Characterization of poxviruses from forest birds in Hawaii.

Two strains of avian pox viruses were isolated from cutaneous lesions in Hawaiian crows (Corvus hawaiiensis) examined in 1994 and a third from a biopsy obtained in 1992 from an infected bird of the Apapane species (Himatione sanguinea) by inoculation of the chorioallantoic membranes (CAM) of developing chicken embryos. The resulting proliferative CAM lesions contained eosinophilic cytoplasmic inclusion bodies characteristic of pox virus infection. The pathogenicity of these three viruses in domestic chickens was mild as evidenced by the development of relatively minor lesions of short duration at the sites of inoculation. Their virulence in this host was similar to that of a fowlpox virus (FPV) vaccine strain and contrasted greatly with the ability of two field strains of FPV to produce extensive proliferative lesions. One of the Hawaiian crow pox virus isolates as well as the one originating from the Apapane species could be propagated in two secondary avian cell lines, QT-35 and LMH. A comparison of the restriction fragment length polymorphisms (RFLP) of the genomes of the two cell line-adapted viruses, generated by EcoRI digestion, revealed a limited degree of similarity. Moreover, neither profile was comparable to those of the two field isolates of FPV, which were almost indistinguishable from each other. Thus, based on the genetic distinctness of the two Hawaiian bird viruses, they appear to represent different strains of avipoxvirus.

Surgical repair of an atrial septal defect in a juvenile Sumatran orangutan (Pongo pygmaeus sumatraensis).

A systolic heart murmur was auscultated in a 2-yr-old female Sumatran orangutan (Pongo pygmaeus sumatraensis) with a slower than expected growth rate. Cardiac ultrasound revealed an 11-mm atrial septal defect. Cardiac catheterization confirmed the diagnosis. Surgical repair was performed during cardiopulmonary bypass using a pericardial patch. The bypass pump was primed with human albumin and donor orangutan whole blood of a compatible type. Hematuria occurred shortly after the initiation of cardiopulmonary bypass. Successful repair was immediately confirmed with transesophageal ultrasonography. The animal was extubated shortly after returning to spontaneous ventilation but had to be reintubated 4 hr later due to tachypnea and decreased SpO2. Additional extubation attempts failed, necessitating continuous positive pressure ventilation, monitoring, and intensive care environment. Thoracic radiographs suggested adult respiratory distress syndrome. The animal required 14 days of intensive care before extubation of the trachea was successful. After 4 wk of isolation, the orangutan was successfully reintroduced to its family group.

Hormonal characteristics of free-ranging female lions (Panthera leo) of the Serengeti Plains and Ngorongoro Crater.

Pituitary responses to gonadotrophin-releasing hormone (GnRH) and prolactin and steroid secretory profiles were examined in two populations of adult, female lions in the Serengeti (one outbred in the Serengeti Plains and one inbred in the Ngorongoro Crater) to determine whether reductions in genetic variability adversely affected endocrine function. GnRH-induced gonadotrophin secretion was also examined after adrenocorticotrophic hormone (ACTH) treatment to determine whether acute increases in serum cortisol altered pituitary function. Anaesthetized lions were administered (i) saline i.v. after 10 and 100 min of blood sampling, (ii) saline at 10 min and GnRH (1 micrograms kg-1 body weight) after 100 min; or (iii) ACTH (3 micrograms kg-1) at 10 min and GnRH after 100 min of sampling. Basal serum cortisol and basal and GnRH-induced gonadotrophin secretion were similar (P > 0.05) between females of the Ngorongoro Crater and Serengeti Plains. After ACTH, serum cortisol increased two- to threefold over baseline values and the response was unaffected (P > 0.05) by location. ACTH-induced increases in serum cortisol had no effect on subsequent basal or GnRH-stimulated luteinizing hormone (LH) or follicle-stimulating hormone (FSH) secretion. Overall mean serum progesterone concentrations ranged from 0.2 to 5.4 ng ml-1 with the exception of four females (two in the Serengeti and two in the Crater; progesterone range, 18.4-46.5 ng ml-1) that were presumed pregnant (three of these females were observed nursing cubs several weeks later).(ABSTRACT TRUNCATED AT 250 WORDS)

Seasonal variation in pituitary-gonadal function in free-ranging impala (Aepyceros melampus).

