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PubMedDate not supplied

Pasteurella multocida in wild mammals and birds in California: prevalence and virulence for turkeys.

Samples collected from the oropharynx of wild mammals and birds trapped on 36 turkey farms in California were evaluated for the presence of Pasteurella multocida. A total of 966 animals were collected from 18 premises that had experienced an outbreak of fowl cholera within the past 2-8 months; samples were collected from 16 of these 18 premises within 2-8 weeks of outbreak notification and while the infected flock was still present. A total of 939 animals were trapped from an additional 18 premises that had not reported any outbreaks of fowl cholera within at least 4 months, if ever. Forty-eight isolates of P. multocida, of a variety of somatic serotypes, were recovered from 6 species of mammals and 3 species of birds. On only 2 of 7 premises was the somatic serotype of the isolates obtained from wildlife the same as the isolate obtained from tissues of turkeys that had died of fowl cholera on the same premises. Tests for virulence to turkeys were conducted with 31 of the isolates. Seventeen of these isolates caused mortality in turkeys. Wide ranges in mortality rates and median times to death were observed.

Animals↗
PubMed1987

The dendritic complexity and innervation of submandibular neurons in five species of mammals.

I have compared the dendritic complexity and innervation of homologous parasympathetic ganglion cells in several closely related species of mammals. In the smaller of these species (mouse, hamster, and rat), submandibular ganglion cells generally lack dendrites altogether and are innervated by a single axon. In the guinea pig, a somewhat larger species, these neurons possess rudimentary dendritic arbors and are innervated by 2 axons, on average. In the largest species investigated, the rabbit, submandibular ganglion cells have moderately complex dendritic arbors and receive innervation from several axons. These findings, together with a previous study of sympathetic ganglion cells in these same species (Purves and Lichtman, 1985a), indicate that relationships among neuronal morphology, convergent innervation, and animal size are widespread in the autonomic nervous system of mammals.

Animals↗
PubMed1978

Some aspects of maternal behaviour in mammals.

Lactation is the one common factor in the behaviour patterns of maternal care in mammals. A series of behaviour patterns is elicited by the different stages of the developing young and these are related to the way of life of the animals concerned. Infants which are born naked, blind and helpless elicit retrieving and nest building and are cleaned and cared for by the female. Older animals or those born with fur, but with poor locomotion, are still carried and cleaned. When the young can move well other behaviour patterns which keep the young and mother together are important, so signals for communication and recognition of individuals develop. At the end of lactation various behaviour patterns bring about weaning. Sometimes this is the result of dispersal by the young, and sometimes the young are actively rejected or deliberately abandoned. Several examples of maternal behaviour are given in relation to the classes of mammals and some related problems are discussed.

Animals↗
PubMedDate not supplied

Fever in mammals: is it beneficial?

Fever appears to protect ectotherms against infectious disease perhaps because it increases their aerobic metabolic capacity, which is temperature-dependent. Mammals, however, have a high aerobic capacity and normally regulate a high body temperature. Thus, the further increase in temperature induced by interleukin-1 may be dangerous, and the resulting increase in aerobic capacity may not be necessary for an effective defense. In fact, recent evidence suggests that although the neuroendocrine cold defense responses that are stimulated in fever enhance the defenses of the host, the increase in temperature harms these defenses. Data, however, are scarce and equivocal, and the function of fever in mammals is still uncertain.

Animals↗
PubMed1986

The enamel ultrastructure of multituberculate mammals: a review.

The enamel ultrastructure of multituberculate mammals has been sampled extensively and studied intensively and is better known than for any other group of early mammals. The enamel of the earliest multituberculates, those of the Late Triassic-Early Jurassic suborder Haramiyoidea and the Late Jurassic-early Early Cretaceous suborder Plagiaulacoidea, is "preprismatic." With only two exceptions, all Late Cretaceous and early Tertiary genera of multituberculates examined have prismatic enamel. Prisms are either small with circular (complete) boundaries or large with arc-shaped (incomplete) boundaries. There is a remarkably consistent relationship between enamel ultrastructural type and subordinal taxa in that small, circular prisms are usually found within the suborder Ptilodontoidea and large, arc-shaped prisms are usually found in the suborder Taeniolabidoidea and in six Late Cretaceous-Early Tertiary genera of indeterminate subordinal status. Research currently in progress suggests that both small, circular prisms and large, arc-shaped prisms are homologous in all multituberculates in which they occur, with one exception. Neoliotomus, a taeniolabidoid, appears to have evolved small, circular prisms independently. In addition, it appears that large, arc-shaped prisms represent the primitive condition in multituberculates with prismatic enamel, not small, circular prisms as has been proposed previously.

