Rodents (1996) / Chapter Skim
Currently Skimming:
6 VETERINARY CARE
6 VETERINARY CARE
Pages 85-113
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 85... ...
, the Public Health Service Policy on Humane Care and Use of Laboratory Animals, or PHS Policy (PHS, 1996) , and the Guide for the Care and Use of Laboratory Animals, known as the Guide (NRC, 1996 et seq.~.
|
From page 86... ...
Sources Rapid advances in animal-production technology and disease-control methods during the past 20 years have made it easier to obtain laboratory rodents of known health status and genetic definition. Commercial animal producers often maintain colonies of hysterectomy-derived mice, rats, and guinea pigs in barrier facilities designed and operated to prevent the introduction of microbial agents.
|
From page 87... ...
airports can also constitute a problem. Laboratory rodents and rodent tissues that are not inoculated with infectious agents do not require a USDA permit; however, U.S.
|
From page 88... ...
This course of action is usually followed only in longstanding, ordinarily "closed" breeding colonies. Animals of undocumented microbiologic status received from any outside source should be serologically tested for a comprehensive list of infectious agents.
|
From page 89... ...
Viable rodent tissues including blood, ascitic fluid, tissue cultures, transplantable tumors, and hybridomas can harbor undesirable agents, and tissues of undocumented microbiologic status should not be introduced into rodent colonies until they are shown to be free of undesirable agents by diagnostic testing (e.g., MAP testing)
|
From page 90... ...
Veterinary programs for overseeing the health of laboratory rodents should have readily available, up-to-date references on the biology and diseases of rodents. Control of Infectious Diseases First and foremost, control of infectious diseases in rodent colonies means preventing their introduction.
|
From page 91... ...
Routine monitoring systems should be in place to detect them as quickly as possible, thereby permitting the start of specific measures to eliminate them or prevent their spread. The key elements of an effective monitoring program are daily observation of the animals to detect clinical diseases and regular microbiologic monitoring to detect subclinical infections.
|
From page 92... ...
Isolation of Sendai virus from guinea pigs has been attempted rarely and described only anecdotallY (Parkers reported bY Van Hoosier and Robinette, 1976~. Failure of transmission of Sendai virus from serologically positive guinea pigs to mice also has been found (W.
|
From page 93... ...
bacillus Ectromelia virus Encephalitozoon cuniculi Hantavirus K virus Kilham rat virus Lymphocytic choriomeningitis virus + Minute virus of mice Mouse adenovirus (MAd-FL, MAd-K87) Mouse cytomegalovirus Mouse hepatitis virus Mouse "orphan" parvovirus Mouse rotavirus Mouse thymic virus Mycoplasma arthritidis Mycoplasma pulmonis Pneumonia virus of mice Polyoma virus Rat coronavirus and sialodacryoadenitis virus + Rat cytomegalovirus Rat "orphan" parvovirus Reovirus 3 Sendai virus Simian virus 5 Theiler's murine encephalomyelitis virus Toolen's H- 1 virus 93 Mice Rats Guinea Pigs Hamsters + + + + + + + + + + + + + + + + + + + + 1 + + + + + + + + + + + + + aAgents for which serologic tests are available are indicated by plus signs.
|
From page 94... ...
Sample Size for Monitoring All animals should be monitored for clinical disease by daily observations. This type of monitoring, combined with a diagnostic workup of animals with unexplained abnormalities, is particularly important for early detection of clinical disease outbreaks.
|
From page 95... ...
More complex calculations can be used once the monitoring program is in place and sufficient data have been accrued on the incidence of positive findings and frequency of disease outbreaks. Those calculations can be used to adjust the sample size and frequency of sampling to achieve the desired confidence levels for disease detection (Selwyn and Shek, 19941.
|
From page 96... ...
In some instances, antibiotics can adversely affect rodents, especially guinea pigs and hamsters, by causing an imbalance of the intestinal microflora and overgrowth of del eterious bacteria (Fekety et al., 1979; Small, 1968; Wagner, 1976J. Other
|
From page 97... ...
