Feline Infectious Diseases

Are cat diseases pretty severe?

The viruses that cats get are hard to treat and control but most co-exist with their viruses without serious disease

What kind of virus is feline panleukopenia viruse (FPV)?

Parvovirus

Very infectious and stable in environment

Likes rapidly dividing cells

What happens to a fetus if mother gets infected with FPV <21d of gestation

Abortion

What happens to a fetus if mother gets infected with FPV >21d of gestation

Cerebellar hypoplasia

What happens to young kittens that get infected with FPV?

Sudden death

Older kittens/cats with FPV?

Intestinal disease (FIE) and severe panleukopenia

What are the clinical signs of feline infectious enteritis (FIE)?

Fever

Inappetence

Anorexia

Vomiting

Severe watery diarrhea in later stages

Secondary bacterial infection

High mortality (25-75%)

What would an x-ray of a cat with FIE look like?

It can look very similar to a foreign body!! Careful not to do FB sx unless sure there is something there

How is FIE diagnosed?

Viral isolation: dookie, oropharyngeal swab, PCR, canine parvo snap tests

Serology (takes a while tho)

How is FIE treated?

Nursing: warmth, rest, cleanliness, palatable food

IV fluids

Anti-emetics: SC maropitant, IV metoclopramide

IV abx

Interferon

Isolate!!!

How is FIE controlled?

Vaccination is very effective!

In outbreaks: strict hygiene, vax all in-contact cats, premises contaminated for 1 year after

What are the pathogens associated with cat flu?

Mainly feline calicivirus and feline herpesvirus

Also bordatella bronchospetica, chlamydophila felis

Some others too but these are the main ones

What are the signs of cat flu?

Usually 1-2 weeks

Range from slight nasal discharge to severe rhinotracheitis

Rarely fatal

What are the signs of FHV?

URT disease + ocular signs

Conjunctivitis, ulcerative keratitis

Big cause of spontaneous ocular ulcers! Can cause blindness

What are the stages of FHV?

The cat can be acutely infection

Then it moves onto clinical recovery

From there, about 20% reach true recovery but 80% become carriers

Carriers are clinically asymptomatic but virus is replicating

Then the virus become latent which means it is no longer replicating, lives in trigeminal ganglion

Stress can cause reactivation ± clinical signs

What does feline calicivirus (FCV) cause?

URT disease, oral ulcerations, viral arthritis, gingivitis/stomatitties

What are the stages of FCV?

Acute infection (can cause chronic damage)

Clinical recover

Carrier - can last 6 months

Then transient shedding (50% still shedding 2mo after infection)

Then either true recovery if low stress or persistent shedding

What is severe FCV? How common is it?

Rare

The virus can change and become very pathogenic

Often fatal

Super high death rates, spreads easily

Outbreaks usually die out bc the population dies

Systemic signs of severe FCV?

Pyrexia

Jaundice

Dermatological

Facial edema

FHV/FCV diagnosis?

Oropharyngeal swabs

FHV only after reactivation

Tx of cat flu?

Nursing: warmth, rest, clean nose, tempting food

Fluids

Abx if secondary infection

Monitor temp

Isolate

What does chlamydophilia felis cause?

Conjunctivitis ± mild rhinitis

How is it diagnosed?

Isolation or serology

Treatment?

Tetracyclines for at least 2 weeks after signs have resolved

Parenterally in severe cases

What virus causes feline infectious periotonitis (FIP)?

Feline coronavirus

Are FeCoV infections severe? Clinical signs?

Most are benign

Mild diarrhea 2-3 days

Predominantly in kittens

But it can mutate which plays a role in development to FIP

When are cats usually infected with FCoV?

When kittens by other cats - kittens from other litters or non-parental adults

What are the two types of FCoV infections? What happens in these diseases?

Enteric disease: mild enteritis

Systemic disease (FIP): Infected monocytes disseminate infection, immune mediated vasculitis, complement fixation, pyogranuloma formation, vascular damage (→ protein leakage)

What is the theory for FIP pathogenesis?

Ingestion

→ Replication in tonsils and intestinal epithelium

• If strong CMI, low dose, no mutation - no disease or mild enteritis

→ Replication in lymphoid tissues

→ Replication in other tissues

• If weak CMI, large dose, pathogenic mutant - wet FIP

• If moderate CMI, moderate dose, moderate pathogenicity - dry FIP

What is FIP?

A sporadic but serous disease caused by feline coronavirus

Has two forms: wet (effusive) and dry (non-effusive)

Dry is slower/more chronic

How is FIP diagnosed?

Only definitive way is by immunohistopathological examination of a biopsy specimen

But can use

• Clinical signs

• Presence of virus: serology, PCR

• Fluid analysis

• History: age, MCH, stress

• Systemic inflammation: hematology, biochem, AGP

Clinical What are the clinical signs of wet FIP?

Effusive lesions

Peritoneal - ascites

Pleural - dyspneaC

CS of dry FIP?

Granulomatous lesion

Neuro signs: ataxia, paresis, nystagmus

Liver and kidney disfunction: jaundice, PUPD

Ocular lesions: iritis, retinitis

CS of both?

Pyrexia, weight loss, depression

Can occur at any age but generally <2 y.o., occasionally >11 y.o.

May have signs of both syndromes

Older = more difficult to treat

What clinical pathology would you see on bloods?

Hyperglobulinemia

Lymphopenia

Neutrophilia

Anemia

High acute phase proteins (inflammation marker)

Differentials of FIP

Liver dz: cholangiohepatitis, lymphpcytic cholangitis

Neuro dz: FIV infection, lymphosarcoma, FSE

Kidney dz: renal lymphosarcoma

Peritoneal/pleural dz: thoracic masses, lymphosarcoma, bacterial peritonitis

If you’re thinking FIP but FCoV serology is negative what does this mean

It is probably not FIP

If you’re thinking FIP and FCoV serology is negative with moderate titers (<320) what does this mean?

It is non-diagnostic

Consider biopsy of lesions

Most cases of dry FIP have moderate titers

If you’re thinking FIP and FCoV serology is positive with high titers (>640), what does this mean?

Possible FIP

Must have clinical signs consistent with it

How do you treat FIP?

Nucleoside analoguesL Remdesiver, GS-441524

How are they treated with Remdesivir?

Injections daily IV or SC

Minimum 12 week course but expect improvement in first week

Monitor biochem and hematology

Verrrry expensive

How do you treat with GS-441524?

Oral tablets

10-15 mg/kg q23 PO

Increase to every 12 hrs if needed

How is FIP controlled?

Vaccination can make the dz worse because the virus gets into cells using the antibody

Either eliminate all coronaviruses by serology or separate infected cats and tolerate occasional outbreaks

There is a vax available in the US but not widely recommended