Objective—To determine efficacy of treatment with a
combination febantel-praziquantel-pyrantel product,
with or without vaccination with a commercial Giardia
vaccine, in dogs with naturally occurring giardiasis.
Animals—16 Beagles naturally infected with Giardia
Procedures—During phase 1, 6 dogs were treated
with the parasiticide for 3 days (4 were also vaccinated).
Four weeks later, all 6 dogs were treated with the
parasiticide again for 5 days and were bathed and
moved to clean cages after the last treatment (phase
2). Nine dogs were treated with the parasiticide for 3
(n = 4) or 5 (5) days and bathed and moved to clean
cages after the last treatment (phase 3). Fecal samples
were collected twice weekly for 24 days after
treatment and tested for cysts with a quantitative zinc
sulfate flotation technique and for Giardia antigen
with an immunoassay.
Results—Dogs in phase 1 were all shedding cysts
again by day 24. In phase 2, only 1 dog shed cysts
after treatment, and shedding was transient (day 17).
In phase 3, neither cysts nor antigen was detected in
fecal samples from 2 of 4 dogs treated for 3 days and
4 of 5 dogs treated for 5 days. In 18 of 57 (31.6%)
fecal samples, cysts were seen, but results of the
immunoassay were negative.
Conclusions and Clinical Relevance—Results suggest
that when a combination febantel-praziquantelpyrantel
product is used to treat dogs with giardiasis,
bathing and changing the environment after treatment
may be more important in preventing recurrence
than duration of treatment. (J Am Vet Med