Rabbits, Rodents, and Ferrets Flashcards
Rabbits vs Hares
- Rabbits: altricial: young (kit) are born hairless and with poor sight (blind)
- Hair: precocial: young (leveret) are born with hair and good eyesight
- Except for cottontails, all rabbits like to live underground (warrens or burrow) and deliver kits underground
- Hares: live above ground and deliver leveret in flattened nests called form
- Hares: usually larger and have longer ears
Rabbits
Uses
- Companionship: use as companion animals (house rabbits)
- Food (meat): rabbits and hares are used for food in Europe, NA, SA, China and Middle East: ranked 5th in the world’s livestock meat production
- Clothing: Fur (pelts) used as accessory (i.e. scarves). Angora rabbits have long fine hair and is sheared like sheep
- Research
Rabbits
- Domestic (European rabbit): Oryctolagus cuniculus was a domesticated from wild rabbit (~600 AD)
- 3rd most popular pet
- Female: Doe
- Male: Buck
- Various sizes (breeds)
- Small: 2-4 lb.
- Medium: 4-14 lb.
- Giant: greater than 14 lbs
Rabbit Meat
Considered leaner than pork, chicken, beef
- Fryers: 4-5lbs (9 weeks of age).
- Roaster: > 5lb (8+ months of age)
- Giblets: heart and liver
What is the largest breed of rabbit?
Continental Giant
Rabbit: Anatomy and Physiology
- Low density/lightweight bones: ~50% the density of cat bones
- Wide set eyes (prey species): no binocular vision as predators.
- Farsighted and low numbers of cones (reduced color and visual acuity)
- Teeth: open rooted and grow continuously. These are worn down by contact with opposite teeth and masticating rough, abrasive hard food.
Common teeth problems in rabbits
Teeth grow constantly
- If overgrown, teeth will cut right through the gums
Rabbit Behaviour
Defensive: use back legs to cause deep scratches
- Will bite if provoked and Bucks will try castrate each other
- Pet rabbits can be house trained
- Rabbits can acclimatize to surroundings and are comfortable at moderate temps (15-29C). Rabbits do not tolerate excessive heat
Rabbit: Nutrition
- Obligate herbivores: will chew food to powder: except cecotropes
- (note ceoptropes = cecotrophs)
- Fiber is very important in a rabbit’s diet (15-17%).If reduced fiber: gastric atony (stomach does not contract; get hairball can lead to fatal impaction), and diarrhea. Rabbits are prone to intestinal dysregulation and severe intestinal infections (dysbiosis)
- Diets with high calcium: urolithiasis (bladder stones)
Urinary sediment/Urolith
Order of severity
- Normal sediment
- Sludge
- urolith (big stine looking thing that you need to cut into with a saw)
Avoid this condition by feeding rabbits good diets
Rabbits and poop
- Rabbits practice coprophagia: eating their own fecal material
- Rabbits pass two forms of stool; soft and hard. The soft stool –cecotrophs (night feces), appears as soft dark mucous covered pellets are relatively poorly digested.
- Nutrients are still present in cecotrophs, and rabbits will consume the material to improve nutrient uptake (amino acids and microbial protein)
- Other fecal material is hard and normal excrement. Rabbits don’t eat these
Rabbit Reproduction
- Induced ovulators: 9-13 hours post copulation.
- Photoperiod sensitive: autumn are less fertile and respective.
- Light cycles: 14 hours light :10 hours dark thefemales are receptive to males
- Bucks: mature 4-5 month
- Does: mature 4-9 month
- Gestation: 29-34 days
- Litter: 4-10 kits
- Wean: 4-6 weeks
Pododermatitis
Rabbits
Pododermatitis (Sore hocks): Usually affects back feet.