Blood, testicular biopsies and electroejaculates were collected from adult male impala, free-ranging in the Kruger National Park (Republic of South Africa), during the breeding (rut; April-May) and nonbreeding (September-October) seasons. Blood samples were collected at 5-min intervals for 120 min from anaesthetized males (n = 7 impala/group) treated intravenously with saline, gonadotrophin-releasing hormone (GnRH: 1 microgram/kg body weight) or human chorionic gonadotrophin (hCG: 10 or 30 iu/kg). Semen was collected from six more animals during the breeding season and 12 animals during the nonbreeding season using a standardized electroejaculation protocol. Ejaculates obtained during the nonbreeding season were of inferior quality to those collected during the breeding season, and were characterized by lower sperm concentrations, poorer sperm motility and more morphologically abnormal sperm forms. Within season, there were no differences in testosterone secretion between the two hCG doses, and these responses were similar to those observed after GnRH, but during the rut, testosterone secretion stimulated by both GnRH and hCG was approximately nine times greater than during the nonbreeding season. This seasonal increase in testosterone production was associated with a doubling in testicular volume and concentrations of luteinizing hormone (LH) receptors. Although concentrations of testicular follicle-stimulating hormone (FSH) receptors were similar between seasons, receptor content increased during rut as a result of increased testicular volume. In contrast to testosterone secretion, basal LH and FSH secretions were unaffected by season and GnRH-induced gonadotrophin secretion was reduced during rut.(ABSTRACT TRUNCATED AT 250 WORDS)

Impact of season on seminal characteristics and endocrine status of adult free-ranging African buffalo (Syncerus caffer).

Pituitary, gonadal and adrenal activity were compared in free-living, adult African buffalo bulls during the breeding and nonbreeding seasons. Frequent blood samples were collected for 2 h from anaesthetized bulls treated intravenously with saline, gonadotrophin-releasing hormone (GnRH, 200 micrograms), human chorionic gonadotrophin (hCG, 10,000 i.u.) or adrenocorticotrophic hormone (ACTH, 1.5 mg). Electroejaculates also were collected from anaesthetized bulls during the breeding and nonbreeding seasons. Pretreatment testosterone concentrations among bulls varied more during the breeding (0.17-23.0 ng/ml) than the nonbreeding (0.15-2.21 ng/ml) season. The variation within the breeding season was attributed to 8 of 25 bulls producing higher (P less than 0.05) serum testosterone (High-T; 16.28 +/- 2.03 ng/ml) and testicular LH receptor (1.53 +/- 0.22 fmol/mg testis) concentrations compared with their seasonal counterparts (Low-T; 0.95 +/- 0.26 ng/ml; 0.38 +/- 0.04 fmol/mg) or with all bulls during the nonbreeding season (0.90 +/- 0.27 ng/ml; 0.31 +/- 0.04 fmol/mg). The magnitude of GnRH- and hCG-induced increases in serum testosterone was similar (P greater than 0.05) between Low-T bulls and bulls during the nonbreeding season. In the High-T animals treated with GnRH or hCG, serum testosterone did not increase, suggesting that secretion was already maximal. Peak serum LH concentrations after GnRH were greater (P less than 0.05) in bulls during the nonbreeding than the breeding season; FSH responses were similar (P greater than 0.05). ACTH treatment did not increase serum cortisol concentrations above the 2-fold increase measured in bulls treated with saline, hCG and GnRH (P greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Developmental changes in pituitary-gonadal function in free-ranging lions (Panthera leo leo) of the Serengeti Plains and Ngorongoro Crater.

