Lecture 28: Viral diseases

Widespread, enteropathogen that can cause outbreaks but also be shed by healthy dogs. Respiratory virus related to bovine, CIRD.

Canine coronavirus

Fecal oral and fomite transmission. Relies on rapidly dividing cells because cannot induce mitosis infected cells. Fever, depression, anorexia, vomiting, diarrhea, bone marrow necrosis and leukopenia. Cerebellar hypoplasia in cats, shock. Diagnosis by ELISA. Vaccination and stringent disinfection.

Canine/feline parvovirus

What is involved in CIRD complex?

Cornavirus, adenovirus type 2, parainfleunza, herpesvirus

Fragile virus, does not survive on dried saliva or contaminated tissue. Unvaccinated animals are at risk. No antemortem diagnosis. DFA on fresh brain is better.

Rabies

CIRD, oronasal contact w/respiratory or genital secretions, transplacental, fading puppies w/ systemic signs. Viral inclusion bodies or PCR, maternal Ab and then maturing puppy immune system.

Herpesvirus

Infectious canine hepatitis, oronasal contact with virus-contaminated secretions/excretions. PCR of secretions and vaccination.

Adenovirus

Papilomas, will resolve

Papillomavirus

GI, limited.

Rotavirus

Associated with raw pork, contact w/ pigs, fatal

Psuedorabies

How do you diagnose feline upper respiratory infections?

PCR for diagnosis

How is feline upper respiratory infections contracte?

Direct contact, infectious discharge, carrier/latetn changes

Fatal neurologic disease

Bornavirus

Rare in US. European and Asia rural cats who hunt rabbits.

Poxvirus

Common but not clinical. Relevant as contaminent in research and vaccine production.

Feline Foamy Virus

Isolated in healthy/sick cats, ocular and GI

Reovirus

All cats have it

Rotavirus

Unclear significance except for zoonosis

Hantavirus

Morbillivirus, replicated in LN, nerves, and epithelial tissues and shed 60-90 days.

Inhalation → macrophages → lymphatics → tonsil, pharyngeal and bronchial LN and replication begins.

Canine distemper virus

Etiology of CDV

Typically unvaccinated, poorly vaccinated, poor passive transfer, 3-6 months of age

CS of CDV

PC: Lethargy and depression, oculonasal symptoms, CNS signs, diarrhea cough

PE: Tonsillar enlargement, fever, mucopurulent discharge, increased bronchial sounds, crackles

Hyperesthesia, seizures, cerebellar or vestibular symptoms, paresis, chorea myoclonus → poor prognosis

Uveitis, optic neuritis/blindness, retinochoroiditis

Diagnosis of CDV

• Initially presumptive

• Serum or CSF Ab titers

• Cytology with viral inclusions, DFA, RT-PCR

• Viral inclusions (only 2-9 days post-infection)

Treatment of CDV

• Ribraviron, interferon alpha, caffeic acid

• Anti-convulsants

• Corticosteroids

• CNS prognosis is POOR

Prevention of CDV

• Isolation

• Vaccination-MLV ore recombinant

What mutations causes FIP?

Spike (S) protein gene and 3c gene

Etiology of the feline coronavirus

Multi-cat households, catteries, young cats, however often only 1-2 cats affected

CS of feline coronavirus

• Limited diarrhea, possibly vomiting, possibly fever

CS of FIA

• Anorexia, lethargy, WL, jaundice, ocular inflammation, abdominal distension, CNS signs, dyspnea

• Fever and WL

• Peritoneal or abdominal effsion vs. granulomatous lesions of particular organs

How do you diagnose feline coronavirus?

• Presumptive

• Anemia, neutrophilia, lymphopenia, liver, azotemia, proteinuria, hyperglobinemia

• NSF on imaging

• Sterile, clear yellow, high protein, mixed inflammation, fibrinous/stringy/viscous/sticky effusion

• Antibody test

• Rivalta’s test

• RT-PCR on effusion, blood CSF

Treatment of feline coronavirus

• Anti-inflammatory, antibiotics, immunomodulation

• GS-441524 and remdesivir

Prevention of feline coronavirus

Routine disinfection, intranasal vaccine safe but questionable efficacy

Etiology of FIV

• Retrovirus, uses reverse transcriptase to insert into host genome

• Replicated in oral lymphoid tissue, T and B lymphocytes, macrophages

• Transmission most commonly via biting

Phases of FIV

1. Low grade, fever, neutropenia, reactive lymphadenopathy

2. Latent phase: decreasing CD4 lymphocytes, decrease in cell-mediated immunity neutrophil and NK-cell

CS FIV

• Fever, lymphadenopathy, anorexia, WL, lethargy

• Small bowel diarrhea, anemia, thrombocytopenia, neutropenia, lymphadeopathy, uveitis, glomerulonephritis, renal insufficiency, hyperglobinemia, stomatitis, malignancy

Diagnosis of FIV

• ELISA demonstrating FIV antibodies in serum or saliva

• Confirmation tests: Virus isolation, PCR

• Neutropenia, thrombocytopenia, anemia, monocytosis, lymphocytosis

• Myelodysplasia in bone marrow, LSA, lymphocytosis

• Decreased CD4, increasing CD8

Treatment of FIV

• Treat secondary bacterial infections

• Interferon, bovine lactoferrin

• Antivrials and reverse transcriptase inhibitors

Prevention of FIV

• Avoid fighting

• Keep indoors

• Virus not transmitted by casual contact and fomites

• Routine cleaning

Etiology of FeLV

• Prolonged contact w/saliva or nasal sections

• Progressive, regressive, and abortive

CS of FeLV

• Anemia

• Lymphoma

• Stomatitis

• Renal

• Ocular

• Secondary infections

• Neuro

• Anorexia, lethargy, WL

Diagnosis of FeLV

• IFA on bone marrow

• ELISA (p27 protein)

