Ticks (Acari: Ixodidae) parasitizing wild carnivores in Phu Khieo Wildlife Sanctuary, Thailand.

Ixodid ticks were collected and identified from 8 wild carnivore species in Phu Khieo Wildlife Sanctuary, northeastern Thailand. Six tick species belonging to 4 genera were recovered and identified from 132 individuals. These included Amblyomma testudinarium (n = 36), Haemaphysalis asiatica (n = 58), H. hystricis (n = 31), H. semermis (n = 3), Rhipicephalus haemaphysaloides (n = 3), and Ixodes granulatus (n = 1). Leopard cats (Prionailurus bengalensis) (n = 19) were infested with 4 tick species, whereas yellow-throated marten (Martes flavigula) (n = 4), clouded leopard (Neofelis nebulosa) (n = 2), and dhole (Cuon alpinus) (n = 1) were infested with 3 tick species, Asiatic golden cat (Catopuma temmincki) (n = 2) with 2 species, and marbled cat (Pardofelis marmorata), binturong (Arctictis binturong), and large Indian civet (Viverra zibetha) each infested with 1 species. This information contributes to the knowledge available on the ectoparasites of wild carnivores in Southeast Asia.

Failure to identify non-bovine reservoirs of Mycobacterium bovis in a region with a history of infected dairy-cattle herds.

The State of Texas had the most (cumulative) tuberculous cattle herds of any state in the United States during the decade ending in 1997. Of the cumulative 18 infected herds in Texas, 12 herds were concentrated in El Paso County (designated the 'El Paso milkshed'). To identify whether non-bovine reservoirs were a source of Mycobacterium bovis infection of cattle in this region, an investigation was conducted on the premises of 14 dairy herds (12 tuberculous and 2 non-affected herds) between May 1995 and June 1997. None of the 670 mammalian, avian and environmental (soil, water and air) samples collected and cultured from the premises of these herds was positive for the presence of M. bovis. None of the 119 human urine samples obtained from employees of these dairies was culture positive for M. bovis. Of 124 dairy-farm workers with tuberculin skin-test results, 48 showed positive test results. There was, however, no difference in percentages of positive skin-test results between farms without, and farms having, bovine tuberculosis within the last two years or longer. The percentage of positive reactions did not increase with length of time employed at a dairy with a history of confirmed tuberculosis. These findings suggest that non-bovine reservoirs appear not to be a factor responsible for tuberculosis of cattle in the El Paso milkshed.

Reticuloendotheliosis in captive greater and Attwater's prairie chickens.

Reticuloendotheliosis in captive greater (Tympanuchus cupido pinnatus) and Attwater's (T. cupido attwateri) prairie chickens is reported for the first time. Between September 1993 and August 1994, two adult female wild-caught greater prairie chickens housed at Texas A&M University (College Station, Texas, USA) were observed with multiple subcutaneous nodules. Both birds were euthanatized. Complete necropsy examinations revealed lesions limited to the skin of each bird. Histopathologic examination of lesions revealed pleomorphic lymphoreticular cells suggestive of reticuloendotheliosis and reticuloendotheliosis virus (REV) was demonstrated in tumor tissue by polymerase chain reaction and virus isolation. Between September 1994 and June 1995, five additional greater prairie chickens and two Attwater's prairie chickens were euthanatized or found dead with evidence of lymphoreticular neoplasia in multiple organ systems. Initial testing of the captive flock in December 1994 for evidence of viremia and antibody to reticuloendotheliosis virus revealed over 50% of the tested birds were viremic, but none developed antibodies. Subsequent testing between January 1995 and January 1996 indicated that once infected with reticuloendotheliosis virus, Attwater's prairie chickens tended to remain outwardly healthy despite persistent viremia compared to infected greater prairie chickens which had higher morbidity and mortality rates within 60 to 90 days after initial detection of viremia and did not usually develop persistent viremia. Antibodies to REV were detected in only three captive greater prairie chickens and only in 1995. Six of the nine birds that were euthanatized or found dead due to reticuloendotheliosis developed viremia prior to death; three birds were not tested prior to death. Testing of free-ranging greater and Attwater's prairie chickens for reticuloendotheliosis is recommended prior to translocation or release.

Northern bobwhites as disease indicators for the endangered Attwater's prairie chicken.

