Inf. diseases II - Cats 1/2 Flashcards
Feline infectious peritonitis (FIP) is a contagious disease of felines, caused by feline coronavirus, and is characterized by
body cavity effusions or neurologic signs.
Causative agent of FIP.
family
serotypes
DNA type
+details
Agent: Feline coronavirus (FCoV)
Family Coronaviridae
Two serotypes (I and II).
Related to TGE virus in pigs, canine, and human coronaviruses.
Largest known RNA – highly susceptible to mutation!
FIP virus is a mutation of benign FCoV
Feline coronavirus (FCoV) survival.
Does not survive in the environment for long (<48h).
In dry environments <6 weeks.
Readily inactivated by most common disinfectants.
FIP virus is a mutation of
benign FCoV.
Serotypes of Feline coronavirus (FCoV)
Two serotypes (I and II).
In Europe and USA mainly serotype I.
In Japan mainly serotype II.
Host range and age demographic of FCoV.
felids
Most widespread infectious disease of cats.
Mostly sporadic cases.
Most susceptible: young cats during postweaning periods.
Peak age: 6 months to 2 years
Males > females
Purebred cats are most susceptible (esp. Asian breeds: Birman, Himalayan).
Risk factors for FCoV.
Risk factors: stress, multicat households
FCoV is widespread or even ubiquitous in multicat environments.
Most susceptible: young cats during postweaning periods.
Males > females
Purebred cats are most susceptible (esp. Asian breeds: Birman, Himalayan).
Morbidity of FCoV.
Morbidity: 90% of cats have antibodies, but only 5% develop clinical dz
Mortality of FIP.
Mortality: 95%
Transmission of FCoV.
Excretion: feces, saliva, urine, respiratory secretions.
Direct contact
Fomites (litter box!)
Route: fecal-oral, oronasal or through saliva (e.g. mutual grooming)
Two forms of FIP:
dry form (noneffusive) and wet form (effusive)
Clinical signs of FIP.
Nonspecific signs: lethargy, inappetence, weight loss
Other signs depend on whether the disease presents as the wet or dry form.
Clinical signs of effusive or wet FIP.
Abdominal distention with palpable fluid wave.
Dyspnea, muffled heart sounds and muffled lung sounds due to pleural effusion.
Also there might be palpable abdominal masses.
Clinical signs of noneffusive or dry FIP.
Ocular abnormalities – change in iris color due to iritis/uveitis, hyphema, aqueous flare, keratotic precipitates, vitreous clouding, vascular cuffing.
Icterus
Palpable abdominal mass(es)/ organomegaly.
E.g. enlarged mesenteric LNs, nodules in other organs, intestinal thickening.
Raised intradermal pustules (nonpruritic cutaneous lesions).
Neurologic signs – ataxia, incoordination, paresis.
Material for diagnosis of FIP.
Blood
Effusion (peritoneal) fluid
Samples from affected tissues
Lab analyses for diagnosis of FIP.
“Rivalta test”
PCR
Histopathology
Serology (but pos. result only tells you about exposure to FCoV, not FIP)
Titers >1:16 000 suggestive of FIP in cats showing signs of dz. False negatives tho.
Most cats with positive serologic titers for FCoV ….
never develop FIP.
It’s only a small portion of these cats in which the (mostly) fatal mutation takes place.
What is the “Rivalta test”?
A in-clinic test for detecting FIP.
- 8ml distilled water + 1 drop of 98% vinegar + 1 drop of effusion fluid
- If the drop disappears – negative (indicates transudate)
- If drop stays - positive (indicates exudate)
However, this is not gold standard, immunohistochemistry is.
Treatment of FIP.
No tx
Provide comfort and supportive/palliative care.
Acute Tx: thoracocentesis, oxygen therapy, IV fluids.
Chronic Tx: antiviral drugs, immunomodulating drugs, immune suppression drugs etc.
Experimental treatment available in the US and far east. Not licensed for use at this point (nucleoside analogues
GS441524 and Remdesivir (GS-5734): is a prodrug of GS-441524).
Prevalence of FIP development out of all cats who have FCoV?
approx. 5%
But outbreaks can occur, even up to 60%.
Concurrent diseases can predispose as well as stress.
A problem in shelters and multi-cat environments.
Prevention of FIP.
fe corona virus Vaccination
Optimize husbandry practices
In catteries: separate seronegative cats from seropositives.
In catteries: remove kittens from positive queens and other adult cats at 5-6 weeks old.
When possible, only seronegative cats should be added to cattery.
Experimental treatment drug for FIP.
nucleoside analog GS-441524
inhibits the multiplication of the agent
Feline immunodeficiency virus (FIV) is a viral disease of cats, caused by Retrovirus, and is characterized by
chronic immunosuppression.