Pituitary-gonadal function was examined in male lions free-ranging in the Serengeti Plains or geographically isolated in the Ngorongoro Crater of Tanzania. Lions were classified by age as adult (6.1-9.8 years), young adult (3.3-4.5 years) or prepubertal (1.4-1.6 years, Serengeti Plains only). Each animal was anaesthetized and then bled at 5-min intervals for 100 min before and 140 min after i.v. administration of saline or GnRH (1 micrograms/kg body weight). Basal serum LH and FSH concentrations were similar (P greater than 0.05) among age classes and between locations. In Serengeti Plains lions, net LH peak concentrations after GnRH were approximately 35% greater (P less than 0.05) in prepubertal than in either adult or young adult animals. GnRH-stimulated LH release was similar (P greater than 0.05) between adult and young adult lions, and these responses were similar (P greater than 0.05) to those measured in Ngorongoro Crater lions. Basal and GnRH-stimulated testosterone secretion was higher (P less than 0.05) in adult than in young adult lions and lowest (P less than 0.05) in prepubertal lions. Age-class differences in testosterone production were related directly to the concentrations of LH receptors in the testis (P less than 0.05). Basal and GnRH-stimulated testosterone secretion and gonadotrophin receptor concentrations within age classes were similar (P greater than 0.05) between lions of the Serengeti Plains and Ngorongoro Crater. Lower motility and higher percentages of structurally abnormal spermatozoa were observed in electroejaculates of young adult compared to adult Serengeti Plains males (P less than 0.05) and were associated with decreased steroidogenic activity. In contrast, there were no age-related differences in ejaculate characteristics of Ngorongoro Crater lions. Seminal quality in the Crater population was poor in adult and young adult animals and was unrelated to alterations in pituitary or testicular function. In summary, only seminal quality in adult male lions was affected by location, whereas age significantly affected both basal and GnRH-stimulated testosterone secretion and seminal quality (Serengeti Plains only) in sexually mature males. The striking seminal/endocrine differences among pride (breeding) males of different ages raises questions about the impact of age on individual reproductive performance in this species.

Efficacy of fenbendazole for endoparasite control in large herds of nondomestic ruminants.

An experimental 4% fenbendazole premix was milled into the feed of 55 nondomestic ruminants (37 antilopines, 12 hippotragines, and 6 caprines). Efficacy of the premix against endoparasites in the ruminants was determined by comparison with pre- and posttreatment fecal egg counts. Dosages calculated from feed consumption percentages were 3.6 to 8.5 mg/kg. Dosages less than 5 mg/kg resulted in 80% to 100% reductions in fecal egg counts, and dosages greater than 5 mg/kg resulted in 98% to 100% reductions in fecal egg counts. With all dosage groups considered, Strongyloides and Nematodirus eggs were most sensitive to treatment, with 100% reductions in fecal egg counts. Strongyle and Trichuris egg counts were reduced 90% and 96%, respectively.

The microcomputer as an aid to medical records management in a zoological park.

A system for computerizing clinical medical records at a zoological park was designed, using microcomputer system components. Records were entered and retrieved in natural language, with minimal coding of information. Commercially available computer programs were used to manage data from anesthesia, radiography, clinical pathology, vaccination records, and tuberculin testing records. Programs written in BASIC language were used for storing and retrieving animal inventory data, daily medical and surgical records, results of fecal examinations, and anthelmintic treatment records.

Parvovirus enteritis in vaccinated juvenile bush dogs.

Parvovirus enteritis developed in 10 of 17 vaccinated juvenile bush dogs (Speothos venaticus) from 4 litters in a 5-month period. Nine dogs died. The first outbreak involved 6 of 9 bush dogs from 2 litters. Each had been vaccinated with a killed feline-origin parvovirus vaccine at 11 and 14 weeks of age. The 6 affected dogs became ill at 29 weeks of age and died. The second outbreak involved a litter of 6 bush dogs. Each had been vaccinated every 2 weeks starting at 5 weeks of age. Two were isolated from the colony at 16 weeks of age for treatment of foot sores. Three of the 4 nonisolated dogs developed parvovirus enteritis at 20 weeks of age; 2 died at 6 and 8 days, respectively, after onset of signs. The 3rd outbreak involved a litter of 2 bush dogs. Both had been vaccinated every 2 to 3 weeks, starting at 6 weeks of age. One of these dogs became ill at 17 weeks and died 13 days later. A litter of 6 maned wolves (Chrysocyon brachyurus) and a litter of 3 bush dogs were isolated from their parent colonies at 13 and 15 weeks of age, respectively. Each animal had been vaccinated weekly, beginning at 8 weeks of age, using an inactivated canine-origin parvovirus vaccine. None of the isolated animals developed the disease. Serologic testing during isolation did not reveal protective titers (greater than or equal to 1:80) against canine parvovirus in the bush dogs until they were 23 weeks old, whereas protective titers developed in the maned wolves when they were 14 to 18 weeks old. One hand-raised bush dog was vaccinated weekly, beginning at 8 weeks of age, and a protective titer developed by 21 weeks of age. It was concluded that the juvenile bush dogs went through a period during which maternal antibodies interfered with immunization, yet did not protect against the disease. When the pups were isolated from the colony during this period, then vaccinated repeatedly until protective titers developed, the disease was prevented.