• PCR for progressive and regressive cats

Treatment of FeLV

• AZT (blocks reverse transcriptase)

• Human interferon alpha (immunodulatory and antiviral properties)

• Feline recombinant interferon omega

• Lymphocyte T-cell immunodultor

• Supportive

Preventions of FeLV

• Virus does not survive

• Prevention

• Vaccination

Canine Distemper Virus (CDV) belongs to which virus family? a) Herpesviridae b) Paramyxoviridae c) Coronaviridae d) Retroviridae

b) Paramyxoviridae

What is the most common route of transmission for Canine Distemper Virus (CDV)? a) Fecal-oral contact b) Blood transfusion c) Oronasal contact with aerosolized secretions d) Direct contact with fomites

c) Oronasal contact with aerosolized secretions

Which structural protein of Canine Distemper Virus (CDV) has the highest level of genetic variation and is important for antigenic recognition? a) Hemagglutinin (H) protein b) Fusion (F) protein c) Phosphoprotein (P) d) Nucleocapsid protein

a) Hemagglutinin (H) protein

Canine Distemper Virus (CDV) is often part of which disease complex in dogs? a) Canine infectious respiratory disease complex b) Canine enteric disease complex c) Canine neurological disease complex d) Canine dermatological disease complex

a) Canine infectious respiratory disease complex

In the initial stages of Canine Distemper Virus (CDV) infection, the virus typically infects which type of cells in the upper respiratory tract? a) Monocytes within lymphoid tissues b) Epithelial cells c) Neurons d) Fibroblasts

a) Monocytes within lymphoid tissues

If a dog infected with Canine Distemper Virus (CDV) mounts an effective cell-mediated and humoral immune response by approximately day 14, what is the likely outcome? a) Severe clinical signs and potential death b) Mild to intermediate clinical signs c) No signs of clinical illness, and the virus can be cleared d) Chronic progressive neurological disease

c) No signs of clinical illness, and the virus can be cleared

Acute Canine Distemper Virus (CDV) infection can lead to significant immunosuppression due to its ability to infect and destroy which type of cells? a) Erythrocytes b) Neutrophils c) Lymphoid cells, especially CD4+ T cells d) Platelets

c) Lymphoid cells, especially CD4+ T cells

Neurologic signs associated with Canine Distemper Virus (CDV) may occur when? a) Only during the initial systemic illness b) Only weeks to months after systemic disease c) Weeks to months after systemic disease or coinciding with systemic illness d) Only in very young puppies

c) Weeks to months after systemic disease or coinciding with systemic illness

What is a characteristic dermatologic finding commonly associated with Canine Distemper Virus (CDV) infection? a) Alopecia b) Pruritus c) Nasal or digital pad hyperkeratosis (hardpad disease) d) Urticaria

c) Nasal or digital pad hyperkeratosis (hardpad disease)

Canine Parainfluenza Virus (CPIV) is a common component of which disease in dogs? a) Canine infectious upper respiratory tract disease b) Canine viral enteritis c) Canine neurological disorders d) Canine skin infections

a) Canine infectious upper respiratory tract disease

Canine Parainfluenza Virus (CPIV) belongs to which virus family? a) Coronaviridae b) Herpesviridae c) Paramyxoviridae d) Retroviridae

c) Paramyxoviridae

What is the primary mode of transmission for Canine Parainfluenza Virus (CPIV)? a) Aerosols and fomites b) Fecal-oral contact c) Blood-borne transmission d) Direct contact with skin lesions

a) Aerosols and fomites

Feline Immunodeficiency Virus (FIV) primarily causes immunosuppression through the depletion of which type of cells in cats? a) CD8+ T cells b) B cells c) Macrophages d) CD4+ T cells

d) CD4+ T cells

What is the primary mode of transmission for Feline Immunodeficiency Virus (FIV)? a) Casual contact and grooming b) Fomites and shared litter boxes c) Bite wound inoculation of virus in saliva d) Aerosol transmission

c) Bite wound inoculation of virus in saliva

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In Feline Immunodeficiency Virus (FIV) infection, antibodies against the virus are typically detected within how many weeks post-infection? a) Within 1 week b) Within 2-4 weeks c) Within 8-12 weeks d) After 6 months

b) Within 2-4 weeks

Feline Leukemia Virus (FeLV) belongs to which virus subfamily? a) Lentivirus b) Oncornavirus c) Spumavirus d) Deltaretrovirus

b) Oncornavirus

What is the most common mode of transmission for Feline Leukemia Virus (FeLV)? a) Close, social contact, primarily through saliva b) Bite wounds c) Fecal-oral route d) Vertical transmission only

a) Close, social contact, primarily through saliva

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What does a positive result on an in-house ELISA test for Feline Leukemia Virus (FeLV) typically indicate? a) Presence of the p27 core viral protein antigen b) Presence of antibodies against FeLV c) Presence of FeLV proviral DNA

a) Presence of the p27 core viral protein antigen

The Rivalta test is a diagnostic tool primarily used in cases of suspected: a) Feline Leukemia Virus (FeLV) b) Feline Immunodeficiency Virus (FIV) c) Feline Infectious Peritonitis (FIP) d) Feline Panleukopenia

c) Feline Infectious Peritonitis (FIP)

abies virus belongs to which virus genus? a) Lyssavirus b) Morbillivirus c) Coronavirus d) Paramyxovirus

a) Lyssavirus