Search Results

Abstract

Objective—To conduct an epidemiological analysis of the spatial and temporal distribution of canine leptospirosis cases in northern California and detect spatial clustering in any region.

Design—Retrospective case-control study.

Animals—67 dogs with leptospirosis and 271 control dogs.

Procedures—Medical records of case and control dogs were reviewed. Spatial coordinates of home addresses of the study population were analyzed visually and statistically via a Cuzick-Edwards test and spatial, temporal, and space-time permutation scan statistics.

Results—Cases were distributed around the San Francisco Bay region as well as in the Sierra Nevada foothills near Sacramento, Calif, whereas controls were principally distributed along route I-80 between San Francisco and Sacramento, Calif. Clustering was found for the second through sixth nearest neighboring cases via the global spatial cluster test. A local spatial cluster of 30 cases was identified in San Francisco (95% confidence interval, 1.3 to 7.0), and a temporal cluster of 18 cases was identified from May 2003 through May 2004 (95% confidence interval, 1.4 to 6.5). No significant space-time cluster was identified.

Conclusions and Clinical Relevance—The use of geographic information systems provided a visual representation of the results of statistical analysis for the location and time at which leptospirosis cases occurred. This useful tool can be used to educate veterinary practitioners and the public about a potentially fatal zoonotic disease and direct vaccination strategies to help prevent disease occurrence.

Abstract

Objective—To determine prevalences of various hemoplasma species among cats in the United States with possible hemoplasmosis and identify risk factors for and clinicopathologic abnormalities associated with infection with each species.

Design—Cross-sectional study.

Animals—310 cats with cytologic evidence of hemoplasmosis (n = 9) or acute or regenerative anemia (309).

Procedures—Blood samples were tested by means of a broad-spectrum conventional PCR assay for hemoplasma DNA and by means of 3 separate species-specific real-time PCR assays for DNA from “Candidatus Mycoplasma haemominutum” (Mhm), Mycoplasma haemofelis (Mhf), and “Candidatus Mycoplasma turicensis” (Mtc).

Results—Overall prevalences of Mhm, Mhf, and Mtc infection were 23.2% (72/310), 4.8% (15/310), and 6.5% (20/310), respectively. Mixed infections were detected in 20 (6.5%) cats. Cats infected with hemoplasmas were more likely to be male than were uninfected cats. Infection with FeLV or FIV was significantly associated with infection with Mhf. Compared with uninfected cats, cats infected with Mhf had higher reticulocyte counts, nucleated RBC counts, and mean corpuscular volume; cats infected with Mhm had higher mean corpuscular volume; and cats infected with Mtc had higher monocyte counts.

Conclusions and Clinical Relevance—Results supported the suggestion that these 3 hemoplasma species commonly occur among cats in the United States and that pathogenicity of the 3 species varies.

Abstract

OBJECTIVE To determine pharmacokinetics and adverse effects after voriconazole administration to cats and identify an oral dose of voriconazole for cats that maintains plasma drug concentrations within a safe and effective range.

ANIMALS 6 healthy cats.

PROCEDURES Voriconazole (1 mg/kg, IV) was administered to each cat (phase 1). Serial plasma voriconazole concentrations were measured for 24 hours after administration. Voriconazole suspension or tablets were administered orally at 4, 5, or 6 mg/kg (phase 2). Plasma voriconazole concentrations were measured for 24 hours after administration. Pharmacokinetics of tablet and suspension preparations was compared. Finally, an induction dose of 25 mg/cat (4.1 to 5.4 mg/kg, tablet formulation), PO, was administered followed by 12.5 mg/cat (2.05 to 2.7 mg/kg), PO, every 48 hours for 14 days (phase 3). Plasma voriconazole concentration was measured on days 2, 4, 8, and 15.

RESULTS Voriconazole half-life after IV administration was approximately 12 hours. Maximal plasma concentration was reached within 60 minutes after oral administration. A dose of 4 mg/kg resulted in plasma concentrations within the target range (1 to 4 μg/mL). Adverse effects included hypersalivation and miosis. During long-term administration, plasma concentrations remained in the target range but increased, which suggested drug accumulation.

CONCLUSIONS AND CLINICAL RELEVANCE Voriconazole had excellent oral bioavailability and a long half-life in cats. Oral administration of a dose of 12.5 mg/cat every 72 hours should be investigated. Miosis occurred when plasma concentrations reached the high end of the target range. Therefore, therapeutic drug monitoring should be considered to minimize adverse effects.

Abstract

Leptospirosis is an archetypal One Health problem as described in the companion Currents in One Health article in the October 2022 issue of the Journal of the American Veterinary Medical Association by Sykes et al. A thorough understanding of leptospirosis requires a detailed analysis of the elaborate interplay among pathogenic leptospiral strains, host species, and the environment. Such an understanding is required to inform appropriate preventative measures including vaccine design, prophylaxis efforts, educational programs that help to reduce exposure to pathogenic spirochetes, as well as policy development. Because of the complex epidemiology of leptospirosis, a One Health approach as defined by the One Health Initiative Task Force is critical—an approach that calls for “the collaborative efforts of multiple disciplines working locally, nationally, and globally, to attain optimal health for people, animals and our environment.” Over the last three decades, progressive advances in cutting-edge molecular typing techniques, as well as our ability to rapidly generate and share large amounts of sequence data through establishment and growth of databases, have been central to accelerating a One Health understanding of the epidemiology of leptospirosis. Nevertheless, our dependence on serotype information because of the serovar-specific nature of current vaccines means that laborious serotyping efforts continue. With the advent of new approaches such as mRNA vaccines that are based on lipopolysaccharide immunogens, sequence- and/or proteomics-based typing methods may replace these methods.

