Lab Animal - Mid Term

• Order: Rodentia
• Means: to gnaw
• Type of teeth: Single pair of upper and lower incisors 
• Name for incisors: Hipsodontic incisors - open rooted grow continously

• Myomorpha: mouse/rat like
• Sciurimorpha: Squrrel-like
• Hystricomorpha: guinea pig-like

• Capybara - 60kg
• Pygmy jerboa -5 gms

• Order: Rodentia
• Genus: Mus musculus

Original breeding stock by Abbie Lathrop. Then further developed by Clarence Cook Little

• Small
• Inexpensive
• Easily maintained
• Reproduces quickly

• Genetically diverse lines that are maintained by a rotational mating scheme to maximize heterozgosity and minimize brother-sister mating
• CD-1 & Swiss webster

• Genetically diverse - Used when genetic diversity doesn't pose a problem or it is desired (Monoclonal antibody production, sentinels)
• Larger, healtier, immunocompetent

• Breeding mice that are closely related to produce genetically identical offspring 
• Balb/C & C57B1/6

• Microphthalmia (C57B1/6) blindness (albino mice)
• Early onset deafness
• Mammary tumors
• Ulcerative dermatitis

For controlled studies, studies that need reproducibility of conclusions (Toxicology; Behavioral studies)

• nu/nu & SCID (severe combine immunodeficiency)
• Tumor biology research, immunology studies
• They require special housing and husbandry procedures.

• Athymic (lacks a thymus gland) & Lacks T-cells
• Lacks B-cells & T-cells

• "Designer mice"
• transgenics and targeted mutations (knockouts or knockins)
• Animal models of human diseases (obesity, heart disease, diabetes, arthritis, cancer)
• Always inbred

• Short coat
• Black, brown, agouti, albino
• 5 toes w/claws for climbing
• 5 pairs of mammary glands
• Whiskers for sensing (thimotaxis)

• Adult weight: 15-40 gms
• Lifespan: 1.5 - 3 years
• Dental formula: 2(I 1/1 C 0/0 PM 0/0 M 3/3)16 - same for rats & hamsters

• Limited ridge (can't vomit) & Large cecum
• spleen

• Bicornuate (2 horn) uterus with 1 cervix
• Prominant seminal vesicles
• Female has 10 nipples; males have none
• Anogenital distance varies between the sexes with male distance > than females

• Heart rate: 400-600 bpm
• Body Temperature: 95-102^o F
• Thermoneutral Zone: 29.6 - 30.5^o C (85.28 - 86.9^o F)
• > 89^o F

Poor regulation of body heat - they can't pant, sweat and they overheat easily.

Burrowing

• Estrus cycle: 4 days 
• dark
• Gestation period: 19-21 days 
• Fertile postpartum estrus: 14-24 hours following, parturition 
• Litter size: 6-10
• Type of breeding: Polyestrus - breed year round

• Blind and hairless (depends on mom)
• Birth weight: 1 gm
• Fully haired at: 10 days
• Eyes open at: 14 days
• Weaned at: 21 days
• 4 weeks (F) 6 weeks (M)

• Ominivorous 
• Food intake: 1.5 g/10 g BW/day 
• Water intake: 1.5 mL/10 g BW/day 
• Linoleic acid essential - Unsaturated omega-6 fatty acid
• Exogenous vitamin C 
• Coprophagy (normal in rodents, rabbits) 
• Nutritionally balanced, pelleted chow

• 1. Prey species that exhibit hiding, running away and freezing behavior
• 2. Social 
• 3. Nest builders for a) Pup survival; b) Temperature regulation; c) Protection from aggressors
• 4. Burrowers 
• 5. Nocturnal
• 6. Communication through pheromones and ultrasonic vocalization
• 7. Dominance hierarchies
• 8. Aggression is Rare towards people but is relatively common Intermale 
• 9. Grooming 
• 10. Cannibalism can occur due to maternal stress/disturbance

• Scientific Name: Rattus norvegicus
• Order: Rodentia
• Genus/species: Mesocricetus auratus

• Mouse
• Brown Rat
• Syrian Hamster

• Toxicology,
• physiology
• drug studies
• Also many naturally occurring disease models for a) Copenhagen, ACI: prostate cancer; b) Fatty Zucker: Diabetes Mellitus, Obesity; c) SHR (spontaneously hypertensive)

