Feline respiratory disease - PowerPoint Presentation

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Feline respiratory disease

What

is

cat flu?

Cat flu is the generic term applied to upper respiratory infection in cats. It can be caused by infection with agents such as feline herpes virus (FHV), feline calicivirus (FCV), Chlamydia felis, Bordetella bronchiseptica and mycoplasma species. FHV and FCV are the most common causes of flu in cats, accounting for about 90% of cases of flu. In some cases, more than one agent may be involved.Once a cat develops cat flu and the upper respiratory tract is compromised, secondary bacterial infections can sometimes occur, making the clinical signs worse

FCV

Feline

calicivirus Family: Caliciviridaess+RNA, spherical, calyx-shaped depressions on the capsidic surface

etiology

FHV-1 (feline herpesvirus-1)

Causes acute serious disease in the

upper

respiratory

tract

viral

rhinotracheitis

in cats

Generalized forms with

pneumonia

,

abortion

and

ulceration

of the

oral

mucosa

fcv

Transmission

Saliva

Nasal or ocular secretionsUrine and faeces (rarely)Contaminated objects with infected secretions (virus on dry surfaces may remain infected for up to one month)People who have touched contaminated objects or an infected catPathogenesis

Incubation

for 2-6

days

Primary replication in

oropharynx

Transient

viraemia

3-4

days

p. i.

Necrosis of the upper respiratory tract epithelial cells Healing in 2– 3 weeks Elimination by oro-nasal secretionsSometimes forms affecting the deeper airways (pneumonia) or joints, with synovial membrane thickening, synovial fluid increase (lameness)Virus has sometimes been found in faeces, urine and macrophages of the joints

Signs

Intense clear tear

Abundant nasal secretionsSneezesFeverUlcers in the mouth (tongue, palate, lips and gums)ScialorrheaAnorexiaInflammation and irritation of the mouth and noseLameness (more frequent in kittens)

FCV

The

carrier status is established with great frequency 75 days p. i. 50% of cats still

actively eliminate the virusEvolution of the capsidic protein, very variable, allows the virus to elude the immune defences and the onset of the carrier stateThe possibility of becoming carriers is not eliminated by vaccination; on the contrary, the condition of a chronic carrier can be established also by live attenuated vaccine virusesVirus is very common in kittensLaboratory diagnostic tests• buffers and pads of oral cavity and oral, nasal, ocular secretions• Serum, faeces and urine (acute stage of disease)Direct Diagnosis• Virus

isolation• RT-PCR• immunohistochemistry (

gold standard)• I.F.D.

Indirect diagnosis• ELISA• serum neutralisationDiagnosis

Lesions and necropsy

Proliferative

ulcerative

chronic stomatitis gumsConjunctivitisInterstitial pneumonia Pneumonia

Epistaxis and severe oral and nasal

skin ulceration

Severe oral and nasal skin ulcerationLingual

ulcers

Nasal

crusty

lesions

fhv

Respiratory

diseaseMay cause keratoconjunctivitis, oral ulcers (not differentiated from those caused by calicivirus

)Receptivity: CatIt’s the most frequent infection of cat upper respiratory tract diseasesdistributed to the environment by nasal, oculo-conjunctival, oral, litter and shared bowlsDirect infection prevailsNasal and conjunctival secretion Corneal

Opacity

Herpetic

nasal ulcersSigns

• Depression, anorexia, sneezing, sneezing

• Milk fever

• nasal and conjunctival secretion

• foamy salivation with difficulty breathing

• cough and cough

• oral cavity ulcers

Conjunctivitis

,

keratitis

,

corneal

opacity.• Neurological manifestations of the brain.• blepharospasm (contraction 3 eyelid)• Descemetocele (prelude to corneal perforation)• miscarriage or miscarriage•High mortality in young people

F

oamy

salivation

KeratoconjunctivitisFluorescin positive corneal ulcers

• Incubation 2-6

days

• Input via aerosol or conjunctival• tributary lymph node

replication• nasal-pharyngeal mucosa, tonsils, conjunctiva• viremia (occasional) latency• Pregnant female may abort or during childbirth infect infants• The disease usually lasts about 20 days

Pathogenesis

• Isolation of virus: initial nasal mucus

• Identification

• Cultivation of virus

• IFD

• PCR

Diagnosis

Lesions and necropsy

Mucous

lesions of the respiratory tract:• mucopurulent exudation• outbreaks of necrosis

• point haemorrhages to the tonsilsLung• laboratory areas, hepatizedHistology• Edema of the submucosa and neutrophilic infiltration caused by bacteriaLung damage

Herpetic ulcers

oral cavity and tongue

How are cats infected

with

cat flu?

Infection spreads via contact with a cat who is shedding one of the infectious agents in ocular, nasal or salivary discharges (these cats may or may not be showing signs of flu), by inhaling infected sneeze droplets or by transmission on bowls, bedding and people (also known as ‘fomite’ transmission). Cats that have been infected with FHV will remain carriers for life. Many will never shed the virus again, but periods of stress may trigger them to start shedding the virus with or without showing mild clinical signs. They usually shed within seven days of a stressful experience and the shedding may last for 14 days. Mycoplasma can be a normal finding in healthy cats.In summary this means that any cat, no matter how healthy they look, could be shedding organisms that have been implicated in cat flu.

Which cats are vulnerable to cat flu?

All cats are potentially vulnerable to cat flu. Vaccination provides some but not complete protection. Very old or very young cats and cats with an already compromised immune system are more susceptible and may show more severe clinical signs.

How is cat flu diagnosed?

Cat flu is diagnosed on the basis of the clinical signs. It is rarely appropriate to test in order to find a specific agent.

How is cat flu treated?

The exact treatment will obviously vary from case to case, and will be at the vet’s discretion.

However, as a first line antibiotic we would recommend considering doxycycline.

How can cat flu be prevented?

It is

impossible

to prevent cat flu completely, however vaccination offers good protection

Vaccinations

against FHV and FCV are commonly given as part of a core vaccination

programme

for cats. Although vaccination does not completely prevent disease it does reduce the severity of clinical

signs.n

against FHV and some protection against FCV.

Thank

you for

your

attention