Morbidity-mortality factors and survival of an urban coyote population in Arizona.

The health of coyotes (Canis latrans) in urban areas has not been studied. Our objectives were to assess the health of coyotes in Tucson (Arizona, USA) by determining the prevalence of antibodies to selected pathogens, estimating survival rates, and identifying sources of mortality. We drew blood from 22 coyotes to evaluate the prevalence of heartworm (Dirofilaria immitis) antigens, and antibodies to canine distemper virus (CDV), infectious canine hepatitis (ICH), canine parvovirus (CPV), and seven serovars of Leptospira interrogans. We trapped and radiocollared 19 coyotes to determine survival rates. We performed necropsies on 19 coyotes to quantify their general health, the presence of internal and external parasites, and causes of mortality. No coyotes tested positive for heartworm antigens. The prevalence of antibody to CDV, ICH, and CPV was 27, 50, and 100%, respectively. Twenty-seven percent of coyotes tested positive for one of five serovars of L. interrogans. The diseases for which coyotes in Tucson possessed antibodies appear to be enzootic in the population. The annual survival rate of coyotes was 0.72. Eleven necropsied coyotes were killed by cars, five coyotes were hit by cars, two were killed by a trapper, and the cause of death for one coyote was unknown. Coyotes in Tucson appear to be exposed to the viral, bacterial, and parasitic infections common in many coyote populations, but humans are the major source of mortality.

Occurrence of rabies in wolves of Alaska.

We describe a rabies epizootic in northwest Alaska (USA) during 1989 and 1990 which resulted in mortality to several different wolf (Canis lupus) packs. Four radio-collared wolves were confirmed to have rabies while evidence for seven others was strongly suggestive but not confirmed. The wolf population declined during the rabies epizootic; thus rabies may have been a significant limiting factor.

Conductive hearing loss in bighorn sheep.

In January 1993 we simulated a conductive hearing loss in three Mexican bighorn sheep (Ovis canadensis mexicana) by placing bone wax or saline solution in their ear canals. Our objective was to test whether lesions of the external auditory canal caused by psoroptic mites (Psoroptes ovis) may lead to conductive hearing loss in bighorn sheep. We assessed the effects of these manipulations using the auditory brainstem response test. Placing saline solution in the external auditory canal, which loads the tympanic membrane, had a more dramatic effect on the auditory brainstem response than did bone wax. We propose that decreased hearing sensitivity or alterations in resonance characteristics of the external auditory canal, due to psoroptic scabies lesions, may make bighorn sheep more susceptible to predation.

Reversal by tolazoline hydrochloride of xylazine hydrochloride-ketamine hydrochloride immobilizations in free-ranging desert mule deer.

We captured 10 free-ranging desert mule deer (Odocoileus hemionus crooki) (five males and five females) by net-gun from a helicopter and immobilized them with xylazine hydrochloride (HCl) (100 mg) and ketamine HCl (300 to 400 mg) injected intramuscularly. Arousal and ambulation times were 13.9 +/- 4.2 and 14.3 +/- 4.2 min in eight deer injected intravenously with tolazoline HCl (3.0 mg/kg). We observed a curvilinear relationship (R = 0.50, P less than 0.01) between rectal temperature and time after induction of anesthesia. Mean peak temperature (41.4 C) occurred at 23.7 +/- 3.2 min postinduction and was greater (P less than 0.01) than the mean temperature measured initially (40.8 C). Heart and respiratory rates (108 beats/min and 75 breaths/min) were elevated prior to immobilization. Mean heart rate increased (P less than 0.05) from 90 +/- 9 beats/min in anesthetized deer to 120 +/- 13 beats/min after tolazoline HCl injection. A 20% capture-related mortality rate suggests this combination of physical and chemical capture has serious limitations. Captive deer permitted to recover from xylazine HCl-ketamine HCl immobilization without a reversal agent were able to walk in 290 +/- 79 min.

Blood and urinary profiles of free-ranging desert mule deer in Arizona.

As a corollary to a more comprehensive study on their ecology, we documented blood and urinary profiles for 10 free-ranging desert mule deer (Odocoileus hemionus crooki) (five males, five females) captured by net-gun shot from a helicopter during February 1988 in Saguaro National Monument, Arizona. Pursuit with the helicopter for netting deer ranged from 3 to 15 min. Blood profiles included seven hematological characteristics and 12 serum chemistries, electrolytes, hormones and enzymes. Urine samples were assayed for urea nitrogen, creatinine, sodium, potassium, calcium and phosphorus. Urinary data were compared as ratios to creatinine. Serum cholesterol was greater (P less than 0.05) in males than females. Pursuit time was correlated with serum non-esterified fatty acids (r = 0.67, P less than 0.05) and influenced urinary specific gravity (r2 = 0.77, P less than 0.004), urea nitrogen: creatinine (r2 = 0.79, P less than 0.005), and potassium: creatinine (r2 = 0.42, P = 0.08) ratios. Increasing specific gravity was related to urinary creatinine concentration (r2 = 0.72, P less than 0.008). All deer exhibited acute adrenal stimulation, accompanied by elevated serum creatine phosphokinase and urinary potassium: creatinine ratios, which were indicative of acute excitement and muscle trauma associated with the capture process. We demonstrated that urinary data are a valuable supplement to serum data in demonstrating effects of intense physical exertion, and both forms of data emphasize the need to assess capture-related excitability as a source of variation in blood and urine characteristics of free-ranging desert mule deer.