• Outbred stocks: Wistar, Sprague Dawley, Long-Evans
• Inbred strains: Fisher 344, Lewis
• Immunodeficient: Athymic Nude rats

• White, brown, hooded, with 6 pairs mammary glands
• Adult weight: 200-400 g 
• Heart Rate: 200-400 bpm 
• Natural life span: about 2-5 years

• No gall bladder 
• Bicornuate uterus with two cervixes 
• Long bones may grow up to one year of age 
• Thermoneutral zone broader than the mouse

• Estrus cycle: 4-5 days 
• Gestation period: 21-23 days 
• Fertile: postpartum estrus 
• Litter size: 8-12

• Blind, hairless (dependent on mom) 
• Birth weight: 5 grams
• Fully haired at: 10 days
• Eyes open at: 14 days
• Weaned at: 21 days
• 4 weeks (F) and 6 weeks (M)

• Type of eater: Omnivores (feed same chow)
• Food intake:  20-30 g/day 
• Water intake: 115 mL/kg/day

• 1. More domesticated than mice 
• 2. Social 
• 3. Intraspecies aggression uncommon in lab setting 
• 4. Aggression toward humans highly strain-dependent 
• 5. "Gentling" (handled often)
• 6. Cannibalism rare 
• 7. Dominance hierarchies 
• 8. Ultrasonic communication

• Scientific name: Mesocricetus aureus
• AKA: golden, "teddy bear" hamsters 
• Order: Rodentia 
• Genus: Mesocricetus auratus

• Developed from a few animals captured in Syria in the 1930's - A desert rodent
• Immunology, cancer research, prion research (mad cow disease), dilated cardiomyopathy

• 1. Short, stocky body
• 2. No tail
• 3. 4 toes on the front feet, 5 on the back
• 4. 4 pairs mammary glands
• 5. Flank glands - secretions used by Males to mark territory & Females are associated with estrus cycle

• Adult weight: 90-150 grams (females larger)
• Heart Rate: 250-500 bpm 
• Respiration: 33-125 bpm (avg 72) 
• Body temperature: 36.2-37.5^o C
• Life span: 1-3 years

Two-compartment stomach with the Nonglandular fore stomach similar to rumen (fermentation) - Glandular distal portion

• "immunologically privileged" - Tumors from man not rejected 
• Used for tumor Implantation & carcinogen studies

• Don't place feed in wire bar lids - OK to feed on floor
• Highly sensitive to many antibiotics - Clostridial enteritis

• Estrus cycle: 4 days - Breed on evening of the 3rd day following appearance of postovulatory vaginal discharge - No fertile postpartum estrus 
• Gestation: 16-18 days 
• Litter Size: 4-12 pups 
• Birth weight: 2-3 grams 
• Exploratory behavior at: 1 week 
• Weaning: 25 days 
• Breed at: 90 days and/or 90 grams

• Type of eater: Omnivorous 
• Daily water requirement: 5mL/100g body weight/day 
• Conserve water by: reduced excretion 
• Consume: 10-15 g commercial pellet/day 
• Diet: Nutritionally balanced, pelleted chow - Suitable stand-alone diet for all life stages in mice, rats, hamsters

• 1. Solitary 
• 2. Nocturnal/crepuscular - Most active during dawn and dusk
• 3. Females larger, more aggressive
• 4. Wake up cranky
• 5. Often fight if housed together
• 6. Escape artists
• 7. Hibernate in the wild to survive the harsh winter enviornment

• Scientific name: Cavia porcellus 
• Order: Rodentia 
• Genus: Cavia

• tuberculosis
• vitamin C metabolism
• pregnancy complications

• Outbred (Hartley) stock
• plastic surgery studies (tattoo removal)
• inbred strains

• Stocky body, short legs, short tail
• Don't jump; poor climbers 
• 4 toes on front feet, 3 on back
• 1 pair mammary glands
• Large adrenal glands

2 (I 1/1, C 0/0, PM 1/1, M 3/3)20

• Adult weight: 750-1000 g (700-1200 g)
• Birth weight: 60-100 g 
• Natural life span: 3-5 years 
• Heart Rate: 240-300 bpm (240-350 bpm) 
• Respiration Rate: 40-150 bpm 
• Body temperature: 99-103^o F