Because of limited access to the endangered Attwater's prairie chicken (Tympanuchus cupido attwateri), we used a related species, the northern bobwhite (Colinus virginianus), as a surrogate for disease evaluation. Free-living northern bobwhites (n = 62) on the Attwater Prairie Chicken National Wildlife Refuge (near Eagle Lake, Texas, USA) were examined during spring and fall 1993 for helminthic endoparasites and specific antibodies against the infectious agents responsible for nine infectious diseases. Trichostrongylus cramae, Raillietina sp., and Strongyloides avium were collected from 97, 44, and 32% of northern bobwhites examined, respectively. Dispharynx nasuta and Syngamus trachea also were found. No gross lesions due to parasites were observed. Specific antibody to Pasteurella multocida was found in 3 of 53 plasma samples. It is possible that potentially pathogenic species such as P. multocida, T. cramae, and D. nasuta could threaten sympatric Attwater's prairie chickens.

Serologic and parasitologic survey of the endangered Attwater's prairie chicken.

Because conservation biologists have postulated that infectious diseases may have potentiated the endangerment of the Attwater's prairie chicken (Tympanuchus cupido attwateri), free-living prairie chickens were surveyed from all remaining populations for helminthic endoparasites and antibody against the etiological agents of nine infectious diseases. Samples from 4 of 27 adult males were positive for anti-Pasteurella multocida antibody. All other serologic tests were negative (n = 19). We identified Dispharynx nasuta, a parasite previously associated with disease in other grouse from North America, in one of three adult Attwater's prairie chickens examined. Evidence of Trichostrongylus cramae was found for eight of nine suitable samples, which represents the first report of this parasite in prairie grouse. The mean intensity of T. cramae in Attwater's prairie chicken was 1,019.3 (Range = 3-1,906; n = 3). Further work is needed to determine whether P. multocida, T. cramae, or D. nasuta are detrimental to Attwater's prairie chicken populations. If so, conservation biologists could reduce the prevalence and incidence of these parasites and potentially gain more time to address the habitat conditions thought to be the ultimate cause of population declines.

Helminths of wintering geese in Texas.

Ten Canada geese (Branta canadensis), 24 snow geese (Chen caerulescens) and 22 white-fronted geese (Anser albifrons) from coastal Texas (USA) were examined for helminths. Three cestode, seven nematode, and three trematode species were collected. Gizzard nematodes (Amidostomum anseris, A. spatulatum and Epomidiostomum crami) infected 53 of 54 birds. Gross lesions were not attributed to helminth infections and the host population does not appear to be impaired by them.

Immobilization of collared peccaries (Tayassu tajacu) and feral hogs (Sus scrofa) with Telazol and xylazine.

A 1:1 mg mixture of Telazol and xylazine hydrochloride (100 mg of Telazol and 100 mg of xylazine per ml) was used to immobilize wild collared peccaries (Tayassu tajacu) and feral hogs (Sus scrofa); mean (+/-SD) intramuscular dosage rate was 4.73 +/- 0.86 mg/kg and 4.35 +/- 0.68 mg/kg for peccaries (n = 107) and hogs (n = 49), respectively. Mean (+/-SD) induction time (time from injection until complete immobilization) was 4.6 +/- 2.5 minutes for collared peccaries and 4.4 +/- 1.9 for hogs. Peccaries became conscious at 64 +/- 29 minutes and first stood at 92 +/- 33 minutes after initial injection. Hogs became conscious at 54 +/- 26 minutes and first stood at 78 +/- 38 minutes after initial injection. A 1:1 mg mixture of Telazol and xylazine provided an effective and safe method to immobilize both species and provided adequate analgesia and anesthesia for short surgical procedures.

A technique for improved fixation of the pigeon central nervous system for electron microscopy.

The central nervous system (CNS) of the pigeon has been difficult to fix with consistency, and consequently this problem has impeded ultrastructural studies of various parts of the pigeon brain. Here we describe a method for effective fixation of the pigeon CNS and discuss the three principal problems associated with good fixation of this animal's brain. The animal was deeply anesthetized and the thoracic cavity was opened without collapsing the pectoral girdle upon the brachiocephalic trunks and the common carotids. The perfusion pressure was raised to 140-150 mm Hg to overcome the high resistance of the small diameter, long common carotids. Heparin was added to the wash buffer to retard coagulation of blood in the vascular bed of the brain. The method is not foolproof, but with care excellent fixation can be achieved.