ANSC 375 Final
Card Set Information
ANSC 375 Final
ANSC 375 Final
Fatal disease seen in pigs that causes neurological issues
Describe the virus that causes teschovirus encephalomyelitis
- belongs to picornavirdae family
- small, single-stranded
Where in the world is teschovirus encephalomyelitis found?
- higher virulent strain in Europe and Africa
- lesser virulent strain W Europe, N America, Australia
How old are the pigs that teschovirus encephalomyelitis affects?
usually young that have just been weened, but occasionally older ones too
How is teschovirus encephalomyelitis transmitted?
- fecal-oral transmissions (ingesting infected feces or contaminated water)
- oral secretions
Where in the body does teschovirus encephalomyelitis replicate and spread to?
- intestinal epithelium (doesn't damage but can be spread with feces)
- tonsils (replicates in)
- CNS (causes most problems here)
What is the incubation period for teschovirus encephalomyelitis ?
- 1-4 weeks
- can shed in feces up to 7 weeks
Clinical symptoms of teschovirus encephalomyelitis
- starts with hind leg muscles spasms
- hind leg paralysis
- usually die from paralysis of respiratory muscles
What is the mortality rate of teschovirus encephalomyelitis ?
Up to 90% in high virulent strain
What effect does teschovirus encephalomyelitis have on the brain?
- causes lesions in grey matter, brain stem, spinal cord
- macrophages and degeneration of neurons
Is there a vaccine for teschovirus encephalomyelitis?
No, infected animals are usually euthanized or die
How resistant is the teschovirus?
- can persist in environment for 5 months
- hard to deactivate
- large pH range (2-9)
- resistant to heat, chemical disinfectants, and lipid solvents
- high doses of radiation, sodium hypochlorite and ethanol can deactivate it
What class list is Teschovirus Encephalomyelitis?
What is an infectious disease that affects horses?
Equine Viral Arteritis
What kind of virus causes Equine Viral Arteritis?
How is EVA transmitted?
- respiratory secretions
- venereal transmission
- contact with infected feces or other bodily secretions
- vertical transmission from mare to foal
How resistant is EVA?
- not very
- destroyed by heat, UV light, detergents/disinfectants
- resistant to freezing thouugh
- can survive in cool or frozen semen for a long time so AI is a main route of transmission
How does EAV affect the the arteries?
- EAV invades and replicates in the macrophages and endothelial cells in the arteries
- causes cell injury and death
- this damages arteries and creates vascular permeability leading to edema and necrosis
Who are the natural host reservoirs of EVA?
- aborted fetuses, placenta, and bodily secretions
What are the symptoms of EVA?
- respiratory signs such as coughing, nasal discharge
- edema of limbs, scrotum, and prepuce
- usually NON fatal in adults
- infected pregnant mares may undergo abortions
- foals may have perivasculitis, severe interstitial pneumonia, and fibrinoid necrosis of muscular arteries which can be fatal
What is the gold standard of diagnosis for EVA?
viral neutralization essay
What role do governing bodies play in control of EVA?
CFIA, OIE, AbVMA
- AbVMA reports any cases of EVA to CFIA who then submits annual report to OIE
How can you prevent EVA?
- isolating new horses for up to 4 weeks
- separating pregnant mares
- testing semen used for AI
- screen breeding stallions
- quarentine mare before and after brewing
- annual vaccinations of non-carrier breeding stallions and immature colts
What are the economic impacts of EVA?
- financially significant
- denied exports markers and reduced commercial value for carrier stallions
- cost of supportive treatment
- implementation of vaccination programs
How much does the horse industry contribute t the economy
- 19.6 billion dollars
- 950,000 horses in canada
- 1520,000 used in breeding
What classification is EVA?
What is a highly contagious disease that affects the suidae family?
African Swine Fever
Describe the african swine fever virus
- double stranded DNA virus
What are the reservoir hosts of African Swine Fever?
- bush pigs, warthogs, and giant forest hogs
How is the african swine fever virus transmitted?
