Analysis of the expression of immunoglobulins throughout lactation suggests two periods of immune transfer in the tammar wallaby (Macropus eugenii)

Marsupial young are born in an under-developed state without mature immune responses. Prior to the maturation of an immune system, marsupial young are heavily reliant upon immune factors secreted in the milk to defend them against potential microbial pathogens in the environment. In this study, we identified and characterized the immunoglobulin heavy chain constant regions, light chains, polymeric Ig receptor (pIgR), J chain, neonatal Fc receptor (alpha chain) (FcRn) and the chemokine CCL28 from the model marsupial species, the tammar wallaby (Macropus eugenii). Low levels of conservation were seen in motifs in C and Cγ associated with receptor binding and or transcytosis, and this may have potential implications for functionality. We evaluated the expression of immunoglobulin genes in the tammar mammary gland throughout lactation and found that two periods of increased expression of immunoglobulin genes occur. These two periods coincide with the birth of the young, and with its first emergence from the pouch. This increased expression may represent a strategy for maternal immunological protection of the pouch young.     

Single-dose pharmacokinetics of oxytetracycline and penicillin G in tammar wallabies (Macropus eugenii)

McLelland, D.J., Barker, I.K., Crawshaw, G., Hinds, L.A., Spilsbury, L., Johnson, R. Single‐dose pharmacokinetics of oxytetracycline and penicillin G in tammar wallabies (Macropus eugenii). J. vet. Pharmacol. Therap. 34 , 160–167. The pharmacokinetics of oxytetracycline and penicillin G was investigated in tammar wallabies (Macropus eugenii). Groups of eight healthy tammar wallabies were administered i.v. oxytetracycline hydrochloride (40 mg/kg), i.m. long‐acting‐oxytetracycline (20 mg/kg), i.v. sodium penicillin G (30 mg/kg), or i.m. procaine/benzathine penicillin G (30 mg/kg). Plasma concentrations of oxytetracycline were determined using high‐performance liquid chromatography. Pharmacokinetic parameters were comparable to those reported for eutherians of equivalent size and suggest that the practice of adjusting allometrically scaled doses to account for the lower metabolic rate of marsupials may not be valid. Long‐acting oxytetracycline and penicillin G both demonstrated depot effects. However, the plasma concentrations achieved question the therapeutic efficacy of the long‐acting preparations.     

Gastric amebiasis due to Entamoeba histolytica in a Dama wallaby (Macropus eugenii)

A 1.5-year-old captive female Dama wallaby (Macropus eugenii) died after a 3-month period of progressive weight loss, anorexia, bloat, and diarrhea. Histopathologic examination revealed numerous Entamoeba histolytica trophozoites within the gastric mucosa and, less frequently, gastric submucosa and submucosal vessels. Immunofluorescent antibody testing confirmed the identity of the trophozoites as E. histolytica. The trophozoites were associated with mild glandular epithelial necrosis, mucosal erosions, and lymphoplasmacytic inflammation. E. histolytica most commonly causes necrotizing and ulcerative colitis in humans and captive nonhuman primates, and it causes necrotizing and ulcerative gastritis in nonhuman primates with sacculated stomachs adapted for leaf fermentation. Rare cases of gastric amebiasis also have been been reported in captive macropods, which also have complex sacculated stomachs. To our knowledge, this is the first report confirming E. histolytica as the cause of gastric amebiasis in a wallaby. The zoonotic potential of this infection in macropods is uncertain.     

Epizootics of sudden death in tammar wallabies (Macropus eugenii) associated with an orbivirus infection

Epizootics of sudden death in tammar wallabies (Macropus eugenii) occurred at six research facilities and zoological gardens in New South Wales, Australia, in late 1998 and at one Queensland research facility in March 1999. There were 120 confirmed tammar wallaby deaths during this period; however, population censuses indicated that up to 230 tammar wallabies may have died. The majority of animals died without premonitory signs. A small proportion of wallabies exhibited increased respiratory rate, sat with a lowered head shortly before death or were discovered in lateral recumbency, moribund and with muscle fasciculations. Gross postmortem findings consistently included massive pulmonary congestion, mottled hepatic parenchyma and subcutaneous oedema throughout the hindlimbs and inguinal region. Approximately 30% of the animals examined also had extensive haemorrhage within the fascial planes and skeletal muscle of the hindlimb adductors, inguinal region, ventral thorax, dorsal cervical region and perirenal retroperitoneal area. The tissues of affected animals became autolytic within a short period after death. Bacteriological examination of tissues from 14 animals did not provide any significant findings. Toxicological examination of the gastric and colonic contents of four animals did not reveal evidence of brodifacoume or other rodenticides. Viruses from the Eubenangee serogroup of the Orbivirus genus were isolated from the cerebral cortex of nine, and the myocardium of two, tammar wallabies and the liver and intestine of another tammar wallaby. A similar orbivirus was also isolated from the cerebrospinal fluid of another tammar wallaby that died suddenly. The disease agent appears to be a previously unrecognised orbivirus in the Eubenangee serogroup. This is the first report of epizootics of sudden deaths in tammar wallabies apparently associated with an orbivirus infection.     