Abstract

Leptospirosis is a quintessential one health disease of humans and animals caused by pathogenic spirochetes of the genus Leptospira. Intra- and interspecies transmission is dependent on 1) reservoir host animals in which organisms replicate and are shed in urine over long periods of time, 2) the persistence of spirochetes in the environment, and 3) subsequent human-animal-environmental interactions. The combination of increased flooding events due to climate change, changes in human-animal-environmental interactions as a result of the pandemic that favor a rise in the incidence of leptospirosis, and under-recognition of leptospirosis because of nonspecific clinical signs and severe signs that resemble COVID-19 represents a “perfect storm” for resurgence of leptospirosis in people and domestic animals. Although often considered a disease that occurs in warm, humid climates with high annual rainfall, pathogenic Leptospira spp have recently been associated with disease in animals and humans that reside in semiarid regions like the southwestern US and have impacted humans that have a wide spectrum of socioeconomic backgrounds. Therefore, it is critical that physicians, veterinarians, and public health experts maintain a high index of suspicion for the disease regardless of geographic and socioeconomic circumstances and work together to understand outbreaks and implement appropriate control measures. Over the last decade, major strides have been made in our understanding of the disease because of improvements in diagnostic tests, molecular epidemiologic tools, educational efforts on preventive measures, and vaccines. These novel approaches are highlighted in the companion Currents in One Health by Sykes et al, AJVR, September 2022.

Abstract

Objective—To determine incidence rates (IRs) and potential risk factors for owner-reported adverse events (AEs) following vaccination of dogs that did or did not receive a Leptospira vaccine.

Design—Observational, retrospective cohort study.

Animals—130,557 dogs.

Procedures—Electronic records of mobile veterinary clinics from June 2012 to March 2013 were searched to identify dogs that received ≥ 1 vaccine in a given visit. Signalment data, vaccinations received, medications administered, and owner-reported clinical signs consistent with AEs that developed ≤ 5 days after vaccination were recorded. Associations between potential risk factors and owner-reported AEs were evaluated by logistic regression analysis.

Results—The IR/10,000 dogs for owner-reported postvaccination AEs was 26.3 (95% CI, 23.6 to 29.2), whereas that for dogs that received a Leptospira vaccine alone or with other vaccines was 53.0 (95% CI, 42.8 to 64.9). Significant factors for increasing or decreasing risk of AEs were as follows: receiving a Leptospira vaccine (adjusted OR, 2.13), age at vaccination 1 to < 7 or ≥ 7 years (vs a referent of < 6 months; adjusted OR, 0.54 and 0.44, respectively), and weight 13.6 to < 22.7 kg (30 to < 50 lb) and 22.7 to < 45.5 kg (50 to 100 lb [vs a referent of < 4.5 kg {10 lb}]; adjusted OR, 0.48 and 0.55, respectively). Hypersensitivity reactions were rare (IR, 6.5/10,000 dogs), and IRs for these events did not differ significantly between dogs vaccinated with or without a Leptospira component.

Conclusions and Clinical Relevance—The overall IR for owner-reported postvaccination AEs was low. Results suggested vaccination against Leptospira (an organism that can cause fatal disease) is safe in the majority of cases, slightly increasing the risk of owner-reported AEs but not associated with a significant increase in hypersensitivity reactions, compared with other vaccinations administered.

Abstract

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.

Design—Retrospective study.

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)

Abstract

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.

Abstract

Objective—To evaluate the performance of a veterinary urine dipstick paddle (UDP) for diagnosis and identification of urinary tract infection (UTI) in dogs and cats.

Design—Prospective, randomized, blinded study.

Sample—207 urine specimens.

Procedures—UDPs were inoculated by 2 investigators and incubated according to manufacturer's instructions. Results, including presence or absence of bacterial growth, organism counts, and identification of uropathogens, were compared between investigators and with microbiology laboratory results. A subset of UDPs with bacterial growth was submitted to the laboratory for confirmation.

Results—The laboratory reported 64 (30.9%) specimens had growth of bacteria. Bacterial growth was reported for 63 (30.4%) and 58 (28.0%) of the UDPs by investigators 1 and 2, respectively. Sensitivity and specificity of the UDP for detection of bacterial growth were 97.3% and 98.6%, respectively, for investigator 1 and 89.1% and 99.3%, respectively, for investigator 2. For UPDs with ≥ 10⁵ colony-forming units/mL, organism counts correlated well between the laboratory and investigators 1 (r = 0.95) and 2 (r = 0.89). Pathogen identification was not always accurate. Only 25 of 33 (75.8%) UDPs submitted for confirmation yielded bacteria consistent with those isolated from the original bacterial culture of urine.

Conclusions and Clinical Relevance—The veterinary UDP system was a sensitive test for screening patients for bacterial UTI, but uropathogen identification was not always accurate. When UDPs have bacterial growth, a fresh urine specimen should be submitted to the laboratory to confirm the identity of the organisms and to permit antimicrobial susceptibility testing.