions and Clinical Relevance—Attenuation of EHPSS in ≥ 5-year-old dogs ameliorated signs of liver dysfunction in surviving dogs, although return of normal liver function occurred less frequently than expected.

Abstract

Objectives—To determine the role of myosin light chain phosphorylation in feline colonic smooth muscle contraction.

Sample Population—Colonic tissue was obtained from eight 12- to 24-month-old cats.

Procedure—Colonic longitudinal smooth muscle strips were attached to isometric force transducers for measurements of isometric stress. Myosin light chain phosphorylation was determined by isoelectric focusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Stress and phosphorylation were determined following stimulation with ACh or SP, in the absence or presence of a calmodulin antagonist (W-7; 0.1 to 1.0 mM), myosin light chain kinase inhibitor (ML-9; 1 to 10 µM), or extracellular calcium - free solutions.

Results—Unstimulated longitudinal colonic smooth muscle contained low amounts (6.9 ± 3.2%) of phosphorylated myosin light chain. Phosphorylation of the myosin light chains was dose and time dependent with maximal values of 58.5% at 30 seconds of stimulation with 100 µM Ach and 60.2% at 45 seconds of stimulation with 100 nM SP. Active isometric stress development closely paralleled phosphorylation of the myosin light chains in ACh- or SP-stimulated muscle. W-7 and ML-9 dose dependently inhibited myosin light chain phosphorylation and isometric stress development associated with ACh or SP stimulation. Removal of extracellular calcium inhibited myosin light chain phosphorylation and isometric stress development in ACh-stimulated smooth muscle.

Conclusions and Clinical Relevance—Feline longitudinal colonic smooth muscle contraction is calcium-, calmodulin-, and myosin light chain kinasedependent. Myosin light chain phosphorylation is necessary for the initiation of contraction in feline longitudinal colonic smooth muscle. These findings may prove useful in determining the biochemical and molecular defects that accompany feline colonic motility disorders. (Am J Vet Res 2002;63:695–702)

Abstract

Objective—To determine whether expression of G proteins (G_i and G_s) is altered in thyroid gland adenomas obtained from hyperthyroid cats.

Sample Population—Adenomatous thyroid glands obtained from 8 hyperthyroid cats and thyroid glands obtained from 4 age-matched euthyroid cats.

Procedure—Expression of G_i and G_s was quantified in enriched membrane preparations of thyroid gland tissue, using immunoblotting with G_i and G_s antibodies and toxin-catalyzed ADP-ribosylation.

Results—Expression of G_i was significantly reduced in thyroid gland adenomas from hyperthyroid cats, compared with normal thyroid gland tissue from euthyroid cats. Expression of G_s was similar between the 2 groups.

Conclusions and Clinical Relevance—A decrease in expression of G_i in adenomatous thyroid glands of cats may reduce the negative inhibition of the cAMP cascade in thyroid cells, leading to autonomous growth and hypersecretion of thyroxine. Understanding the molecular mechanisms for hyperthyroidism in cats may lead to better treatment or, ultimately, prevention of the disease. (Am J Vet Res 2000;61:874–879)

Abstract

OBJECTIVE To sequence exons and splice consensus sites of the dynactin subunit 1 (DCTN1) gene in Leonbergers and Labrador Retrievers with clinical laryngeal paralysis.

ANIMALS 5 unrelated Leonbergers with laryngeal paralysis, 2 clinically normal Leonbergers, 7 unrelated Labrador Retrievers with laryngeal paralysis, and 2 clinically normal Labrador Retrievers.

PROCEDURES Primers were designed for the entire coding regions of the DCTN1 gene, a noncoding exon at the 5´ end of the gene, and a 900-bp single-nucleotide polymorphism (SNP)-rich region located 17 kb upstream of the DCTN1 gene by use of the CanFam3 assembly of the canine genome sequence. Sequences were generated and compared between clinically normal and affected dogs. The SNPs flanking the DCTN1 gene as well as a previously identified nonsynonymous SNP in exon 32 were genotyped in affected and clinically normal Leonbergers and Labrador Retrievers.

