Chapter 12 Flashcards
What virus causes feline viral rhinotracheitis?
Feline herpesvirus type 1 (FHV-1)
FHV-1 is a _____ sensitive virus.
temperature
Note: he mentions this like 5 times, do not forget it
What is the character of feline viral rhinotracheitis?
Localized upper respiratory infection - fever, hypersalivation, sneezing, coughing, dyspnea, and conjunctivitis
Why do younger cats typically have more severe disease caused by FHV-1?
Since FHV-1 is temperature sensitive, younger kittens that do not have the ability to thermoregulate are more susceptible to hypothermia thus creating an ideal environment for the virus to replicate
What differentials should you consider when considering FHV-1?
Feline calicivirus and Chlamydopila psittaci
What is the goal of the FHV-1 virus?
to prevent clinical disease; does not prevent infection or shedding
What disease does Gallid Herpesvirus type 1 cause?
Avian infectious laryngotracheitis
How does Gallid herpesvirus type 1 infection lead to death?
GHV-1 causes a localized upper respiratory infection which can eventually lead to hemorrhaging and suffocation on blood in the trachea
What differentials should be considered when considering GHV-1?
- Avian infectious bronchitis
- Avian Influenza
- Newcastle’s disease
What family do the influenza viruses belong to?
Orthomyxoviridae
What are the 2 important glycoproteins of the influenza viruses and where are they found?
Hemagglutinin and Neuraminidase
In the envelope
What is the function of hemagglutinin?
It is a fusion protein that binds to sialic acid residues
What is the function of neuraminidase?
It cleaves sialic acid
What do antiviral influenza drugs target?
neuraminidase
What is antigenic drift?
Minor antigenic change due to point mutations in viral RNA
What is antigenic shift?
Major antigenic change due to reassortment of viral genes - very sudden
What are the components that go into naming every influenza virus?
To be named in this order: Type (A,B, or C) Animals species isolated from Place isolated Number of the isolate Year of isolation The H and N subtypes
What is the major reservoir of influenza viruses?
waterfowl
What veterinary species are impacted by influenza A?
equine, swine, avian, dogs
Why are swine considered the mixing vessels for influenza?
Swine cross infect with bird and human influenza viruses where different strains can mix. Swine therefore serve as the ‘mixing vessels’ for avian and swine flu strains, that can then be passed to human and equine populations
What type of influenza is Equine influenza virus? What subtypes are equine subtypes?
Influenza virus type A - H7N7 and H3N8
Which equine influenza subtype is the current circulating strain?
H3N8
Where does equine influenza localize?
in the respiratory tract
What clinical signs are associated with equine influenza?
High fever, nasal discharge, depression, anorexia, weight loss, coughing, lymphadenopathy, and tachypnea
What did canine influenza first emerge as?
a respiratory pathogen in dogs following cross0species transmission and spread of H3N8 equine influenza virus
True or False: Part of the H3N8 equine influenza viruse genome is adapted to the canine species to emerge as a new canine-specific virus.
False: the ENTIRE H3N8 equine influenza
How did the H3N2 canine influenza virus come about?
There was a second cross species event from avian to canine. The entire genome of avian H3N2 transferred to dogs
What does clinical disease caused by canine influenza mimic?
kennel cough
What is the sequela that is typical of infection with influenza virus in dogs and horses?
secondary bacterial infections
What genera of influenza causes classic swine influenza and what subtypes currently affect swine?
Influenza A - subtypes H1N1, H3N2, H1N2
What type of disease is swine influenza?
respiratory (all influenza viruses are)
What differentials should be considered when considering swine influenza?
Mycoplasma hyopneumoniae and Actinobacillus pleuropneumonia
Characterize low pathogenic avian influenza (LPAI).
- Strains most common in domestic birds
- Localized infection of respiratory and/or enteric tract
- Respiratory disease most common
- Diarrhea can occur
- Drop in egg production
How does high pathogenic avian influenza (HPAI) arrise?
It arises from mutation of LPAI virus in infected poultry at the HA0 proteolytic cleavage site - only H5 and H7 subtypes
Characterize HPAI.
- Severe systemic infections with high mortality
- Historically been called fowl plague
- Short clinical course with very high mortality
What differentials should you consider with LPAI?
Avian infectious laryngotracheitis and others
What differentials should you consider with HPAI?
Pasteurellosis and Newcastle’s disease
What is the role for sialic acid linkage in influenza host range?
Sialic acids are linked to sugars. These linkages differ between species and tissues. HA subtypes recognize different linkages. Therefore HA subtypes differ between species depending on their sugar linkages
How has human H5N1 changed over the years?
