Emerging canine leptospirosis in Sydney and the role of population demographics.

An outbreak of canine leptospirosis commenced in Sydney, Australia in 2017. The aim of this retrospective study was to determine if clusters of leptospirosis occurred during this outbreak, and if these were associated with host factors, to assist investigation of the drivers of emerging leptospirosis at this location. Within the City of Sydney local government area, 13 cases were reported during the outbreak. Administrative data on the canine population were collected and mapped. Clusters of leptospirosis cases were detected using a retrospective space-time analysis and a discrete Poisson probability statistical model. Sydney dog population registration [55.6%, 95% confidence interval (CI) 51.8-58.1%] was lower than the Australian national average (80%). The distribution of dog types, based on the United Kennel Club standards, was significantly (p < .0001) different to that of the national profile: there was a distinct preference in Sydney for companion dogs. The age distribution of dogs in Sydney did not reflect a typical right-skewed curve; instead, a relatively uniform distribution was observed between the age group of 1 to 8 years. A primary disease cluster (radius 1.1 km) in the eastern area of the Sydney City Council was identified (4 cases observed between 24 May and 9 August 2019 vs. 0.10 cases expected), p = .0450. When adjusted for the age, breed type and sex distribution of the population, similar clusters were identified; in the case of age-adjustment, the spatiotemporal cluster identified was larger and of longer duration (seven cases observed between 28 June and 11 November 2019 versus 0.34 cases expected), p = .0025. The presence of clusters of canine leptospirosis in the City of Sydney during this outbreak, which persisted after adjustment for demographics (age, sex, breed type), suggest that environmental factors - rather than host or pathogen factors - might be responsible for the emergence of leptospirosis. Environmental factors that potentially might be linked to this outbreak of canine leptospirosis and the clusters observed require investigation.

Current status on treatment options for feline infectious peritonitis and SARS-CoV-2 positive cats.

Feline infectious peritonitis (FIP) is a viral-induced, immune-mediated disease of cats caused by virulent biotypes of feline coronaviruses (FCoV), known as the feline infectious peritonitis virus (FIPV). Historically, three major pharmacological approaches have been employed to treat FIP: (1) immunomodulators to stimulate the patient's immune system non-specifically to reduce the clinical effects of the virus through a robust immune response, (2) immunosuppressive agents to dampen clinical signs temporarily, and (3) re-purposed human antiviral drugs, all of which have been unsuccessful to date in providing reliable efficacious treatment options for FIPV. Recently, antiviral studies investigating the broad-spectrum coronavirus protease inhibitor, GC376, and the adenosine nucleoside analogue GS-441524, have resulted in increased survival rates and clinical cure in many patients. However, prescriber access to these antiviral therapies is currently problematic as they have not yet obtained registration for veterinary use. Consequently, FIP remains challenging to treat. The purpose of this review is to provide an update on the current status of therapeutics for FIP. Additionally, due to interest in coronaviruses resulting from the current human pandemic, this review provides information on domesticated cats identified as SARS-CoV-2 positive.

Pharmacokinetic Profile of Oral Administration of Mefloquine to Clinically Normal Cats: A Preliminary In-Vivo Study of a Potential Treatment for Feline Infectious Peritonitis (FIP).

The pharmacokinetic profile of mefloquine was investigated as a preliminary study towards a potential treatment for feline coronavirus infections (such as feline infectious peritonitis) or feline calicivirus infections. Mefloquine was administered at 62.5 mg orally to seven clinically healthy cats twice weekly for four doses and mefloquine plasma concentrations over 336 h were measured using high pressure liquid chromatography (HPLC). The peak plasma concentration (Cmax) after a single oral dose of mefloquine was 2.71 ug/mL and time to reach Cmax (Tmax) was 15 h. The elimination half-life was 224 h. The plasma concentration reached a higher level at 4.06 ug/mL when mefloquine was administered with food. Adverse effects of dosing included vomiting following administration without food in some cats. Mild increases in serum symmetric dimethylarginine (SDMA), but not creatinine, concentrations were observed. Mefloquine may provide a safe effective treatment for feline coronavirus and feline calicivirus infections in cats.