Animals↗
PubMed1985

Attraction to mammals of male mosquitoes with special reference to Aedes diantaeus in Sweden.

During investigations in central Sweden on the ecology of mosquito vectors of Ockelbo disease, large numbers of Aedes diantaeus males and lesser numbers of Ae. communis, Ae. excrucians and Ae. intrudens males were captured in animal-baited (rabbit, guinea pig, hen, dove, unbaited control) suction- and net-traps. In the five suction-traps, 57% of the diantaeus captured (N = 1,896) were males. Although the guinea pig-baited suction-trap captured the highest mean number of diantaeus males, data showed that these males, like the females, were mainly attracted to the largest mammal, i.e., the rabbit. These males assembled in the vicinity of the rabbit presumably to intercept females coming to feed. The net-trap data showed that orientation by the males to the rabbit presumably involved olfactory cues emanating from the mammal.

Aedes↗
PubMed1977

The life-span of mammals.

Various parameters in the life cycle of mammals were investigated to find a possible correlation between these parameters and the life-span. Twenty-two factors were calculated to determine the true life-span of any mammal. In addition a single formula, by means of which the life-span could be determined, was constructed. The life-spans of certain species, as calculated by means of the formula, are compared with authorative estimates.

Animals↗
PubMed1983

[Different modes of cell reproduction in the placental differentiation of mammals].

Summarized is the total evidence on the role of various modes of cell reproduction in the course of differentiation of various trophoblast population cells. The giant trophoblast cells, reaching a tremendously high (for mammals) degree of ploidy (512-4096c), blast cells, reaching a tremendously high for (mammals) degree of ploidy (512-4096c), give an example of cells that display a "non-classical" form of polyteny with not regular polyteny in chromosomes. For the trophoblast cells, a period of easy recognition with not regular, polyteny in chromosomes. For display a "non-classical form of polyteny with not regular polyteny in chromosomes. For the trophoblast cells, a period of easy recognition polytene chromosome has been established timed to definite stages of cell differentiation and of the polytene nucleus cycle. The start of phagocytic activity in trophoblast cells coincides in time with their transition to endoreduplication, both the processes terminating also simultaneously. It does not seem unlikely that such that each a correlation may appear due to a strict programmed appearance of numerous features of trophoblast cells, including their lifespan both in situ and under condition of -transplantation to different organs. Biological importance of various ways of reproduction in trophoblast cells (mitosis, non-completed polyploidizing mitosis, endoreduplication) in various parts of placenta is discussed in relation to their roles in development and functioning of this organo.

Animals↗
PubMed1984

[Comparative anatomic studies of the vomeronasal complex and the rostral palate of various mammals].

The structures of the rostral palate in regard to the vomeronasal complex of different species of mammals were studied. In all cases, we find a very interesting system of furrows which preserves a connection between the nasopalatine ducts and the preoral surroundings. For rodents, lagomorphs, Solenodon, Setifer, and Echinops, we find a special situation in this part of the palate. Here the incisors are not separated by a diastema nor the oral openings of the nasopalatine ducts are overgrown by a bipartite caudal branch of the rhinarium. The results of the anatomic studies of the vomeronasal complex and the rostral palate of the mammals investigated are discussed: First of all, some elements of the vomeronasal complex needed to be analysed in regard to structure and nomenclature, specifically the cartilago paraseptalis with its outer bar, the cartilago ductus nasopalatini and the cartilago palatina. Because of 2 criterions, the vomeronasal complex could be classified as either primitive or progressive. We find a primitive one in Didelphis, Tupaia, Solenodon, Oryctolagus, and all rodents. In contrast, the other insectivores studied and all primates show progressive structures at their vomeronasal complex. Finally, conclusions in regard to the function of the organs of Jacobson are derived from these studies. The significance of the "flehmen" mechanism for the functioning of the organs is questioned.