• Sexually mature at: 4-6 weeks
• Gestation period: 59-72 days; 
• Pups characteristics: large, haired, mobile 
• Birth weight: 70-100g 
• Litter Size: 2-5 
• Weaning age: 21 days 
• Common complications: Dystocia, hypocalcemia, uterine prolapse

• Type of eater: Herbivores and cecal fermenters - Coprophagy for Vit B and K - Grass is primary constituent of natural diet 
• Food intake: 6 grams feed/100 g body weight/day 
• Water intake: 10 mL/100g body weight/day 
• Special nutritional requirements: Only laboratory animal (other than primates) that require Vitamin C (ascorbic acid) because they are unable to synthesize it

• Defective collagen 
• Stunted growth 
• Bleeding 
• Delayed wound healing
• Impaired tooth and bone formation

• 1. Very social- always house together if possible
• 2. Thigmotactic (feels way around cage)
• 3. Not aggressive with people
• 4. Will bite one another, chew off ear tags
• 5. "stampeding" behavior - Haphazard running to confuse predators/aggressors
• 6. Messy eaters - tend to stuff bedding into sipper tubes

• Housing 
• Food 
• Water 
• Sanitation

• Shoebox caging using Mouse micro isolator cages with filter in tops that excludes pathogens, traps moisture and gases. The caging is made up of polycarbonate material (strongest, most expensive) 
• The shoebox caging is stored on Rack systems that are Flat shelves and ventilated. Ventilated systems help to keep the cages dry and allows for longer intervals between change outs. Ventilated systems can be used with water bottles or auto water systems

• Municipal (tap) water
• 1) R/O (reverse osmosis) 2) Autoclaving; 3) Acidification 4) Hyperchlorination
• 1) Automatic water delivery systems; 2) Water bottles which are labor intensive and have ergonomic issues; 3) Sipper sacks

• Must be soft, absorbent, no aromatic oils, safe if ingested
• Corncob; Cellulose products; Wood pulp and wood chips

• Light cycle: 12:12 typical; may be 14:10 in breeding rooms 
• Light intensity: 30 foot candles 1 meter from floor in center of room 
• Temperature: 64-79^o F 
• Air changes per hour(room): 10-15 
• Humidity: 30-70%

• 1. Overcrowding - Breeding cages not separated at weaning
• 2. Fight wounds - Switching mice between cages & overcrowding
• 3. Wet cages due to a leaky bottle, animals playing with drinking valves or diabetic animals
• 4. "lost" litters, pregnancy failures related to implantation failure due to noise/vibration or cannibalism due to stress (any reason)

• Poor breeding performance: Check light cycle 
• Ammonia odor in room: Time for a change-out? - Check air balance, number air change-outs/hour
• Thin, hunched posture: - Check environment - Check water supply - Check teeth

The act of inducing a painless death

• 1. Painless method
• 2. Time it takes to produce unconsciousness
• 3. Time until death is accomplished
• 4. Reliability of method
• 5. Repeatability of method
• 6. Personnel safety
• 7. Stress on animal
• 8. Non-reversibility
• 9. Compatible with scientific protocol
• 10. Aesthetically acceptable
• 11. Drug availability and abuse potential 

• 1. Use gentle restraint and handling 
• 2. Use tranquilizers or sedatives
• 3. Prevent conscious animals from observing the euthanasia of others, especially their own species

• Hypoxemia of brain tissues
• Depression of vital brain centers
• Physical damage to brain tissue

• 1. Inhalant anesthetics (Agents -halothane, isoflurane) 
• 2. Carbon dioxide

Place the animal in a closed container containing cotton or gauze soaked with agent; vapors are inhaled, animal becomes deeply anesthetized, respiration ceases and animal expires. Do not allow animal to come into contact with agent or allow air to circulate in the container. Not commonly used as a stand alone method. May be used to anesthetize an animal before a secondary method is used.