The current viruses are more virulent and appear to have expanded host range
What is the structure of Paramyxoviridae viruses?
Large enveloped, ss (-) RNA with helical nucleocapsid symmetry
Where do Paramyxoviridae viruses replicate?
in the cytoplasm
What causes parainfluenza viruses in dogs, cattle, sheep, horses, and other species?
Respirovirus
What typical signs are associated with Respovirus infections?
mild, localized upper respiratory infections
Where does canine parainfluenza virus replicate?
in cells of the nasal mucosa, pharynx, trachea, and bronchi
How does Bovine Parainfluenza-3 virus (PI-3) contribute the bovine respiratory disease complex?
It serves as a initiator because it can lead to a development of secondary bacterial pneumonia
What can contribute to the suppression of host defenses which contributes to shipping fever?
Transportation over long distances, passage through auction markets, nutritional stress associated with a change to high-energy rations in the feedlot
What causes newcastle disease virus?
Avian parainfluenza I
What are the three general forms of Newcastle Disease and what is their relative pathogenicity?
Lentogenic - mildly pathogenic
Mesogenic - moderately pathogenic
Velogenic - markedly pathogenic
How do patients become infected with avian parainfluenza virus 1?
it enters either by mouth or by aerosol transmission
What clinical signs are associated with Newcastle disease in adult chickens?
- Sudden onset with mild depression, anorexia
- Drop in egg production
- Mild respiratory signs, rare CNS disease
- Mortality is low or absent
What clinical signs are associated with Newcastle disease in young chickens?
- Sudden onset with marked respiratory signs
- CNS disease may accompany or closely follow the onset of respiratory signs
- Mortality of 50-95%
What are the two forms of velogenic avian parainfluenzavirus-1?
Viscerotropic form and neurotropic form
What are the clinical signs associated with the viscerotropic form of velogenic avian parainfluenza virus 1?
- Marked dyspnea
- Conjunctivitis, Subcutaneous swelling around eye
- Greenish watery diarrhea
- Severe depression progressing to prostration and death
- Nervous signs may be seen
What are the clinical signs associated with the neurotropic form of velogenic avian parainfluenza virus 1?
- Conjunctivits, dyspnea
- Nervous tremors of head
- Torticollis, wing, or leg paralysis
- Death in two to three days
What differentials should you consider along with avian parainfluenza virus 1?
- Avian influenza
- Infectious laryngotracheitis
- Fowl cholera
Is newcastle disease reportable?
yes
List 3 veterinary diseases and 1 human disease caused by Morbillivirus.
Veterinary: - Rhinderpest -Peste des petits ruminants virus (PPR) - Canine distemper virus Human: Measles
What are the three forms of diseases of canine distemper?
Acute, CNS, chronic
What clinical signs are associated with acute canine distemper?
- Fever - often biphasic
- Rhinitis, serous nasal discharge, conjunctivitis
- Bronchitis, catarrhal pneumonia
- Gastroenteritis with vomiting and diarrhea
How is the CNS form of canine distemper characterized?
- Neurological disease with encephalitis, siezures in some dogs
- Usually in animals with overwhelming infections
- Virus invades the brain, establish inflammatory brain disease, and perhaps persist for many months
How is chronic distemper characterized?
- Seen in post-distemper dogs
- Infection of foot-pad epithelium and dental epithelium
- Can lead to old-dog encephalitis
How does canine distemper enter the bdoy?
across the nasopharyngeal mucous membranes
What differentials should be considered when considering canine distemper?
- Parainfluenza virus
- Canine adenovirus
- Infectious canine hepatitis
- Parvovirus, rabies
When are maternal antibodies usually absent?
by 12-14 weeks of age
What role does bovine respiratory syncytial virus in bovine respiratory disease complex?
Like IBR and PI-3 in shipping fever, it makes the animal susceptible to secondary infections because it causes respiratory tissue damage
What are the general properties of Caliciviruses?
- Non-enveloped, non-segmented RNA virus, (+) ss
- Very similar to Picornavirus
- Cause respiratory and/or enteric diseases in host
- Three genera based on capsid protein
What are the significant veterinary caliciviruses?
- Feline calicivirus
- Vesicular exanthema of swine
- San Miguel sea lion virus
- Calf enteritis calicivirus
- Rabbit Calicivirus
What clinical signs are common for a vesivirus feline calicivirus infection?
- Fever
- Sneezing and coughing
- Nasal and Ocular discharge
- Hypersalivation
- Ulceration of tongue, hard palate, tip of nose