- Excessive pressure on feet: hair loss and callus. Can progress to skin wounds and ascending infections into tendon, muscle and joints
Causes: hair loss (hereditary; Rex rabbits), obese, small confinement, wired flooring, poor sanitation (wet) and individual rabbits that ‘thump’ feet
Mild cases treatable. More severe cases, prognosis is guarded
Pasteurellosis
Rabits
Rabbit snuffles (pneumonia): is a disease caused by Pasteurella multocida (Gram (–) rod bacteria) that causes significant morbidity and mortality in rabbits
- Its endemic (always present) in rabbit colonies and the young rabbits usually acquired it usually from adults by direct nasal contact or aerosolized (sneezing).
- It can also be contracted by venereal and blood contact
Clinical Signs of Pasteurellosis
Sudden death, sneezing, difficulty breathing (dyspnea) , watery eyes (conjunctivitis), runny nose (rhinitis), inner ear infection (otitis media or otitis interna) wry neck (torticollis), uterine & testicular infection (infertility, pyometra, orchitis), lung infection (pneumonia)0
Viral Hemorrhagic Disease of Rabbits (RHD)
RHD: is a highly contagious and fatal (~90%) disease of rabbits caused by a Calicivirus
- Its present in Asia, Australia, Europe
- It’s transmitted by direct contact, (mouth, eyes, nose).
Clinical signs (usually in animals over 40 days of age):
- dullness
- difficulty breathing
- sudden death
Reportable disease in USA
Treatment: none; depopulate the rabbits
Australia rabbit control program (RHD
The virus was introduced in Australia (1991) under highly controlled quarantine system.
- The agent was to be used as a biological control agent to rid Australia and New Zealand of the rabbits (feral rabbits that became pests).
- 1995 lab accident: released the Calicivirus that terminated 10 million rabbits in 8 weeks.
- It killed the adult but not young and eventually the rabbits became immune and effectively mitigated any successful control program
What does RHD do to rabbits
Systemic hemorrhages: epistaxis (nose), lungs, heart
Kidney, spleen etc.
Liver necrosis and failure
Acute, fast death
New RHD
- 2017- spring the Australian Govt. will release new strain of virus
- Korean stain- RHD virus K5 - carrots
- Its overcome previous immunity of first RHD virus present in rabbit population – overcome pervious immunity- little cross protection
- 0-50% expected death
History and transmission
Rabbit: Tularemia (Rabbit Fever)
Zoonoses
Names: Rabbit fever, Deerfly fever, O’Hara’s disease, Francis disease
- Usually, a disease in rural communities and acquired by different mechanism:
- direct contact from contaminated water, food, soil, animal tissues
- rabbit skinners/trappers of old, hikers (ticks), laboratory technicians
- Natural and weaponized (bioweapon form of the organism
- Considered: one of the most infectious pathogenic bacteria known
The causitive agent
Rabbit: Tularemia (Rabbit Fever)
- Tularemia (Francisella tularensis)
- Very small pathogens
- Gram negative Intracellular pathogen
- Lives in macrophages and escapes immune protection
- Target organs: liver spleen lungs kidneys, lymph nodes
- Survives 3-4 months in environment and dead animals
- 3-4 months in mud, water dead animals
- Lives years in frozen meat
- Easily killed by heat and disinfectant
Types of Tularemia (Rabbit Fever)
F. tularensis biovar tularensis (Type A):
- most virulent
- found in hares, rabbits, ticks
- present in North America
F. tularensis biovar palaearctica (Type B):
- found in North America, Europe and Asia
- Less virulent
-Present in rodents (muskrats, rats, mice voles)
incidence of infection in livestock (sheep) and companion animals
Infective dose for tularemia (Rabbit Fever)
Dose for exposure:
- inhalation or injection (10-50 bacteria)
- Oral ingestion (10 million bacteria)
Transmission: rabbit and ticks main cause
Clinical Signs
Tularemia (Rabbit Fever)
Animals: 1-10 days incubation
Clinical signs: may be non-existent,
generalized to sudden death
- Rabbits are depressed, anorectic and lethargic
- Cats/dogs weight loss and vomiting
What are the 6 forms of tularemia (Rabbit Fever)
- Ulceroglandular (Skin, mucous membrane)
- Glandular
- Oculoglandular (eye, skin, mucous membrane)
- Oropharyngeal (throat)
- Typhoid (Systemic, septicemia)
- Pneumonic
Rodents
- Kingdom: Animalia
- Phylum: Chordata
- Subphylum: Vertebrata
- Class: Mammalia
- Order: Rodentia
~2277 species of rodents, comprising 40% of mammalian species
- Important in ecosystem: reproduce rapidly and are food source for predators, seed disposal and for disease dissemination (population control
Uses of rodents
food, pelts, and research
chinchillas are commonly used for pelts and research
- Good model for barrel trauma
- Measuring blast effects on soldiers
Rodent teeth
Characterized by continually growing upper and lower incisors
- Need continually gnaw on food to wear down teeth
- No canine teeth and few molars
Why are deer mice a health concern?