Animals↗
PubMed1984

[Comparative anatomical studies of the vomeronasal complex and the rostral palate of various mammals. I].

The anatomy of the vomeronasal complex and, in connection with this, the structures of the rostral palate were studied in different species of mammals, namely members of the order Marsupialia, Scandentia, Insectivora, Primates, Rodentia, and Lagomorpha. The following results were obtained: The organs of Jacobson of all forms studied are well-developed. The organ of Jacobson is situated at the base of the nasal septum and opens rostrally, always closely connected to the nasopalatine duct. Even in rodents, lagomorphs and Solenodon, where the openings of the organs are positioned rostral to the ductus, both systems are nevertheless connected by means of special furrows. Accordingly the organs of Jacobson are functionally much more closely related to the oral cavity than to the nasal cavity, which they actually belong to. This can be emphasized by the peculiar structures of the rostral palate inclosing the papilla palatina and with it the oral openings of the nasopalatine ducts. In all species studied, the anterior part of the upper jaw presents a very interesting situation because the median furrow of the rhinarium communicates directly or indirectly with the sulcus papillae palatinae, thus forming a very distinct system of grooves which preserves a connection between the nasopalatine ducts and the preoral surroundings. In rodents, lagomorphs, and Solenodon, we find in this part of the palate a special situation because of their unusually arranged incisors, which are not separated by a diastema. However, also in these cases, there are distinct connecting passages between the papilla palatina and the extraoral surroundings. The conditions found in Ratufa bicolor and in early stages of the rat demonstrate that the extraordinary topography of the rostral palate in rodents is a secondary formation by means of ontogeny and phylogeny. Cebus apella, a platyrrhine simian, shows already a clear reduction of palatal structures compared to those found in prosimians. In Setifer setosus and Echinops telfairi, we find the papilla palatina and with it the oral openings of the nasopalatine ducts overgrown by a bipartite caudal branch of the rhinarium. The neonate Setifer allows us to reconstruct the mechanism of this overgrowing procedure. We find a similar situation in Erinaceus, where the papilla palatina remains uncovered, however. Because of contradictory bibliographical data, some elements of the vomeronasal complex in mammals needed to be carefully analysed in regard to structure and nomenclature: in many species the paraseptal cartilage bifurcates rostrally into a dorsal and a ventral branch.(ABSTRACT TRUNCATED AT 400 WORDS)

Aging↗
PubMedDate not supplied

[Small wild mammals and arboviruses in Italy].

In 1980 and 1981, sera of 256 small wild mammals (rodentia, insectivora, carnivora) were collected in Piemonte and Southern Italy. They were then tested for antibody against 12 arboviruses by haemagglutination inhibition and complement fixation tests. In the North of the country, 42.8% of sera were found positive against Tahyna or Sicilian Sandfly fever viruses. In the Southern provinces, 44.3% of sera reacted with Bhanja, West Nile or other flaviviruses, Tahyna, Sicilian Sandfly fever and Arumowot viruses. These results lead to suspect the possible role of some small mammals (muridae, Clethrionomys glareolus, Talpa caeca, Talpa romana) in circulating these arboviruses in Italy.

Animal Population Groups↗
PubMed1983

[Mallophaga from birds and mammals in zoological gardens].

Almost 1,850 Mallophagen individuals from 95 host species (birds and mammals) most of which from the Zoological Gardens in łódź and Wrocław (both in Poland) have been investigated. As regards bird biting lice Amblyceran species were found to be more frequent than Ischnoceran ones. The great majority of species and individuals of Mallophaga were host-specific. Stragglers were mainly found on relatively big birds. The "populations" of bird biting lice in the two Zoological Gardens were found to be of smaller quantity and poorer quality than in free nature. Differences of that kind could not be observed with biting lice of mammals.

