Kate F. Hurley

A Clonal Outbreak of Acute Fatal Hemorrhagic Pneumonia in Intensively Housed (Shelter) Dogs Caused by Streptococcus equi subsp. zooepidemicus

An outbreak of acute, fatal, hemorrhagic pneumonia was observed in more than 1,000 mixed breed dogs in a single animal shelter. The Department of Anatomic Pathology at the University of California at Davis School of Veterinary Medicine performed necropsies on dogs that were found moribund in acute respiratory distress or found dead with evidence of nasal bleeding. All dogs had hemothorax and an acute, fibrinosuppurative pneumonia. Large numbers of gram-positive cocci were observed within the lungs of all dogs and within septic thromboemboli of remote organs in about 50% of cases. Bacterial cultures from the dogs and their environment revealed widespread beta-hemolytic Streptococus equi subspecies zooepidemicus (Lancefield Group C). Extensive diagnostic testing failed to reveal the consistent presence of copathogens in individual cases. The clinical, epidemiologic, molecular biologic, and pathologic data indicate that a single clone of S. zooepidemicus was the cause of an acutely fatal respiratory infection in these dogs.

Pathologic, Immunohistochemical, and Electron Microscopic Findings in Naturally Occurring Virulent Systemic Feline Calicivirus Infection in Cats:

Infection with feline calicivirus (FCV) is a common cause of upper respiratory and oral disease in cats. FCV infection is rarely fatal, however, virulent, systemic strains of FCV (VS-FCV) that cause alopecia, cutaneous ulcers, subcutaneous edema, and high mortality in affected cats have recently been described. Seven cats with natural VS-FCV infection all had subcutaneous edema and ulceration of the oral cavity, with variable ulceration of the pinnae, pawpads, nares, and skin. Other lesions that were present in some affected cats included bronchointerstitial pneumonia, and pancreatic, hepatic, and splenic necrosis. Viral antigen was present within endothelial and epithelial cells in affected tissues as determined by immunohistochemical staining with a monoclonal antibody to FCV. Mature intranuclear and intracytoplasmic virions in necrotic epithelial cells were identified by transmission electron microscopy. VS-FCV infection causes epithelial cell cytolysis and systemic vascular compromise in susceptible cats, leading to cutaneous ulceration, severe edema, and high mortality.

2013 AAFP Feline Vaccination Advisory Panel Report

Rationale: This Report was developed by the Feline Vaccination Advisory Panel of the American Association of Feline Practitioners (AAFP) to provide practical recommendations to help clinicians select appropriate vaccination schedules for their feline patients based on risk assessment. The recommendations rely on published data as much as possible, as well as consensus of a multidisciplinary panel of experts in immunology, infectious disease, internal medicine and clinical practice.

Update on feline calicivirus: new trends.

In addition to being important upper respiratory tract pathogens of cats, FCVs are increasingly reported as a cause of a highly contagious febrile hemorrhagic syndrome. Strains causing this syndrome are genetically different from the vaccine strain and other nonhemorrhagic FCV isolates. They apparently differ from one outbreak to another. The syndrome is characterized variably by fever; cutaneous edema and ulcerative dermatitis; upper respiratory tract signs; anorexia; occasionally icterus, vomiting, and diarrhea; and a mortality that approaches 50%. Adult cats tend to be more severely affected than kittens, and vaccination does not appear to have a significant protective effect. Rapid recognition of the disease through identification of clinical signs and appropriate testing, followed by strict institution of disinfection, isolation, and quarantine measures, are essential to prevent widespread mortality resulting from the infection.

Associations among weight loss, stress, and upper respiratory tract infection in shelter cats

OBJECTIVE To identify associations among change in body weight, behavioral stress score, food intake score, and development of upper respiratory tract infection (URI) among cats admitted to an animal shelter. DESIGN Prospective cohort study. Animals-60 adult cats admitted to an animal shelter. PROCEDURES Body weight was measured on days 0 (intake), 7, 14, and 21. Behavioral stress and food intake were scored daily for the first 7 days; cats were monitored daily for URI. RESULTS 49 of the 60 (82%) cats lost weight during at least 1 week while in the shelter. Fifteen (25%) cats lost ≥ 10% of their body weight while in the shelter. Thirty-five of the 60 (58%) cats developed URI prior to exiting the shelter, and only 4 cats remained at least 21 days without developing URI. Cats with high stress scores during the first week were 5.6 times as likely to develop URI as were cats with low stress scores. Food intake and stress scores were negatively correlated (r = -0.98). CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that cats admitted to an animal shelter were likely to lose weight while in the shelter and likely to develop URI, and that cats that had high stress scores were more likely to develop URI.

2006 AAHA Canine Vaccine Guidelines

In 2005, AAHAs Canine Vaccine Task Force met to reexamine and revise guidelines on the use of vaccines in dogs. The results of the Task Forces work are summarized and tabulated in this article and are published in their entirety on the AAHA website (www.aahanet.org). The 2006 AAHA Canine Vaccine Guidelines contain information on new technological developments in vaccines, an introduction to conditionally licensed vaccines, and detailed recommendations on the use of available vaccines. Perhaps the most noteworthy addition to the guidelines is a separate set of recommendations created for shelter facilities. Vaccines are classified as core (universally recommended), noncore (optional), or not recommended. The Task Force recognizes that vaccination decisions must always be made on an individual basis, based on risk and lifestyle factors.

Virulent systemic feline calicivirus infection: local cytokine modulation and contribution of viral mutants.

Virulent systemic feline calicivirus (VS-FCV) is a novel, emerging pathogen with mortality up to 67% even in previously healthy adult cats; VS-FCV has resulted in at least six epidemics since 1998. Affected cats have systemic vascular compromise and hemorrhagic-fever like signs in part due to viral invasion of epithelium and endothelium, coupled with host cytokine responses. Affected skin tissues had, on average, 3.8 elevated cytokines compared with control tissue, with prominent upregulation in IL-10, TNF-α, and MIP-1α. Sequencing of most of the genomes of two VS-FCV strains documented patterns of virus relatedness and implicated changes in the capsid gene in the emerging phenotype, possibly through initiation of immune mechanisms manifest in the cytokine changes. Understanding the features contributing to the emergence of this disease is critical for management and prevention of this and similar outbreaks attributable to RNA viruses in animals and humans.

Effects of dietary lysine supplementation on upper respiratory and ocular disease and detection of infectious organisms in cats within an animal shelter.

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.

Fatal Streptococcus canis Infections in Intensively Housed Shelter Cats

Three independent, fatal outbreaks of Streptococcus canis infection occurred in a 2-year period in shelter cats. The outbreaks occurred in Northern California (Yolo County), Southern California (Kern County), and North Carolina (Guilford County). An estimation of the affected population is >150 cats among 3 affected shelters, with a mortality rate of up to 30%. Among 20 cats submitted for necropsy there were 2 distinct pathologic presentations. The first (shelters 1 and 2) was skin ulceration and chronic respiratory infection that progressed, in some cats, to necrotizing sinusitis and meningitis. The second (shelter 3) was rapid progression from necrotizing fasciitis with skin ulceration to toxic shock-like syndrome, sepsis, and death. S canis was the sole pathogen identified in most cases. Whether hypervirulent S canis strains exist is unknown; there is little understanding of how these bacteria cause invasive disease in cats.

Feline infectious disease control in shelters

No single factor determines whether a population remains healthy or disease rages out of control. All host and environmental factors taken together provide a number of tools to protect the vulnerable feline shelter population,however. A well-conceived infectious disease control program contributes to improved public perception, increased adoptions, and a healthier feline population within the shelter and in the community in general.