Small Mammals — Rodents

Question 1

What is a rodent?

Answer 1

Mammal with a single pair of continuously growing incisors in each of the upper and lower jaws.

Question 2

2 divisions of rodents seen in practice and animals that fall under each division

Answer 2

Small rodents = hamsters, rats, mice, gerbils.
Herbivorous rodents = Guinea pigs and chinchillas.

Question 3

What are myomorphs?

Answer 3

Mouse-like rodents

Question 4

Define elodont.

Answer 4

Having open-rooted incisors.

Question 5

Define anelodont.

Answer 5

Closed-rooted cheek teeth.

Question 6

What are hystricomorphs?

Answer 6

Porcupine-like rodents.

Question 7

What type of incisors and cheek teeth do herbivorous rodents have?

Answer 7

Elodont (open-rooted)

Question 8

Where in the GI tract does fermentation take place in the herbivorous rodents?

Answer 8

Hindgut

Question 9

Guinea pig important features. Consider legs, bodies, digestive tract, body cavities.

Answer 9

Short legs, round bodies, hindgut fermentation, gut takes up large proportion of internal body space, coprophagic (eat own faeces) , relatively small chest cavity.

Question 10

Why is it beneficial for Guinea pigs to be coprophagic?

Answer 10

So they can obtain nutrients that may have been missed the first time round and prevent illnesses.

Question 11

How is sex determined in Guinea pigs?
What is the name for a female?
What is the name for a male?

Answer 11

Anogenital distance, shape, presence of testicles.
Female shorter and y shaped, male longer, presence of scrotum and testicles.
Female = sow
Male = boar

Question 12

Considerations with breeding Guinea pigs.

Answer 12

Females should be bred from less than 6-8 months old if at all.
Ideal is 12 weeks.
Pubic symphysis fuses after around 8 months so dystocia can occur if bred after this.
Dystocia can also be a result of foetal oversize and obesity.

Question 13

Ideal daily Guinea pig diet
Care with what food type?
Avoid?

Answer 13

Ad lib hay and grass.
Small amount of good quality Guinea pig specific pellet (stored correctly)
Handful of leafy greens.
Care with fruit as high in sugar.
Avoid commercial “treats”.
Avoid mixes contained nuts and dried fruits.

Question 14

Fibre content of diet.
Crude protein content of diet.

Answer 14

12-16%
18-20%

Question 15

Point about vitamin c and Guinea pigs.
Requirements for vitamin C.

Answer 15

Not able to synthesise it themselves so must be provided in diet.
Non-breeding adults require ~10mg/kg/day.
Breeding/lactating and stressed/ill Guinea pigs require 30-50mg/kg/day.

Question 16

How to ensure adequate vitamin c provided.

Answer 16

Feed complete pelleted diet.
Ensure in date and stored correctly.
Provide leafy greens.
Add additional supplements.

Question 17

Average daily water intake of Guinea pigs.
Recommended way of water provision?
Disadvantage of this?

Answer 17

100-200ml/kg/day

Bowls rather than bottles.
Guinea pigs are messy and can kick water bowls over or soil them.

Question 18

Housing considerations? Companionship, prey species, temperature, flooring, security, substrate, bedding.

Answer 18

House in pairs or groups.
Provision of hiding places.
Ideal temperature = 20-22 degrees c.
Well insulated, draught free, out of direct sunlight.
Solid flirting, smooth, easy to clean.
Raised off ground if outside.
Cage sides at least 40cm high.
Wood shavings dust extracted, shredded paper.
Bedding dust free and absorbent, shredded paper, hay/straw.

Question 19

Common problem with bay and straw.

Answer 19

Corneal lacerations.

Question 20

Access to what gives good enrichment to Guinea pigs?

Answer 20

Grass

Question 21

External features of chinchillas?
Consider bodies, ears, legs, tails, coat, digestive tract, body cavities, original environment (+ consideration)

Answer 21

Round bodies, large ears, short legs, long tails.
Dense and soft coats,
Hindgut fermenters, but takes up large proportion of internal body space.
Relatively small chest cavities.
Originally from arid mountain environment — avoid high humidity.

Question 22

Sexing of chinchillas?

Answer 22

Anogenital distance.
Longer in males, shorter in females.
Testes not always reliable way of sexing as can retract into abdomen.
More of a slit rather than rounded hole opening to genitalia.
Urinary papilla in females can look like a penis.

Question 23

Ideal chinchilla diet

Answer 23

Grass-based pellets (25-50g)
Ad lib hay and dried grasses (in rack)
Fresh wild plants, herbs, flowers, berries, roots, shoots, veg
Intro changes gradually

Question 24

Chinchilla housing
Consider space, mesh size, prey species. Material to avoid?
Substrate, bedding, enrichment, coat maintenance and requirements, companionship, temperature, humidity.

