Pyogranulomatous panophthalmitis with systemic coronavirus disease in a domestic ferret (Mustela putorius furo)

Detection of Airborne Influenza A and SARS-CoV-2 Virus Shedding following Ocular Inoculation of Ferrets

Despite reports of confirmed human infection following ocular exposure with both influenza A virus (IAV) and SARS-CoV-2, the dynamics of virus spread throughout oculonasal tissues and the relative capacity of virus transmission following ocular inoculation remain poorly understood. Furthermore, the impact of exposure route on subsequent release of airborne viral particles into the air has not been examined previously. To assess this, ferrets were inoculated by the ocular route with A(H1N1)pdm09 and A(H7N9) IAVs and two SARS-CoV-2 (early pandemic Washington/1 and Delta variant) viruses. Virus replication was assessed in both respiratory and ocular specimens, and transmission was evaluated in direct contact or respiratory droplet settings. Viral RNA in aerosols shed by inoculated ferrets was quantified with a two-stage cyclone aerosol sampler (National Institute for Occupational Safety and Health [NIOSH]). All IAV and SARS-CoV-2 viruses mounted a productive and transmissible infection in ferrets following ocular inoculation, with peak viral titers and release of virus-laden aerosols from ferrets indistinguishable from those from ferrets inoculated by previously characterized intranasal inoculation methods. Viral RNA was detected in ferret conjunctival washes from all viruses examined, though infectious virus in this specimen was recovered only following IAV inoculation. Low-dose ocular-only aerosol exposure or inhalation aerosol exposure of ferrets to IAV similarly led to productive infection of ferrets and shedding of aerosolized virus. Viral evolution during infection was comparable between all inoculation routes examined. These data support that both IAV and SARS-CoV-2 can establish a high-titer mammalian infection following ocular exposure that is associated with rapid detection of virus-laden aerosols shed by inoculated animals. IMPORTANCE Documented human infection with influenza viruses and SARS-CoV-2 has been reported among individuals wearing respiratory protection in the absence of eye protection, highlighting the capacity of these respiratory tract-tropic viruses to exploit nonrespiratory routes of exposure to initiate productive infection. However, comprehensive evaluations of how ocular exposure may modulate virus pathogenicity and transmissibility in mammals relative to respiratory exposure are limited and have not investigated multiple virus families side by side. Using the ferret model, we show that ocular exposure with multiple strains of either coronaviruses or influenza A viruses leads to an infection that results in shedding of detectable aerosolized virus from inoculated animals, contributing toward onward transmission of both viruses to susceptible contacts. Collectively, these studies support that the ocular surface represents a susceptible mucosal surface that, if exposed to a sufficient quantity of either virus, permits establishment of an infection which is similarly transmissible as that following respiratory exposure.

Ferret Systemic Coronavirus in Alpha-1 Antitrypsin Knockout Ferrets

Ferret systemic coronavirus (FRSCV) causes a highly fatal disease of ferrets (Mustela putorius furo). It is believed to be a mutated variant of ferret enteric coronavirus (FRECV) and has a clinical presentation similar to that of feline infectious peritonitis virus (FIPV) in cats. The interplay of infectious diseases and host genetics will become a greater issue in the research environment as genetically modified species other than rodents become available due to advances in gene editing technology. In this case series, we present the clinical and histopathologic features of a FRSCV outbreak that affected 5 out of 10 ferrets with α-1 antitrypsin knockout (AAT KO) over an approximately 1-y period. Clinical features varied, with the affected ferrets presenting with some combination of wasting, hind limb paralysis, incontinence or sudden death. Multiple ferrets had gross pathologic lesions consistent with FRSCV, but the lesions were typically mild. Microscopic pyogranulomatous inflammation was present in 4 ferrets. Immunohistochemistry using an anti-feline coronavirus antibody that cross reacts with ferret coronavirus confirmed infection of intralesional macrophages in 4 out of 5 animals with suspected FRSCV infection. PCR testing of formalin fixed tissue was negative for all ferrets. PCR testing of feces from healthy wild-type ferrets indicated that the endemic presence of FRECV genotype 2, while PCR surveillance testing of other in-house AAT KO ferrets revealed both enteric coronavirus genotypes 1 and 2. This case series highlights the potential for greater disease incidence in the future as genetically modified ferrets are used more often, and may support exclusion of FRECV and similar viruses from highly susceptible ferret genotypes.

