Urine electrolytes do not predict desoxycorticosterone pivalate efficacy in dogs with hypoadrenocorticism.

OBJECTIVE: To determine if urine electrolyte assessments can be used to monitor the adequacy of mineralocorticoid therapy in dogs with hypoadrenocorticism (HA). ANIMALS: 29 dogs with naturally occurring glucocorticoid- and mineralocorticoid-deficient HA. PROCEDURES: Urine sodium and potassium concentrations, sodium-to-potassium ratios, sodium-to-creatinine ratios, and potassium-to-creatinine (K:Cr) ratios were evaluated in dogs with newly diagnosed HA that were treated with desoxycorticosterone pivalate (DOCP). Dogs underwent measurements of urine and serum sodium, potassium, and creatinine concentrations and plasma renin activities twice monthly for up to 3 months. Regression analyses and calculation of coefficients of determination (R2) were performed to investigate potential associations between urine and serum variables. Urine variables also were compared between dogs considered to be undertreated or overtreated based on plasma renin activities. RESULTS: Urine K:Cr ratios were significantly associated with serum potassium concentrations 10 to 14 days (P = .002) and 30 days (P = .027) after the initial DOCP injection, but R2 values were only 0.35 and 0.17, respectively. Urine K:Cr ratios (median [IQR]) also were higher in dogs that were overtreated with DOCP (1.3 [0.7 to 2.3]) as compared to those dogs that were undertreated with DOCP (0.8 [0.5 to 0.9]) at 10 to 14 days after the initial DOCP injection (P = .039) but not at 30 days after the initial injection. Other urine variables were not significantly different between undertreated and overtreated dogs. CLINICAL RELEVANCE: Measures of urine electrolytes were not useful for assessing the adequacy of mineralocorticoid therapy in HA dogs that were treated with DOCP.

Evaluation of urine electrolytes for the diagnosis of hypoadrenocorticism in dogs.

BACKGROUND: Most dogs with primary hypoadrenocorticism (HA) have a mineralocorticoid deficiency, which decreases renal tubular sodium reabsorption and potassium excretion. Limited information is available concerning the clinical value of measuring urine electrolytes to aid in an HA diagnosis. OBJECTIVES: We aimed to evaluate the diagnostic utility of urine electrolyte measurements in dogs with HA. METHODS: Urine sodium and potassium concentrations were measured in 89 dogs, including 39 dogs with HA and 50 controls with nonadrenal illness. Fractional excretions of sodium (FENa ) and potassium (FEK ) were also calculated. Urine electrolytes and fractional excretion values were compared between the groups. Sensitivities and specificities were determined for various cut-points. RESULTS: The median urine sodium to potassium (Na:K) ratio was twofold greater (P < .001), and median FENa was fourfold greater (P < .001) in HA dogs as compared with controls. However, no cut-point for any variable with >90% sensitivity or specificity provided a corresponding specificity or sensitivity of >50%. When only dogs with abnormal serum or plasma electrolytes were included in the analyses, absolute urine electrolyte concentrations and FENa were not different between study populations (P > .05 for all comparisons), but the FEK was increased (P = .005) and the urine potassium:creatinine ratio was decreased (P < .001) in the control dogs compared with the dogs with HA. CONCLUSIONS: Urine electrolyte concentrations and fractional excretions are altered in dogs with HA. However, substantial overlap exists with control dogs with nonadrenal illness. Therefore, these values are unlikely to have diagnostic utility for dogs with HA.

Safety and Efficacy of Felid Herpesvirus-1 Deletion Mutants in Cats.

