Existing reports on parasitic helminths were investigated for 24 species and 2 subspecies of alien mammals introduced into Japan. These reports described 10 trematode, 2 cestode, 1 acanthocephalan and 15 nematode species in 8 host species. Additionally, 1 alien nematode species each has been obtained from 2 species of alien mammals recently. The host species with the most helminth species reported in Japan is the racoon, Procyon lotor, with 5 trematode and 6 nematode species, including Baylisascaris procyonis, reported from this host species in some zoos in Japan. Most of these helminth species in introduced racoon were apparently transferred from native animals in Japan. The host species with the most reports on parasitic helminths is the Siberian weasel, Mustela sibirica, with 4 trematode and 4 nematode species in 14 reports, although this host species was not differentiated from the Japanese weasel, M. itatsi, in some reports, Most studies on the parasitic helminths of alien mammals have been conducted from the viewpoint of medicine and public health. However, it will become necessary to research and protect the native parasitic helminth faunas of wild Japanese mammals against the disturbance from alien parasitic helminths. It is suggested that the introduction of alien parasitic helminths of mammals into Japan may have become easy because the native helminths of Japanese mammals have often become extinct with the small host populations in the geographical conditions of Japan, and artificial reduction of the host populations. The disturbance of native helminth faunas is also considered an ubiquitous problem, even if some problems of alien organisms, such as competition with native organisms, do not apply in the case of alien parasitic helminths.
We examined the availability of DNA fingerprinting in paternity determination of the captive Japanese black bear, Ursus thibetanus japonicus. The DNA fingerprint using the restriction enzyme Hinf I and (GATA)4 probe was available for individual identification and paternity determination. Eleven females and their 13 cubs born from 1995 to 1997 along with 22 males were tested in the paternity determination. Seven male bears were determined as putative fathers of the 13 cubs. Two males in particular were the putative fathers of 8 cubs. Our study suggests that, under captive conditions, some male bears achieved higher reproductive success, even though the females had the opportunity to breed with many males.
Plasma samples were collected from two female Brazilian tapirs (Tapirus terrestris) in captivity once a week. Changes in plasma progesterone concentrations (P4) were determined by enzyme immunoassays (EIAs). As the result of cyclic change in P4, it was assumed that the estrous cycle length was approximately four weeks. Birth month of Brazilian tapirs in Japanese zoos during the years of 1960-2001 were surveyed. Although their births had occurred throughout the year, high incidence of birth was observed in March to June. From the P4 profiles, it was suggested that there was no obvious reproductive seasonality and Brazilian tapir could be an annual breeder. However, the incidence of birth throughout the year was biased, it was supposed the breeding may be influenced by climate factors.
Lungworm disease of five Japanese serows was studied parasitologically and pathologically. All cases were found in the water near Towada of Aomori Prefecture in the term from April to June, 2000. The parasites isolated from the nodules in the lung were identified into Protostrongylus shiozawai. Their fine morphology was observed by scanning electron microscopy. Pathologically, hyperplasia of smooth muscle bundles and lymphatic apparatus in the lung interstitium was characterized concerned with parasitizm. In addition, characteristic aqueous emphysema that developed in the non-parasitized tissue was suggested as the possible cause of their accidental death in the water. This is the first report about P. shiozawai parasitism in the Japanese serow inhabited in Aomori Prefecture.
Feeding management for 23 Malayan tapirs (Tapirus indicus) by Japanese zoos was surveyed in order to obtain basic data on their nutritional management. Digestibility of feeds was analyzed in 4 of the 23 tapirs to obtain information on the amount of digestible organic matter intake (DOMI) needed for growth and maintaining body weight. At 10 zoos, 2,302-9,026 g and 201-1,433 g of dry matter and crude protein, respectively, are fed per day. The amounts varied greatly among the zoos. Carbohydrates in the feeds can be classified into 5 groups based on the amounts of starch (sweet potato) and fibrous materials (grasses and other leaves). Digestibilities of crude fat and total fiber (neutral detergent fiber) were low at 25.7% and 27.9%, respectively. There were large variations among the individual tapirs. On the other hand, digestibility of non-fibrous carbohydrates was high at 85.5%, and the variation among individual tapirs was small. Judging by digestibilities of feeds and body weight changes, we concluded that the amount of digestible organic matter intake for a Malayan tapir to maintain or increase its body weight slightly ranges 2,590-3,208 g per day.
We used the cone-beam type CT (Computed Tomography) scanning to study the nasal region of the orang-utan carcass head. The cone-beam type CT is the simplest and the most reasonable way to obtain 3 D data from the dead bodies of animals. In the orang-utan head, the complicated structure of the nasal conchae and the laterally-enlarged maxillary sinus were observable in a non-destructive 3 D imaging analysis. These findings will be effective in morphologically detailing the olfactory function of this species in the future.
Clinical, parasitological and pathological examinations were performed on a 5-year-old female white whale (Delphinapterus leucas) which was kept in an aquarium and died in association with anorexia, diarrhea and occasional vomiting. Trematoda in the small intestine and nematodas in the bronchus and ureter were observed in the white whale. Pathological examination revealed interstitial pneumonia with marked interstitial fibrosis and occasional parasitic eggs in alveoli.
A louse (Haematomyzus elephantis) infection was found on the epidermis of three Asian elephants (Elephas maximus) in captivity. Although each elephant showed heavy itching sensation with scratching their bodies on the wall or ground in the facility, no bruises or papules on their bodies were observed. The local treatment by dipping on the parasite using a synthetic pyrethroid liquid was not effective. Good expulsion was attained with the treatment with a carbaryl-based shampoo 5 to 7 times during more than two months. It is necessary to inspect for louse infections of imported elephants to zoos at the time of quarantine.
A case of calcinosis circumscripta in the limbs of a Malay box turtle(Cuora amboinensis kamaroma) was examined. At death, the turtle showed severe enlargement of the fore and hind limbs. There were multifocal nodules with a chalky appearance and gritty consistency in the subcutis and muscle layers of the limbs. Histologically, the nodules contained multiple lobular lesions of various sizes and shapes, surrounded by varying amounts of fibrous connective tissue. The lesions consisted of various amounts of amorphous basophilic material that were positive for PAS and von Kossa's reaction. The morphological features of the lesions closely resembled those of calcinosis circumscripta in dogs and humans.
A case of squamous cell carcinoma originating from the left cervical region in a 14-year-old male Canadian lynx (Lynx canadensis) was studied. At necropsy, a marked fibrous thickening with ulcers in the skin of the left cervical region, as well as subcutaneous irregular yellowish-white mass involving left parotid and latter part of the mandible was observed. Microscopically, the masses consisted of infiltrative growth of a well-differentiated squamous cell carcinoma with prominent fibrous reaction. The tumor showed wide and deep invasions, particularly around the trachea. The tumor cells were positive for keratin, cytokeratin AE 1 and AE 3. The morphological features of the tumor closely resembled to those in cats.