Viro - Midterm Cat Viruses 1

isabellepjk's version from 2017-10-01 20:21

Viral Dzs of cats overview

Question Answer
All of these dzs have vaccines except forFIV
Systemic feline dzs are?Feline Acquired Immunodeficiency Syndrome (FIV), Feline Leukemia, Feline Infectious Peritonitis, Feline Panleukopenia (also reproductive & neonatal dz)
CNS feline dzs?Rabies
Respiratory dzs?Feline Calicivirus dz, Feline Rhinotracheitis

Feline Retroviruses overview

Question Answer
Etiologic agentW/in the Retroviridae family; Lentivirus genus (Feline Immunodeficiency Virus) & Gammaretrovirus genus (Feline Leukemia & Feline Sarcoma Viruses) (when you have AIDS you eat a lot of lentils, & gamma rays would destroy any WBCs in its path & cause cancer)
DNA or RNA?SSRNA, diploid
Enveloped or naked?Enveloped
How do Retroviruses replicate?Reverse transcription of virion RNA into DS DNA by reverse transcriptase with integration into the host Chromosomal DNA (provirus state)
What is the most common non-accidental cause of death in cats??FELINE LEUKEMA (FeLV) (FuckLiVing)
What can cause uveitis?FeLV, FIP, & FIV

Feline Immunodeficiency Virus (FIV)

Question Answer
Etiological agent?Lentivirus (of the Retrovirus family)
How is FIV transmitted?BITE! Queens in acute infxn state can infect kittens through colostrum & milk.
Is FIV zoonotic?NO
Clinical signs of FIV is broken into 3 stages1) Initially temporary (enlargement of lymph nodes, fever)
2) Then long subclinical stage
3)- Finally a progressive deterioration of health. Persistent fever, poor coat & progressive weight loss, gingivitis & stomatitis (50% of cases), loss of appetite. Recurrent infxns of skin, urinary bladder & upper respiratory tract. Also seen, behavior changes, neurological disorders occasionally
In what way is FIV a lifelong dz?Most cats remain persistently viremic for life (but not actively infected)
How would you diagnose FIV? (WHAT Are you detecting?) WHEN? (2)SEROLOGY to detect AB by ELISA , 8-12 weeks after infxn. BUT false + are 2-20%
Also PCR(NOT RT-PCR bc you are detecting the provirus)
Western Blot to confirm
Baby FIV cats hould be retested at 60 day intervals until they are 6 months old d/t maternal Abs
What issues is there w/ the ELISA serology test for FIV? (2)(1) ELISA (Ab) → window of FALSE NEGATIVES 8-12 weeks after infxn, after that it starts to show up, so either retest or use other test (false positives 2-20% experimental vx from cell culture may have allotypic antigens)
(2) YOUNG (less than 6 months Old) FIV positive cats should be retested at 60 days interval until they are 6 months old (could be a false positive due to maternal antibodies)
Is there a vx for FIV?No
How can you treat/control FIV?No specific treatment although AZT (aka Zidovudine, which works against the RT enzyme) has been tried w/ modest success. Control is performed through test & removal programs. NO vaccine

Feline Leukemia (FeLV)

