We evaluated the efficacy of acyclovir against experimentally induced herpesvirus infection (Pacheco's parrot disease) in Quaker parakeets. Thirty-two of 40 birds were challenge-exposed with 0.1 ml of a suspension of herpes-virus (10(4) median cell culture infective doses CCID50 ) given IM. Treatment with acyclovir was started 24 hours later and was continued for 7 days. The birds were allotted to 5 groups of 8 birds each. There was a considerable difference in mortality between groups 1-5. Of 8 birds in each group, 6 died in group 1 (control), 1 died in group 2 (gavage), 3 died in group 3 (low dose, IM), 4 died in group 4 (high dose, IM), and none died in group 5 (contact controls). There was a significant (P = 0.023) difference in mortality between groups 1 and 2, thus the oral form of acyclovir administered by gavage was the most efficacious therapeutic regimen. Clinical signs and death occurred after discontinuation of acyclovir in groups 2 and 3, whereas the mean time of death for the control group was 6 days after challenge exposure. Herpesvirus was recovered by inoculation of chick embryo cell culture with pooled tissue suspensions from all birds that died. Histologic evidence of herpesvirus infection was found in most birds that died, with the control group having the most severe lesions. Surviving Quaker parakeets were transferred to cages with seronegative Quaker parakeets with no known exposure to herpesvirus. There have been no deaths attributable to herpesvirus infection in a period exceeding 2 years.

Studying of palatability of bait blisters applied for oral immunization of wild carnivores against rabies was realized in the conditions of the Republic of Belarus by an example of foxes which were administrated with liquid viral vaccines against rabies. Foxes were divided into 5 groups with 8 animals in each. Animals of the first group were immunized with a liquid viral vaccine in blister baits Lisvulpen-VBF which was produced from an attenuate strain of rabies virus SAD-BERN (Belarus). Animals of the second group were immunized with liquid viral vaccine Belvak TM BP produced from the cultural living strain KMIEhV-V101 (Belarus). Animals of the rest three groups were immunized with liquid viral vaccine in blister baits which was produced from a modified strain of a fixed attenuate rabies virus KMIEV-94. Foxes of the forth group were additionally fed with ascorbic acid with baits in the doze of 0,1 g, and foxes of the fifth group were fed with 5 ml immune response modifier Nuklevit. All mentioned blister baits were studied in accordance with the following parameters: bait flavor and attraction to animals; form and size of bait; bait consistency; blister and its size in relation to bait; palatability of bait; degree of damage of bait containing a vaccine; quantity vaccine which was got into animal oral cavity; postvaccinal complication. Palatability of liquid viral vaccines in blister baits Lisvulpen-VBF was 96%, Belvak TM BP - 94%, KMIEV-94 - 80%

In the conditions of the Republic of Belarus by means of application of a scanning electron microscopy there was realized a morphological assessment of the efficiency of mono- and associated antiviral vaccines. It is shown, that analyzed biological preparations invoke in poultry a number of structural disorders among which it is possible to mention both immunomorphological changes, and pathomorphological processes. The highest reactogenicity was showed by of monovaccines against infectious bronchitis (produced by Research Institute of Animal Protection, Russia); infectious laryngotracheitis (Institute of Experimental Veterinary of S.N.Vyshelesskij, Belarus); and also an associated vaccine against infectious bronchitis, infectious bursal disease and Newcastle disease (Research Institute of Animal Protection, Russia). These vaccines caused essential structural disorders in tissues at a place of administration, liver and kidneys. Administration of the vaccine against infectious bursal disease and associated vaccines against infectious bronchitis, infectious bursal disease, infectious laryngotracheitis and Newcastle disease (Institute of Experimental Veterinary of S.N.Vyshelesskij) strengthened the processes of lymphatization in fabricic bursa. All studied biological products caused activization of morphological reorganization of immune apparatus of a spleen and did not render essential influence on thymus structure. | С использованием сканирующей электронной микроскопии проведена морфологическая оценка эффективности моно- и ассоциированных противовирусных вакцин. Показано, что указанные биопрепараты вызывают в организме птиц ряд структурных нарушений, среди которых можно выделить как иммуноморфологические изменения, так и патоморфологические процессы. Наибольшую реактогенность проявляли моновакцины против инфекционного бронхита кур (ФГУ ВНИИЗЖ, Россия), инфекционного ларинготрахеита (ИЭВ им. С.Н. Вышелесского), а также ассоциированная вакцина против ИБК, инфекционной бурсальной болезни и болезни Ньюкасла (ФГУ ВНИИЗЖ, Россия), которые вызывали существенные структурные нарушения в ткани на месте введения, печени и почках. Использование вакцины против ИББ и ассоциированной вакцины против ИБК, ИББ, ИЛТ и БН (ИЭВ им. С.Н. Вышелесского) усиливало процессы лимфатизации в фабрициевой бурсе. Все изучаемые биопрепараты вызывали активизацию морфологической перестройки иммунного аппарата селезенки и не оказывали существенного влияния на структуру тимуса.