Updates on Coronavirus-Related Ocular Manifestations: From the Past to COVID-19 Pandemic

Context: Coronaviruses are the largest RNA viruses associated with some ocular manifestations. There are various contradictory reports about the ocular manifestations of coronaviruses in humans. Different ocular tissues can affect coronavirus-associated infectious diseases. Evidence Acquisition: All manuscripts were collected from PubMed, Google Scholar, and other relevant databases. All searches were done by specific keywords, including "coronavirus," "ocular disease," and "eye." Results: There are various contradictory reports about the ocular effects of coronaviruses in humans. Different ocular tissues are involved in coronavirus-associated infectious diseases. The ductal connection between the upper respiratory tract and eye mucosa through the nasolacrimal duct can be an entrance to respiratory viruses, such as coronaviruses. The coronavirus can infect the retina, conjunctiva, cornea, and uvea of the eye. The primary SARS-CoV-2 receptor, ACE2, is mainly expressed in the posterior tissues of the eye, such as the retina and RPE. Feline CoV, SARS-CoV, MERS-CoV, and infectious bronchitis virus (IBV) are responsible for conjunctiva involvement in coronavirus-related ocular pathogenesis. Also, various studies are held on COVID-19 and the impact of the conjunctiva on diagnosis and medical complications. Given that the cornea has an acceptable expression of ACE2 and TMPRSS2 genes compared to lung tissue, some studies were done on the impact of the cornea in COVID-19. Feline infectious peritonitis virus (FIPV) is also related to uvea complications. The experiments of human and animal models on the effects of coronaviruses on the retina and cornea in the event of various epidemics of coronaviruses and new and unknown ocular complications can be of great help to future studies. Conclusions: Given the importance of investigating the pathogenesis and other routes of SARS-CoV-2 infection, especially in areas other than the respiratory tract, this report attempts to highlight the importance of eye infections caused by the virus, its role in maintaining the virus transmission chain, and its impact on public health.

Coronaviruses Associated with the Superfamily Musteloidea

Among the animal superfamily Musteloidea, which includes those commonly known as mustelids, naturally occurring and species-specific alphacoronavirus infections have been observed in both mink (Mustela vison/Neovison vison) and domestic ferrets (Mustela putorius furo). Ferret systemic coronavirus (FRSCV), in particular, has been associated with a rare but fatal systemic disease. In recent months, it has become apparent that both minks and ferrets are susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a betacoronavirus and the cause of the coronavirus disease 2019 (COVID-19) pandemic. Several mink farms have experienced SARS-CoV-2 outbreaks, and experimental models have demonstrated susceptibility of ferrets to SARS-CoV-2. The potential for pet ferrets to become infected with SARS-CoV-2, however, remains elusive. During the 2002-2003 SARS epidemic, it was also apparent that ferrets were susceptible to SARS-CoV and could be utilized in vaccine development. From a comparative standpoint, understanding the relationships between different infections and disease pathogenesis in the animal superfamily Musteloidea may help elucidate viral infection and transmission mechanisms, as well as treatment and prevention strategies for coronaviruses.

Granulomatous inflammation in pulmonary pathology of 2019 novel coronavirus pneumonia: case report with a literature review

Background

Coronavirus disease 2019 (COVID-19), which started in Wuhan, China, in late December 2019, was declared a pandemic, infecting more than twelve million people worldwide. Few studies have reported the findings of lung biopsies in COVID-19. Here, granulomatous inflammation was reported for the first time in COVID-19 lung biopsy.

Case presentation

A 54-year-old woman presented to a primary care facility with fever, dry cough, and fatigue. Antibiotherapy was administered for 10 days with the diagnosis of upper respiratory tract infection. However, her condition did not improve and she was admitted to the hospital. In physical examination, crepitant rales were heard in both lungs. Anemia and thrombocytopenia were detected in laboratory tests and she was referred to the hematology clinic. Bone marrow aspiration and flow cytometry showed she had acute myeloid leukemia. Computed tomography-integrated positron emission tomography with a history of previous breast cancer revealed a heterogeneous mass-like lesion in the left lung. The primary malignancy could not be ruled out and tru-cut biopsy was performed. Tests for tuberculosis were negative. Throat swab sample was taken and a real-time polymerase chain reaction confirmed that she had COVID-19. Radiological findings were evaluated as the progression of COVID-19 pneumonia on computed tomography 6 days after biopsy. Alveolar damage, edema, vascular congestion, mild inflammatory infiltration, type-2 pneumocyte hyperplasia, interstitial fibrosis, early fibrotic changes, fibrinous, organized pneumonia pattern, noncaseating granulomatous inflammation, and desquamation in alveolar epithelial cells were noted in lung biopsy.

Conclusions

There were only a few case reports that described lung biopsy findings in COVID-19 at the time of manuscript preparation. This was the first case of noncaseating granulomatous inflammation described in a COVID-19 case.

Disease Overview of the Urinary Tract in Exotic Companion Mammals and Tips on Clinical Management

Diseases of the urinary tract are reviewed, covering infectious (bacterial, viral, parasitic), degenerative, congenital, metabolic, nutritional, neoplastic, obstructive, and toxic causes. Some clinical presentations and diagnostic procedures are described for ferrets, rabbits, guinea pigs, hamsters, mice, rats, chinchillas, hedgehogs, and sugar gliders, as well as therapies.

