Whole-genome QTL analysis of Stagonospora nodorum blotch resistance and validation of the SnTox4-Snn4 interaction in hexaploid wheat

Necrotrophic effectors (also known as host-selective toxins) are important determinants of disease in the wheat-Stagonospora nodorum pathosystem. To date, five necrotrophic effector-host gene interactions have been identified in this system. Most of these interactions have additive effects while some are epistatic. The Snn4-SnTox4 interaction was originally identified in a recombinant-inbred population derived from a cross between the Swiss winter wheat cultivars 'Arina' and 'Forno' using the S. nodorum isolate Sn99CH 1A7a. Here, we used a recombinant-inbred population consisting of 121 lines developed from a cross between the hexaploid land race Salamouni and the hexaploid wheat 'Katepwa' (SK population). The SK population was used for the construction of linkage maps and quantitative trait loci (QTL) detection using the Swiss S. nodorum isolate Sn99CH 1A7a. The linkage maps developed in the SK population spanned 3,228 centimorgans (cM) and consisted of 441 simple-sequence repeats, 9 restriction fragment length polymorphisms, 29 expressed sequence tag sequence-tagged site markers, and 5 phenotypic markers. The average marker density was 6.7 cM/marker. Two QTL, designated QSnb.fcu-1A and QSnb.fcu-7A on chromosome arms 1AS and 7AS, respectively, were associated with disease caused by the S. nodorum isolate Sn99CH 1A7a. The effects of QSnb.fcu-1A were determined by the Snn4-SnTox4 interaction and accounted for 23.5% of the phenotypic variation in this population, whereas QSnb.fcu-7A accounted for 16.4% of the phenotypic variation for disease but was not associated with any known effector sensitivity locus. The effects of both QTL were largely additive and collectively accounted for 35.7% of the total phenotypic variation. The results of this research validate the effects of a compatible Snn4-SnTox4 interaction in a different genetic background, and it provides knowledge regarding genomic regions and molecular markers that can be used to improve Stagonospora nodorum blotch resistance in wheat germplasm.     

Experimental canine leptospirosis caused by Leptospira interrogans serovars pomona and bratislava

OBJECTIVE: To evaluate gross, histopathologic, and serum biochemical findings caused by Leptospira interrogans serovars pomona and bratislava inoculated in dogs. ANIMALS: Twenty-seven 8-week-old female Beagles. PROCEDURE: Dogs were randomly assigned to challenge or control groups. Challenge groups were conjunctivally inoculated on 3 successive days with 5 x 10(7) L interrogans serovar pomona (n = 12) or serovar bratislava (11). Clinical signs were recorded throughout the experiment, and clinical pathology assays, bacteriologic culture, and necropsies (6 or 7 dogs necropsied at each time point) were done on postinoculation day (PID) 7, 10, 14, and 20. RESULTS: Infection could not be confirmed in any serovar bratislava-inoculated dog, and control dogs remained healthy throughout the experiment. Positive culture and fluorescent antibody test results were confirmed in 11 of 12 serovar pomona-inoculated dogs. Fever and lethargy starting at PID 7 were the most common clinical signs in serovar pomona-infected dogs. On day 10, gross lesions included multifocal renal and pulmonary hemorrhage and perirenal edema. Serovar pomona-inoculated dogs had histopathologic lesions including hepatitis, interstitial nephritis, and pneumonia at PID 7, 10, 14, and 20. Increases in BUN, anion gap, and bilirubin concentration occurred on PID 10, 14, and 20. Platelet counts in dogs with positive results of bacteriologic culture were decreased from baseline values on PID 10, 12, and 14. CONCLUSIONS AND CLINICAL RELEVANCE: Conjunctival inoculation with L interrogans serovar pomona resulted in a high rate of infection with concomitant hemorrhagic and inflammatory lesions of the kidneys, liver, and lungs.     

Clinical and pathologic comparison of acute leptospirosis in dogs caused by two strains of Leptospira kirschneri serovar grippotyphosa

OBJECTIVE: To develop a method for inducing acute leptospirosis in dogs. ANIMALS: 31 nine-week-old female Beagles. PROCEDURE: Beagles were randomly assigned to 2 inoculation groups or a control group. Dogs were inoculated on 3 successive days by conjunctival instillation of 5 x 10(7) cells of Leptospira kirschneri serovar grippotyphosa strain 82 (12 dogs) or strain RM 52 (14 dogs). Control dogs (n = 5) were similarly inoculated with sterile leptospiral culture media. Clinical signs, clinicopathologic variables, anti-leptospiral antibody titers, and evidence of leptospires in tissues and body fluids were evaluated. Dogs were euthanatized and necropsied on days 7, 14, 22, or 28 after inoculation or as required because of severe illness. RESULTS: Clinical signs in infected dogs included conjunctivitis, lethargy, diarrhea, dehydration, vomiting, and icterus. Consistent clinicopathologic alterations included azotemia, hyperphosphatemia, increased anion gap, hyperbilirubinemia, and an increase in alkaline phosphatase activity. Leptospires were cultured from the kidneys (11/12), urine (6/9), aqueous humor (9/12), blood (12/12), and liver (12/12) of dogs inoculated with strain 82. Only 3 of 14 dogs became infected after inoculation with strain RM 52. Histopathologic lesions in infected dogs included interstitial nephritis, renal tubular degeneration and necrosis, pulmonary hemorrhage, and hepatic edema and perivasculitis. CONCLUSIONS AND CLINICAL RELEVANCE: Conjunctival exposure to L kirschneri serovar grippotyphosa strain 82 resulted in acute leptospirosis in all inoculated dogs, but only 3 of 14 dogs inoculated with strain RM 52 became infected. This method of infection by serovar grippotyphosa can be used to study the pathogenesis and prevention of leptospirosis in dogs.     