• Advantages 1) Good for small animals or for animals that are hard to restrain; 2) Many clinics have anesthesia machines; 3) Most agents are nonflammable and non-explosive
• Disadvantages 1) Some struggling and anxiety may occur; 2) Cannot be used without good ventilation or an anesthetic machine; 3) May require a secondary method

Small animals that are hard to restrain and birds - most likely will just anesthetize the animal and then inject with a barbiturate or exsanguinate

Place animal in chamber filled with CO2. Animal loses consciousness due to anesthetizing effect of CO2, then asphyxiates. This method is commonly used for rodents in research. A secondary method must be used, such as tissue removal or exsanguination

• Advantages - Inexpensive, nonflammable, non-explosive
• Disadvantages - Cannot be used on neonatal animals

Good for small laboratory animals, except neonates or very young animals

• Barbiturates
• Potassium chloride

• Pentobarbital, thiopental
• Method-intravenous in most animals, or other routes if animal is already unconscious. Pentobarbital overdose can be given IP to rodents. Thiopental must be given IV.

• Advantages - Fast and Minimal discomfort to the animal in most cases
• Disadvantages - 1) Necessitates trained personnel to restrain animal and give injection; 2) Regulated-must have DEA number; 3) Terminal gasp is aesthetically objectionable; 4) Excitability is occasionally possible as animal passes through stages of anesthesia

• Preferred method for dogs, cats and many other small animals, can be used in large animals
• IP injection of pentobarbital is acceptable in rodents 
• Apprehensive animals may require pre-tranquilization with Valium, acepromazine or other sedatives

• Agent-Supersaturated solution of potassium chloride (KCI) 
• Method-Given IV only in DEEPLY anesthetized animals. Too much KCI added to IV fluids could also harm the animal-be careful if you're adding this to IV fluids!

• Advantages - Inexpensive; Fast; and Non-regulated 
• Disadvantages - Animal must be anesthetized; and Painful if animal is not deeply anesthetized

Potassium chloride

• Captive bolt pistol 
• Method - Animal is restrained. Pistol is placed between the eyes and perpendicular to the skull and then discharged.
• Action - The bolt penetrates the skull and significantly damages the brain to cause unconsciousness.

• Advantages - Humane method for large animals that cannot be euthanized with drugs if used correctly
• Disadvantages - Aesthetically displeasing and Death may not occur

Acceptable for large animals when chemical agents cannot be used, as long as it is followed by exsanguination or transection of spinal cord at base of brain to ensure death.

• Cervical dislocation
• Exsanguination 
• Rapid freezing

Method - Place thumb and index finger on either side of the neck at the base of the skull. With the other hand, the base of the tail is quickly pulled to separate the neck vertebrae.

• Must be done in anesthetized animals.  
• Considered appropriate for small birds, mice and rats under 200 grams; and rabbits under 1 kg

Method - Remove 75% of the blood volume after the animal has been anesthetized

Can be used in all anesthetized animals to ensure death. In research, is used when large volumes of blood are needed or when tissues must be used for histopathology or other tests.

• Method - liquid nitrogen is used to freeze brain tissues
• Used in research when brain biochemistry is important for the study

• Wear PPE (personal protective equipment) consisting of mask, gloves and gown
• Discard PPE when finished and wash hands well
• Leave room if necessary

Rattus norvegicus, the Norway rat,

Mus musculus, the house mouse of N. America and Europe 

• Short term handling only for the mouse and rat
• grasp tail at the base (fat part) not the tip
• Grasping tail tip may cause the skin to "slough" off

• Used for: mouse - Provides greater restraint 
• Start with tail hold, place mouse on surface it can grip. Continue to hold tail, then grasp the loose skin at the back of the neck (the "scruff'). Grasp the skin close to the head to prevent bites. Hold tail between 4th and 5th fingers to steady mouse

• Used for: rat - Provides better restraint of rat
• Place hand over rat's body. Restrain head with first and second fingers. Place thumb and third finger behind front legs. For aggressive rats, wear leather or mail gloves

Plexiglas restrainer - tail, other areas for injections, drawing blood

Decapicone

• Centrifuge tubes
• Cut hole in end for air

• Pros: 1. No movement; 2. Good access anywhere on body; 3. Short or long periods
• Cons: 1. Must monitor anesthetic depth; 2. Vaporizers are expensive; 3. Chemical anesthetics - need DEA number; 4. Anesthetics may cause vasoconstriction

• Cage ID
• Individual ID

Should list investigator's name, species, strain, vendor, age, sex, arrival date

• Ear tags
• Ear punches 
• Tail tattoos 
• Toe amputation (hairless neonates only) 
• Nontoxic dyes 
• Shave patterns into fur

