Viro - Midterm Canine Viruses

isabellepjk's version from 2017-10-01 19:00

Viral dzs of dogs- Overview

Question Answer
What are the CNS dz's of dogs?Rabies
What are the systemic dz's of dogs?Canine Distemper, Infectious Canine Hepatitis, Canine Parvovirus dz*
What are the GI dz's of dogs?Canine Coronavirus diarrhea
What are the Reproductive & neonatal dzs dz's of dogs?Hemorrhagic Dz of pups
What are the skin dz's of dogs?Canine Papillomatosis


Question Answer
What is the etiological agent?Member of the Lyssavirus genus of the Rhabdoviridae
DNA or RNA/ appearance of the virus? (Shape?)RNA SS-, enveloped, w/ a BULLET SHAPED APPEARANCE (shaped like the treatment)
Enveloped or naked?Enveloped, has spike projections
Where does the virus replicate in the cell, & notable things about this?RNA → CYTOPLASM replication. It leaves intracytoplasmic inclusion bodies (Negri bodies) ← pathognomonic
What would you say about the hosts of Rabies?WIDE RANGE OF THEM. obv dogs included.
What does the fact that there are distinct genotypes in the US found imply?Not much, bc they are ALL THE SAME SEROTYPE, so diagnostic tests work on all, & vx work on all of them
What is the major source of cattle Rabies?SKUNK Rabies
How can Rabies be transmitted?In man, usually by the bite of an animal (usually dog). Bat caves can facilitate of the aerosolization of the virus. Also organ xplant
What is the incubation time of Rabies? What is it doing during this time?Virus replicates in the striated or connective tissue at the site of inoculation & enters the peripheral nerves through the neuromuscular junction.
Incubation time is 14-90 days but CAN be YEARS
Is Rabies centripetal or centrifugal?CENTRIPETAL! (Trip in) → goes from peripheral nerves (like near the bite) & moves up them into the CNS (after that it will move centrifugally, to the salivary glands for instance, & thats why the bite is then infective)
What are the 2 clinical forms of Rabies, & who do you usually see in which category?(1) Furious (cats/dogs/horses/wild animals)
(2) Dumb/Paralytic (cattle & lab animals)
Although there is widespread CNS involvement, what is weird about Rabies?Very few neurons infected w/ the virus actually show structural abnormalities
Describe the furious type of Rabies (why are they called furious? what do they do, what cant they do, why is it furious in a biological explanation?)Restless, nervous, aggressive, no fear of humans & bite everything. Cannot swallow (also called hydrophobia) & there is excessive salivation, exaggerated response to light & sound. Virus reaches the limbic system (replicates extensively & release the cortical control of behavior (furious)
Describe the dumb/Paralytic Rabies (biological reasons for this? symptoms? precautions?)Replication in the neocortex give the Paralytic signs (ataxia, paralysis of throat, inability to swallow, profuse salivation, progression of paralysis, coma & death). Don’t inspect the mouth w/ bare hands!!!!
What are the terminal signs of Rabies? When do they occur, in relation to clinical signs & death?Terminally there are convulsive seizures, coma & respiratory arrest w/ death occurring 2-14 days after onset of clinical signs. So, by the time you see clinical signs, it's basically too late- rapid progression
RT-PCR can also be used
*How would you use serology for Rabies?YOU DONT! It is not useful bc Rabies proteins are highly immunogenic but humoral or cell mediated responses are not stimulated in early stages after bite. By the time they show up enough, it's too late
How is there control of Rabies in urban areas?Usually canine Rabies, so stray dog control, vaccination of dogs, laboratory diagnosis to confirm cases, surveillance & quarantine of imported animals & public education: Responsible pet ownership

