Objective—To determine the prevalence of infections
developing postoperatively, document the contribution
of infection to increased risk of death, and identify risk
factors associated with the development of infectious
complications in cats after renal transplantation.
Animals—169 cats that received renal allograft transplants.
Procedures—Medical records of cats receiving renal
transplants at the University of California from January
1987 through December 2003 were reviewed.
Results—47 infections developed in 43 of 169 cats.
Bacterial infections were most common (25/47 cats),
followed by viral (13/47), fungal (6/47), and protozoal
(3/47) infections. The median duration from transplant
surgery to development of infection was 2.5 months.
Infection was the second most common cause of
death after acute rejection of the transplant, accounting
for 14% of deaths overall. Cats with concurrent
diabetes mellitus had a significantly increased risk of
developing an infection after renal transplantation.
Sex, increasing age, concurrent neoplasia, and previous
treatment for transplant rejection were not associated
with development of infection.
Conclusions and Clinical Relevance—Infection was
a common complication and an important cause of
death or euthanasia in cats after renal transplantation.
Development of diabetes mellitus after transplantation
significantly increased the risk of infection. (J Am
Vet Med Assoc 2005;227:948–953)
Objectives—To evaluate clinical, laboratory, and necropsy findings in dogs with infective endocarditis (IE).
Design—Retrospective case series.
Animals—71 dogs with possible or definite IE.
Procedures—Medical records were reviewed for signalment, clinical features, and results of clinicopathologic testing and diagnostic imaging. Yearly incidence and the effect of variables on survival were determined by use of survival curve analysis.
Results—The overall incidence of IE was 0.05%. Most affected dogs were of large breeds, and > 75% were older than 5 years. The aortic valve was affected in 36 of the 71 (51%) dogs, and the mitral valve was affected in 59%. Lameness caused by immune-mediated polyarthritis, septic arthritis, or peripheral arterial thromboembolism was observed in 53% of the dogs. Neurologic complications were diagnosed in 17 of 71 (24%) dogs. Thromboembolic disease was suspected in 31 of 71 (44%) of dogs. The mortality rate associated with IE was 56%, and median survival time was 54 days. Factors negatively associated with survival included thrombocytopenia, high serum creatinine concentration, renal complications, and thromboembolic complications.
Conclusions and Clinical Relevance—A diagnosis of IE should be suspected in dogs with fever, systolic or diastolic murmur, and locomotor problems. Dogs with thrombocytopenia, high serum creatinine concentration, thromboembolism, or renal complications may have a shorter survival time.
Objective—To evaluate microbiologic findings in dogs with infective endocarditis (IE) and determine whether there were differences in clinical features of disease caused by different groups of infective agents.
Design—Retrospective case series.
Animals—71 dogs with suspected or definite IE.
Procedures—Medical records were reviewed for results of bacterial culture and susceptibility testing, serologic assays for vector-borne disease, and PCR testing on vegetative growths. Cases were grouped by causative organism and relationships among infectious agent group, and various hematologic, biochemical, and clinical variables were determined. Survival analyses were used to determine associations between infecting organisms and outcome.
Results—Causative bacteria were identified in 41 of 71 (58%) dogs. Gram-positive cocci were the causative agents in most (21/41; 51%) infections, with Streptococcus canis associated with 24% of infections. Gramnegative organisms were detected in 9 of the 41 (22%) dogs. Infection with Bartonella spp was detected in 6 of 31 (19%) dogs with negative results for microbial growth on blood culture. Aortic valve involvement and congestive heart failure were more frequent in dogs with endocarditis from Bartonella spp infection, and those dogs were more likely to be afebrile. Infection with Bartonella spp was negatively correlated with survival. Mitral valve involvement and polyarthritis were more frequent in dogs with streptococcal endocarditis.
Conclusions and Clinical Relevance—Streptococci were the most common cause of IE and were more likely to infect the mitral valve and be associated with polyarthritis. Dogs with IE secondary to Bartonella spp infection were often afebrile, more likely to develop congestive heart failure, rarely had mitral valve involvement, and had shorter survival times.
Objective—To determine within a cat shelter effects of dietary lysine supplementation on nasal and ocular disease and detection of nucleic acids of Chlamydophila felis, feline calicivirus (FCV), and feline herpesvirus (FHV-1).