Felid herpesvirus-1 (FeHV-1) is an important respiratory and ocular pathogen of cats and current vaccines are limited in duration and efficacy because they do not prevent infection, viral nasal shedding and latency. To address these shortcomings, we have constructed FeHV-1 gE-TK- and FeHV-1 PK- deletion mutants (gE-TK- and PK-) using bacterial artificial chromosome (BAC) mutagenesis and shown safety and immunogenicity in vitro. Here, we compare the safety and efficacy of a prime boost FeHV-1 gE-TK- and FeHV-1 PK- vaccination regimen with commercial vaccination in cats. Cats in the vaccination groups were vaccinated at 3-week intervals and all cats were challenge infected 3 weeks after the last vaccination. Evaluations included clinical signs, nasal shedding, virus neutralizing antibodies (VN), cytokine mRNA gene expression, post-mortem histology and detection of latency establishment. Vaccination with gE-TK- and PK- mutants was safe and resulted in significantly reduced clinical disease scores, pathological changes, viral nasal shedding, and viral DNA in the trigeminal ganglia (the site of latency) following infection. Both mutants induced VN antibodies and interferons after immunization. In addition, after challenge infection, we observed a reduction of IL-1ß expression, and modulation of TNFα, TGFß and IL10 expression. In conclusion, this study shows the merits of using FeHV-1 deletion mutants for prevention of FeHV-1 infection in cats.

Retrospective analysis of diagnoses and outcomes of 45 cats with micturition disorders presenting as urinary incontinence.

BACKGROUND: In contrast to dogs, the causes and outcomes of urinary incontinence (UI) in cats are largely unknown. OBJECTIVES: To determine the causes, identify comorbid conditions, and assess outcomes of cats with micturition disorders presenting as UI. ANIMALS: Forty-five cats with UI. METHODS: Retrospective study. Medical records of cats presented from January 2006 to December 2017 were searched using 45 keywords related to UI. History, presenting complaint, and physical examination findings were used to confirm a diagnosis. Cases were categorized based on functional and anatomic localizations. RESULTS: Forty-five cats met inclusion criteria. Spinal cord disease was the most common cause of UI (n = 18), followed by urethral (n = 17), bladder (n = 9), and ureteral (n = 1) disorders. Proportions of voiding and storage phase disorders were similar (53% and 47%, respectively). However, voiding-phase disorders were observed more frequently in males and younger-aged cats (P < .03). Urinary tract infection was detected in 11 of 28 (39%) cats. Outcomes were available in 38/45 cases; 16 cats (42%) regained continence, 3 (8%) improved with treatment, and 19 (50%) remained incontinent or were euthanized. Multiple variable logistic regressions indicated that spinal cord disease was significantly more likely to be associated with poor outcomes compared to bladder or urethral disorders (P < .04). CONCLUSIONS AND CLINICAL IMPORTANCE: Urinary incontinence in cats was associated with a variety of congenital and acquired disorders that affected both phases of micturition with similar frequency. Incontinent cats with spinal cord disorders were common and warrant a more guarded prognosis than do cats with bladder or urethral disorders.

High-resolution MRI of kidney microstructures at 7.05 T with an endo-colonic Wireless Amplified NMR detector.

To map the hemodynamic responses of kidney microstructures at 7.05 T with improved sensitivity, a Wireless Amplified NMR Detector (WAND) with cylindrical symmetry was fabricated as an endoluminal detector that can convert externally provided wireless signal at 600.71 MHz into amplified MR signals at 300.33 MHz. When this detector was inserted inside colonic lumens to sensitively observe adjacent kidneys, it could clearly identify kidney microstructures in the renal cortex and renal medullary. Owing to the higher achievable spatial resolution, differential hemodynamic responses of kidney microstructures under different breathing conditions could be individually quantified to estimate the underlying correlation between oxygen bearing capability and local levels of oxygen unsaturation. The WAND's ability to map Blood Oxygen Level Dependent (BOLD) signal responses in heterogeneous microstructures will pave way for early-stage diagnosis of kidney diseases, without the use of contrast agents for reduced tissue retention and toxicity.

Evaluation of Immunomodulatory Properties of Feline Mesenchymal Stem Cells.

