Changes in behavioural and physiological parameters associated with Taenia pisiformis infection in rabbits (Oryctolagus cuniculus) that may improve early detection of sick rabbits

Abstract

[EN] The purpose of the present experiment was to describe rabbits' early behavioral responses to illness, and its relation with physiological changes to help improve early detection of infection, particularly those induced by Taenia pisiformis in rabbits. Twenty adult female New Zealand rabbits were randomly allocated in two groups, to determine whether changes in behavior and some physiological parameters can be induced in rabbits after a T. pisiformis infection. Infected animals were orally inoculated with 3,000 eggs of T. pisiformis, while controls only received saline solution. Behavioral activity was recorded daily from 19:00 to 21:00 h starting two days before infection. Mate choice and rank status were assessed, and blood samples were collected at -2, 7, 14 and 25 days 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 euthanized 25 dpi after last sampling. Infected animals spent more (P<0.01) time lying down (87 vs. 17%) and less (P<0.05) time grooming (43 vs. 57%) and drinking (26 vs. 74%) 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. Leucocyte 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 corroborate hepatic lesions and presence of the parasite in all infected animals. It was concluded that an infection with 3,000 eggs of T. pisiformis induced changes in behavioral patterns, supported by some changes in hematological and hepatic parameters that could improve early detection of illness, regardless of clinical signs.