Question Answer
Etiologic agent? (Genus)Gammaretrovirus genus
How common is FeLV?Most common non-accidental cause of death in cats!!!
Clinical presentation of FeLV?Lymphosarcomas (Pred t-lymphos but B are in alimentary tract) $ major forms are based on location of primary tumor
Multicentric, thymic, alimentary, and unclassified
Unclassified lymphosarcomas (tumor found in non-lymphoid tissues) usually show up where?Skin, eyes, CNS
Explain the anemia component of FeLV- how does it happen, what cells are involved?Transformation of the erythropoietic cells may produce erythroblastosis (erythroblasts in the blood), erythroblastopenia(↓ of RBC) or pancytopenia all of which are associated w/ anemia
What is a common result of the immunopathogenic presentation of FeLV? (The dzs caused by this) (4)UVEITIS! (This can also show up in FIV & FIP too, tho), also glomerulonephritis, lymphoid cells depletion, ADCC (Ab dependent cell mediated cytotox)
What are the four types of anemias/myeloprolif dz found in FeLV?Erythromyelosis, granulocytic leukemia, erythroleukemia, myelofibrosis
Clinical presentations of FeLV immunopath dz?Cats fail to thrive, their growth is stunted & their hair coat is harsh. They have repeated infxns: stomatitis, gingivitis, non-healing skin lesions, subcutaneous abscesses, chronic respiratory dzs, etc. These cats have higher incidence of FIP, Toxo & Hemobartonella & may present poor reproductive performance, infertility or Abortions.
What are the three types of neoplasia recognized in FeLV and the two types of neoplastic dx?Neoplasia - Lymphosarcoma
Myeloproliferative dz
Neoplastic dz -
Anemia and Immunopath dz
What is FOCMA? Is it good or bad? Explain it (Pathogenesis)(Feline Ocornavirus-associated Cell Membrane Antigen) All 3 antigenic types, A, B, C of Leukemia virus (based on their envelope antigens) or Feline Sarcoma Virus when transforming a cell (but not when just infecting) will make the host cell express a novel viral antigen termed FOCMA, which are the target of protecting antibodies. So, these FOCMAS stick around on the outside of the cells & Abs can attach to them. (IT IS IMMUNOGENIC) (FOCMA IS WHEN TRANSFORMING A CELL, NOT INFECTING.
What is P27? Explain it. (Is it good? is it bad? does it do anything?)Unlike FOCMA which is on the surface of the cell & Abs can find it, P27 is an INTERNAL protein, so it is not protective (Abs cant get to it in the cell) & they can be involved in IMMUNE COMPLEX DZ
Which is the good viral antigen that is produced? Which is the bad?FOCMA is protective (Abs can attach to it), P27 is not protective & might cause immune complex dz
What are the 2 host-virus relationships that can develop? Which is most common?(1) Persistent active infxn: viremia, lack of neutralizing & FOCMA antibodies, constant shedding, lasts until Leukemia or virus-related dz (usually immunosuppression) cause death)
(2) Self-limiting infxn: (most common) it becomes latent (it does not get eliminated)
What techniques can you use to diagnose FeLV? What are you detecting (general & specific)NOT SEROLOGY!!!! DO AG DETECTION!!! By indirect IF(detects viral Ag in blood), Hardy test (detects P27 in the cytoplasm of peripheral blood leukocytes) → DETECTS CELL ASSOCIATED 2ry VIREMA!!!!!! (you LV needs more than a fluid in blood. or think that the fluid in blood is unreliable bc FeLV destroyed it. or think that hardy & indirect IF go together & they aren't doing serology)
How do you make sure that there wasn't just a false positive for FeLV in your tests?A persistently viremic cat has 2 positive tests in 12 weeks
How do you detect a latent FeLV infxn?Can only be detected by bone marrow culture & cell reactivation
What is the most important source of infxn (not cause) for FeLV?SALIVA (Feline Lick virus)
What are the methods of transmission?Well, source is saliva, but usually PROLONGED DIRECT EXPOSURE is needed (mutual grooming, maybe fleas) Biting is also an important method of transmission as well as iatrogenic transmission through blood transfusion
Is there a Vx for FeLV?YES (Vaccines, inactivated or subunit are effective. Do not vaccinate kittens younger than 6 weeks (maternal Ab interfere). know that usually not attenuated, not all produce anti FOCMA abs, vxs dont protect 100% against challenge)
What is important about how the dz is produced?Replication and release and NOT required
ELISA vs IFA in FeLV?ELISA is more sensitive, detects earlier stages of dz and is more prone to give FALSE POS.
Can be POS to ELISA and NEG to indirect IFA in early infections.

Feline Sarcoma Virus

Question Answer
Etiologic agentGammaretrovirus genus
How is Feline Sarcoma Virus able to cause tumors?The virus is replication defective, carrying a v-onc → so need a co-infxn to cause dz. usually the viruses recovered from fibrosarcomas show that their envelopes were provided by FeLV (Gp part of envelope)
What kinda sarcoma is usually caused by Feline Sarcoma Virus?Fibrosarcomas
What is the weirdo thing about this virus that can happen in KITTENS?On rare occasion in kittens Fe sarcoma virus can produce a multifocal subcutaneous fibro sarcoma which is anaplastic, rapidly growing & usually metastatic

Feline Infectious Peritonitis (FIP)

