Page 18 - Problem-Based Feline Medicine

10 PART 1 CAT WITH UPPER RESPIRATORY TRACT SIGNS

● Infection rates may reach 100% in unvaccinated – If a cattery problem occurs, vaccinate litters as
cats and kittens. early as 4 weeks of age, and repeat every 3–4
● Young kittens (5–8 weeks of age) are most suscep- weeks until 14 weeks of age.
tible. ● Intranasal vaccine is a modified live vaccine,
● Occasionally kittens are born with infection. which produces rapid immunity (1–4 days). Some
cats have transient mild sneezing and naso-ocular
Most infections occur via direct close contact with
discharge after vaccination.
infected cats.
– Vaccinate with a single dose. If less than 10
● Fomites are also important in spread, especially
weeks of age at the first dose, give second dose
unwashed hands, food, bowels and contaminated
3–4 weeks later.
cages.
– If a cattery problem occurs, divide the dose
● Airborne transmission occurs over short distances
amongst the litter and give at 2 weeks of age, and
(approximately 1.2 m (4 feet)). Virus is present in
follow with a parenteral vaccination every 4
the droplets formed by sneezing.
weeks until 14 weeks of age.
● Virus is shed in secretions (ocular, nasal and oral)
● The combination of intranasal and subcuta-
for 1–3 weeks after infection.
neous vaccination reduced the incidence of upper
Spread in boarding catteries, shelters and veterinary respiratory tract disease (31% of cats developed
hospitals is facilitated by the high frequency of car- signs) in a shelter compared with subcutaneous
rier cats in the population that shed virus at times of vaccination alone (51% of cats developed signs),
stress or glucocorticoid treatment and may show no and was cost-effective.
signs of infection.
The frequency of booster vaccinations is controver-
Vertical transmission occasionally occurs from a sial. Annual boosters are typically recommended, par-
carrier queen, resulting in kittens born with disease. ticularly because occurrence of upper respiratory tract
● More usually, carrier queens shed virus 4–6 weeks signs is common in vaccinated cats, especially when
after queening, infecting kittens at the time mater- exposed to stress. However, measurement of serum
nal immunity is waning. titers suggests that humoral immunity lasts for 48
months or more. Serological titers are not equivalent
Feline herpesvirus is relatively fragile, and is stabile
to protection from challenge, although the predictive
for less than 24 h outside the host.
value for resistance to challenge for a positive serum
● The virus is susceptible to most disinfectants.
antibody titer was 70% for herpesvirus and 92% for
calicivirus. Additional boosters are recommended
Prevention before a heavy challenge, e.g. boarding in a cattery.
Live parenteral vaccine can produce signs of upper res-
Vaccination piratory tract disease if aerosolized or spilt on the cat’s
Parenteral and intranasal vaccines are available in hair, so take care with administration.
combination with feline calicivirus vaccine.
Maternal antibodies can block the effect of the vaccine.
Combinations with feline parvovirus, chlamy- ● Antibody levels vary between kittens, and may last
dophila, rabies and/or feline leukemia vaccines are 5–6 weeks with herpesvirus (7–8 weeks with cali-
also available. civirus).
● Parenteral vaccines for subcutaneous administra-
Vaccinating queens 1–4 weeks before partum increases
tion are available as modified live or inactivated
colostrum-derived maternal immunity.
vaccines.
● DO NOT USE WITH LIVE PANLEUKOPENIA
– Administer twice with a 3–4-week interval
VACCINE in pregnant queens.
between doses.
– If the kitten is less than 8 weeks old at the first Localized viral infection can occur in vaccinated cats,
dose, give a third dose 3–4 weeks after the sec- and may produce mild ocular and nasal discharge, and
ond dose. viral shedding.