Causative agent of FIV.
genus, family, DNA type
Agent: Feline immunodeficiency virus (FIV)
Genus Lentivirus,
family Retroviridae
RNA virus
Serotypes of FIV.
Five serotypes (A-E).
In Europe: A, B, C and D
One cat can be infected with multiple serotypes at the same time causing superinfection.
Host range and age demographic of FIV.
all felidae
Male > female
- Adult male sexually intact free-roaming cats (“fighting cats”) are at higher risk for infection.
Adults > kittens
- Most common infections in > 6 year-olds.
Prevalence of FIV.
Worldwide
Prevalence higher where more free-roaming cats (e.g. Italy, Japan).
Prevalence in U.S.:
- Client-owned cats 2.5-6%
- Stray cats 3.5-23%
Transmission of FIV.
Excretion: saliva, blood
Direct contact
(In utero)
Route: via bite wounds, mating
Clinical signs of FIV.
FIV infection most often occurs without overt clinical signs.
When clinical manifestation occurs, usually associated with:
- Secondary infections that develop due immunosuppression.
- Signs due to neoplasia (increased risk of lymphoma)..
- FIV-associated neurologic dysfunction
Phases of FIV progression.
Acute, latent, terminal phases.
Acute phase is usually unnoticed but may cause fever, lethargy or lymphadenopathy. (Lasts days to a few weeks)
Latent phase is asymptomatic (Lasts for months to several years).
Terminal phase (feline AIDS) clinical signs related to:
- Secondary infections (enteric, respiratory, cutaneous, or other)
- Tumors
- Infection of the CNS – behavioral changes, seizures, paresis
Material for diagnosis of FIV.
blood
Lab analyses for diagnosis of FIV.
ELISA (antibodies)
- Can’t distinguish antibodies from vaccine and from infection.
- Up to 8 weeks required to produce antibodies after infection.
- Kittens: maternal antibodies <12 weeks.
- False-positives
PCR
<50% false-negatives
Tx of FIV.
lifestyle management
Staying indoors – prevents transmission and secondary infections.
If secondary infections – ABs .
FIV-positives may have excellent quality of life for years – not a reason for euthanasia!
Prevention of FIV.
vaccination
don’t allow positive cats to roam and spread it.
Feline leukemia virus (FeLV) is a contagious disease of cats, caused by Retrovirus, and is characterized by
immunosuppression, myelosuppression and neoplasia.
Causative agent of FeLV.
genus
family
DNA type
Agent: Feline leukemia virus (FeLV)
Family Retroviridae
ss RNA
Subgroups of FeLV.
Three subgroups (A, B and C).
A – present in all infected cats
B – common in cats with neoplasia
C – rare, can cause nonregenerative anemia
FeLV survival.
Virus is highly sensitive to desiccation, disinfectants and heat.
Susceptible to most common disinfectants, incl. common soap.
Survives only minutes outside the host.
Host range of FeLV.
Host range: domestic cats
- Rarely wild felids
Young cats (<1 year) are more likely to become persistently viremic.
Male > female
Free-roaming cats more likely to be exposed.
Latent carriers
Found worldwide.
Transmission of FeLV.
Excretion: saliva, blood
Direct contact
In utero
Route: alimentary (grooming), transplacental
IP of FeLV.
IP: months (or even years)
Clinical signs FeLV.
Often nonspecific, Poor body condition,
Depression, Weakness, Lymphadenopathy
These signs are due to:
- Immunosuppression with secondary infection
- Myelosuppression (mainly non-regenerative anemia)
- Or neoplasia (mainly lymphoma)
“Fading kitten syndrome” – death within the first 2 weeks of life
FeLV induced Lymphoma may cause:
- Dyspnea due to mediastinal mass and pleural effusion
- Diarrhea from intestinal lymphoma
- Vomiting from renal failure due to renal lymphoma
- Icterus due to hepatic lymphoma
Diagnosis of FeLV.
Material: Blood
Antigen ELISA and IFA
- Elisa is more sensitive and detects viremia earlier.
- Both positive: infection >3 weeks
- ELISA positive, IFA negative: infection <3 weeks (early infection) – retest after 6 weeks.
- Latently infected cats are negative for both!
Blood smears
PCR
What is IFA?
Immunofluorescence assay (IFA)
a standard virologic technique to identify the presence of antibodies by their specific ability to react with viral antigens expressed in infected cells; bound antibodies are visualized by incubation with fluorescently labeled antibody.
Tx of FeLV.
Tx: ABs if secondary infections
Keep cat indoors to prevent secondary infections!
Diagnosis of FeLV is not a reason for euthanasia!
Infected cats can live several years with good quality of life.
Prevention of FeLV.
Keep cats indoors
Vaccination
