R. Mitchell Bush

Comparing ovulation synchronization protocols for artificial insemination in the scimitar-horned oryx (Oryx dammah)

Ovarian response and pregnancy success in scimitar-horned oryx (n=28) were compared, following treatment with two synchronization protocols and fixed-time artificial insemination (AI) with frozen-thawed semen. Each oryx received two injections of 500 microg of prostaglandin-F(2alpha) analogue (PGF(2alpha)-only) 11 days apart, and half received PGF(2alpha) in combination with an intravaginal progesterone-releasing device (CIDR11+PGF(2alpha)). Semen was collected by electroejaculation from anaesthetised adult oryx and cryopreserved. Anaesthetised females were transcervically inseminated 56.0+/-1.1 h (+/-S.E.M.) after PGF(2alpha) injection and/or device withdrawal using 28.0+/-1.5x10(6) motile thawed sperm. Ovarian endocrine response was monitored in 20 females by analysing faecal oestrogen and progesterone metabolites. Periovulatory oestrogen peaks were detected in 19/20 (95%) females after synchronization. There were no between-treatment differences in oestrogen concentrations or peak characteristics (P0.05). Luteal development after synchronization was delayed in half the progesterone treated (CIDR11+PGF(2alpha)) females, and faecal progestin excretion profiles indicated that the ovulatory follicle associated with synchronization either failed to ovulate or to fully lutenise. Pregnancy was diagnosed by ultrasonography and/or rectal palpation and was monitored by faecal progestin excretion. More (P=0. 013) pregnancies resulted from the PGF(2alpha)-only treatment (37.5%, 5/14) than from the CIDR11+PGF(2alpha) treatment (0/14), and four healthy scimitar-horned oryx calves were born, three after gestation intervals of 247 days and one after 249 days.

Hematology and serum chemistry values for captive Dorcas gazelles: variations with sex, age and health status.

Blood samples obtained from 55 captive Dorcas gazelles (Gazella dorcas), collected over a 9-year period, were analyzed for hematology and serum chemistry values. Variations associated with differences in sex, age, and health-status were identified.

Renal medullary amyloidosis in Dorcas gazelles

Between January 1976 and September 1987 renal medullary amyloidosis (RMA) was diagnosed in 17 Dorcas gazelles; the necropsy prevalence rate was 17/32 (53%). The most severe amyloid deposits were in the renal medulla; glomeruli were spared. Renal cortical lesions of interstitial fibrosis and tubular atrophy and dilatation significantly correlated with RMA (P < 0.01) and were considered to be secondary changes. There were varying degrees of lymphoplasmacytic inflammation and tubular cast formation which did not significantly correlate with RMA. Amyloid was confirmed histochemically and by electron microscopy and was identified as AA type by the permanganate method. Progressive renal failure was the cause of death or necessitated euthanasia in 7/17 (41%) gazelles. RMA in Dorcas gazelles does not appear to be familial. A high prevalence of chronic or recurring Actinomyces (Corynebacterium) pyogenes infections may be an important factor.

MORTALITY OF CAPTIVE BLACK-FOOTED FERRETS (MUSTELA NIGRIPES) AT SMITHSONIAN'S NATIONAL ZOOLOGICAL PARK, 1989–2004

Abstract Black-footed ferret (Mustela nigripes) mortality was investigated retrospectively based on the pathology records of 107 captive animals held at Smithsonians National Zoological Park from 1989 to 2004. The majority of deaths in neonates were due to cannibalism (n = 42; 64.6%) and maternal trauma (n = 11; 16.9%); both of these causes of mortality decreased during the study period. Prior to 2001, juvenile mortality was most often caused by gastrointestinal disease (n = 11; 52.4%), including coccidiosis, salmonellosis, and clostridium infection. In 2001, improvements in husbandry, hygiene, and medical treatment led to decreases in juvenile mortality associated with gastrointestinal disease. The most common causes of death in adult ferrets were renal or neoplastic disease. The etiology of the high prevalence of renal disease in the last 4 yr of the study is unknown; it was not associated with increasing age or inbreeding. Improved hygiene and vigilant monitoring for signs of gastrointestinal and renal disease will continue to improve the success of the captive propagation of this species.

Reproductive traits including seasonal observations on semen quality and serum hormone concentrations in the Dorcas gazelle

Abstract Seminal traits, testicular volume, body weight and serum testosterone levels were determined monthly for one year in 3 adult male Dorcas gazelles ( Gazella dorcas ). Serial blood samples were evaluated for cortisol and testosterone concentrations to determine the acute effect of electroejaculation, and the longevity of spermatozoal viability in vitro also was assessed. High percentages of progressively motile, normal spermatozoa were collected from all males throughout the year. Positive correlations were found between spermatozoal concentrations, testicular volume and body weight; however, no relationship existed between serum testosterone and either testes volume or seminal quality. No evidence of seasonality was observed in either seminal or hormonal traits. Serum cortisol and testosterone concentrations were not significantly different between anesthetized-electroejaculated gazelles and the same males subjected to anesthesia only. Spermatozoa longevity in vitro was prolonged by the addition of tissue culture solution to raw semen and further improved when seminal plasma was removed following centrifugation. This study 1) provides a data base for a little-studied nondomestic species, the Dorcas gazelle; 2) indicates that seminal traits and serum testosterone concentrations are not influenced by season; 3) demonstrates that electroejaculation is an effective technique for repeatedly collecting semen samples without acutely or chronically influencing gonadal or adrenal function.

