Guinea pigs are susceptible to this (also in dogs) 

Bordetella

Chinese hamster is predisposed to this and is used for research

Diabetes

Sebaceous gland in male hamsters that aids in territorial marking and mating

Flank gland

Lawsonia intracellularis or Clostridium dificile

Wet tail

20-40% of gerbils suffer this from 2 months of age

Epilepsy

Three ways to prevent post-partum cannibalism

Provide proper nesting supplies, supply enough food and water before birth, don't disturb mother

Prone to ovarian tumors/cysts

Gerbils

Why Timothy hay is chosen over alfalfa

Alfalfa is high in calcium which can lead to stones

When a guinea pig lacks an enzyme to breakdon glucose to ascorbic acid

Scurvy

Treatment for scurvy (2)

Parenteral administration of ascorbic acid (then orally), provide dark leafy greens and Vitamin C in water

Protein deficiencies in hamsters can cause this

Alopecia

5-7 years

Guinea pigs

3-4 years

Gerbils

1.5-2 years

Hamsters

Coprophagia gives this

Vitamin B and proteins

Guinea pig temp

99-103.1

Guinea pig heart rate

230-300

Guinea pig respiration

70-130

Hamster temperature

100-103

Hamster heart rate

300-500

Hamster respiratory

~100

Gerbil temperature

101-103

Gerbil heart rate

360

Gerbil respiration

90

Transmissible ileal hyperplasia

wet tail

Way to prevent barbering

provide roughage