RESULTS None of the affected dogs were homozygous for any mutation affecting coding regions or splicing consensus sequences. Of the 16 dogs tested for the missense SNP in exon 32, all were homozygous for the reference allele, except for 2 affected and 1 clinically normal Labrador Retriever and 1 clinically normal Leonberger. The DCTN1 gene sequences (5 dogs) and haplotypes of polymorphic markers surrounding the DCTN1 gene (all dogs) were not consistent with the hypothesis that laryngeal paralysis was associated with inheritance of the same DCTN1 disease-causing allele within all Labrador Retrievers or Leonbergers evaluated.

CONCLUSIONS AND CLINICAL RELEVANCE Mutations in the DCTN1 gene did not appear to cause laryngeal paralysis in Leonbergers or Labrador Retrievers.

Abstract

Objective—To describe a method for ultrasonographic and color-flow Doppler ultrasonographic imaging of the 4 direct cutaneous arteries commonly used for axial pattern skin flaps in dogs.

Design—Descriptive report.

Animals—20 clinically normal dogs.

Procedures—Dogs were manually restrained and fundamental and harmonic ultrasonographic and colorflow Doppler ultrasonographic examinations of the superficial cervical, thoracodorsal, deep circumflex iliac (cranial and caudal branches), and caudal superficial epigastric arteries were performed by a resident in diagnostic imaging. The level of confidence in locating these vessels was subjectively graded as high, moderate, or low.

Results—High-frequency fundamental and harmonic ultrasonography was important for maximizing image resolution, and color-flow Doppler ultrasonography was important for vessel identification. The superficial cervical artery was the most difficult vessel to identify; confidence in correct vessel identification was low or moderate. The thoracodorsal and deep circumflex iliac arteries were identified with a moderate or high level of confidence. The caudal superficial epigastric artery was the easiest vessel to identify; confidence in correct vessel identification was high. Except for the superficial cervical artery, the level of confidence in correct vessel identification improved over time as operator experience increased.

Conclusion and Clinical Relevance—Results suggest that the combination of fundamental ultrasonographic and color-flow Doppler ultrasonographic imaging is an easy and noninvasive method for identifying the 4 direct cutaneous arteries commonly used for axial pattern skin flaps in dogs. This method could be useful in planning axial pattern skin flaps, particularly in dogs with regional soft tissue trauma in which the integrity of the vessel is in question.

Abstract

Objective—To describe a modified Blalock-Taussig shunt (mBT) procedure and assess its use in dogs with clinical signs associated with tetralogy of Fallot (TOF).

Design—Descriptive report.

Animals—6 dogs with severe TOF-associated clinical signs.

Procedures—Each dog had TOF (confirmed echocardiographically or angiographically) and underwent an mBT shunt procedure for surgical palliation of signs. The surgery was performed through a left fourth rib resection or a left fifth intercostal thoracotomy. The left subclavian artery was dissected free from surrounding mediastinal tissue. The main pulmonary artery trunk was exposed through an incision in the overlying pericardium. A shunt comprised of a 6-mm-diameter tube of expanded polytetrafluoroethylene (5 dogs) or a segment of carotid artery (1 dog) was sutured end to side between the left subclavian artery and pulmonary artery trunk.

Results—5 of the 6 dogs survived the immediate postoperative period. The dog that died shortly after surgery was the smallest of the dogs (weight, 2.9 kg [6.38 lb]) and had received the carotid artery autograft. Three dogs survived long term and 2 dogs died of unknown causes 6 years after undergoing the mBT shunt procedure. In all dogs that survived the mBT procedure, shunt patency was confirmed and quality of life appeared improved.

Conclusions and Clinical Relevance—These findings have suggested that the mBT shunt procedure safely provides long-term palliation of TOF-associated clinical signs in dogs. In addition, it may offer an effective low-risk and lower-cost alternative to open heart repair of TOF.

Abstract

Abstract

Objective—To describe the use of thoracoscopic-assisted pulmonary surgery (TAPS) for partial and complete lung lobectomy in small animal patients and to evaluate short-term outcome.

Design—Retrospective case series.

Animals—11 client-owned dogs and cats.