• Mice: 20 gauge, 1 ½ inch
• Rats: 18 gauge, 3 inch

Restrain animal and measure distance from mouth to last rib with feeding needle. Note how far you have to pass needle to be in stomach Place gavage needle in mouth and pass it down esophagus by sliding it along roof of mouth.  Animal should swallow as needle passes. At correct depth, give fluid.  Monitor for signs of discomfort, difficulty breathing, abnormal behavior

• Some antibiotics or pain medications can be placed in the animal's water bottle
• A sweet flavored antibiotic can be given by dropper into the back of the mouth

• Subcutaneous (SC or SQ) injections
• Intraperitoneal (IP) injections
• Tail vein (IV) injections 
• Intramuscular (lM) injections

• mice: 25-27 gauge, ½ - ¾ inch
• rats: 22-25 gauge, ½ - ¾ inch

• Restrain rodent against table or in restrainer
• Insert needle under skin of scruff and advance
• Aspirate to ensure needle is not in a blood vessel
• Inject fluids 

up to 2-3 mLs (mouse), 10 mLs (rat)

• mice: 25-27 gauge, ½ - ¾ inch
• rats: 22-25 gauge, ½ - 1 inch

• Restrain rodent's body with head lower than body - This allows abdominal organs to move
• away from injection site
• Enter abdomen in lower left quadrant
• Aspirate to ensure proper needle placement. If aspiration is ok, give fluid
• Monitor animal afterwards for signs of pain, labored breathing, abnormal behavior

up to 2 mls (mice); 10 mls (rats)

• Mice: 25-27 gauge, ½ inch
• Rats: 22-25 gauge, ½ inch

• Restrain rodent (restrainer or anesthesia)
• Vasodilate tail via Heating lamp, heating pad, warm water, hair dryer
• Grasp tail, rotate slightly to see veins and choose injection site a little over half way down the tail
• Insert needle through skin with the bevel up
• Usually cannot check for placement by aspirating 
• Inject fluid and check for clearing of vein
• If SQ lump forms, you are not in vein - Withdraw needle, try again closer to body

up to 0.2 mls (mice); 0.5 mls (rats) 

Intramuscular Injections

• Needle: rat: 25 gauge, ½ inch 
• Restrain rat: hand-held, restrainer, anesthesia
• Inject fluid into posterior (caudal) thigh muscles 
• Can give up to 0.3 mls (rats)

• Mouse: 70-80 ml/kg or approx. 5.5% of body weight 
• Rat: 50-65 ml/kg or 6-7% of body weight 

• Lateral tail vein 
• Ventral tail artery 
• Saphenous vein 
• Retro-orbital venous sinus 
• Cardiac puncture

• Vasodilate tail vessels 
• Restrain mouse so that vein is visible
• Use a scalpel blade to nick the skin and pierce the vein
• Collect blood as droplet wells up in Microtainer or capillary tube
• When finished, hold pressure on site or cauterize
• Can obtain up to 0.2 mls of blood

• Vasodilate tail vessels 
• Restrain rat so that vein is visible
• Use a 25 gauge needle on a 1 cc syringe to withdraw blood
• Alternatively, place a 25 gauge needle in vein without syringe and collect blood in capillary tube

• Vasodilate tail vessels 
• Restrain animal and lift tail - Artery runs on the ventral side
• Use a scalpel blade to nick the skin and pierce the vessel and collect blood as the droplet wells up in a Microtainer or capillary tube
• Can also use a 25 gauge and 1 cc syringe to withdraw blood in rats

up to 0.4 mls (mice); 1.0 ml (rats)

• Vasodilate the animal with a heating lamp/pad
• Restrain mouse in centrifuge tube
• Can use Isoflurane anesthesia for rat
• Use clippers to shave fur over site on rear leg
• Place small amount petroleum jelly on site
• Use a 20-22 gauge needle to pierce the skin and nick the vessel
• Collect the blood as a droplet wells using a Microtainer or capillary tube
• When finished, hold pressure on the site or cauterize
• Monitor for further bleeding from site

• The animal MUST be anesthetized 
• Use a capillary tube or Pasteur pipette to place pressure on the conjunctiva at the medial canthus (inner comer) of the eye 
• Twist slightly until the tube pops into the venous sinus
• Place a gauze pad over eye, closing eyelids and use gentle pressure to prevent hematomas

