Comparative studies of Giardia spp. in small mammals in southern Ontario. III. Duration and cyst production in natural and experimental infections

1979 ◽  
Vol 57 (2) ◽  
pp. 307-313 ◽  
Author(s):  
David R. Grant ◽  
Patrick T. K. Woo
Keyword(s):  
Small Mammals ◽  
Deer Mice ◽  
Meadow Voles ◽  
Southern Ontario ◽  
Laboratory Rats ◽  
Experimental Infections ◽  
Cyst Production ◽  
Faecal Samples ◽  
Giardia Muris ◽  
Rats And Mice

Experimental infections of Giardia-free laboratory rats and mice with their respective parasites (Giardia simoni in rats and Giardia muris in mice) demonstrated that the infections persisted for the duration of the study period (4 months). Similarly, naturally infected meadow voles (with Giardia microti) and deer mice (with Giardia peromysci) retained their infections during their captivity (6 months). Rigorous precautions were taken to prevent contamination and coprophagy. The relative numbers of cysts in consecutive faecal samples varied considerably and there were periods when the numbers of cysts were extremely low. The excretions of cysts were cyclical and there were periods of 7 and 8 days between peaks in laboratory rats and mice infected with G. simoni and G. muris respectively.

Comparative studies of Giardia spp. in small mammals in southern Ontario. I. Prevalence and identity of the parasites with a taxonomic discussion of the genus

1978 ◽  
Vol 56 (6) ◽  
pp. 1348-1359 ◽  
Author(s):  
David R. Grant ◽  
Patrick T. K. Woo
Keyword(s):  
Rattus Norvegicus ◽  
Microtus Pennsylvanicus ◽  
Deer Mice ◽  
Laboratory Mice ◽  
Meadow Voles ◽  
Southern Ontario ◽  
Laboratory Rats ◽  
Wistar Strain ◽  
Brown Rat ◽  
Giardia Muris

Giardia microti Kofoid and Christiansen, 1915 was identified in 98.8% (322 of 326) of meadow voles (Microtus pennsylvanicus) and G. peromysci Filice, 1952 emend, in 98% (48 of 49) of deer mice (Peromyscus maniculatus) that were livetrapped at six locations in southern Ontario. One feral brown rat (Rattus norvegicus) was infected with Giardia simoni Lavier, 1924 and Giardia muris Grassi, 1881. Laboratory rats (Wistar strain) harboured only G. simoni and laboratory mice (C3H strain) were infected with G. muris. Golden hampsters (Mesocricetus auratus) were infected with Giardia mesocricetus Filice, 1952 emend.Giardia spp. were separated into two morphologically distinct groups. Trophozoites of G. muris and G. mesocricetus were almost as wide as long and had round or oval centrally situated median bodies. Trophozoites of G. microti, Giardia peromysci, and G. simoni were elongate with long curved median bodies lying perpendicular to the long axis of the trophozoite.Further differentiation of species was not possible by comparing trophozoite morphology but was accomplished by comparing the average lengths and widths of trophozoites.

Control of Small Mammals on a Hardwood Plantation by Poison-Bait Feeders

1977 ◽  
Vol 53 (2) ◽  
pp. 96-99
Author(s):  
Arthur M. Martell ◽  
Andrew Radvanyi
Keyword(s):  
Small Mammals ◽  
Microtus Pennsylvanicus ◽  
Meadow Vole ◽  
Low Density ◽  
Meadow Voles ◽  
Southern Ontario

Poison-bait feeder stations were placed on a hardwood plantation in southern Ontario in 1973 to attempt long-term control of a meadow vole (Microtus pennsylvanicus) population by continuous dispensing of poisoned grain. Baiting by means of feeders successfully reduced the numbers of meadow voles and maintained them at a low density, about 3-6/ha (1.2-2.4/acre), through April 1976. During the same period, the density of meadow voles on surrounding unpoisoned areas declined from a 1973 peak to about the same as that found on the poisoned plot by fall and winter 1975-76. Despite that low density, less than 4/ha (1.6/acre), severe gnawing and girdling of young hardwoods occurred during winter. Poison-bait feeders are efficient at reducing meadow vole populations from high to low density, but it cannot be assumed that even those low-density populations will not damage hardwood plantations.