Procedures—Medical records of dogs and cats that underwent a partial or complete TAPS lung lobectomy were reviewed. All patients underwent general anesthesia and were positioned in lateral recumbency with the affected hemithorax uppermost. One-lung ventilation was not implemented in any patient. For initial exploration, a 5- to 10-mm incision was made for insertion of a 30° telescope approximately 5 to 7 rib spaces away from the site of the pulmonary lesion in the dorsal third of the thorax. All subsequent incision placements were case dependent and determined by the location of the lesion to be resected. Following lesion localization, a 2- to 7-cm minithoracotomy incision was made with direct thoracoscopic visualization without the use of rigid rib retractors. In 10 of 11 patients, a 360° wound retraction device was placed at the minithoracotomy site prior to exteriorization and resection of the affected lung. Lymph nodes were inspected intraoperatively, but biopsies were not performed; incisions were closed routinely, and a thoracostomy tube was placed in all patients.

Results—3 cats and 8 dogs underwent successful partial (5) or complete (6) TAPS lung lobectomy over a 5-year period (2008 through 2013). Median surgery time was 92.7 minutes (range, 77 to 150 minutes). Thoracostomy tubes were removed a median of 22.3 hours after surgery (range, 18 to 36 hours). The median time to discharge was 3.1 days (range, 1 to 6 days). No intraoperative complications were encountered. All patients were discharged from the hospital, with 9 of 11 patients alive 6 months after surgery.

Conclusions and Clinical Relevance—Results of this study suggested that lung lobectomy by means of TAPS can be successfully performed in dogs and cats. When compared with total thoracoscopic surgery, TAPS may offer a more technically feasible approach from both a surgical and anesthetic standpoint, because it provides the benefits of minimally invasive thoracic surgery without the necessity of 1-lung ventilation.

Abstract

Objective—To determine the prevalence of exposure to canine influenza virus (CIV) in dogs in a metropolitan animal shelter.

Design—Serologic survey.

Animals—74 dogs.

Procedures—Dogs were randomly selected from the canine shelter population. A physical examination was performed, and blood samples were obtained and submitted for serologic testing for the detection of antibodies against CIV. Logistic regression analysis was performed to evaluate the association of factors (body condition score, nasal discharge, coughing, rectal temperature, number of days in the shelter, and relinquished vs stray) with positive results.

Results—31 of 74 (42%) dogs were seropositive for antibodies against CIV. Positive serologic test results were detected for 6 of 39 (15%) dogs housed in the shelter for ≤ 7 days and for 25 of 35 (71%) dogs housed in the shelter for ≥ 8 days. Number of days in the shelter was the only factor significantly associated with positive serologic test results. For every 3 days in the shelter, the odds of a positive serologic test result increased significantly by 2.2 (95% confidence interval, 1.5 to 3.4).

Conclusions and Clinical Relevance—Analysis of the results suggested that more dogs were exposed to CIV in the shelter than were exposed in the urban environment. This has serious implications for design and management of animal shelters.

Abstract

Objective—To determine the prevalence of nonneoplastic middle ear disease among cats undergoing necropsy and the prevalence of clinical abnormalities in cats in which nonneoplastic middle ear disease was identified.

Design—Retrospective case series.

Animals—59 cats that underwent necropsy between January 1991 and August 2007.

Procedures—Medical records were searched to identify cats in which nonneoplastic middle ear disease was identified at necropsy. For cats included in the study, data that were recorded included signalment, initial complaint, whether the cat had any clinical signs of middle or external ear disease, whether the cat had upper respiratory tract disease, necropsy diagnosis, gross appearance of the bullae, and reason for euthanasia. Signs of middle ear disease that were considered included unilateral peripheral vestibular disease without motor deficits, Horner syndrome, and facial nerve paralysis.

Results—Of the 3,442 cats that underwent necropsy during the study period, 59 (1.7%) had nonneoplastic middle ear disease. Six of the 59 (10%) cats, including 1 cat that was affected bilaterally, had clinical signs of middle ear disease. Of these, 5 had signs of unilateral peripheral vestibular disease, and 1 had Horner syndrome.

Conclusions and Clinical Relevance—Results suggested that most cats with nonneoplastic middle ear disease did not have associated clinical signs. Findings may be of clinical relevance for cats in which middle ear disease is identified as an incidental finding during computed tomography or magnetic resonance imaging for unrelated diseases.