• 0.2 mls (mice) 
• 0.5 mls (rats)

• Animal MUST be anesthetized
• After anesthetized place animal on its back 
• Insert the needle (22 gauge, 1 inch) under the xiphoid cartilage at a 30^o angle
• Aspirate slowly as needle is advanced slightly until blood enters syringe 
• Can also approach from behind left foreleg with animal lying on its right side

Recommend that this be used as a terminal procedure only

up to 1.0 ml (mice); 6 mls or more(rats)

• 1. Identify the problem
• 2. Review peer literature, interview experts in field and obtain other information on your subject through literary search.
• 3. Determine the system or model to be used in experimental study.
• 4. Create a clear and concise hypothesis
• 5. Test theory using step by step schedules, baselines, control groups and experimental treatment groups
• 6. Record the findings
• 7. Analyze and document the results
• 8. Report findings

An educated theory on the outcome of the experiment.

• Safety concerns and how to minimize them
• Describe any animal manipulations and methods for minimizing adverse effects on animals
• Make sure all personnel are properly trained on seaftey precautions, handling and accessing the animals welfare (eating, drinking, activity)

• To funding agency
• To safety committee 
• To institutional animal care and use committee 

• Federal government 
• State and local governments 
• Institutional regulations and policies

• Epizootic: Acute outbreak; usually associated with clinical signs. Example - Mouse Pox virus 
• Enzootic: Disease exists within the colony but usually at a subclinical level. Example - Mouse Parvo virus 
• Fomite: an inanimate object that transmits a disease agent. Examples - bedding, gloves, instruments 
• Vector: a living thing that transmits a disease agent. Example - mosquitoes and Heartworm disease 

to stop breeding and introductions of new animals while allowing a colony to be infected by, and recover from, a disease agent. Results in immunity of resident animals and stops transmission to new inhabitants. Example - Mouse Hepatitis Virus 

• Mouse hepatitis virus
• Mouse Parvovirus/Minute virus of mice
• Epizootic diarrhea of infant mice
• Ectromelia virus
• Sendal virus

Mouse Hepatitis Virus (MHV)(Corona Virus)

Fecal-oral, aerosol, direct contact, vertical, fomites, and Biologic products

None. Virus eventually clears itself. May consider burn-out

• Fomites: resistant to disinfection 
• Direct contact with feces or urine
• Biological products

• None. Some strains clear the virus; in others can persist for months
• Once established in a colony, cannot be eliminated (no burn-out)

Epizootic Diarrhea of Infant Mice - EDIM (Rotavirus)

Fecal-oral; fomites

Stunted growth; animal losses 

• Acute, self-limiting;
• older mice resistant and can be carriers.
• Supportive care of affected infants

Sendai Virus

• Respiratory 
• Direct contact/fomites

Effects on immune system; death of susceptible mice

Ectromelia (Pox virus)

• C57BL/6 more resrstant
• C3H and BALB/c susceptible

• Biological products- most common vector today 
• Fecal/oral
• Direct contact, fomites

Microisolator caging prevents mouse-to-mouse transmission.

None. Cull affected mice

• Helicobacter
• Corynebacterium bovis
• Staphylococcal diseases
• Citrobacter rodentium

Helicobacter spp.

Fecal-oral

• Medicated food 
• Metronidazole/amoxicillin

Corynebacterium bovis

Direct contact

• Effects immune system 
• Persistent Infection

Supportive care

Staphylococcus

• Part of normal flora
• Inoculation from direct contact/fomites/grooming/bite wounds

Staphylococcus

Antibiotics (Baytril, sulfa drugs, others)

Citrobacter rodentium

Stunted growth

Self-limiting

• Pinworms
• Fur mites

• Syphacia obvelata
• Aspicularis tetraptera

• Myobia musculi
• Mycoptes musculinus 
• Radfordia affinis

• Fecal-oral, direct contact
• Fomites: eggs resistant to disinfection; lightweight; sticky

• Fenbendazole medicated feed 
• Quarantinel

Fur mites (Myobia musculi, Mycoptes musculinus, Radfordia affinis)

