Immobilization of white-tailed deer with xylazine hydrochloride and ketamine hydrochloride and antagonism by tolazoline hydrochloride.

Fourteen penned and 17 free-ranging white-tailed deer (Odocoileus virginianus Rafinesque) were singularly or repeatedly immobilized with 100 mg xylazine hydrochloride (HCl) and 300 mg ketamine HCl. The mean times from intravenous injection to ambulation for 1.0, 2.0, and 4.0 mg/kg body weight doses of tolazoline HCl were 13.5, 10.5, and 9.2 min. Deer not receiving tolazoline HCl recovered in an average of 168 min. Heart rates significantly (P less than 0.001) increased from 47 to 83 beats/min after tolazoline HCl administration, representing a return to normal rate. Tolazoline HCl had no effect on respiratory rate. A total of 85 reversals with tolazoline HCl resulted in no apparent adverse reactions.

Effects on fawn survival of multiple immobilizations of captive pregnant white-tailed deer.

Fawn viability was tested in captive, pregnant white-tailed deer (Odocoileus virginianus) immobilized with xylazine hydrochloride and ketamine hydrochloride and reversed by yohimbine hydrochloride or tolazoline hydrochloride. Nine pregnant does were immobilized 10 times each from December 1984 to May 1985. Their mean parturition date was 8 June. The number of fawns produced per pregnant doe was 1.88. Mean weight of newborn fawns was 4.18 kg. Seventy-five percent of the does produced twins or triplets. Three (20%) fawns died postnatally within 48 hr, but the remaining 12 survived for the full 72 hr they were allowed to remain with their dams. These observations compare favorably with those of non-immobilized captive deer on similar diets.

Yohimbine hydrochloride as an antagonist to xylazine hydrochloride-ketamine hydrochloride immobilization of white-tailed deer.

Thirteen captive and one free-ranging white-tailed deer (Odocoileus virginianus) were immobilized one to six times each with ketamine hydrochloride and xylazine hydrochloride during winter and spring in northern Minnesota. Administration of 0.09 to 0.53 mg of yohimbine hydrochloride per kg IV after each trial reversed the immobilization. The deer raised their heads within a median time of 2.0 min, stood in 6.0 min and walked away in 9.5 min. No adverse side effects were observed for several weeks following the immobilization.

Hematology and serum chemistry of bobcats in northcentral Minnesota.

Hematology and serum chemistry values were determined for 27 (18 male, 9 female) wild-caught bobcats (Felis rufus Schreber) greater than or equal to 1.0 yr old from northcentral Minnesota. Most blood parameters were similar to normal values for both captive bobcats and domestic cats. Deviations from these normals were likely the result of capture stress, nutritional status, and/or reproductive condition.

Hormonal correlates of hypophagia in white-tailed deer.

Deer exhibit a number of adaptive annual changes in common with hibernators. Each winter deer have a period of voluntary hypophagia and losses of body weight. This is accompanied by a shift to fat metabolism and increased recycling of urea nitrogen to maintain positive nitrogen balance. Deer also show alterations in activity patterns and decreased metabolic rates, heart rates, and body temperatures during winter. Male deer exhibit an additional period of hypophagia associated with rut. Rut-associated hypophagia is either directly controlled by serum testosterone or internally coupled to the annual testosterone cycle. The adaptive value of rut-associated hypophagia is unknown but may be associated with insuring reproductive success. Both winter and rut-associated hypophagia are most likely synchronized to the environment by photoperiod. The winter adaptive changes may be caused by a primary alteration in appetite control with secondary changes in thyroid hormone economy, or the hypophagia may be independent but internally coupled to other neuroendocrine changes.

Reproductive steroids in the white-tailed deer (Odocoileus virginianus borealis). I. Seasonal changes in the female.

PIP: Seasonal changes of reproductive steroids in the female white-tailed deer (Odocoileus virginianus borealis) were investigated. 161 blood samples were collected from 77 does during 1971 through 1974 in Minnesota and were utilized to make a characterization of the estrogen and progesterone levels in pregnant and nonpregnant does. Progesterone levels (measured by radioimmunoassay) during December through February were similar for pregnant and nonpregnant does. Progesterone levels (measured by radioimmunoassay) during December through February were similar for pregnant and nonpregnant animals. However, the pregnant does had higher (p less than .01) progesterone levels during March through May. Progesterone levels during June to early November were low and similar for lactating and nonlactating animals. Estrogen levels during the year only changed during the period before parturition in the pregnant does when they were elevated. 2 nonpregnant adult does were sampled every 5 days from late January throught early March. Progesterone levels revealed a cyclic pattern of about 28 days duration while estrogen levels revealed no distinct pattern but tended to be inversely related to progesterone. These results suggest 1) that deer exhibit estrous cycles of about 25-30 days in length, 2) that estrous cycles recorred in nonpregnant does from November through early March, 3) that progesterone levels are similar for pregnant and the luteal phase of the estrous cycle, and 4) that late pregnancy is characterized by high estrogen levels as compared with early pregnancy and the estrous cycle.^ieng