They carry hantavirus
- High infection rate in farmers
Size and lifespan
Mice
- Omnivore
- Height surface area: body weight ratio. Very high metabolic activity and can be prone to hypothermia (wet cages)
- Primarily nocturnal animals
- Life span: 1.5-3.0+ years
- Breeding age: 50-60days
- Estrous cycle: 4-5 days
- Litter size: 4-12 pups
- Gestation 20-30 days (average 21 days)
- Weaning: 21-28 day
Rats
- Omnivore
- Primarily nocturnal animals
- Life span: 2.5-3.5+ years
- Breeding age: 65-110 days
- Estrous cycle: 4-5 days
- Litter size: 6-12 pups
- Gestation 20-23 days
- Weaning: 21-25 days
Rat and Mice eyes
- Pups fully haired 7-10 days
- Open eyes 14-17 days
- Nictitating membrane (3rd eyelid)
- Harderian gland: secrete fluid to lubricate 3rd eye lid. Accessory lacrimal duct
- Stressed Rats: porphyrin staining.’blood tears’
- This is not blood (ie blood
from ‘eye’ blood vessels)
- This is not blood (ie blood
Rat and Mice Husbandry
Husbandry: high metabolism: water must be present at all times
- Usually housed same sex: stops fighting and unwanted mating
- Note: in many breeds of mice males will fight
- Temp: 18-30 C
- Humidity: 40-70%:
- Low humidly: Ringtail and respiratory problem in young rats
- Ringtail: skin becomes dry and get contraction: decreased blood flow
Causitive agent of bubonic plague
Yersinia pestis: a non–motile, facultative intracellular, Gram-negative rod bacteria
Transmission of the plague
Flea bite (78%)
Direct animal contact (20%)
- Tissues, body fluids, scratches, bites
- Enters through break in skin
Aerosol (2%):
- Person to person, animal to person
Persitance of Plague
Survive for long periods of time in organic material.
- Blood 100 days
- Human bodies: 9 months
- Water, moist soil; several weeks
- Can be destroyed by heat: 55 C for 15 minutes, sunlight (several hours)
Virulence factors of Plague
- F1 exotoxin [protects against phagocytosis],
- Endotoxin (LPS),
- phospholipase D [needed to transport to fleas]
- coagulase, pesticin, plasminogen activator [important in pneumonic forms].
What are the 2 epidemiologic forms of Plague
Sylvatic (wild)
Urban (domestic)
Resivoirs of plague
- Rock squirrels
- Ground squirrels
- Prairie dogs
- Mice, rats
Enzootic vs Epizootic Plague
Enzootic: fleas stay in same host: not much affect on rodents
Epizootic: fleas change to new host. Massive ‘die-offs’ of rodent (carrier).
New host can amplify the flea population. If these animals move to urban settings, these can become a significant public health threat
What are the 3 presentations of plague in humans
Clinical signs: 1-6 days post exposure: depends on form
- Bubonic
- Septicemic
- Pneumonic
Bubonic Plague
Bubo: painful swollen lymph nodes.
- Vomiting, painful liver and spleen, headaches
- General malaise
- Can develop into septicemic plague
Septicemic plague
Septicemia: bacteria dividing in the blood
- Can cause systemic organ failure.