Question Answer
What is the etiological agent?Feline Coronavirus (FeCoV) is a member of the antigenic group I of the Coronaviridae SS RNA of positive polarity & linear → BUT THAT DOESNT MAKE FIP. Feline Infectious Peritonitis Virus (FIPV), is a mutant of Feline Enteric Coronavirus (FeCoV) w/in the host
How common is FeCoV (feline Coronavirus)? What does this mean?VERY common, which means there is a higher chance of it spreading, & all it takes is a mutation to change to FIP
Should you tweak if there are Abs to FIP?No because having Abs doesn't really mean FIP will develop
What are the 2 forms of FIP? Which is more common?Effusive (wet) & non-effusive (dry). Wet is more common. (which is good, bc it's the one that's easier to diagnose)
What is the one clinical sign BOTH forms of FIP will show?Hyperglobulinemia
Clinical signs of wet (effusive) FIP?Most characteristic clinical sign of effusive FIP is the accumulation of fluid w/in the abdomen or chest (then a bunch of nondescript symptoms like fever, anorexia, weight loss....)
Clinical signs of dry (non-effusive) FIP?Anterior uveitis or neurological signs are the main different ones, along w/ the other nondescript ones (fever/anorexia/jaundice/etc)
Clinical signs of feline Corona virus?Usually asymptomatic, maybe mild diarrhea
How are cats infected w/ FeCoV? Anything to know about the transmitters?Inhaling/ingesting the virus, often fecal-oral but fomites can play a role. Asymptomatic cats can still pass on the virus. Any cat with Feline Corona virus has a chance that the virus will mutate and turn into the FIP causing form.
What are the chances that a cat w/ FeCoV will have the mutation into FIP? Are there things that ↑ these chances?It can basically mutate in any cat w/ FeCoV, but the chances arent super high (1/5000). However, mutation chances are ↑ if the cat is immunocompromised (super old or young)
Once mutated, what is the cell tropism like for FIP?The virus can invade & grow in MACROPHAGES
How does the immune system play a role in FIP?It is an IMMUNE MEDIATED DZ! Deposition of immune complexes & consequent complement activation exacerbates inflammation causing vascular damage that permits leakage of fluid. Humoral immunity is not protective, it may be detrimental!
What do FIP Gross lesions look like?Multiple greyish nodules, 1-10mm in the serosa of liver, lungs, spleen, omentum, intestines & kidneys
Microscopic lesions of FIP look like?Acute immune mediated perivascular necrosis which progresses to a chronic pyogranulomatous lesion (can be found in many places)
What does the effusion in the wet form look like microscopically/contain?The effusion has high protein, relatively low cellularity & no bacteria
What’s going on w/ the blood vessels in FIP?Vascular lesions occur due to Ab-Ag complexes. NOT D/T toxins, viral endothelium attack, autoabs, fibrin deposition, etc
How do you diagnose FIP?This is VERY DIFFICULT & there is no definitive diagnosis. Usually determined by clinical suspicion, presence of fluid in effusive form, & examining tissue for FIP virus. A presumptive diagnosis is made based on clinical signs & evaluation of abdominal or chest fluid, if available
Tissue biopsy and IHC post mortem of affected tissues
Once you have some abdominal fluid, how can you see if it's FIP fluid?Rivalta test (if you drop the ab fluid into the tube & it doesn't diffuse, it's positive for being an exudate (FIP fluid is a pyogranulomatous exudate), yellow in color with elevated protein levels
Can an ELISA help diagnose FIP at all?Antibody ELISA can help a presumptive diagnosis by looking for Coronavirus antibodies & elevated protein
Would a Coronavirus titer help diagnose FIP? Would a HIGH or low titer indicate anything?Not alone --> Not considered dx, bc Coronavirus has such a high prevalence. A high vs low titer of FeCoV will not be a clue as to whether or not it will mutate/be FIP
How can you control FIP? → ie, Do you need to quarantine for FIP (why or why not)?QUARANTINE IS NOT NECESSARY! FIP is not an infectious dz. not only is it mutated away from the FeCoV, but it also lives in the macrophages so it's not really able to be transmitted.
Prognosis for FIP?POOR
How do you cure FIP?There is not cure, tx is symptomatic and palliative only. Immunosuppressants can HELP but...not for long.
cytotoxic drugs can can help improve appetite but it's fatal