On the clinical chemistry of the Bennett's wallaby (Macropus rufogriseus rufogriseus)

The following parameters were determined in blood serum of apparently healthy Bennett's wallabies (Macropus rufogriseus) using the Hitachi 917 (Roche Diagnostics, Mannheim, Germany) and/or the Vettest 8008 (IDEXX-GmbH, Woerrstadt, Germany): alkaline phosphatase, alanine aminotransferase, ammonia, alpha-amylase, aspartate aminotransferase, Ca, Cl, cholesterol, cholinesterase, creatine kinase, creatinine, gammaglutamyltransferase, glucose, iron, lactate dehydrogenase, magnesium, phosphate, potassium, protein, sodium, total bilirubin, triglyceride, and urea. The results for cholesterol, glucose, total protein, triglyceride and for the enzymes alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, gamma-glutamyltransferase and lactate dehydrogenase differed significantly between both methods (P < 0.05). There is a negative correlation between the age of the Bennett's wallabies and the activity of the alkaline phosphatase. Five protein fractions could be separated on cellulose acetate electrophoresis. The mean concentrations of fructosamine and beta-hydroxybutyrate were 447.3 micromol/L and 0.27 mmol/L, respectively. The estimated vitamin A intake had no influence on the vitamin A concentration in serum. The serum vitamin E concentration was in general low and vitamin E was below the detection limit of 0.82 micromol/L in 29 out of 42 serum samples. The use of these analytes is discussed concerning the knowledge about the physiology, nutrition and diseases of macropods.     

Pharmacokinetics of oxytetracycline in clinical cases in the red-necked wallaby (Macropus rufogriseus)

Oxytetracycline, administered at 40 mg kg-1 by intravenous injection, was used as part of the treatment of three female red-necked wallabies, Macropus rufogriseus, with suspected Fusobacterium necrophorum infections. The plasma concentrations of this drug in blood samples collected at intervals up to 24 hours after administration were measured using a biological assay. The pattern of decline in plasma oxytetracycline concentration with time was consistent with a two-compartment model. The half-life of the elimination phase was calculated to be 11.4 hours and the apparent volume of distribution was found to be 2.041 litres kg-1. These results provide a basis for devising appropriate oxytetracycline dosage regimes for the species.     

Vaccination against lumpy jaw and measurement of antibody response in wallabies (Macropus eugenii)

Successful protection against lumpy jaw disease in a colony of captive wallabies (Macropus eugenii) was induced by vaccination with a commercial ovine footrot vaccine. No mortalities attributable to lumpy jaw were observed in 69 vaccinated animals while six of 42 unvaccinated control wallabies died of the disease. Vaccinated animals exhibited significant increases in antibody titres to Bacteroides nodosus after the first and second doses of vaccine. Titres were measured by an enzyme-linked immunosorbent assay.     

Toxoplasmosis in Tammar wallabies (Macropus eugenii) in the Budapest Zoo and Botanical Garden (2006-2010)

Smaller macropodid species (commonly referred to as wallabies) are extremely susceptible to toxoplasmosis: in most cases, infection with Toxoplasma gondii leads to death within a short time. Between June 2006 and July 2010, T. gondii was detected by immunohistochemical examination in six Tammar wallabies (Macropus eugenii) that died in the Budapest Zoo and Botanical Garden; in another four specimens histopathology revealed T. gondii-like organisms (which could not be differentiated from Neospora caninum solely by morphology), and in another 11 animals toxoplasmosis as the possible cause of death could not be excluded. The current zoo population of 12 Tammar wallabies was tested for T. gondii IgG antibodies by the modified agglutination test (MAT), with negative results. We suppose that most of the deaths were due to acute toxoplasmosis resulting from a recent infection.     

Toxoplasma gondii inclusions in peripheral blood leukocytes of a red-necked wallaby (Macropus rufogriseus)

Abstract A 2-year-old, male, red-necked (Bennett's) wallaby ( Macropus rufogriseus ) from a zoological facility was presented for peracute onset of severe depression, unresponsiveness, ataxia, and loose feces. Serum biochemical abnormalities included azotemia, hypoalbuminemia, increased alanine aminotransferase activity, hyperbilirubinemia, hyperphosphatemia, and hyperkalemia, consistent with multi-organ system failure. Severe thrombocytopenia suggested possible disseminated intravascular coagulation. Peripheral blood smear examination revealed numerous ovoid, protozoal inclusions within monocytes and occasionally within neutrophils. Despite aggressive supportive therapy, the patent died within 5 hours of presentation. Gross necropsy and histopathologic findings included severe multifocal necrotizing lesions in multiple organs. Numerous intralesional protozoal organisms were observed and were identified as Toxoplasma gondii by immunohistochemistry. Macropods (wallabies and kangaroos) are known to be highly susceptible to toxoplasmosis, with high mortality rates; diagnosis most often is obtained at necropsy. Detection of protozoal organisms in peripheral blood leukocytes is reported rarely and has not been documented previously in a macropod. Parasitemia in this case was attributed to severe, disseminated disease. Careful examination of peripheral blood smears in macropods suspected of toxoplasmosis may be warranted.     