Mesenchymal stem cells (MSC) offer a novel approach to treatment of inflammatory disorders in humans and companion animals. Cats spontaneously develop a wide variety of inflammatory disorders and may potentially benefit from MSC-based therapies. Multiple genes are involved in immunomodulation by MSC and interspecies differences between expressions of these genes exist. The goals of the study were to characterize the expression of genes known to be involved in MSC-based immunomodulation and determine the effect of MSC on proliferation of T cells in coculture experiments with peripheral blood mononuclear cells (PBMC). Unstimulated MSC expressed all immunomodulatory genes studied except for IL-10. Levels of iNOS and FASL were low or undetectable at the RNA level. INFγ stimulation resulted in significant dose-dependent upregulation of IDO1, PD-L1, IL-6, COX2, and HGF. Levels of kynurenine were increased after 3-day incubation with INFγ. TNFα stimulation increased expression of IL-6 at both RNA and protein level as well as upregulated COX2 gene expression and PTGES1.Stimulation with both INFγ and TNFα resulted in significant increase in PGE2 levels in cell culture medium. MSC significantly decreased proliferation of ConA-stimulated PBMC in coculture experiments at 1:5 ratio. Our results suggest that feline MSC have similar immunomodulatory gene expression and react to inflammatory cytokines in a manner similar to human MSC. Thus, MSC may play an important role in treatment of feline disease as well as serve as an important translational species to evaluate MSC-based therapies of diseases common to both humans and cats.

Comparison of foods with differing nutritional profiles for long-term management of acute nonobstructive idiopathic cystitis in cats.

OBJECTIVE: To evaluate the effect of nutrition on recurrent clinical signs of lower urinary tract (LUT) disease in cats with idiopathic cystitis. DESIGN: Randomized, controlled, masked clinical trial. ANIMALS: 31 cats with acute nonobstructive idiopathic cystitis. PROCEDURES: Cats were assigned to receive 1 of 2 foods (a cystitis prevention or control food) that differed in mineral (calcium, phosphorous, and magnesium), antioxidant, and fatty acid profiles. Owners documented LUT signs daily for up to 1 year. The primary endpoint was the number of recurrent episodes in which a cat had multiple (≥ 2 concurrent) LUT signs within a day (defined as multiple-sign day). Consecutive days in which a cat had multiple LUT signs were considered as a single episode. RESULTS: 4 cats fed prevention food and 2 cats fed control food were excluded from analysis because of noncompliance, gastrointestinal signs, food refusal, or owner voluntary withdrawal. The proportion of cats fed prevention food that had ≥ 1 recurrent episode of multiple-sign days (4/11) was not significantly lower than that of cats fed control food (9/14). However, cats fed prevention food had significantly lower mean incidence rates for recurrent episodes of multiple-sign days (0.7 episodes/1,000 cat-days) and episodes of hematuria (0.3 episodes/1,000 cat-days), dysuria (0.2 episodes/1,000 cat-days), and stranguria (0.2 episodes/1,000 cat-days) as single LUT signs, compared with cats fed control food (5.4, 3.4, 3.1, and 3.8 episodes/1,000 cat-days, respectively). Significantly fewer cats fed prevention food required analgesics (4/11), compared with cats fed control food (12/14). CONCLUSIONS AND CLINICAL RELEVANCE: Foods with differing nutritional profiles appeared to impact mean incidence rates of recurrent feline idiopathic cystitis-associated signs.

Efficacy of two commercially available, low-magnesium, urine-acidifying dry foods for the dissolution of struvite uroliths in cats.

