A One Health approach to the epidemiology, management, surveillance, and control of leptospirosis relies on accessible and accurate diagnostics that can be applied to humans and companion animals and livestock. Diagnosis should be multifaceted and take into account exposure risk, clinical presentation, and multiple direct and/or indirect diagnostic approaches. Methods of direct detection of Leptospira spp. include culture, histopathology and immunostaining of tissues or clinical specimens, and nucleic acid amplification tests (NAATs). Indirect serologic methods to detect leptospiral antibodies include the microscopic agglutination test (MAT), the enzyme-linked immunosorbent assay (ELISA), and lateral flow methods. Rapid diagnostics that can be applied at the point-of-care; NAAT and lateral flow serologic tests are essential for management of acute infection and control of outbreaks. Culture is essential to an understanding of regional knowledge of circulating strains, and we discuss recent improvements in methods for cultivation, genomic sequencing, and serotyping. We review the limitations of NAATs, MAT, and other diagnostic approaches in the context of our expanding understanding of the diversity of pathogenic Leptospira spp. Novel approaches are needed, such as loop mediated isothermal amplification (LAMP) and clustered regularly interspaced short palindromic repeats (CRISPR)-based approaches to leptospiral nucleic acid detection.

Background: Awareness of prescribing practices helps identify opportunities to improve antibiotic use (AU). Objectives: To estimate AU prevalence in dogs and cats in U.S. veterinary teaching hospitals (VTHs) and identify antibiotic drugs commonly prescribed, indications for use, and evidence of bacterial infection. Animals: Medical record data were collected from dogs and cats examined at 14 VTHs. Methods: Data were collected from VTH medical records of dogs and cats examined by primary care, urgent care, emergency and critical care, internal medicine, and surgery services on a single day during August 13-September 3, 2020. Data included signalment; clinical service; inpatient or outpatient status; clinical conditions; diagnostic tests; evidence of bacterial infection; intended reason for AU; name and route of antibiotics prescribed. Results: Of 883 dogs and cats, 322 (36.5%) were prescribed at least 1 antibiotic. Among 285 antibiotics administered systemically intended for treatment of infection, 10.9% were prescribed without evidence of infection. The most common class of antibiotics presribed for systemic administration was potentiated penicillin for dogs (115/346, 33.3%) and cats (27/80, 33.8%). For dogs and cats, first-generation cephalosporins (93/346, 26.9% and 11/80, 13.8%, respectively) and fluoroquinolones (51/346, 14.7% and 19/80, 23.8%, respectively) was second or third most-prescribed. Common AU indications included skin, respiratory, and urinary conditions, and perioperative use. Conclusions and Clinical Importance: Collaborative data collection provides a sustainable methodology to generate national AU prevalence estimates and bring attention to areas requiring additional research and detailed data collection. These efforts can also identify practice improvement opportunities in settings where future veterinarians are trained.

Feline infectious peritonitis (FIP) is a fatal disease of cats that currently lacks licensed and affordable vaccines or antiviral therapeutics. The disease has a spectrum of clinical presentations including an effusive (“wet”) form and non-effusive (“dry”) form, both of which may be complicated by neurologic or ocular involvement. The feline coronavirus (FCoV) biotype, termed feline infectious peritonitis virus (FIPV), is the etiologic agent of FIP. The objective of this study was to determine and compare the in vitro antiviral efficacies of the viral protease inhibitors GC376 and nirmatrelvir and the nucleoside analogs remdesivir (RDV), GS-441524, molnupiravir (MPV; EIDD-2801), and β-D-N⁴-hydroxycytidine (NHC; EIDD-1931). These antiviral agents were functionally evaluated using an optimized in vitro bioassay system. Antivirals were assessed as monotherapies against FIPV serotypes I and II and as combined anticoronaviral therapies (CACT) against FIPV serotype II, which provided evidence for synergy for selected combinations. We also determined the pharmacokinetic properties of MPV, GS-441524, and RDV after oral administration to cats in vivo as well as after intravenous administration of RDV. We established that orally administered MPV at 10 mg/kg, GS-441524 and RDV at 25 mg/kg, and intravenously administered RDV at 7 mg/kg achieves plasma levels greater than the established corresponding EC₅₀ values, which are sustained over 24 h for GS-441514 and RDV.

Background Candida urinary tract infections occur in both dogs in cats but there is limited data about risk factors. Objective To identify risk factors for candiduria in dogs in cats. Animals Eighteen dogs and 8 cats with candiduria. Methods A retrospective case‐control study, using univariate exact logistic regression. Medical records were searched for a diagnosis of Candida and animals with culture‐confirmed candiduria were enrolled. Controls had bacterial cystitis (dogs and cats) or cutaneous Malassezia infection (dogs only). Results Administration of antibacterial drugs in the 30 days before diagnosis was associated with candiduria in dogs compared to controls with bacterial cystitis (OR 14.5; 95% CI 3.1‐66.9) or with Malassezia infection (OR 26.4; 95% CI 3.4‐206.7). Antecedent antibacterial drug administration was associated with candiduria in cats (OR 15.7; 95% CI 1.9‐132.3). Immunosuppression was associated with candiduria in dogs when compared to controls with Malassezia infection (OR 4.2, 95% CI 1.4‐12.8), but not significantly when compared to dogs with bacterial cystitis (OR 2.7, 95% CI 0.9‐8.0). Lower urinary tract diseases other than infection were associated with candiduria in cats (OR 6.7, 95% CI 1.6‐27.9), but not significantly in dogs (OR 2.5, 95% CI 0.7‐8.7). Neither diabetes mellitus nor history of hospitalization was significantly associated with candiduria in either species. Conclusions and clinical importance The recent administration of antibacterial drug therapy is a potential risk factor for development of candiduria in dogs and cats. Judicious use of antibacterial drugs might help to prevent candiduria.