Distal extremity necrosis in captive birds.

The necropsy files of the National Zoological Park and Baltimore Zoological Society were reviewed for cases of distal extremity necrosis (DEN) in birds. Nineteen cases of DEN occurred following either trauma or frostbite. Six birds developed an apparently primary type of DEN in which no predisposing factors were obvious clinically. The toes and feet were most commonly involved, and in several cases the beak was also affected. Some pathologic evidence is provided that certain cardiovascular lesions may predispose birds to DEN by compromising circulation of the extremities.

Cyclic dermatitis associated with Fusarium sp infection in pinnipeds.

Dermatitis associated with Fusarium sp infection developed in 3 California sea lions (Zalophus californianus) and 3 gray seals (Halichoerus grypus) at the National Zoological Park in Washington DC. The lesions were papular or nodular and were distributed mainly on the face, trunk, and flippers. One sea lion died 6 weeks after extensive cutaneous involvement. The lesions regressed after 1 mild exacerabtion in the other 2 sea lions. In the gray seals, the skin condition appeared to worsen during the summer and to regress during the winter, despite oral and topical treatment with miconazole and thiabendazole. Fusarium sp was repeatedly isolated from biopsy specimens of lesions. Hyperplasia of epidermal and follicular epithelium was associated with acute and chronic inflammation and fungal hyphae. The species of the fungus in 1 of the gray seals was determined to be F solani, a type occasionally associated with keratitis and opportunistic infections in human beings. Initial excessive chlorination and high fluctuating pool temperatures attributed to a faulty water treatment system were considered as factors in promoting fungal growth.

Cranial computed tomography in the evaluation of neurologic disorders in two nonhuman primates.

Cranial computed tomography (CCT) was used to evaluate neurologic disorders in 2 primates. In the 1st case, acute left hemiparesis developed in an adult female proboscis monkey (Nasalis larvatus). A CCT scan revealed a right frontal lobe abscess that was subsequently surgically drained. In the 2nd case, a juvenile black spider monkey (Ateles fusciceps) experienced recurrent seizures following an episode of trauma and anoxia. A CCT scan demonstrated enlarged lateral ventricles and cerebral atrophy. Computed tomography proved to be a valuable technique for localizing and characterizing brain lesions in these 2 primates, after more conventional methods of investigation had failed to establish diagnoses.

Clinicopathologic correlations of tuberculosis in large zoo mammals.

In August 1978, a black rhinoceros at the National Zoological Park died with generalized tuberculosis caused by Mycobacterium bovis. A 2nd black rhinoceros was euthanatized 9 months after M bovis was cultured from its lungs. After these 2 deaths, numerous large zoo mammals that had been potentially exposed were subjected to various procedures to ascertain their status regarding tuberculosis. The procedures were: intradermal tuberculin testing, evaluation of delayed hypersensitivity reaction on biopsy specimens, enzyme-linked immunosorbent assay (ELISA) testing, and culture of various secretions and organs. Several of the animals in this series died during the study. These were necropsied and examined for evidence of mycobacterial infection. The results of tuberculin testing varied from species to species and from site to site within a species. Delayed hypersensitivity responses generally correlated well with the amount of swelling at the tuberculin site. In some cases, however, positive reactions were found without any delayed hypersensitivity response. Results of ELISA testing were confirmatory in tuberculous animals. Several species were judged to be nonspecific reactors, based on positive or suspect tuberculin test results, with negative ELISA results and necropsy findings.