ALAT - Assistant Laboratory Animal Technician Animal Husbandry and Care 2 — Questions and Answers
Question 1: What factors determine the appropriate cage size for a group of laboratory mice?
- Only the number of animals
- Number of animals, body weight, reproductive status, species-specific behavioral needs, and any protocol-specific requirements (Correct answer)
- Only the available rack space
- The researcher's preference
Correct answer: Number of animals, body weight, reproductive status, species-specific behavioral needs, and any protocol-specific requirements
Cage size is determined by: number and body weight of animals (per Guide floor space tables), reproductive status (breeding pairs need more space), behavioral needs (enrichment space), and protocol requirements (equipment, food access).
The Guide provides minimum floor space based on body weight. Additional considerations: breeding cages need space for nest and litter; male mice may need individual housing if fighting occurs; protocol-specific needs may require larger cages. ALAT technicians should know Guide minimums and monitor for overcrowding as animals grow.
Question 2: How should an ALAT handle the introduction of new animals into an existing group?
- Place new animals directly into the existing cage
- Follow institutional protocols which may include quarantine, gradual introduction, monitoring for aggression, and using neutral territory or clean cages (Correct answer)
- New animals never need special introduction procedures
- Only the veterinarian can introduce new animals
Correct answer: Follow institutional protocols which may include quarantine, gradual introduction, monitoring for aggression, and using neutral territory or clean cages
Introducing new animals requires careful management: quarantine assessment, health status verification, using clean cages as neutral territory, monitoring for aggression, and following species-specific protocols for social introduction.
Mixing unfamiliar rodents can trigger severe fighting, particularly in male mice. Best practices: use a clean cage with fresh bedding (neutral territory), introduce during the dark cycle when animals are more active, monitor closely for 24-48 hours, and separate if aggressive fighting occurs. New arrivals should complete quarantine before joining established colonies.
Question 3: What is the proper procedure for feeding laboratory rabbits?
- Unlimited pelleted food only
- Measured pellets based on body weight plus unlimited timothy hay for fiber and dental health, with fresh water always available (Correct answer)
- Only fresh vegetables and no pellets
- Feed once weekly with large portions
Correct answer: Measured pellets based on body weight plus unlimited timothy hay for fiber and dental health, with fresh water always available
Rabbits should receive measured pellets (based on body weight to prevent obesity), unlimited timothy hay (essential for GI motility and dental wear), and continuous access to fresh water. Hay constitutes the most important component of their diet.
Rabbits are hindgut fermenters requiring high fiber for normal GI function. Timothy hay provides fiber for cecal fermentation and promotes natural dental wear of continuously growing molars. Pelleted diet provides balanced nutrition but can cause obesity if fed ad libitum. Water must always be available. Diet changes must be gradual (3-7 days) to prevent fatal enterotoxemia.
Question 4: Why is it important to check cage lids, feeders, and water systems during cage changes?
- Only for aesthetic reasons
- To ensure proper function and prevent hazards: cage lids must secure to prevent escape, feeders must allow food access without trapping, and water systems must deliver water reliably (Correct answer)
- These components never malfunction
- Only the maintenance team checks equipment
Correct answer: To ensure proper function and prevent hazards: cage lids must secure to prevent escape, feeders must allow food access without trapping, and water systems must deliver water reliably
Each component must be verified functional: lids must be secure (prevent escape, predation by wild rodents), feeders must allow access without trapping animals, and water delivery must be reliable (sipper tubes clear, bottles full, automated systems flowing).
Equipment failures are preventable causes of animal welfare problems. Common issues: cracked cage lids allowing escape, food hoppers positioned too high for young/small animals, wire feeders with gaps that trap limbs, clogged sipper tubes, and leaking water bottles that flood cages. Systematic checking during cage changes catches these problems before they cause harm.
Question 5: What bedding depth is generally recommended for laboratory rodents?
- A light dusting of bedding material
- Approximately 1/4 to 1/2 inch depth, or as specified by institutional SOPs, sufficient to absorb waste and allow burrowing behavior (Correct answer)
- Filled to the cage rim
- Bedding is not necessary if cages are cleaned daily
Correct answer: Approximately 1/4 to 1/2 inch depth, or as specified by institutional SOPs, sufficient to absorb waste and allow burrowing behavior
Bedding should be deep enough (typically 1/4 to 1/2 inch) to absorb urine, control ammonia, provide insulation, and allow natural burrowing behavior. Depth varies by bedding type and institutional protocols.
Bedding serves as absorbent (urine management), insulation (thermoregulation), enrichment (burrowing, nesting substrate), and comfort (cushioning on cage floor). Too little bedding increases ammonia and reduces comfort; too much can interfere with food access, cage lid closure, or IVC rack connections. Contact bedding types (corncob, paper, aspen) have different absorbency rates and may require different depths.
Question 6: How should an ALAT manage a cage where fighting has resulted in visible injuries?
- Leave the animals together and hope they work it out
- Separate the injured animal, assess wounds and report to veterinary staff, document the incident, and consider permanent separation if aggression recurs (Correct answer)
- Only separate if an animal dies
- Apply topical medication without veterinary consultation
Correct answer: Separate the injured animal, assess wounds and report to veterinary staff, document the incident, and consider permanent separation if aggression recurs
Immediate separation of the aggressor or injured animal, wound assessment, veterinary notification for treatment evaluation, incident documentation, and consideration of permanent housing changes to prevent recurrence.
Fighting is common in group-housed male mice (especially C57BL/6 and BALB/c strains). Steps: (1) Separate the injured animal immediately. (2) Assess wound severity. (3) Report to veterinary staff for treatment. (4) Document the incident. (5) Identify the aggressor if possible. (6) Consider permanent single housing for the aggressor or pair housing. (7) Provide enrichment that may reduce aggression (shelters with multiple exits). Report patterns to the PI as aggression may affect research data.
ALAT - Assistant Laboratory Animal Technician Animal Husbandry and Care 2
What factors determine the appropriate cage size for a group of laboratory mice?