Canine Distemper

Question Answer
Etiological agent of Distemper? (Family & genus)Paramyxoviridae, Morbillivirus genus
Enveloped or no? Appearance?Enveloped! Large peplomers, & characteristic herring bone nucleocapsid
*What are some distinct characteristics that this virus histologically shows?Forms syncytiums & intracytoplasmatic & intranuclear inclusion bodies
How is the mortality/morbidity/level of contagious of Distemper?Highly contagious (for non vx), w/ high levels of mortality & morbidity
Who is most susceptible to Distemper?YOUNG ANIMALS, after maternal Abs have dropped (4-6mo) but CAN affect all ages
What is the acute form of Distemper most often seen in puppies? (Describe)Severe multisystemic (mainly respiratory, enteric & CNS) severe lymphopenia & death
What form of Distemper often affects older dogs? (Describe, what happens, prog?)"Old dog Encephalitis" → (years after initial infxn, virus persists in the CNS) fatal
What are the 2 presentations of Distemper that are kind of odd(1) HARD PAD DZ → Hyperkeratosis of foot pads & nose
(2) Enamel hypoplasia
Describe some of the clinical signs, & how they correlateAnorexia, catarrah, Conjunctivitis & depression are usually first seen. Biphasic fever (up to 105.8 F), second peak corresponds to onset of *severe Leukopenia* & other clinical signs. Some dogs have more GI than resp, for others it's the opposite.
Describe the CNS signs (also remember the other major components are resp & GI signs)B/H CHANGES, forced movements, local myoclonic (involuntary muscle contractions), tonic-clonic spasms, epileptic-type attacks, ataxia or paresis
What is the duration of Distemper like?Varies DEPENDING ON HOST IMMUNE RESPONSE & possible complications of 2⁰ bacterial infxns
Describe the subacute neurological formMay follow any of the acute or appear after subclinical infxn. It’s characterized by frank Encephalitis w/ convulsions & most surviving dogs have permanent CNS sequelae (nervous ticks or involuntary leg movements)
What are the 2 late forms (may occur in dogs w/ no history of clinical Distemper dz) of Distemper?The old dog Encephalitis & the hard pad dz
What is pantropic? Is Distemper pantropic?AFFECTS ALL TISSUES. & yes it is. (So, outcome depends on immune response)
Diagnosis of severe Distemper dz the signs (symptoms) are pathognomonic(Respiratory, enteric, CNS), bloodwork shows marked lymphopenia but laboratory confirmation is needed
*If you want to do antigen detection for Distemper, where do you take what samples, & when?If antemortem - impression smears of conjunctiva or peripheral blood lymphocytes. If postmortem- lung, stomach, intestinal or bladder
*How is Distemper transmitted? When/how is it shed? (Enveloped) so *****direct***** contact required, only viable for a short amt of time. Mainly through droplets & aerosols. *****This virus is shed in all secretions & excretions from the 5th day of infxn (before onset of clinical signs) & continues for weeks***
Which dog is more at risk for Distemper: a farm dog, or apartment in the city dog?There is herd immunity in urban dogs, but rural dogs are isolated for outbreaks occur more frequently
What must you know about the vx for Distemper?YOU NEED TO KEEP BOOSTERING!!! Young are at risk, but you dont know when the maternal Abs are gonna stop messing w/ the vx

Infectious Canine Hepatitis

Question Answer
*What is the etiological agent of ICH? (Family & genus)Canine Adenovirus ****1**** belongs to the Mastadenovirus genus in the Adenoviridae family (the LIVER, I AdenoED, as the MASTA organ- hes #1)
DNA or RNA?DNA, DS, linear
Enveloped or naked?NAKED, have penton fibers (your liver can make fibers)
Histologically distinguishing marks?Intranuclear inclusion bodies are found sometimes forming large Paracrystalline arrays (visualize a liver made out of the finest crystal)
Clinical signs of Canine hepatitis in MOST cases?Most CAV-1 infxns are asymptomatic or present as undifferentiated resp (WUTTTT) dz
Describe the Peracute dz of Infectious Canine HepatitisDeath in 4 hrs w/ no other signs (pretty effin real deathtime)
describe the Acute dz of ICH(May be fatal) vomiting, bloody diarrhea, petechial hemorrhages in the gums, pale mucous membranes & jaundice (GI signs bc liver has to do w/ that, then bleeding stuff & icterus, bc liver has to do w/ that)
*What is a distinguishing sign of CAV-1, & what situations cause this?****BLUE EYE****!! (Bilateral corneal edema) In convalescent stages of natural infxn & after a week post live-attenuated CAV-1 vaccination. Will go away on its own. Due to AbAg complexes (infect the liver till its blue)
What are some lab diagnostic techniques for canine hepatitis?PCR of oropharynx/conjunctiva. serology w/ Ab ELISA (PS: check your liver)
How is CAV-1 usually transmitted? Time frame?Viruria = Major source of transmission, + feces & saliva. Virus is shed in urine up to 6mo (pee your liver out-thats pretty sick. 6months?? evil)
Explain the vx (2 points)Now vaccinate against CAV-2 (crossprotection) to prevent the corneal edema w/ CAV-1 vaccine. ALSO the attenuated viral vaccine is shed, secondarily immunizing other dogs& creating herd immunity