Viral, bacterial, and parasitic infections are usually eliminated by euthanatizing and repopulating the colony with disease-free animals after the room, cages, and other equipment have been decontaminated or, in the case of particular viruses, by allowing the infection to run its course in a closed population to produce noninfected, immune survivors. The latter procedure has been used successfully with such viruses as Sendai virus and mouse hepatitis virus, which are highly contagious, usually remain in the animals for a short time, and are relatively unstable in the animal-room environment (Barthold.
|
From page 98... ...
Therefore, a list of names and phone numbers should be posted prominently in the facility and maintained in the security office. Provisions for emergency veterinary care should be made as well (9 CFR 2.33b2; NRC, 1996 et sequin MINIMIZATION OF PAIN AND DISTRESS Many internal and external environmental factors can induce physiologic or behavioral changes in laboratory animals.
|
From page 99... ...
The drugs routinely used to prevent or control pain in laboratory rodents are generally classified as either opioids or nonsteroidal anti-inflammatory agents. Drugs reported to be effective analgesics in rodents are published elsewhere (Blum, 1988; CCAC, 1980; Clifford, 1984; Flecknell,
|
From page 100... ...
Additional factors that should be considered in selecting an analgesic include species, strain, age, sex, health status, nutritional status, period for which pain prevention or control will be required, recommended route of administration, volume of drug required for effect, compatibility with other pharmacologic agents that the animal will be receiving, cost, and availability (C.
|
From page 101... ...
It might be necessary to perform experimental surgery on animals whose health has been compromised by naturally occurring or experimentally induced disease, but generally only healthy rodents should be used in experimental surgical procedures. Before being used in experimental surgery, rodents should be allowed sufficient time to acclimate to a new environment and overcome the stress of transportation.
|
From page 102... ...
Criteria for selecting tranquilizers and anesthetics and their dosages should include species, strain, age, sex, health status, temperament, environmental conditions of the animal holding rooms, drug availability, drug side effects, recommended route of administration, equipment required, length of time that drug effect is desired, and skills and experience of the anesthetist. Doses quoted are often extrapolations from doses for other species with little or no scientific evidence to support them.
|
From page 103... ...
When ethylene oxide gas or a liquid chemical agent is used, care should be taken to ensure that all toxic residues are eliminated before the instruments and supplies are used for surgical procedures. Instruments and supplies that are to be sterilized with methods other than contact with liquid agents should be wrapped in paper, cloth, plastic, or similar materials in such a way as to prevent contamination after steril
|
From page 104... ...
Guinea pigs, however, can maintain a pedal reflex under anesthesia; for them, the pinna reflex is more appropriate for assessing the plane of anesthesia (C.
|
From page 105... ...
should be specified in any protocol for a terminal study or for a study in which the animals are likely to experience pain and distress that cannot be adequately controlled or prevented with pharmacologic agents, including studies associated with infectious diseases or tumor growth. Each investigator should consult with the attending veterinarian to decide on a humane endpoint that will allow collection of the required data without causing undue pain and distress (Amyx, 1987; Montgomery, 1987~.
|
From page 106... ...
Carbon dioxide is a very safe and inexpensive agent for euthanatizing laboratory rodents. In all but neonates, it causes rapid, painless death by a combination of CNS depression, which is produced by a fall in the pH of the cerebrospinal fluid, and hypoxia.
|
From page 107... ...
It can be concluded that in some cases anesthesia can interfere with the interpretation of data obtained from postmortem tissue samples and that appropriately trained personnel can perform decapitation humanely in rodents without anesthesia. REFERENCES ACLAD (American Committee on Laboratory Animal Disease)
|
From page 108... ...
1988. Laboratory Animal Anesthesia.
|
From page 109... ...
Pp. I.G.1-I.G.3,tin Manual of Microbiologic Monitoring of Laboratory Animals, A
|
From page 110... ...
1981. Anesthesia of laboratory animals.
|
From page 111... ...
, Institute of Laboratory Animal Resources, Committee on Long-Term Holding of Laboratory Rodents.
|
From page 112... ...
Pp. 35-42 in Manual of Microbiologic Monitoring in Laboratory Animals, K
|
From page 113... ...
1994. Manual of Microbiologic Monitoring of Laboratory Animals, 2nd ed.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.