Two new species of trypanosomes (subgenus Schizotrypanum) in bats from southern Ontario

1981 ◽  
Vol 59 (3) ◽  
pp. 530-545 ◽  
Author(s):  
Susan M. Bower ◽  
Patrick T. K. Woo
Keyword(s):  
Homo Sapiens ◽  
Myotis Lucifugus ◽  
Deer Mice ◽  
Laboratory Mice ◽  
Southern Ontario ◽  
Laboratory Rats ◽  
Cardiac Muscles ◽  
Fresh Plasma ◽  
Centrifugation Technique

From November of 1976 to May of 1979, the blood of 529 bats from 12 sites in southern Ontario was examined for trypanosomes using the haematocrit centrifugation technique. Trypanosoma hedricki n.sp. was found in 62 of 216 Eptesicus fuscus and Trypanosoma myoti n.sp. in 16 of 313 Myotis lucifugus. Blood forms of both species were morphologically similar to Trypanosoma cruzi. These trypanosomes were readily cultured in diphasic blood–agar medium.Cultures of T. hedricki n.sp. and T. myoti n.sp. were infective when inoculated orally or injected intraperitoneally into laboratory reared E. fuscus and M. lucifugus respectively. Pseudocysts of amastigotes were found in cardiac muscles of both bat species and in the intestinal smooth muscle of M. lucifugus. Trypanosoma hedricki n.sp. was not infective to M. lucifugus nor was T. myoti n.sp. infective to E. fuscus. Unlike T. cruzi, cultures were not infective to Mus musculus, Peromyscus maniculatus, Microtus pennsylvanicus, Mesocricetus auratus, Rattus norvegicus, and Cavia porcellus.After in vitro incubation in fresh plasma from deer mice, hamsters, laboratory rats, guinea pigs, little brown bats, and Homo sapiens, T. hedricki n.sp. could not be cultured. However, positive cultures were obtained after incubation in fresh plasma from E. fuscus and occasionally in fresh plasma from laboratory mice. Positive cultures were always obtained when the plasma was heat inactivated.

Comparative studies of Giardia spp. in small mammals in southern Ontario. II. Host specificity and infectivity of stored cysts

1978 ◽  
Vol 56 (6) ◽  
pp. 1360-1366 ◽  
Author(s):  
David R. Grant ◽  
Patrick T. K. Woo
Keyword(s):  
Deer Mice ◽  
Laboratory Mice ◽  
Temperature Dependent ◽  
Laboratory Rats ◽  
Exponential Decrease ◽  
Brown Rat ◽  
Cross Transmission ◽  
Rate Of Decline ◽  
Giardia Muris ◽  
Cessation Of Treatment

Carefully controlled cross transmission experiments showed that some species of Giardia (Giardia simoni from laboratory rats, Giardia muris from laboratory mice, and Giardia peromysci from deer mice) are highly host specific while others are not. Although Giardia microti infected hamsters, and Giardia mesocricetus infected laboratory rats, these species are morphologically dissimilar from the Giardia spp. which are normally found in these animals. This study also shows that there are two varieties or subspecies of G. muris. Giardia muris from laboratory mice and from a feral brown rat were identical in morphology and dimensions, but differed in host specificity.Infectivity of cysts of G. simoni in faecal suspensions stored at three temperatures was tested using the eosin dye test and by administering portions of suspensions to Giardia-free rats at regular intervals. An exponential decrease in the proportion of cysts that resisted penetration by eosin was observed. The rate of decline was temperature dependent. Rats could not be infected when less than approximately 50% of cysts in suspension were eosin negative.Metronidazole (Flagyl) and quinacrine hydrochloride (Atabrine) did not have a prophylactic effect in rats treated for 7 days. Infections were established in animals inoculated with cysts of G. simoni 24 h after cessation of treatment.

scholarly journals Estimating mouse and rat use in American laboratories by extrapolation from Animal Welfare Act-regulated species

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Larry Carbone
Keyword(s):  
United States ◽  
Animal Welfare ◽  
The United States ◽  
Animal Research ◽  
Government Agencies ◽  
Laboratory Rats ◽  
Tier System ◽  
Western Nations ◽  
Rats And Mice ◽  
Usage Data

AbstractAlone among Western nations, the United States has a two-tier system for welfare protections for vertebrate animals in research. Because its Animal Welfare Act (AWA) excludes laboratory rats and mice (RM), government veterinarians do not inspect RM laboratories and RM numbers are only partially reported to government agencies1. Without transparent statistics, it is impossible to track efforts to reduce or replace these sentient animals’ use or to project government resources needed if AWA coverage were expanded to include them. I obtained annual RM usage data from 16 large American institutions and compared RM numbers to institutions’ legally-required reports of their AWA-covered mammals. RM comprised approximately 99.3% of mammals at these representative institutions. Extrapolating from 780,070 AWA-covered mammals in 2017–18, I estimate that 111.5 million rats and mice were used per year in this period. If the same proportion of RM undergo painful procedures as are publicly reported for AWA-covered animals, then some 44.5 million mice and rats underwent potentially painful experiments. These data inform the questions of whether the AWA needs an update to cover RM, or whether the NIH should increase transparency of funded animal research. These figures can benchmark progress in reducing animal numbers in general and more specifically, in painful experiments. This estimate is higher than any others available, reflecting the challenges of obtaining statistics without consistent and transparent institutional reports.

scholarly journals Giardia muris and Giardia duodenalis groups: ultrastructural differences between the trophozoites

