Myomorph rodents Flashcards
What rodents are classed as myomorphs?
Hamsters
Gerbils
Rats
Mice
Do myomorph teeth grow constantly?
Incisors grow constantly
Cheek teeth do not
Why are gastrointestinal diseases relatively rare in rats and mice?
Simple gut physiology
Less prone to problems
Why are hamsters more prone to GI diseases than other myomorph species?
More complex GI system
Store food that can become spoiled
Stress and overcrowding can contribute to GI disease. What are the symptoms of GI disease in myomorph rodents?
Increased frequency of defaecation Liquid faeces/diarrhoea Lethargy Wet tail (perineal soiling) Anorexia/weight loss Hunched posture
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?
Clostridium difficile Due to PLACE antibiotics Penicillin Linomycin Ampicillin Erythromycin
What bacteria is responsible for wet tail in hamsters?
Lawsonia intracellularis
What age of hamsters are most prone to wet tail?
Less than 5 weeks
Appear to develop immunity over 12 wks
What problems are associated with the cheek pouch in hamsters?
Impaction
Evertion
Trauma
Neoplasia
What bacteria is the most common cause of respiratory disease in rats?
Mycoplasma pulmonis
Similar signs to COPD
How are chronic respiratory diseases treated in myomorph rodents?
Oxygen therapy
Doxycycline, enrofloxacin, tylosin, azithromycin
Corticosteroid - if chronic inflm
Nebulisation with hypertonic saline/other agents
What species of fungi cause ringworm in myomorphs?
Trichophyton spp
Microsporum spp
Are neoplasias usually malignant or benign in rats and mice?
Benign in rats
Malignant in mice
What causes ring tail in rats, mice and gerbils?
Low humidity
What causes tail slip in gerbils/rats?
Improper handling
What is barbering?
Plucking hair from self or other animal
removing individual only helps for a while
Nasal dermatitis is usually seen in what myormorph rodent species?
Gerbils
Hamsters
What diseases are associated with the scent glands in myomorph rodents?
Hyperplasia
Infection
Neoplasia
How is hamster polyomavirus transmitted? What does it cause?
Urine
Young animals - mesenteric lymphoma
Older animals - epethlioma
What skin changes are seen in myomorph rodents with hyperadrenocorticism?
Thin skin
Hyperpigmentation
Bilateral symmetrical alopecia
Pyometra is often seen in which myomorph species?
Hamsters
Hydrometra and mucometra is often seen in which myomorph species?
Mice
Are c-sections possible in myomorph rodents?
Yes - but interference may lead to cannibalism
Cystic ovaries are very common in what age of female myomorphs?
Over 2 years
What are the clinical signs of cystic ovaries in myomorphs?
Abdo distension
Bilateral symmetrical alopecia
Weight loss and anorexia
Infertility
How are cystic ovaries diagnosed and treated in myomorph rodents?
Dx - palpation (cannot rule out neoplasia)
Tx - ovariohysterectoy or HCG
What are the possible causes of haematuria in myomorph rodents?
Cystitis
Urolithiasis
Uterine varices (varicose veins)
Uterine/renal neoplasia
What is the most common tumour in rats?
Mammary gland tumour
adenoma or carcinoma
How many mammary glands do rats have?
12
What rats are most at risk of mammary tumours?
Females over 1 (can occur in males)
Rats on high fat diets
Rats with pituitary tumours
How can the risk of mammary tumours in rats be reduced?
Early neutering
All rats with mammary tumours have elevated levels of what hormone in their blood?
Prolactin
(Both genders)
Prolactin also secreted with pituitary tumours
What are the suggested treatments of rat mammary tumours?
Carbeglone, deslorelin, leuprolide
Tamoxifen - if oestrogen receptor adenocarcinom Dx
Pituitary tumours cause a hyper secretion of which hormone?
Prolactin
associated with mammary tumours or abnormal lactation
What are the clinical signs of pituitary adenomas/tumours in rats?
Abnormal lactation (prolactin - also mammary tumours)
Bilateral exophthalmus
Neuro signs
What hormone induces pituitary disease/adenocarcinoma in rats?
Oestrogen
Why is lymphocytic choriomeningitis virus (LCMV) a significant virus of mice and hamsters?
Zoonotic
Exposure to bodily fluids or fomites causes mild febrile illness
How is leptospirosis spread?
Urine from infected rats
What is chromadocryorrhea?
Porphyrin pigmented tears secreted by Harderian gland
Due to stress, overcrowding, poor husbandry or underlying disease
(Symptom rather than disease)