Lab Animal Handling & Care

Cheatsheet Content

### Common Laboratory Animals - **Rats (Rattus norvegicus):** - **Characteristics:** Intelligent, social, easy to handle, widely used in toxicology, nutrition, and behavioral studies. - **Handling:** Grasping at the base of the tail (for short periods), or scooping with hands/tunnels. For restraint, scruffing firmly behind the ears. - **Mice (Mus musculus):** - **Characteristics:** Small size, short generation time, extensive genetic models available, used in immunology, genetics, cancer research. - **Handling:** Grasping at the base of the tail (briefly), or scooping. For restraint, scruffing firmly. - **Rabbits (Oryctolagus cuniculus):** - **Characteristics:** Good for antibody production, ophthalmology, cardiovascular studies. Can be easily startled. - **Handling:** Support the entire body, especially the hindquarters, to prevent "rabbit kick" leading to spinal injury. Never lift by ears. - **Guinea Pigs (Cavia porcellus):** - **Characteristics:** Require high vitamin C, sensitive to stress, often used in immunology, audiology, and nutrition. - **Handling:** Support the body, one hand under the chest, other supporting the hindquarters. Gentle and slow movements are key. ### Handling and Care of Lab Animals #### 1. General Principles - **Respect & Ethics:** Treat all animals humanely, minimizing stress and pain. Adhere to IACUC (Institutional Animal Care and Use Committee) guidelines. - **PPE:** Always wear appropriate Personal Protective Equipment (gloves, lab coat, sometimes masks/goggles). - **Acclimation:** Allow animals to acclimate to new environments before procedures. - **Record Keeping:** Maintain accurate records of animal health, treatments, and experimental procedures. #### 2. Housing - **Cages:** Appropriate size, ventilation, and enrichment (e.g., bedding, nesting material, toys). - **Environment:** Controlled temperature, humidity, light/dark cycles. Minimize noise and vibrations. - **Bedding:** Absorbent, non-toxic, dust-free. Changed regularly to maintain hygiene. #### 3. Nutrition & Hydration - **Food:** Species-specific, commercially prepared diets. Available ad libitum unless restricted by protocol. - **Water:** Fresh, clean water always available, often via sipper bottles or automatic watering systems. Checked daily. #### 4. Health Monitoring - **Daily Checks:** Observe animals for changes in behavior, appetite, activity, coat condition, posture, and signs of illness or distress. - **Weight Monitoring:** Regular weighing can indicate health changes. - **Veterinary Care:** Access to trained veterinary staff for health issues. ### Methods of Animal Inoculation Inoculation is the introduction of substances (e.g., pathogens, drugs, cells) into an animal. - **General Considerations:** - **Aseptic Technique:** Essential to prevent contamination and infection. - **Restraint:** Proper restraint is crucial for animal safety and accurate administration. - **Needle Size:** Appropriate gauge and length for the chosen route and animal size. - **Volume:** Administer appropriate volumes for the chosen route to avoid tissue damage. #### 1. Parenteral Routes - **Subcutaneous (SC/SQ):** - **Site:** Loose skin, typically scruff of the neck or flank. - **Technique:** Tent the skin, insert needle parallel to the body, inject. - **Absorption:** Slower than IM or IV. - **Intramuscular (IM):** - **Site:** Large muscle masses (e.g., thigh, gluteal). - **Technique:** Insert needle perpendicular to the muscle, aspirate (if appropriate), inject slowly. - **Absorption:** Moderate; potential for muscle damage. - **Intraperitoneal (IP):** - **Site:** Lower abdominal quadrant, off-midline to avoid vital organs. - **Technique:** Restrain animal, tilt head down, insert needle at a shallow angle through abdominal wall. - **Absorption:** Rapid due to large surface area of peritoneum. - **Intravenous (IV):** - **Site:** Tail vein (mice/rats), ear vein (rabbits), jugular or saphenous vein (various species). - **Technique:** Locate vein, insert needle parallel to vein, confirm placement (blood flash), inject slowly. - **Absorption:** Immediate and complete systemic distribution. Most challenging. #### 2. Other Routes - **Oral (PO):** - **Site:** Administrated directly into the stomach via gavage needle or mixed with food/water. - **Technique:** Gavage needle carefully inserted into esophagus. - **Absorption:** Dependent on gastrointestinal factors. - **Intradermal (ID):** - **Site:** Dermis layer of skin. Small volumes. - **Technique:** Insert needle superficially into the skin, creating a bleb. - **Absorption:** Very slow; used for allergy testing, vaccine studies. - **Intranasal (IN):** - **Site:** Nostrils. - **Technique:** Administer drops into nares. - **Absorption:** Local effect in respiratory tract or systemic via nasal mucosa. ### Examination of Inoculated Animals Post-inoculation, careful monitoring is critical to assess the effects of the substance and animal welfare. #### 1. Clinical Observation - **Frequency:** Dependent on the study and substance; often multiple times daily, especially in acute phases. - **Parameters:** - **General Appearance:** Coat condition (roughened fur), posture (hunched), activity level (lethargy, hyperactivity). - **Behavior:** Changes in feeding/drinking, social interaction, vocalization, signs of pain (e.g., guarding, grimacing). - **Respiration:** Rate, depth, presence of labored breathing or nasal discharge. - **Circulation:** Mucous membrane color (pallor, cyanosis), capillary refill time. - **Excretions:** Changes in urine (color, volume) or feces (diarrhea, constipation). - **Body Weight:** Significant changes can indicate illness. - **Temperature:** Fever or hypothermia (if relevant to study). #### 2. Local Site Examination - **Injection Site:** Check for swelling, redness, inflammation, necrosis, abscess formation. - **Skin:** Rashes, lesions, hair loss. #### 3. Specific Symptoms - **Neurological:** Tremors, convulsions, paralysis, ataxia (incoordination). - **Gastrointestinal:** Vomiting (if species can vomit), diarrhea, abdominal distension. - **Respiratory:** Coughing, sneezing, difficulty breathing. #### 4. Scoring Systems - Develop objective scoring systems for clinical signs to quantify severity and track progression. This aids in decision-making for intervention or euthanasia. #### 5. Humane Endpoints - Establish clear humane endpoints in the protocol to minimize suffering. This defines the point at which an animal must be removed from the study, treated, or humanely euthanized.