Canine Parvovirus

Question Answer
Etiologic agentParvovirus of Parvoviridae family
Enveloped or naked?Naked (very stable, resist 60ºC for an hour & pH 3 to 9)
Specific ways to ID this virus? (Not lab test)Replicates in **DIVIDING CELLS**! & leave large intranuclear inclusion bodies! & hemagglutinate
3 different age-related dz syndromes? (What are the ages, what is the syndrome)(1) Generalized neonatal dz syndrome (rare)
(2) The myocarditis syndrome is usually recognized in pups (4-8 wks) by sudden death (usually w/o any other clinical signs)
(3) The Leukopenia/Enteritis syndrome most common in pups 8-12 wks old
What are some of the clinical signs of the Leukopenia/Enteritis syndrome?Vomiting is usually the first sign, anorexia, lethargy & diarrhea follow. Dehydration occurs rapidly. Feces can vary between being streaked w/ blood to being frankly hemorrhagic & remain fluid until recovery or death, which occurs usually in young pups or untreated dogs bc of dehydration or endotoxemia
Pathogenesis of Canine Parvovirus (wheres it start, wheres it go, what happens then....)The virus entry is via the oropharynx; initial replication occurs in tonsils & regional lymph nodes, viremia occurs by day 2, then spreads to thymus, spleen & bone marrow, where cells of the myeloid, erythroid & megakaryocytic series are destroyed
What do these viruses require of the host cells?THEY MUST BE IN S-PHASE (replication phase)
How is the recovery from Parvovirus? (explain diff situations & time frames)IF they survive, recovery is rapid (neutralizing antibodies are detected by day 3-5 & have high titer by day 7, regeneration of affected tissues is relatively rapid, virus clears rapidly (day 6-8) & shedding stops at the same time). IF the myocarditis syndrome, will continue to have heart probs for life
What is the most common lab diagnosis of Parvo?IN HOUSE SNAP TEST! It detects the **antigen**!!!!!
How do you control Parvo?**COMPLETE** VX SCHEDULE! Keep pups away from parks etc until complete vaccination is achieved, quarantine+disinfect contaminated areas w/ bleach

Canine Influenza

Question Answer
Etiologic agentInfluenzavirus A genus of the Orthomyxoviridae family ( A flu will make you feel like you need Orthotics)
DNA or RNA?SS RNA linear genome, negative sense & SEGMENTED SO, MUTATES FAST!!!
Enveloped or naked?Enveloped
Who does this virus affects?ALL ages & breeds (just like the flu for us)
Clinical signs of Canine Influenza?Mild- Kennel Cough!
Severe- fever, dyspnea, pneumonia. Mortality can reach 5% (so...the flu)
How can you diagnose this?Serology (paired samples), HI (hemagglutination inhibition) (after 7 days). **NO ANTIGEN ELISA!(bc antigen keeps changing from being segmented)
Explain the viral sheddingShedding occurs for a week after post onset of clinical signs; continuous cough doesn’t mean viral shedding

Canine Parainfluenza

Question Answer
Etiologic agentRubulavirus genus of the Paramyxoviridae family (RUBY PAIR of slippers makes a witch ill)
DNA or RNA?SS- RNA linear
Enveloped or naked?Enveloped
Clinical signs?Usually causes inapparent or mild respiratory dz but can also cause CNS dz. There is sudden onset of serous nasal secretion, cough & fever that last 3-14 days
How do you control Parainfluenza?Vaccines (usually in Kennel Cough combo). Isolate the dog if in a group setting. (You can vaccinate against the pair fruit- who would have known)

Hemorrhagic Dz of pups

Question Answer
Etiologic agentMember of the Herpesviridae family
DNA or RNA?Ds DNA genome, linear
Enveloped or naked?Enveloped
How can you histologically ID Hemorrhagic Dz of pups?Intranuclear inclusion bodies
CHV in adult dogs- affects them where, spread how, causes what?HERPES STDs! Infects repro tract so can be STD or pass to puppies during birth. Abortion, stillbirths, & infertility, rarely Kennel Cough. Intermittent shedding in vaginal secretions, penile secretions, & discharge from the nose. Raised sores in the vagina or on the penis may be seen during these times
Why is CHV worse in puppies?KEEP PUPPIES WARM! Their lower body temp allows the virus to spread & infect the rest of the body (usually hangs out in the cooler nasal passages, outside genitals, etc)
What are the clinical signs of CHV? (Pups) prognosis?Vasculitis that result in hemorrhage around the blood vessels. Bruising of the belly may occur. Eye lesions include keratitis, uveitis, optic neuritis, retinitis, & retinal dysplasia. There is a high mortality rate → death w/in 1-2 days
Treatment/careVery difficult. Injecting some Abs in to abdomen might help some. KEEP PUPPIES WARM!
How do you control CHV?Spread of the dz is controlled by not breeding dogs known to have it

Canine Papillomatosis

Question Answer
Etiologic AgentPapovaviridae family, Papillomavirus genus
DNA or RNA?Ds DNA genome
Enveloped or naked?Naked
Where are lesions from this virus located? Describe the lesionsCutaneous & mucous membranes, warts can be raised or inverted, single or multiple
Clinical signs of Papillomatosis? (What, where, how long?)Oral, ocular, genital usually in young dogs, cutaneous at all ages Lesions usually regress w/in months but can take up to 2 years it a wart? Yes? Well there you go