Effects of long-term administration of enalapril on clinical indicators of renal function in dogs with compensated mitral regurgitation

OBJECTIVE: To determine the effect of long-term administration of enalapril on renal function in dogs with severe, compensated mitral regurgitation. DESIGN: Randomized controlled trial. ANIMALS: 139 dogs with mitral regurgitation but without overt signs of heart failure. PROCEDURE: Dogs were randomly assigned to be treated with enalapril (0.5 mg/kg [0.23 mg/lb], PO, q 24 h) or placebo, and serum creatinine and urea nitrogen concentrations were measured at regular intervals for up to 26 months. RESULTS: Adequate information on renal function was obtained from 132 dogs; follow-up time ranged from 0.5 to 26 months (median, 12 months). Mean serum creatinine and urea nitrogen concentrations were not significantly different between dogs receiving enalapril and dogs receiving the placebo at any time, nor were concentrations significantly different from baseline concentrations. Proportions of dogs that developed azotemia or that had a +/- 35% increase in serum creatinine or urea nitrogen concentration were also not significantly different between groups. Conclusions: And Clinical Relevance: Results suggest that administration of enalapril for up to 2 years did not have any demonstrable adverse effects on renal function in dogs with severe, compensated mitral regurgitation.     

Influence of combined angiotensin-converting enzyme inhibitors and spironolactone on serum K, Mg, and Na concentrations in small dogs with degenerative mitral valve disease

ObjectiveTo determine if the administration of an angiotensin-converting enzyme inhibitor (ACEI) plus spironolactone caused hyperkalemia, hypermagnesemia, or hyponatremia in elderly small dogs with degenerative mitral valve disease (MVD).BackgroundACEIs and spironolactone can increase serum potassium and magnesium concentrations and lower serum sodium concentrations. It has been recommended to either not combine these drugs or to do so with caution.Animals, material and methodsFifty client-owned dogs with MVD, left atrial dilation, and without congestive heart failure or azotemia were evaluated retrospectively. Baseline data sets, followed by 1–9 (mean = 2.66) data sets, comprised of serum urea nitrogen (SUN), creatinine, sodium, potassium, and magnesium concentrations, were tabulated. Each dog received an ACEI plus spironolactone for a mean of 23.8 ± 26.6 weeks (range: 2–150) and a median of 15 weeks. No cardiac drugs other than an ACEI and spironolactone were administered during the study period.ResultsThere were no significant differences between baseline and follow-up serum sodium or potassium concentrations. Serum magnesium concentrations increased significantly (p = 0.02) with time >20 weeks compared to baseline.ConclusionsThe combination of an ACEI and spironolactone results in no significant difference between baseline and follow-up serum sodium or potassium concentrations. Although serum magnesium concentrations may increase significantly with time >20 weeks compared to baseline concentrations, hypermagnesemia appears to be rare, mild, and unlikely to be of clinical importance. The combination of an ACEI and spironolactone is safe in elderly small dogs with MVD with normal SUN and creatinine concentrations.     

Repair of physeal fractures of the tuber olecranon in the horse, using a tension band method

Physeal fractures of the tuber olecranon of 4 horses were treated, using the tension band method of compression fracture repair. A cortical bone screw and Steinmann pin were placed through the proximal fragment into the distal parent bone parallel to the palmar border of the olecranon. The tension band was placed dorsal to the Steinmann pin and anchored in a hole through the shaft of the ulna 10 cm distal to the tuber olecranon. Of the 4 foals, 2 became pasture sound, 1 is now being worked under saddle, and the 4th showed no signs of lameness 5 months after surgery.     

Functional ectopic adrenal carcinoma in a dog

An 11-year-old spayed female pit bull terrier was presented with a 2-month history of polyuria, polydipsia, polyphagia, and panting. Serum chemistry, blood and urine analysis, and tests for hyperadrenocorticism suggested an adrenal tumor. Abdominal ultrasound identified a mass caudal to the right kidney. The mass was completely excised and histopathology was consistent with endocrine carcinoma. Three years later there was no evidence of recurrence or metastasis.