Page 21 - Problem-Based Feline Medicine

2 – THE CAT WITH ACUTE SNEEZING OR NASAL DISCHARGE 13

● Fomite transmission occurs, e.g. food and water Clinical signs
bowls, cages, human hands, shoes and clothing.
Conjunctivitis is often initially unilateral, but pro-
● Virus can survive several days, and in some situa-
gresses to bilateral involvement.
tions up to 8–10 days, on contaminated objects.
● Conjunctiva are hyperemic, which is usually mild
Virus is shed in secretions from the mouth and nose of but can be severe, and are occasionally edematous
sick cats. and chemotic.
● Ocular discharge is initially seromucous, but rap-
The carrier state is common, and may last years.
idly becomes mucopurulent.
Carrier cats provide a source of infection, and shed
virus continuously, mainly from the tonsils. Sneezing and nasal discharge result from ocular dis-
charge draining through the nasolacrimal duct.
Virus is resistant to lipotrophic disinfectants, and
sodium hypochlorite (1:32 dilution of household Pneumonia occasionally occurs in kittens.
bleach) is efficacious.
Chlamydophila may cause abortion and infertility,
although this is controversial and poorly documented in
Prevention cats.

Vaccines are available combined with feline
herpesvirus vaccine (see herpesvirus (page 10) for
Diagnosis
administration details).
Visualization of inclusion bodies in epithelial cells
Vaccination decreases severity and duration of signs.
obtained from conjunctival scraping (Diff-Quick stain)
● Vaccination may not afford 100% protection if
is diagnostic.
challenged by a subtype that is different from the
● Inclusion bodies are visible as groups or clusters of
vaccine strain.
organisms in the cytoplasm (in the same plane as
Cattery control involves vaccination, isolation of incom- the nucleus).
ing cats and good hygiene (see herpesvirus, page 11). ● Inclusions are most often visible in the first 2 weeks
of infection, and numbers decrease with chronicity.
CHLAMYDOPHILA FELIS Antibody-based detection in conjunctival scrapings
(CHLAMYDOPHILA FELIS PSITTACI)**
using ELISA or latex agglutination is available. False
positives occur with both tests if many bacteria are
Classical signs
present.
● Conjunctivitis, initially acute but ● Use a dry swab, and roll well to get sufficient tissue
progressing to chronic inflammation. for the test.
● Sneezing and nasal discharge is usually
PCR is becoming more commonly available from
mild and often becomes chronic.
diagnostic laboratories, and is the technique now used
predominantly for studies involving chlamydophila.
See other reference on page 1215 for details (The Cat
With Ocular Discharge or Changed Conjunctival
Appearance). Differential diagnosis
Herpesvirus generally produces more severe ocular-nasal
Pathogenesis discharge and systemic signs. If ulcerative keratitis is pres-
ent, it is usually diagnostic for herpesvirus.
Chlamydophilosis causes approximately 20% of upper
respiratory tract disease in cats, but is a frequent cause Calicivirus typically causes oral ulcers, which are not
of conjunctivitis. present with chlamydophila.
Infection may occur concurrently with herpes or cali- Mycoplasma may not be clinically distinguishable
civirus infection. from chlamydophila.