OBJECTIVE: To compare the efficacy and safety of using 2 commercially available, low-magnesium, urine-acidifying dry foods to dissolve sterile struvite uroliths in cats. DESIGN: Prospective, multicenter, randomized clinical trial . SAMPLE: 37 cats with presumed struvite uroliths. PROCEDURES: Cats were randomly assigned to be fed 1 of 2 low-magnesium, urine-acidifying dry foods (food A or B). For each cat, physical examination, urinalysis, and abdominal radiography were performed weekly to assess treatment response. RESULTS: 32 cats had complete urolith dissolution. Mean ± SD times for a 50% reduction in urolith size (0.69 ± 0.1 weeks) and complete urolith dissolution (13.0 ± 2.6 days) were significantly shorter for cats fed food A, compared with those (1.75 ± 0.27 weeks and 27.0 ± 2.6 days, respectively) for cats fed food B. At study termination, mean ± SD urine pH (6.083 ± 0.105) for cats fed food A was lower than that (6.431 ± 0.109) for cats fed food B. In 5 cats, uroliths did not dissolve and were subsequently determined to be composed of 100% ammonium urate (n = 4) or 100% calcium oxalate (1). Adverse events associated with diet were not observed in any of the cats. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that dietary dissolution is safe and effective for eradication of sterile struvite uroliths in cats. Cats fed food A had faster urolith dissolution than did cats fed food B. Lack of a reduction in urolith size at 2 weeks after diet initiation was indicative of misdiagnosis or noncompliance.

Acquisition and persistence of antimicrobial-resistant bacteria isolated from dogs and cats admitted to a veterinary teaching hospital.

OBJECTIVE: To assess antimicrobial resistance among bacteria isolated from dogs and cats admitted to a veterinary teaching hospital (VTH), determine the incidence of acquisition of and frequency of persistent colonization by antimicrobial-resistant organisms among these animals, and identify risk factors associated with these variables. DESIGN: Prospective longitudinal study. ANIMALS: 622 dogs and 92 cats admitted to a VTH and expected to stay ≥ 48 hours. PROCEDURES: Samples were collected with rectal and nasal or oropharyngeal swabs at admission and discharge. Isolates of enterococci, staphylococci, and Escherichia coli were tested for antimicrobial resistance via microbroth dilution methods. A subset of isolates was analyzed with pulsed-field gel electrophoresis and multilocus sequence typing. Significant trends in proportions of organisms with antimicrobial resistance over the 3-year study period were assessed. RESULTS: The proportion of staphylococci with antimicrobial resistance increased, whereas the proportion of E coli with resistance decreased, over time; resistance among enterococci was more variable. For 506 dogs with paired admission and discharge samples, multidrug-resistant (MDR) E coli was acquired by 40 (8%) and methicillin-resistant Staphylococcus aureus (MRSA) was acquired by 7 (1.4%); hospitalization for > 3 days was significantly associated with both variables. Most (5/7 isolates) acquired MRSA was of sequence type (ST) 5. CONCLUSIONS AND CLINICAL RELEVANCE: Extended hospitalization was associated with increased risk of acquiring MDR E coli or MRSA, although few animals acquired MRSA. It is unclear whether associations were confounded by illness severity or use of infection control measures. Additionally, MRSA of ST5, which has been associated with small animal medicine, was the most commonly acquired MRSA in this study.

Successful treatment of intracardiac and intraocular blastomycosis in a dog with combination azole therapy.

A 4 yr old spayed female Labrador retriever with clinical signs of blindness, cutaneous lesions, coughing, inappetence, and lethargy was diagnosed with disseminated blastomycosis based on cytologic (skin and lymph node aspirates) and histopathologic (skin biopsy) examinations of tissue samples. The dog deteriorated clinically during hospitalization and developed sustained ventricular tachycardia. Echocardiography revealed pericardial effusion, a nodule associated with the left ventricular papillary muscle, and a right atrial mural lesion. Therapy for myocardial performance and glaucoma was initiated. A combination of itraconazole and fluconazole successfully treated the dog. The dog regained vision in the left eye (oculus sinister [OS]) and had no residual cardiac disease detectable by either electrocardiography or echocardiography. This report is unique in documenting survival from intracardiac blastomycosis and in the use of combination azole therapy for treating disseminated disease with intraocular involvement.

Clinical features and risk factors for development of urinary tract infections in cats.