Answer 24

Large and secure, at least 2mx2mx1m
Wire mesh maximum 15mmx15mm
Hides and nest boxes
Avoid plastic — will destroy! And risk of ingestion.
Wood shavings as substrate
Shredded paper for bedding to absorb and avoid humidity. Change regularly.
Enrichment with toys, branches, platforms.
Dust bath to maintain coat. Chinchilla specific dust, 4-6cm deep, change regularly, not for neonates.
Keep in pairs or groups.
Keep indoors at 10-15 degrees c.
Get agitated at 21 degrees c, may die at over 30 degrees c.
Keep draught free and dry.

Question 25

Give 4 hamster breeds.

Answer 25

Russian, Chinese, golden/Syrian, Roborovski

Question 26

Hamster important features. Sleep/wake, cheeks, digestion

Answer 26

Generally nocturnal Large paired cheek pouches for food storage. Well-developed hindgut but not exclusively hindgut fermenters.

Question 27

What is a particularly important feature in Syrian hamsters?

Answer 27

Bilateral pigmented sebaceous glands on flanks.

Question 28

Important feature in Russian dwarf hamsters

Answer 28

Ventral scent gland

Question 29

Sex differentiation in hamsters

Answer 29

Anogenital distance Males longer, females shorter, males have notable testicles.

Question 30

Ideal hamster diet.

Answer 30

Commercial hamster pelleted mix. Small amounts of fresh fruit and veg. Some animal protein once or twice a week — hard boiled egg, mealworms/crickets. Small amount of timothy hay.

Question 31

Housing for hamsters. Security, enrichment. Be vigilant with what?

Answer 31

Escape-proof, safe Enriched with burrows, hides, and various environments, gnawing items Food hoards with fresh food. Needs to be found so does not grow mould.

Question 32

Specific housing for Syrian hamsters Sociable? Temperatures? Sleep/wake? Russian dwarf hamsters sociable? Roborovski and Chinese hamsters sociable? (Risk?)

Answer 32

Solitary. Hibernate at <5 degrees c. Nocturnal. Russian dwarf = sociable so house in pairs or groups. Roborovski and Chinese hamsters can be house on own or in pairs/groups. Risk of fighting in mature adult Chinese hamsters.

Question 33

Rat important features? Bodies, tails, ears. Herbivores, omnivores or carnivores? Environments? Requirement?

Answer 33

Elongated body, long and hairless tails, large and rounded ears. Omnivores Adapted to various environments. Require good ventilation for respiratory health.

Question 34

What varieties of rats seen in practice?

Answer 34

Hooded, dumbo, Rex

Question 35

Rat sex differentiation

Answer 35

Females have nipples. Anogenital distance . Males longer than females. Prominent testicles in males.

Question 36

Rat diets and enrichment

Answer 36

Commercial balance pelleted diet. Supplement with small amounts of fruit and veg Avoid sugary treats and chocolate — dental issues and dental issues. Scatter feed and hide food/treats. Change out enrichment to keep minds busy.

Question 37

Mouse important features. Bodies, tails, ears. Herbivores, omnivores, carnivores? Requirements?

Answer 37

Slender body. Blunt/tapered tail. Prominent ears. Omnivores. Require good ventilation to maintain respiratory health.

Question 38

Sexing of mice Name for male mouse. Name for female mouse.

Answer 38

Anogenital distance. Male longer than female. Testicles prominent in mature male mouse. Male = buck Female = doe

Question 39

Mouse housing

Answer 39

Hiding places. Highly social so house in pairs or groups. Inquisitive so have enrichment. Have a distinctive smell.

Question 40

Important features of gerbils Body, tail, ears, face shape, sleep/wake, natural habitat, requirement.

Answer 40

Slender bodies Blunt furred tails Small ears Face more blunt than mice Nocturnal Arid, rocky, scrubland Good ventilation, low humidity

Question 41

Sexing gerbils

Answer 41

Anogenital distance Males longer than females. Testes relatively obvious.

Question 42

Notable gland? Common disease?

Answer 42

Ventral scent gland Infection and tumours

Question 43

Common condition in gerbils? Gland associated with condition? Causes? What is the gland’s normal function?

Answer 43

Nasal dermatitis. Harderian gland Caused by hyper secretion of porphyrin pigment due to stress caused by overcrowding or high humidity. Gland normally secretes normal amounts which mix with saliva and are groomed onto the coat. Also helps with thermoregulation.

Question 44

Gerbil diet and enrichment Daily water consumption.

Answer 44

Commercial gerbil specific pelleted food. Must be supplemented with small amounts of fresh fruit and veg such as carrots and apples. Can have occasional treat e.g. dried pumpkins food. Scatter feed for foraging. 2-4ml/100g/day

Question 45

Gerbil housing Enclosure type and lid, substrate, bedding, enrichment, temperature, bathing, humidity, sociability

Answer 45

Glass/plastic tank with close-fitting wire mesh lid, deep substrate to burrow — sawdust/paper, paper-based bedding, enrichment toys etc, out of direct sunlight and away from radiators to keep temp 20-22 degrees c, sand bath for coat maintenance and thermoregulation, humidity less than 50%. Sociable but highly territorial. House in same sex pairs. Introduce before puberty or before 10 weeks old.