CHANGES IN BEHAVIOURAL AND PHYSIOLOGICAL PARAMETERS ASSOCIATED WITH TAENIA PISIFORMIS INFECTION IN RABBITS (ORYCTOLAGUS CUNICULUS) THAT MAY IMPROVE EARLY DETECTION OF SICK RABBITS

The purpose of this experiment was to describe early behavioural responses to illness in rabbits and their relation with physiological changes to improve early detection of infection by Taenia pisiformis in rabbits. Twenty adult female New Zealand rabbits were randomly allocated to 2 groups to determine whether changes in behaviour and some physiological parameters can be induced in rabbits after a T pisiformis infection. Infected animals were orally inoculated with 3000 eggs of T pisiformis, while controls received only saline solution. Behavioural activity was recorded daily from 19:00 to 21:00 h starting 2 d before infection. Mate choice and rank status were assessed, and blood samples were collected at -2, 7, 14 and 25 d post infection (dpi) for hematological and hepatic function determinations. All animals were observed for clinical signs every other day from the beginning of the experiment and euthanised 25 dpi after last sampling. Infected animals spent more (P < 0.01) time lying stretched (3.78 +/- 1.77 vs. 0.77 +/- 0.03%) and less (P < 0.01) time grooming (1.95 +/- 1.31 vs. 2.58 +/- 0.10%) and at the watering trough (1.20 +/- 1.13 vs. 3.35 +/- 0.02%) than controls. These differences were noticeable 6 dpi and remained until the end of the experiment. No changes (P > 0.05) were observed in the time spent at the feeder, rank status or mate choice. Leukocyte and lymphocyte concentrations increased (P < 0.05), while heterophil counts decreased in infected rabbits as the experiment progressed. Furthermore, infected animals had larger concentrations of alkaline phosphatase as soon as 7 dpi. No clinical signs of the disease were detected. Necropsy findings corroborated hepatic lesions and presence of the parasite in all infected animals. It was concluded that an infection with 3000 eggs of T pisiformis induced changes in behavioural and physiological parameters that may improve early detection of sick rabbits.