The clinical and diagnostic features of 155 cats with urinary tract infection (UTI) and 186 controls with negative urine culture/s were characterized retrospectively (signalment, clinical signs, urinalysis, urine culture, concurrent diseases, lower urinary tract diagnostic/therapeutic procedures). Multivariable logistic regression was used to identify risk factors associated with UTI. Cats of all ages were affected by UTI with no sex/breed predisposition. Lower urinary tract signs were absent in 35.5% of cats with UTI. Pyuria and bacteriuria had sensitivities of 52.9% and 72.9%, and specificities of 85.5% and 67.7% for detection of UTI, respectively. Risk factors significantly associated with increased odds of UTI were urinary incontinence [odds ratio (OR)=10.78, P=0.0331], transurethral procedures (OR=8.37, P<0.0001), urogenital surgery (OR=6.03, P=0.0385), gastrointestinal disease (OR=2.62, P=0.0331), decreased body weight (OR=0.81, P=0.0259) and decreased urine specific gravity (OR=0.78, P=0.0055). Whilst not independently significant, renal disease and lower urinary tract anatomic abnormalities improved statistical model performance and contributed to UTI.

Prevalence and antimicrobial resistance of Enterococcus spp and Staphylococcus spp isolated from surfaces in a veterinary teaching hospital.

OBJECTIVE: To determine the prevalence and antimicrobial resistance of enterococci and staphylococci collected from environmental surfaces at a veterinary teaching hospital (VTH). DESIGN: Longitudinal study. SAMPLE: Samples collected from surfaces in 5 areas (emergency and critical care, soft tissue and internal medicine, and orthopedic wards; surgery preparation and recovery rooms; and surgery office and operating rooms) of a VTH. PROCEDURES: Selected surfaces were swabbed every 3 months during the 3-year study period (2007 to 2009). Isolates of enterococci and staphylococci were identified via biochemical tests, and antimicrobial susceptibility was evaluated with a microbroth dilution technique. A subset of isolates was analyzed to assess clonality by use of pulsed-field gel electrophoresis. RESULTS: 430 samples were collected, and isolates of enterococci (n = 75) and staphylococci (110) were identified. Surfaces significantly associated with isolation of Enterococcus spp and Staphylococcus spp included cages and a weight scale. Fourteen Enterococcus spp isolates and 17 Staphylococcus spp isolates were resistant to ≥ 5 antimicrobials. Samples collected from the scale throughout the study suggested an overall increase in antimicrobial resistance of Enterococcus faecium over time. Clonality was detected for E faecium isolates collected from 2 different surfaces on the same day. CONCLUSIONS AND CLINICAL RELEVANCE: Although not surprising, the apparent increase in antimicrobial resistance of E faecium was of concern because of the organism's ability to transmit antimicrobial resistance genes to other pathogens. Results reported here may aid in identification of critical control points to help prevent the spread of pathogens in VTHs.

Evaluation of modified Wright-staining of dried urinary sediment as a method for accurate detection of bacteriuria in cats.

BACKGROUND: Urinary sediment examination and quantitative urinary culture results are frequently discordant. OBJECTIVES: The aims of this study were to compare accuracy of light microscopic examination of wet-mounted unstained (wet-unstained) and air-dried modified Wright-stained (dry-stained) sedimented preparations of urine with results of quantitative aerobic bacterial culture for detection and characterization of bacteriuria in cats. In addition, the presence of pyuria detected by urinalysis and potential risk factors were assessed. METHODS: A blinded prospective study was conducted on 472 urinary samples collected from 410 cats by cystocentesis. The age and sex of each cat were recorded. Complete urinalyses were performed and included quantification of WBCs. Quantity and morphology of bacteria in each specimen were determined by light microscopic examination of wet-unstained (performed by certified medical technologists) and dry-stained (performed by a veterinary clinical pathologist) sedimented preparations of urine and compared with results of quantitative bacterial cultures. RESULTS: Of 472 urinary specimens, 29 were positive for bacteriuria by culture and considered true positives and 443 were considered true negatives. Compared with these results, examination of wet-unstained and dry-stained urines had sensitivities of 75.9% and 82.8%, specificities of 56.7% and 98.7%, and test efficiencies of 57.8% and 97.7%, respectively. Positive likelihood ratios were 1.8 and 63.7 and negative likelihood ratios were 0.42 and 0.17 for wet-unstained and dry-stained examinations, respectively. Compared with 29 culture-positive samples, the wet-unstained method had morphologic concordance and misclassification rates of 37.9% and 62.1%, respectively, whereas the dry-stained method had morphologic concordance and misclassification rates of 65.5% and 34.5%, respectively. Only 34% of samples with bacteriuria had pyuria. Frequency of bacteriuria was not significantly different based on age and sex of the cats, but there was a tendency for increased frequency in female cats and in cats >10 years old. CONCLUSIONS: Staining dried urinary sediment with a modified Wright-stain significantly improved sensitivity, specificity, and test efficiency of microscopic detection and classification of bacteriuria compared with the wet-unstained method. Pyuria should not be a criterion for determining the presence or absence of bacteriuria.

