Onset of immunity in kittens after vaccination with a non-adjuvanted vaccine against feline panleucopenia, feline calicivirus and feline herpesvirus.

The induction of a quick onset of immunity against feline parvovirus (FPV), feline herpesvirus (FHV) and feline calicivirus (FCV) is critical both in young kittens after the decline of maternal antibodies and in cats at high risk of exposure. The onset of immunity for the core components was evaluated in 8-9 week old specific pathogen free kittens by challenge 1 week after vaccination with a combined modified live (FPV, FHV) and inactivated (FCV) vaccine. The protection obtained 1 week after vaccination was compared to that obtained when the challenge was performed 3-4 weeks after vaccination. The protocol consisted of a single injection for vaccination against FPV and two injections 4 weeks apart for FHV and FCV. At 1 week after vaccination, the kittens showed no FPV-induced clinical signs or leukopenia following challenge, and after FCV and FHV challenges the clinical score was significantly lower in vaccinated animals than in controls. Interestingly, the relative efficacy of the vaccination was comparable whether the animals were challenged 1 week or 3-4 weeks after vaccination, indicating that the onset of protection occurred within 7 days of vaccination. Following the 1-week challenge, excretion of FPV, FHV and FCV was significantly reduced in vaccinated cats compared to control kittens, confirming the onset of immunity within 7 days of vaccination.

Seroprevalence of canine herpesvirus-1 in the Belgian dog population in 2000.

Canine herpesvirus-1 (CHV-1) is known to be associated with fertility and fecundity disorders as well as neonatal mortality in puppies of less than 3 weeks of age. The virus is presumed to be enzootic in dogs all over the world and recent studies in several European countries suggest a high seroprevalence among the dog population. In the year 2000, a total of 647 Belgian canine sera from 102 privately owned patients and 545 breeding dogs were analysed with an enzyme-linked immunosorbent assay (ELISA). Furthermore 77 of the samples were submitted to two serum neutralization (SN) tests for comparison. An overall CHV-1 seroprevalence of 45.75% was observed in the Belgian dog population. No significant differences could be observed based on breeding status, reason for consultation or sex. The correlation between the ELISA and both SN tests appeared to be moderate with a significantly greater sensitivity of the ELISA. This study also demonstrated that the CHV-1 seroprevalence in the Belgian dog population is similar to that in other recently investigated European countries and that the incidence in breeding units is not necessarily higher than in non-breeding dogs.

[Demonstration of cell death process by apoptosis in cat lymphocytes infected by FIV (feline immunodeficiency virus)]. / Mise en évidence d'un phénomène de mort cellulaire par apoptose dans les lymphocytes de chats infectés par le FIV (feline immunodeficiency virus).

Feline immunodeficiency virus (FIV), the causative agent of feline AIDS, induces a disease syndrome in cats characterized by a decreased lymphocyte-proliferative response to mitogens at all stages of infection and selective depletion of CD4 lymphocyte subsets. In this work, we report that peripheral blood lymphocytes isolated from FIV-infected cats undergo a spontaneous death, in vitro, according to a programmed cell death (PCD) or apoptosis. This phenomenon has also been seen in peripheral blood lymphocytes from HIV-infected humans and SIV-infected macaques. Four different techniques were used to document PCD in FIV-infected cats. DNA gel electrophoresis has shown a DNA fragmentation pattern with DNA fragments displaying sizes corresponding to multiples of oligonucleosomes DNA length unit (180 bp). Transmission electron microscopy revealed condensation of both nuclear chromatin and cytoplasm. An increase in the percentage of fragmented DNA was demonstrated by Burton's technique. In addition, flow cytometric analysis detected a cell population with condensed chromatin. The spontaneous PCD in FIV-infected cats could not be inhibited by RNA synthesis inhibitors or protein synthesis inhibitors. Our results could have implications for understanding the pathogenesis of FIV-infection and establishing specific strategies against apoptosis in cats and humans.