Animals—261 adult cats.
Procedures—Cats were fed a diet containing 1.7% (basal diet; control cats) or 5.7% (supplemented diet; treated cats) lysine for 4 weeks. Plasma concentrations of lysine and arginine were assessed at the beginning (baseline) and end of the study. Three times a week, cats were assigned a clinical score based on evidence of nasal and ocular disease. Conjunctival and oropharyngeal swab specimens were tested for FHV-1, FCV, and C felis nucleic acids once a week.
Results—Data were collected from 123, 74, 59, and 47 cats during study weeks 1, 2, 3, and 4, respectively. By study end, plasma lysine concentration in treated cats was greater than that in control cats and had increased from baseline. There was no difference between dietary groups in the proportion of cats developing mild disease. However, more treated cats than control cats developed moderate to severe disease during week 4. During week 2, FHV-1 DNA was detected more commonly in swab specimens from treated versus control cats.
Conclusions and Clinical Relevance—Dietary lysine supplementation in the amount used in our study was not a successful means of controlling infectious upper respiratory disease within a cat shelter. Rather, it led to increases in disease severity and the incidence of detection of FHV-1 DNA in oropharyngeal or conjunctival mucosal swab specimens at certain time points.
Objective—To determine whether the active metabolite of leflunomide, A77 1726 (A77), inhibits replication of feline herpesvirus-1 (FHV-1) in cell culture.
Study Population—Crandell Rees feline kidney (CRFK) cell cultures.
Procedures—Cell cultures were inoculated with FHV-1 and treated simultaneously with concentrations of A77 ranging from 0 to 200μM. The antiviral effect of A77 was determined by use of conventional plaque reduction assays. The effect of A77 on viral load was determined via real-time PCR analysis, and transmission electron microscopy was used to evaluate the effect of A77 on viral morphology. To determine whether the antiviral effect was attributable to alterations in CRFK cell viability and number, CRFK cells were treated with various concentrations of A77 and stained with Annexin V and propidium iodide to assess apoptosis and a mitochondrial function assay was used to determine cell viability.
Results—Concentrations of A77 ≥ 20μM were associated with substantial reduction in plaque number and viral load. Concentrations ≥ 100μM were associated with complete suppression of plaque formation. At low concentrations of A77, clusters of intracytoplasmic virus particles that appeared to lack tegument and an external membrane were detected. Treatment of uninfected CRFK cell monolayers with A77 was associated with reduction in mitochondrial function with minimal evidence of apoptosis.
Conclusions and Clinical Relevance—Leflunomide may be an alternative to current calcineurin-based immunosuppressive protocols used in feline organ transplantation because of its antiherpesviral activity.
Objective—To compare clinical features of cryptococcosis among cats and dogs in California, determine whether the distribution of involved tissues differs from distribution reported previously in a study in southeastern Australia, and identify Cryptococcus spp isolated from the study population.
Design—Retrospective case series.
Animals—62 cats and 31 dogs with cryptococcosis.
Procedures—Medical records of cats and dogs with cryptococcosis were reviewed. Information collected included geographic location, species, signalment, and tissues or organs involved. Cryptococcosis was confirmed via serology, cytology, histology, or microbial culture, and molecular typing was performed. Odds ratios and 95% confidence intervals were calculated to determine significant associations among variables. Other comparisons were evaluated via χ2 or unpaired t tests.
Results—American Cocker Spaniels were overrepresented, compared with other dog breeds. Serum cryptococcal antigen test results were positive in 51 of 53 cats and 15 of 18 dogs tested. Cryptococcus gattii was more commonly detected in cats (7/9 for which species identification was performed), and Cryptococcus neoformans was more commonly detected in dogs (6/8). Six of 7 C gattii isolates from cats were molecular type VGIII. Distribution of involved tissues was different between cats and dogs in California and between populations of the present study and those of the previously reported Australian study.
Conclusions and Clinical Relevance—Strains of Cryptococcus spp appeared to have host specificity in dogs and cats. Differences in lesion distribution between geographic locations may reflect strain differences or referral bias. Antigen assays alone may not be sufficient for diagnosis of cryptococcosis in cats and dogs.