Comparison of three immunodiagnostic assays for antemortem detection of Mycobacterium bovis stimulation in domestic cats.

Mycobacterium bovis causes disease in numerous mammalian species including humans, thus making research, surveillance, and control important in the eradication of tuberculosis. Domestic cats are susceptible to multiple mycobacterial species including Mycobacterium bovis; however, their role in the epidemiology of bovine tuberculosis is not fully documented. The current study was an evaluation of the immune response in specific pathogen-free (SPF) cats stimulated with sensitinogen, a heat-killed M. bovis product, using the rapid test, multiple antigen print immunoassay (MAPIA), and bovine-purified protein derivative (bPPD) single skin test. Six cats were inoculated with sensitinogen subcutaneously on days 0 and 24; 2 noninoculated cats and 49 non-SPF cats were controls. Serial serum samples were collected during 135 days and assayed for M. bovis antibodies by rapid test and MAPIA. On day 123, bPPD skin test was performed and read at 48 and 72 hr. The bPPD test at 72 hr had a mean skin thickness of 0.3 mm for stimulated cats and 0.1 mm for controls. Rapid test identified 4 of 6 stimulated cats after bPPD injection. The MAPIA detected antibody against MPB83, 16/83, 16 kDa, and M. bovis culture filtrate (MBCF) antigens. All assays differentiated between stimulated and control cats; however, 7 of 49 non-SPF control cats had a reaction for either antigen MBCF or 16/83. These preliminary studies show potential for antemortem detection of M. bovis among domestic cats. Additional studies to better characterize virulent M. bovis infection in cats would be of value.

Complete genomic sequence and an infectious BAC clone of feline herpesvirus-1 (FHV-1).

Infection with feline herpesvirus-1 (FHV-1) is a major cause of upper respiratory and ocular diseases in Felidae. We report the first complete genomic sequence of FHV-1, as well as the construction and characterization of a bacterial artificial chromosome (BAC) clone of FHV-1, which contains the entire FHV-1 genome and has the BAC vector inserted at the left end of U(L). Complete genomic sequences were derived from both the FHV-1 BAC clone and purified virion DNA. The FHV-1 genome is 135,797bp in size with an overall G+C content of 45%. A total of 78 open reading frames were predicted, encoding 74 distinct proteins. The gene arrangement is collinear with that of most sequenced varicelloviruses. The virus regenerated from the BAC was very similar to the parental C-27 strain in vitro in terms of plaque morphology and growth characteristics and highly virulent in cats in a preliminary in vivo study.

In vitro comparison of plain radiography, double-contrast cystography, ultrasonography, and computed tomography for estimation of cystolith size.