2-Aminoethoxydiphenyl borate (2-APB) reduces alkaline phosphatase release, CD63 expression, F-actin polymerization and chemotaxis without affecting the phagocytosis activity in bovine neutrophils

2-Aminoethoxydiphenyl borate (2-APB) interferes with the Ca(2+) influx and reduces the ROS production, gelatinase secretion and CD11b expression in bovine neutrophils. Moreover, it has been suggested that inhibition of the Ca(2+) channel involved in the store operated Ca(2+) entry (SOCE) is a potential target for the development of new anti-inflammatory drugs in cattle, however it is unknown whether 2-APB affects neutrophil functions associated with the innate immune response. This study describes the effect of 2-APB, a putative SOCE inhibitor, on alkaline phosphatase activity a marker of secretory vesicles, CD63 a marker for azurophil granules, F-actin polymerization and in vitro chemotaxis in bovine neutrophils stimulated with platelet-activating factor (PAF). Also, we evaluated the effect of 2-APB in the phagocytic activity against Escherichia coli and Staphylococcus aureus bioparticles. We observed that doses of 2-APB ≥10 μM significantly reduced alkaline phosphatase activity and in vitro chemotaxis, whereas concentrations of 2-APB ≥50 μM reduced CD63 expression and F-actin polymerization. Finally, we observed that 2-APB did not affect the phagocytic activity in neutrophils incubated with E. coli and S. aureus bioparticles. We concluded that inhibition of Ca(2+) influx could be a useful strategy to reduce inflammatory process in cattle.     

Use of antibiotic impregnated polymethylmethacrylate beads for the treatment of chronic mandibular osteomyelitis in a Bennett's wallaby (Macropus rufogriseus rufogriseus)

Antibiotic impregnated polymethylmethacrylate beads were surgically implanted into the mandible of an adult Bennett's wallaby (Macropus rufogriseus rufogriseus) suffering from chronic mandibular osteomyelitis that had proven refractory to systemic antibiotic treatment. Although a discrete inflammatory mass remained, clinical signs of inappetance and a discharging sinus were alleviated following implantation of the beads. This procedure resulted in a more satisfactory outcome than other methods of treatment used previously for this condition and avoided the problems associated with regular handling and prolonged medication.     

Histochemical activity of alkaline phosphatase and acid phosphatase in the epididymis of mature intact and androgen-deprived bulls

The histochemical localization of alkaline phosphatase (ALP) and acid phosphatase (ACP) was determined in regions I to VI of the epididymis in mature intact, orchidectomized, and orchidectomized testosterone-treated bulls. The intensity of ALP activity was essentially the same in all regions; however, its localization varied depending upon the region. Although the stereocilia and luminal border of epithelial cells were strongly-positive in regions I to III, these were negative in regions IV to VI. The basement membrane and circumtubular smooth muscle cells were strongly ALP reactive in all regions. Epithelial ALP activity was abolished completely by orchidectomy; however, it was restored to normal concentration by testosterone treatment implying its dependence on circulating testosterone. The ACP activity was present in the epithelial cells of all regions with the strongest activity in the supranuclear region. Similar to ALP, ACP activity was markedly reduced in the epithelial cells by orchidectomy. However, in contrast to ALP activity, lost ACP activity was only minimally increased by testosterone treatment in all regions, except in region VI where it was restored to a normal concentration. These observations imply that although the epithelial ACP activity of region VI was mainly under the influence of circulatory testosterone, there may be other factors such as luminal androgens, testicular fluid, and sperm that may be important in regulating the ACP activity of regions I to V of the epididymis. The importance of ALP and ACP in the epididymal epithelium was discussed.     

A retrospective and prospective study of megaesophagus in the parma wallaby (Macropus parma) at the San Diego Zoo, California, USA

At the San Diego Zoo (California, USA), 22 cases of megaesophagus were diagnosed in the parma wallaby (Macropus parma), yielding a prevalence of 21.1%. Parma wallabies often have no clinical signs until severe and chronic dilation of the esophagus is present. Clinical signs of advanced disease include weight loss, swelling of the cervical region, regurgitation without reswallowing of ingesta, short flight distance, depression, collapse, dyspnea, and sudden death. Retrospective and prospective studies at the San Diego Zoo and a multi-institutional survey in the United States were used to try to determine the cause of megaesophagus. The retrospective study did not identify an etiology. The prospective study revealed megaesophagus and severely delayed esophageal transit time in eight of eight animals. Myasthenia gravis, lead toxicosis, toxoplasmosis, and thyroid disease were eliminated as possible causes. Of 286 living and dead parma wallabies surveyed at other institutions, three cases of esophageal diverticulum and one case of megaesophagus were reported. The cause of megaesophagus in parma wallabies was not determined.