Ocular Examination and Corneal Surface Disease in the Ferret

This article provides a brief, clinically relevant review of corneal surface disease in the ferret. A description of the ophthalmic examination of the ferret is provided. Stepwise descriptions of the most common ophthalmic abnormalities are provided, along with common rule-outs.

Protease inhibitors broadly effective against feline, ferret and mink coronaviruses

Ferret and mink coronaviruses typically cause catarrhal diarrhea in ferrets and minks, respectively. In recent years, however, systemic fatal coronavirus infection has emerged in ferrets, which resembles feline infectious peritonitis (FIP) in cats. FIP is a highly fatal systemic disease caused by a virulent feline coronavirus infection in cats. Despite the importance of coronavirus infections in these animals, there are no effective commercial vaccines or antiviral drugs available for these infections. We have previously reported the efficacy of a protease inhibitor in cats with FIP, demonstrating that a virally encoded 3C-like protease (3CLpro) is a valid target for antiviral drug development for coronavirus infections. In this study, we extended our previous work on coronavirus inhibitors and investigated the structure-activity relationships of a focused library of protease inhibitors for ferret and mink 3CLpro. Using the fluorescence resonance energy transfer assay, we identified potent inhibitors broadly effective against feline, ferret and mink coronavirus 3CLpro. Multiple amino acid sequence analysis and modelling of 3CLpro of ferret and mink coronaviruses were conducted to probe the structural basis for these findings. The results of this study provide support for further research to develop broad-spectrum antiviral agents for multiple coronavirus infections. To the best of our knowledge, this is the first report on small molecule inhibitors of ferret and mink coronaviruses.

Pancreatitis and Systemic Coronavirus Infection in a Ferret (Mustela putorius furo)

A 1-y-old spayed female ferret (Mustela putorius furo) was referred for additional diagnostic evaluation after physical examination by the referring veterinarian revealed a cranial abdominal mass. The ferret had a 2-wk history of inappetence, weight loss, and lethargy. On presentation, the ferret was thin, and an approximately 3-cm mass was palpable in the cranial abdomen. No other abnormalities were noted. Abdominal ultrasonography confirmed the presence of a soft-tissue structure, with a moderate blood supply and mesenteric lymphadenopathy. Fine-needle aspirates of the mass were nondiagnostic. Exploratory laparotomy revealed multiple nodules and thickened tissues throughout the mesentery, a thickened and nodular pancreas, and a small amount of free abdominal fluid. Histopathology of mesenteric, lymphatic, and pancreatic biopsies revealed suppurative pancreatitis and necrotizing and pyogranulomatous mesenteric steatitis. Positive immunohistochemistry for feline coronavirus confirmed a diagnosis of ferret systemic coronavirus disease (FSCD). The ferret was treated medically with oral prednisolone, improved dramatically, and was still doing well 22 mo after diagnosis. Although FSCD has been reported extensively, this case is noteworthy for the presence of suppurative pancreatitis and the positive long-term outcome after corticosteroid therapy.

Radiographic and ultrasonographic findings of the spleen and abdominal lymph nodes in healthy domestic ferrets

Objective

To describe the radiographic and ultrasonographic characteristics of the spleen and abdominal lymph nodes in clinically healthy ferrets.

Materials and Methods

Fifty‐five clinically healthy ferrets were prospectively recruited for this cross‐sectional study. Three‐view whole body radiographs and abdominal ultrasonography were performed on awake (23 out of 55) or sedated (32 out of 55) ferrets. On radiographs splenic and abdominal lymph node visibility was assessed. Splenic thickness and echogenicity and lymph node length, thickness, echogenicity, number and presence of cyst‐like changes were recorded.

Results

The spleen was radiographically detectable in all ferrets. On ultrasound the spleen was hyperechoic to the liver (55 out of 55) and mildly hyperechoic (28 out of 55), isoechoic (15 out of 55) or mildly hypoechoic (12 out of 55) to the renal cortices. Mean splenic thickness was 11.80 ±0.34 mm. Lymph nodes were radiographically discernible in 28 out of 55 ferrets and included caudal mesenteric and sublumbar nodes. An average of 9 ±2 lymph nodes (mean± standard deviation; mode 10) were identified in each ferret using ultrasound. A single large jejunal lymph node was identified in all ferrets and had a mean thickness of 5.28 ± 1.66 mm. For other lymph nodes the mean thickness measurements plus one standard deviation were less than 4.4 mm (95% confidence interval: ≤ 3.72 mm).

Clinical Significance

The information provided in this study may act as a baseline for evaluation of the spleen and lymph nodes in ferrets.