Experimental induction of feline viral rhinotracheitis virus re-excretion in FVR-recovered cats.
The re-excretion of feline viral rhinotracheitis (FVR) virus (feline herpesvirus I) by FVR-recovered cats is recorded both spontaneously and following a variety of stimuli, namely, corticosteroid administration, change of housing, and parturition and lactation. At least 27 of 33 (82%) FVR-recovered cats studied were shown to be viral carriers. The carrier state was characterised by periods of viral latency interspersed with episodes of viral shedding. Administration of 0-75 mg dexamethasone trimethylacetate and 2-25 mg prednisolone on days 0,2 and 4 resulted in re-excretion after a mean lag period of 7-2 days in 22 of 32 (69%) FVR-recovered cats on a total of 31 of 57 (54%) occasions. Rehousing resulted in virus re-excretion after a mean lag period of 7-2 days in four of 22 (18%) cats tested on a total of six of 40 (15%) occasions. Apparently spontaneous shedding occurred on a total of 10 occasions in nine of 31 (29%) cats during a mean observation period of 8-8 months. Four of six FVR-recovered queens in a total of four of 10 litters (40%) shed virus within two to 10 weeks of parturition. Serum neutralising antibody titres were generally boosted at the time of first re-infection but afterwards remained essentially constant. Although 82% of cats in these studies were shown to be viral carriers, only 45% of cats shed virus spontaneously or as a result of the natural stress situations and it is postulted that these naturally excreting cats are of most significance epidemiologically.
D000818:Animals; D002353:Carrier State / Q000382:microbiology / Q000662:veterinary*; D002371:Cat Diseases / Q000382:microbiology*; D002415:Cats; D003907:Dexamethasone / Q000494:pharmacology; D005260:Female; D006564:Herpesviridae / Q000302:isolation & purification; D006566:Herpesviridae Infections / Q000382:microbiology / Q000662:veterinary*; D006799:Housing, Animal; D007743:Labor, Obstetric; D007774:Lactation; D011239:Prednisolone / Q000494:pharmacology; D011247:Pregnancy; D013312:Stress, Physiological / Q000662:veterinary
D003907:Dexamethasone; D011239:Prednisolone