- direct contact
- indirect contact contact via fomites, contaminated meat tissues or feed
- soft ticks are the only vectors
Are the reservoir hots with African swine fever symptomatic?
No. This contrasts with the domestic swine who do show symptoms
What are the clinical signs of african swine fever?
- very high mortality
- symptoms range from subclinical to sever acute hemorrhaging
- virus invades macrophages and monocytes
- after replication, the virus triggers apoptosis
- lymphocytes in the lymph nodes, spleen, and thymus are infected the most leading to immunocompromised animals
How resistant is african swine fever?
- can survive months in animal tissues
- survives 15 days in decomposing serum
- 11 days in feces
- but, does not remain infectious long
How is trade affected by african swine fever?
Canada does not import pork from any ASV positive countries
What are the economic impacts of african swine fever?
- closure of borders to pork can decrease national amount and therefore increasing prices
- the net benefit of the US preventing the introduction of ASF is 4.5 billion
How to prevent African swine fever?
- no preventative vaccine or therapeutic treatment
- strict import policies on pork
- erradication programs
- CFIA to inspect swine coming into canada and test any with symptoms
What is a disease that effects the respiratory systems of chickens and other birds?
Avian Infectious Laryngotracheitis (ILT)
Describe the virus that causes avian infectious laryngotracheitis
- double stranded DNA
- iltovirus genus
- Gallid herpesvrius 1 species
- herpesviridae family
How does the virus that causes avian infectious laryngotracheitis replicate?
- enters cells through fusion uptake
- viral DNA goes into nucleus through nuclear pores
- viral DNA replicates in rolling circular method
- virus packages an envelope when it leaves nuclear membrane
- then released in cytoplasm via cell lysis or exocytosis to infect other host cells
How is avian infectious laryngotracheitis transmitted?
- main sours is aerosol contact
- dirty litter, feces, nasal discharge
How resistant is avian infectious laryngotracheitis?
It can persist and be spread by fomites and vectors but can be killed with heat, sunlight, and most disinfectants
What are some of the symptoms of avian infectious laryngotracheitis?
- moist rales
- conjunctivitis (pink eye)
- nasal discharge
- drop in egg production and weight
- bloody mucus in trachea
- inflammation/ necrosis of GI tract
What do lesions in the mild form of infectious avian laryngotracheitis look like?
- mucous, conjuctivitis, sinusitis, mucoid tracheitis
What do lesions in the severe form of infectious avian laryngotracheitis look like?
- hemorrhagic and diptheritic changes of the trachea and larynx with severe degeneration and necrosis of tissue
What is the standard method for infectious avian laryngotracheitis?
What does infectious avian laryngotracheitis look like on a viral isolation?
opaque plaques inside check embryo
What is the main method for preventing and controlling infectious avian laryngotracheitis?
Is infectious avian laryngotracheitis economically significant?
How is infectious avian laryngotracheitis classified?
Describe the malignant catarrhal fever virus
- double stranded DNA
- belong to herpesviridae family
- subfamily gammaherpesvirinae
What MCF virus is found in wildebeest?
What MCF virus is found in sheep?
What MCF virus infects bison?
What are the reservoir animals for MCF?
Sheep and wildebeest
How is MCF transmitted?
- nasal, ocular, and urogenital secretions
- transmitted through upper respiratory tract
- indirectly via fomites/vectors and long range aerosol transmission
What is meant by bison being "dead-end hosts" of MCF?
Once they get MCF they cannot give it to anyone else
How does the MCF virus infect it's host?
- virus enters lung lymphocytes where it's latent
- sheds in the lytic form
- invades lymphoblasts and replicates before latency period where animal is asymptomatic
- reverts to lytic form where CD8 T cell hyperplasia occurs
- vasculitis occurs causing lesions in circulatory system, vision, mucosal surfaces, and nervous system
What are the symptoms of MCF?
- enlarged lymph nodes
- nasal and ocular discharge
- bloody urine
- corneal opacity