1989 ◽  
Vol 31 (4) ◽  
pp. 242-247 ◽  
Author(s):  
Maria Inês L. Sogayar ◽  
Elisa Aparecida Gregório
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Giardia Duodenalis ◽  
Dorsal Surface ◽  
Distal Extremity ◽  
Transmission Electron ◽  
Marginal Plate ◽  
Marginal Plates ◽  
Giardia Muris ◽  
Rats And Mice

Trophozoites of the Giardia muris group from hamsters, domestic rats and mice and of the Giardia duodenalis group from hamsters and domestic rats were examined by transmission electron microscopy. The basic ultrastructure of the trophozoites was similar. Differences were shown in the morphology of the ventrolateral flange of the trophozoites of Giardia muris and Giardia duodenalis groups. Marginal plates are less developed in the species of the Giardia duodenalis group. In this group, the distal extremity of the lateral flange is short and thick and the marginal plate does not penetrate into the distal extremity of the flange. In the Giardia muris group, the ventro-lateral flange is well developed and narrow and the marginal plate penetrates the distal extremity of the flange. The osmiophilic lamella, which accompanies the dorsal surface of the marginal plate is seen only in the Giardia muris group.

A Good Life for Laboratory Rodents?

ILAR Journal ◽  
2020 ◽  
Author(s):  
I Joanna Makowska ◽  
Daniel M Weary
Keyword(s):  
Environmental Enrichment ◽  
Good Life ◽  
Standard Of Care ◽  
Active Engagement ◽  
Behavioral Repertoire ◽  
Laboratory Rats ◽  
Laboratory Rodents ◽  
Patient Model ◽  
Rats And Mice ◽  
Free Ranging

Abstract Most would agree that animals in research should be spared “unnecessary” harm, pain, or distress, and there is also growing interest in providing animals with some form of environmental enrichment. But is this the standard of care that we should aspire to? We argue that we need to work towards a higher standard—specifically, that providing research animals with a “good life” should be a prerequisite for their use. The aims of this paper are to illustrate our vision of a “good life” for laboratory rats and mice and to provide a roadmap for achieving this vision. We recognize that several research procedures are clearly incompatible with a good life but describe here what we consider to be the minimum day-to-day living conditions to be met when using rodents in research. A good life requires that animals can express a rich behavioral repertoire, use their abilities, and fulfill their potential through active engagement with their environment. In the first section, we describe how animals could be housed for these requirements to be fulfilled, from simple modifications to standard housing through to better cage designs and free-ranging options. In the second section, we review the types of interactions with laboratory rodents that are compatible with a good life. In the third section, we address the potential for the animals to have a life outside of research, including the use of pets in clinical trials (the animal-as-patient model) and the adoption of research animals to new homes when they are no longer needed in research. We conclude with a few suggestions for achieving our vision.

Evaluating body condition in small mammals

2001 ◽  
Vol 79 (6) ◽  
pp. 1021-1029 ◽  
Author(s):  
A I Schulte-Hostedde ◽  
J S Millar ◽  
G J Hickling
Keyword(s):  
Body Condition ◽  
Small Mammals ◽  
Isotope Dilution ◽  
Condition Index ◽  
Dry Mass ◽  
Fat Content ◽  
Body Water ◽  
Deer Mice ◽  
Fitness Consequences ◽  
Neotoma Cinerea

Body condition (energy reserves) can have important fitness consequences. Measuring condition of live animals is typically done by regressing body mass on measures of body size and using the residuals as an index of condition. The validity of this condition index was evaluated by determining whether it reflected measured fat content of five species of small mammals (yellow-pine chipmunks (Tamias amoenus Allen), bushy-tailed wood rats (Neotoma cinerea Ord), deer mice (Peromyscus maniculatus Ord), red-backed voles (Clethrionomys gapperi Vigors), and meadow voles (Microtus pennsylvanicus Ord)). We also determined whether body water could predict fat content, enabling the use of hydrogen-isotope dilution for estimating condition. For all five species, condition estimates weakly predicted fat content and more accurately predicted variation in lean dry mass and water content. The relationship between body water and fat content was inconsistent among the five species, discouraging against the general use of isotope dilution in these animals. Although ecologically important, these indices are best interpreted as explaining variation in all constituents of body composition.

scholarly journals Natal nest location and small mammal tracking with a spool and line technique

1986 ◽  
Vol 64 (4) ◽  
pp. 1034-1036 ◽  
Author(s):  
Rudy Boonstra ◽  
Ian T. M. Craine
Keyword(s):  
Success Rate ◽  
Small Mammals ◽  
Small Mammal ◽  
Inexpensive Method ◽  
Natal Nest ◽  
Meadow Voles ◽  
Nest Location ◽  
Nest Sites

We describe a simple, inexpensive method for tracking small mammals accurately for distances up to 180 m. A small spool of thread is attached to the back of the animal with srgical glue. As the animal moves along, it leaves behind it a trail of thread that can be followed along the route taken and to nest sites. Of 157 lactating meadow voles spooled, we found 62 nests with young. This success rate can probably be doubled by reducing two sources of spooling failure and by spooling a second time within the same trapping session.

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