OBJECTIVE: To compare accuracy of estimates of cystolith size obtained by means of plain radiography, double-contrast cystography, ultrasonography, and computed tomography. SAMPLE POPULATION: 30 canine cystoliths ranging from 1 to 11 mm in diameter with various mineral compositions. PROCEDURES: A bladder phantom model was created by filling a rubber balloon with saline (1% NaCl) solution and positioning it on top of a 2% gelatin cushion at the bottom of a water-filled 4-quart container. Cystoliths were individually placed in the bladder phantom and imaged by each of the 4 techniques. For each image, cystolith size was measured by 2 radiologists with computerized calipers, and size estimates were compared with actual cystolith size. RESULTS: Mean cystolith size estimates obtained by means of radiography, cystography, and computed tomography did not differ significantly from each other. However, for ultrasonographic images, mean +/- SD difference between actual and estimated cystolith size (2.95 +/- 0.73 mm) was significantly higher than mean difference for radiographic, cystographic, and computed tomographic images. For ultrasonography, mean +/- SD percentage overestimation in cystolith size was 68.4 +/- 51.5%. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that measurements of cystolith size obtained by means of ultrasonography may overestimate the true size. This suggests that cystolith size estimates obtained by means of ultrasonography should be interpreted with caution whenever cystolith size may influence patient management.

Changing paradigms of feline idiopathic cystitis.

Since 1996, when the authors assembled the existing body of knowledge about lower urinary tract disease in cats, the understanding of the biological behavior and pathologic features of naturally occurring feline idiopathic cystitis has increased. No single model explains all the biological variability observed in cats with idiopathic cystitis. The authors' experience and available evidence indicate that feline idiopathic cystitis represents a syndrome resulting from a number of separate underlying but potentially interrelated mechanisms rather than a disease with a single cause. Identification of safe and effective treatment and prevention strategies of feline idiopathic cystitis will likely vary, depending on the underlying causes.

Analysis of 451,891 canine uroliths, feline uroliths, and feline urethral plugs from 1981 to 2007: perspectives from the Minnesota Urolith Center.

Urolithiasis is a general term referring to the causes and effects of stones anywhere in the urinary tract. Urolithiasis should not be viewed conceptually as a single disease with a single cause, but rather as a sequela of multiple interacting underlying abnormalities. Thus, the syndrome of urolithiasis may be defined as the occurrence of familial, congenital, or acquired pathophysiologic factors that, in combination, progressively increase the risk of precipitation of excretory metabolites in urine to form stones (ie, uroliths). The following epidemiologic discussion is based on quantitative analysis of 350,803 canine uroliths, 94,778 feline uroliths, and 6310 feline urethral plugs submitted to the Minnesota Urolith Center from 1981 to 2007.

Prevalence of serum antibodies against six Leptospira serovars in healthy dogs.

OBJECTIVE: To determine the prevalence of antibodies against 6 Leptospira serovars and determine risk factors associated with positive Leptospira titers in healthy client-owned dogs in Michigan. DESIGN: Cross-sectional study. ANIMALS: 1,241 healthy dogs at least 4 months of age. PROCEDURES: Dogs were examined by veterinarians at private practices. Vaccinated and unvaccinated dogs were enrolled in the study, which occurred prior to the availability of a 4-serovar (Canicola, Grippotyphosa, Icterohaemorrhagiae, and Pomona) Leptospira vaccine. Sera were tested by use of the microscopic agglutination test to determine antibody titers against Leptospira serovars Bratislava, Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, and Pomona. A questionnaire was used to collect demographic information about each dog to identify risk factors associated with seropositive status. RESULTS: 309 of 1,241 (24.9%) dogs had antibody titers against at least 1 of the 6 Leptospira serovars, which suggested exposure to Leptospira spp. Prevalence of antibodies was highest to serovar Grippotyphosa, followed by Bratislava, Canicola, Icterohaemorrhagiae, and Pomona. Age, travel outside Michigan, exercise outside fenced yards, and exposure to livestock and wildlife were significant risk factors for positive titers. CONCLUSIONS AND CLINICAL RELEVANCE: Among healthy dogs from the lower peninsula of Michigan, > 20% have antibodies against leptospiral serovars historically considered uncommon but more recently incriminated as causing clinical canine leptospirosis. Wildlife and livestock may be of increasing importance as reservoirs for canine leptospirosis as urbanization continues to occur. Expanded vaccination strategies may partially mitigate these trends.