SERUM OXYTETRACYCLINE CONCENTRATIONS IN AFRICAN ELEPHANT (LOXODONTA AFRICANA) CALVES AFTER LONG-ACTING FORMULATION INJECTION

Abstract Serum oxytetracycline pharmacokinetics were studied in 18 African elephant (Loxodonta africana) calves. Each elephant received separate injections of oxytetracycline at approximately 18 mg/kg i.m. and 8 mg/kg i.v. in a cross-over study. Blood samples were drawn at 0, 24, 48, 72, and 96 hr postinjection. An additional sample was drawn 110 hr before the animals were reinjected in the cross-over study and a final blood sample was drawn 48 hr after the second dose. No lameness or stiffness was observed following i.m. injections. Serum oxytetracycline concentrations >0.5 µg/ml were present 48 hr after initial dosing for all elephants (i.m., i.v., high or low dosage). Only elephants given the high i.m. dosage (18 mg/kg) maintained levels >0.5 µg/ml 72 hr postinjection. No significant difference in serum oxytetracycline concentration with time was observed between the groups given different i.v. dosages. These studies demonstrated that quantifiable serum oxytetracycline concentrations can be maintained in young African elephants with a low-dosage multidose i.m. regimen.

Subcutaneous Atypical Mycobacteriosis in Captive Tiger Quolls (Dasyurus maculatus)

From July 1989 to October 1998, 9/37 (24%) adult captive tiger quolls (Dasyurus maculatus) were diagnosed with atypical mycobacterial infection involving the subcutis and skin. Females were more often affected than males (seven females, two males). Grossly, lesions presented as focal thickenings, plaques, and abscesses within the subcutis, often with fistulous tracts. The subcutis and skin overlying cervical and thoracic regions were the primary sites of infection. Cytology of subcutaneous impression smears from all nine affected tiger quolls revealed pyogranulomatous inflammation admixed with several acid-fast bacilli. Histologically, all tiger quolls had nodular to diffuse pyogranulomatous panniculitis and cellulitis. Small numbers of acid-fast bacilli were noted histologically in 7/9 (78%) animals. Skin cultures from seven tiger quolls were positive for one or more different Runyon group IV mycobacteria. The disease described in these tiger quolls is similar to subcutaneous atypical mycobacteriosis of humans and domestic animals.

The use of xeroradiographic imaging to evaluate fracture repair in avian species

The purpose of the study was to determine how fracture healing occurs in avian species and to document if there are any major differences between medullary and pneumatized bone repair. The avian skeleton with both types of bones in a single species affords an opportunity to evaluate the importance of hemorrhage and bone marrow in the fracture healing process. The general concept of fracture healing in humans is well documented but certain specific aspects of fracture repair remain unclear. Two of these issues are the importance of hemorrhage and the influence of bone marrow in fracture healing. Utilizing correlative studies, we wished to determine if xeroradiographic images reflected histologic changes as healing occurred and to determine if this form of radiographic imaging provides an appropriate monitoring study to assess progress of fracture repair in the clinical circumstance. Correlating the xeroradiographic images with the histologic findings evident of fracture healing was discerned before the actual callus formation occurred. Xeroradiographic imaging was quite helpful in visualizing callus formation and was found to be superior to plain radiographic studies.The purpose of the study was to determine how fracture healing occurs in avian species and to document if there are any major differences between medullary and pneumatized bone repair. The avian skeleton with both types of bones in a single species affords an opportunity to evaluate the importance of hemorrhage and bone marrow in the fracture healing process. The general concept of fracture healing in humans is well documented but certain specific aspects of fracture repair remain unclear. Two of these issues are the importance of hemorrhage and the influence of bone marrow in fracture healing. Utilizing correlative studies, we wished to determine if xeroradiographic images reflected histologic changes as healing occurred and to determine if this form of radiographic imaging provides an appropriate monitoring study to assess progress of fracture repair in the clinical circumstance.Correlating the xeroradiographic images with the histologic findings evident of fracture healing was discerned before the actual callus formation occurred. Xeroradiographic imaging was quite helpful in visualizing callus formation and was found to be superior to plain radiographic studies.

Positive contrast peritoneography and herniography in primate animals. With special reference to indirect inquinal hernias

In a number of primate animals contrast medium was injected intraperitoneally to diagnose hernias as well as evaluate the normal anatomical relationships. The technical considerations are discussed. Contrast herniography and peritoneography appear useful under certain clinical circumstances.