Animals↗
PubMed1983

Small mammals as reservoirs and transmitters of leptospires in livestock-breeding farms and their surroundings.

From 1976 to 1978, we examined 1723 wild small mammals, representing 15 species, from three animal production farms and their surroundings in the Trebon basin, south Bohemia, in order to detect antibodies against leptospirosis. Antibodies were found against the serovars grippotyphosa, sorex-jalna, sejroe and/or istrica. The serological positivity was higher in wet grassland stands and fields bordering fishponds. The dominant serovar was grippotyphosa against which antibodies were detected in 8 species of exoanthropic and synanthropic mammals. Owing to the wide ecological valence of the main natural reservoir of L. grippotyphosa--Microtus arvalis, this serovar was present even within the confines of the farms. M. arvalis, together with Apodemus sylvaticus, entering the farm buildings in the cold winter months, can introduce the serovar to the stables housing the farm animals.

Animals↗
PubMedDate not supplied

[Lice fauna (Anoplura) of small mammals from the Charskaya Hollow].

5 species of lice, Hoplopleura acanthopus Burm., H. longula Neum., Hoplopleura sp., Polyplax hannswrangeli Eich., Polyplax sp., were recorded from 15 species of small mammals of the Charskaya hollow, Kalarsky region, Chita district. H. acanthopus is most abundant and occurs on almost all species of small mammals.

Animals↗
PubMed1982

Small terrestrial mammals as reservoirs of leptospires in the Sava Valley (Croatia).

Small mammals trapped in seven sites along the river Sava in Croatia were examined for leptospiral infection by renoculture and serological methods. Of the 1749 animals caught 702 were examined by renoculture method and 626 were tested by microagglutination-lysis. The dominant animals species caught were Microtus arvalis (672 animals) and Apodemus agrarius (552 animals). Of the 115 strains of leptospires isolated the dominant serotypes were L. grippotyphosa (40) and L. pomona (35). Five strains of L. sejroe, 9 strains of L. australis, 1 strain of L. bataviae and 25 undetermined strains were isolated, the infection rate ranging from 3 to 32%. Serologic evidence of infection was demonstrated in 91 animals, the prevalence ranging from 0 to 43% of animals depending on the trapping site. Specific agglutinins most frequently encountered were those against L. pomona (50) and L. grippotyphosa (26), though agglutinins against L. jalna (5), L. bataviae (4), L. bratislava (3) etc., were also found. A high degree if association between L. grippotyphosa and the common vole as well as between L. pomona and the field mouse was found indicating that as far as these two types of leptospires are concerned the Sava valley may be considered as their vast natural focus. It was also concluded that wild small mammals in this region of Croatia may be a source of leptospiral infection for the local population as well as for outdoor-reared domestic animals (swine, bovine).

Animals↗
PubMedDate not supplied

[Presence of adiaspores of Emmonsia crescens Emmons and Jellison, 1960, a moniliaceous, aleurioid fungus, in the lungs of small wild mammals in northern Morocco].

The authors examine the lungs of 133 small mammals caught in the North of Morocco and belonging to 7 species: 12,8% of the animals (14/95 A. sylvaticus, 1/18 M. spretus and 2/11 C. russula) possess one adiaspore of E. crescens or more hundred. The relatively damp climate of this region can explain this strong percentage of infestation. That is the first time that the adiaspiromycosis is noticed in small mammals in North Africa and the second time on the African continent.

Animals↗
PubMed1981

[Molineinae parasites of mammals].

