Myomorph rodents

Question 1

What rodents are classed as myomorphs?

Answer 1

Hamsters
Gerbils
Rats
Mice

Question 2

Do myomorph teeth grow constantly?

Answer 2

Incisors grow constantly

Cheek teeth do not

Question 3

Why are gastrointestinal diseases relatively rare in rats and mice?

Answer 3

Simple gut physiology

Less prone to problems

Question 4

Why are hamsters more prone to GI diseases than other myomorph species?

Answer 4

More complex GI system

Store food that can become spoiled

Question 5

Stress and overcrowding can contribute to GI disease. What are the symptoms of GI disease in myomorph rodents?

Answer 5

Increased frequency of defaecation
Liquid faeces/diarrhoea
Lethargy 
Wet tail (perineal soiling)
Anorexia/weight loss
Hunched posture

Question 6

Antibiotic associated enteritis is a condition in myomorph rodents due to use of inappropriate antibiotics. What are these inappropriate antibiotics? What bacteria causes this condition?

Answer 6

Clostridium difficile
Due to PLACE antibiotics
Penicillin
Linomycin
Ampicillin
Erythromycin

Question 7

What bacteria is responsible for wet tail in hamsters?

Answer 7

Lawsonia intracellularis

Question 8

What age of hamsters are most prone to wet tail?

Answer 8

Less than 5 weeks

Appear to develop immunity over 12 wks

Question 9

What problems are associated with the cheek pouch in hamsters?

Answer 9

Impaction
Evertion
Trauma
Neoplasia

Question 10

What bacteria is the most common cause of respiratory disease in rats?

Answer 10

Mycoplasma pulmonis

Similar signs to COPD

Question 11

How are chronic respiratory diseases treated in myomorph rodents?

Answer 11

Oxygen therapy
Doxycycline, enrofloxacin, tylosin, azithromycin
Corticosteroid - if chronic inflm
Nebulisation with hypertonic saline/other agents

Question 12

What species of fungi cause ringworm in myomorphs?

Answer 12

Trichophyton spp

Microsporum spp

Question 13

Are neoplasias usually malignant or benign in rats and mice?

Answer 13

Benign in rats

Malignant in mice

Question 14

What causes ring tail in rats, mice and gerbils?

Answer 14

Low humidity

Question 15

What causes tail slip in gerbils/rats?

Answer 15

Improper handling

Question 16

What is barbering?

Answer 16

Plucking hair from self or other animal

removing individual only helps for a while

Question 17

Nasal dermatitis is usually seen in what myormorph rodent species?

Answer 17

Gerbils

Hamsters

Question 18

What diseases are associated with the scent glands in myomorph rodents?

Answer 18

Hyperplasia
Infection
Neoplasia

Question 19

How is hamster polyomavirus transmitted? What does it cause?

Answer 19

Urine
Young animals - mesenteric lymphoma
Older animals - epethlioma

Question 20

What skin changes are seen in myomorph rodents with hyperadrenocorticism?

Answer 20

Thin skin
Hyperpigmentation
Bilateral symmetrical alopecia

Question 21

Pyometra is often seen in which myomorph species?

Answer 21

Hamsters

Question 22

Hydrometra and mucometra is often seen in which myomorph species?

Answer 22

Mice

Question 23

Are c-sections possible in myomorph rodents?

Answer 23

Yes - but interference may lead to cannibalism

Question 24

Cystic ovaries are very common in what age of female myomorphs?

Answer 24

Over 2 years

Question 25

What are the clinical signs of cystic ovaries in myomorphs?

Answer 25

Abdo distension Bilateral symmetrical alopecia Weight loss and anorexia Infertility

Question 26

How are cystic ovaries diagnosed and treated in myomorph rodents?

Answer 26

Dx - palpation (cannot rule out neoplasia) | Tx - ovariohysterectoy or HCG

Question 27

What are the possible causes of haematuria in myomorph rodents?

Answer 27

Cystitis Urolithiasis Uterine varices (varicose veins) Uterine/renal neoplasia

Question 28

What is the most common tumour in rats?

Answer 28

Mammary gland tumour | adenoma or carcinoma

Question 29

How many mammary glands do rats have?

Answer 29

12

Question 30

What rats are most at risk of mammary tumours?

Answer 30

Females over 1 (can occur in males) Rats on high fat diets Rats with pituitary tumours

Question 31

How can the risk of mammary tumours in rats be reduced?

Answer 31

Early neutering

Question 32

All rats with mammary tumours have elevated levels of what hormone in their blood?

Answer 32

Prolactin (Both genders) Prolactin also secreted with pituitary tumours

Question 33

What are the suggested treatments of rat mammary tumours?

Answer 33

Carbeglone, deslorelin, leuprolide | Tamoxifen - if oestrogen receptor adenocarcinom Dx

Question 34

Pituitary tumours cause a hyper secretion of which hormone?

Answer 34

Prolactin | associated with mammary tumours or abnormal lactation

Question 35

What are the clinical signs of pituitary adenomas/tumours in rats?

Answer 35

Abnormal lactation (prolactin - also mammary tumours) Bilateral exophthalmus Neuro signs

Question 36

What hormone induces pituitary disease/adenocarcinoma in rats?

Answer 36

Oestrogen

Question 37

Why is lymphocytic choriomeningitis virus (LCMV) a significant virus of mice and hamsters?

Answer 37

Zoonotic | Exposure to bodily fluids or fomites causes mild febrile illness

Question 38

How is leptospirosis spread?

Answer 38

Urine from infected rats

Question 39

What is chromadocryorrhea?

Answer 39

Porphyrin pigmented tears secreted by Harderian gland Due to stress, overcrowding, poor husbandry or underlying disease (Symptom rather than disease)