- Thrombosis (blood vessels with clots)
- Disseminated intravascular coagulation (DIC): severe blood clotting followed (thrombosis), by failure to clot blood (hemorrhage)
Pneumonic plague
- Occurs following inhalation of bacteria
- Cough productive cough with blood tinged and foamy sputum
- Quick onset of dyspnea (difficulty breathing), cyanotic and death follows rapidly
Its in the lungs and hard to treat
Ferrets
Ferret is the domestic mammal of the Mustela (family) and is a dimorphic predator
- Highly adaptable strict carnivores
- Domesticated 2400 BC form wild Eurasian or America black-foot species
- Ferrets are clean, easily house trained, (can be gentle)
- For 50+ years: Popular pets and used in Research (infectious disease, physiology, endocrinology, embryology)
Concerns about ferrets as pets?
Concerns that ferrets will become feral: kill wildlife, bite people, associated with major out-breaks of disease (never has happened)
- Prohibited as pets: Hawaii, California
Average litter size of ferrets
8-10 kits
This is pretty big
Special glands
Ferrets
- Paired anal glands: secrete material when threatened
- Sebaceous glands (skin): causes ‘musky odor’. Under androgen control. So neutering will reduce smell.
-
Few sweat glands: Don’t
tolerate high temps (> 26.7 C)
Humidity: 40-65%
True or False
Ferrets have small lung capacities
False
How often do ferrets molt?
Each spring and fall
True or false
Ferrets do not have a cecum
True
Ferret Reproduction
- Male receptivity: photoperiod dependent. In North America (March-August) breeding period
- If photoperiod extends (increase hours of daylight), receptivity will extend as well.
- Polyesters
- Gestation: 41-42 days, litter size 8 10 kits
- Wean: 6-8 weeks
- Eyes and ears open: 30-35 days
Pseudopregnancy
Ferret
Prolonged periods with elevated estrogen levels (i.e. during pseudopregnancy, prolonged heat). Common worldwide
- Adrenal disease: major cause of increased estrogen levels (USA)
All animals are sensitive to chronic exposure to estrogen
Ferrets (similar to dog and cat) are quite sensitive to prolonged estrogen levels and is toxic to bone marrow
Aplastic anemia (pancytopenia): complete failure of bone marrow to produce blood cells. (WBC, RBC, platelets)
Bleeding disorder also caused by estrogen induced liver injury
50% of Jills remain in estrus – can develop Aplastic anemi
When do you usually see pseudopregnancy in ferrets?
Usually seen in ferret in estrus (heat): greater than 3 weeks
How do you treat pseudopregnancies in ferrets?
Spay ferret immediately
Condition can be fatal. Treatment can be unrewarding if not initiated early
- PVC < 25%: blood transfusion prior to surgery
- PVC < 15%: prognosis is grave
May take several weeks following the spay for the ferret to return to normal.
- Supportive care is needed
Ferret: Adrenal gland tumor
Pseudopregnancies
Note: NOT the same as Cushing’s Disease in a dog (Cushing disease = increased cortisol- zona fasciculata)
Estrogen toxicity due to increased sex steroid (estrogen) produced from zona reticularis
Canine Distemper
But in ferrets
Canine distemper is caused by a paramyxovirus that will cause multisystemic disease
Effects:
- Gastrointestinal
- respiratory (pneumonia)
- central nervous system
- integument (thick skin)
- immune system (immunosuppression)
Canine distemper is a very contagious and almost always fatal (~100%) in ferret.
Cause: naïve ferrets being exposed to dogs or other ferrets carrying the virus
PureVax treatment schedual for canine distemper
Ferrets
Vaxination is the best way to prevent your animal from catching it
Give at 8 weeks
Boost at 11 and 14 weeks
What’s the fancy name for the hard nose and hard pad that are symptoms of Canine distemper
Both Dogs and Ferrets
hyperkeratotic (thick skin) dermatitis
