Rats and mice: Exotics

Rat basic traits

• Lifespan 4-6y

• Social

• Larger

• Litter trainable

• Neoplasia: more benign

Mice Basic Traits

• Lifespan 1-2y

• Solitary

• Smaller

• Neoplasia: More malignant

Rat behaviour

• female-female or male - female pairs only

  • male - male pairs = aggression

• “boggle” eyes when chewing

  • happy

Preventive medicine

• NO vax

• Proteinuria normal in males

• Venipuncture: Subgingival vein, Lateral saphenous veins, Tail, jugular, mandibular, retro-orbital, cardiac

• Supplemental fluids: give SC in dorsal neck and upper back

  • 10 ml/100 g body weight daily, 2-3x daily

• Female rats are healthier if spayed

  • Pyometra, Ovarian tumors, Prolactinoma, Mammary tumors

  • Paralumbar ovariectomy technique

Dentition

• Only incisors hypsodont

  • Long incisors roots

• I 1/1 C 0/0 PM 0/0 M 3/3

• Mandibular symphysis not fused

  • fibrous

Anatomy

• 3 pr thoracic, 2 pr inguinal mammary glands

  • Open inguinal canals.

  • Males have no nipples

• No tonsils

• Stomach is partly glandular/non-glandular

• Obligate nasal breathers

• Cant vomit

• Harderian lacrimal gland

  • red tears

• Rats have no gallbladders

Chromodacryorrhea

• Porphyrin, red-stained tears

• Normal, stress, or pain

Sexing

• Females have teats, males dont

• Larger urogenital distance M>F

Neoplasia

• often benign in rats, malignant in mice

• mammary, lung, zymbal’s gland, lymphosarcoma

• Pituitary Adenoma

  • Walk abnormally and Head tilt

  • Females> Males

  • TX: Carbergoline, Bromocriptine, Steroids, Antiseizure meds, Prophylactic antibiotics

Diseases

• Rat Respiratory Dx

  • Mycoplasmosis or Sendai virus (paramyxovirus)

    • direct contact, aerosol, intrauterine transmission

  • CS: porphyrin staining, sneezing, labored breathing, anorexia, death

• Tyzzer’s Dx

  • Clostridium piliforme

    • fecal-oral transmission

  • CS: Unthriftiness, Death

  • TX: none, sanitation

• Rat Bite Fever

  • Streptobacillus moniliformis

  • CS: fever, vomiting, joint pain, rash