A revision of Molineinae parasitic in mammals is proposed with the following taxonomic changes: 1) Removal of the genera Ortleppstrongylus Durette-Desset, 1970, from a Bathyergidae of South Africa and Moguranema Yamaguti, 1941, from a Talpidae insectivore of Japan. Both genera are placed in Trichostrongylidae-Cooperiinae for the first, Trichostrongylidae-Haemonchinae for the second. 2) Division of the genus Molineus into two groups separated principally by the arrangement of the bursal rays. a) Molineus sensu stricto, parasitic in Carnivores throughout the world and in South american monkeys; with rays 2 and 3 grouped together and parallel, and with rays 4 equidistant between the 3 and 5. b) Brygoonema n. gen., Hugotnema, n. gen., Nochtia (Nochtia) Travassos and Vogelsang, 1929, and Nochtia (Tenrecola) n. sub. gen., parasitic in Tenrecoidea insectivores of Madagascar and Africa, and Erinacoidea insectivores and lemurs of Africa, with rays 2 and 3 diverging and the papilla of the ray 4 closer to the 3 than the 5. 3) Resurrection of the genus Shattuckius Sandground, 1938 parasitic in Solenodon of Hispaniola. 4) Synonymy of Hooperstrongylus Lie Kian Joe et Ow Yang, 1963 with Pithecostrongylus Lubimov, 1930. The species Molineus vogelianus De Muro, 1933 and M. teocchii Quentin, 1970, parasitic in lemurs are placed in Pithecostrongylus. Hypotheses on the evolution of the Molineinae of mammals are presented, based primarily on the evolution of the bursa. From the basic pattern observed in Molineinae of amphibians and reptiles (rays 2-3 grouped, ray 4 with common base with the 5-6, rays 5-6 grouped), evolution has followed two principal lines: 1) Displacement of the papilla of the ray 4 towards the anterior and disappearance of the common base with the 5-6. 2) Extremities of rays 2-3 and 5-6 converging forming two separate pincer-like formations. Following these and other secondary characters, an evolutionary hierarchy is proposed for the 13 genera. The parasites of Tenrecoidea of Madagascar are apparently of central importance in this evolution. A list of genera and species is given.

Animals↗
PubMed1980

A study of small mammals in the Ciloto field station area, West Java, Indonesia, with special reference to vectors of plague and scrub typhus.

From June 1977 to June 1978 a study of smal mammals was carried out in the Ciloto field station area, West Java, Indonesia by the WHO Vector Biology and Control Research Unit-II. The objectives of the investigations were to determine the diversity and density of rodent species, to find potential plague and scrub typhus vectors and to study their host-parasite relationships. In the 13 month period a total of 6 species of murids were identified; two species of campestral rats (R. tiomanicus and R. argentiventer), one species of peri-domestic (R. exulans), one species of domestic (R.r. diardii), and two species of forest rats (R. bartelsii and R. bukit). In addition, three species of insectivores (Suncus murinus, Hylomys suillus and Crocidura monticola), and one species of carnivore were found. Of the three habitats studies (mixed, ricefield and lalang), 10 species of small mammals were found in the mixed while four species of commensal murids were found in both the ricefield and the lalang. Of the four commensal murid species R. exulans had the highest density. R. tiomanicus was common but not abundant, and least common was R. argentiventer. R.r. diardii was occasionally found in the field. The mean litter size of gravid R. tiomanicus was 7.1, R. exulans 4.3, R. argentiventer 7.5 and R.r. diardii 9. Male R. tiomanicus, R. argentiventer and R.r. diardii with spermatozoa present in animals over 55 gm. Animals of less than 50 gm had no sperm. In R. exulans spermatozoa were present in specimens weighing 24-66 gm. No sperm were detected in those below 20 gm. The flea index of Xenopsylla cheopis and Stivalius cognatus as determined for R. tiomanicus was 0.3 and 2.3;l for R.r. diardii 2.2 and 1.7; for R. exulans 0.3 and 0.5; and for R. argentiventer 0.4 and 1.7 respectively. S. cognatus had a significantly higher density than X. cheopis among the campestral and peridomestic rats, but the density of X. cheopis was significantly in the domestic rat. Overall infestation rates were equally high in both mixed and lalang habitats, but low in the ricefield. Flea indices were highest in the mixed habitat, lower in lalang, and lowest in ricefield. The putative vector of scrub typhus (Leptotrombidium (L.) deliense) was quite prevalent on campestral rats, less so on domestic ones and least on peridomestic. Overall infestation rates were equally high in both mixed and lalang habitats and low in the ricefield. Chiggers load per animal was significantly higher in the mixed habitat, lower in lalang and lowest in the ricefield.

Animals↗