Direct contact

lvermectin, selamectin, moxidectin

• Malocclusion 
• Fight wounds 
• "B6 dermatitis" 
• Barbering

Malocclusion

Clip teeth every 2-4 weeks; initial support with moistened pellets, gel pack

• Mostly males but girls do it too
• Some strains (FVB, Balb/C) worse

Secondary skin infections, chronic stress can invalidate research

• Minor wounds: enrichment. monitor
• More serious: separate aggressor,
• antibiotic treatment of victims

C57BI/6 mice and GEM on B6 backgrounds

"B6 dermatitis"

Alters immune responses; severely affected mice must be euthanized

• No treatment 100 successful 
• Antibiotics 
• Topical steroid ointments 
• Vitamin E

• Vice
• Females
• Try enrichment devices

• Sialodacryoadenitis virus (SDAV)
• Murine respiratory mycoplasmosis
• Pneumocystis carinii
• Pinworms: Syphacia muris
• Furmites: Radfordia ensifera; Ornithonyssus bacoti

Sialodacryoadenitis virus - SDAV (Rat Corona Virus)

Aerosol, direct contact, fomites

• None. Supportive care
• Becomes enzootic if burnout procedures aren't used

Murine respiratory mycoplasmosis (MRM)

• Direct contact, aerosols
• Biological products

• Tetracyclines suppress disease
• Carrier state is common

Pneumocystis carinii

Ornithonyssus bacoti: Tropical rat mite

Ornithonyssus bacoti: Tropical rat mite

• Direct contact
• Environmental- hides in cracks and comes out to feed

Permethrins (apply to nestlets and place in cage)

• Lymphocytic choriomeningitis virus
• Lawsonia intracellularis
• Pinworms: Syphacia spp.
• Mange: Denodex criceti; Demodex aurati

Lymphocytic choriomeningitis virus.

• Horizontal (shed in urine and saliva) and vertical
• Rare in research animals but can be transmitted via biologicals and feral rodents

None. Euthanize due to risk of human transmission.

Lawsonia intracellularis

Pinworms

• Pneumonia - Bordetella pneumonia & Streptococcal pneumonia
• Chlamydial conjuctivitis
• Cervical lymphadenitis
• Mange: Trixacarus caviae

Bordetella bronchiseptica pneumonia

Contact, aerosols, fomites

• Enrofloxacin, chlormaphenicol, sulfa drugs
• Don't house guinea pigs and rabbits together because rabbits are often asymptomatic carriers

Rats and people

Chlamydial conjuctivitis (Chlamydia psittici)

Contact with carrier animals (mom). Enzootic in some colonies.

Maybe but it is questionable that it is passed from Human to Guinea Pig

Cervical lymphadenitis "lumps" (Strep. zooepidemicus)

Orally via wounds from rough feed; bites

Open, drain, ABs 

Acariasis -mange (Trixacarus caviae)

Acariasis -mange (Trixacarus caviae)

Contact

Ivermectin, lime sulfur, pyrethrins 

• Pododermatitis & mastitis 
• Hypovitaminosis C
• Pregnancy toxemia & dystocia 
• Malocclusion 
• Be aware of: 
• Dermatophytosis (ringworm)
• Trichophyton mentagrophytes
• Pediculosis (lice)
• Gliricola procellus & Gyropus ovalis

• bumblefoot
• Overweight, dirty wire floors and Secondary Staph infection
• Good nursing care, soft bedding, soak feet in iodine solution

• Common in: lactating Guinea Pigs 
• Caused by: Mixed bacterial infections 
• Affects: Wean babies at birth; ABs

Hypovitaminosis C: scurvy

• Autoclaving of nonautoclavable diet
• Keeping diet past expiration date (3 mo)
• Feeding standard rodent diet

• Feed Guinea pig diet
• Supplemental Vitamin C (tablets, fresh fruits/veggies; Vit C in water)

Multiparous sows in last two weeks of pregnancy or first week postpartum

Pregnancy toxemia

• Fluids, steroids, calories
• Poor prognosis

• Affects: SOWS > 6 mo, first litter 
• Caused by: Fusion of pelvic symphysis 
• Normal delivery: very fast (1/2 hour)

• slobbers 
• Different in GPs effects: molars or premolars, not incisors, most commonly affected 
• Typical clinical sign: Drooling

• Native to: high altitudes and low temperatures 
• Can develop heat stroke if: temperatures suddenly increase over 80^o F.