Yarmouth Veterinary Center

75 Willow Street
Yarmouth , ME 04096

(207)846-6515

www.yarmouthvetcenter.com

GUINEA PIG BIOLOGY

  • Scientific name: Cavia porcellus
  • Origin: South America
  • Related to chinchilla and porcupine
  • Naturally grazing animals; hay should always be available
  • Most active in the morning and early evening; prefer to sleep during the day
  • Three main breeds: English/common (short straight hair); Abyssinian (rough wiry hair in whorls; Peruvian (long straight silky hair)
  • Crosses of all breeds sold as pets; purebreds of 11 different breeds used for shows
  • Average weight (grams): male 900-1200, female 700-900
  • Age at puberty (days): male 90-120, female 60-90
  • Lifespan (years): 4-8, average 5
  • Body Temperature: 99.0-103.1
  • Heart rate: 230-380
  • Respiratory rate (breaths per minute): 40-100
  • Dental formula: I 1/1 C 0/0 P 1/1 M 3/3, all teeth open-rooted
  • Sex determination: males have large scrotums and their penises can be easily extruded; females are usually smaller than males
  • Sexually mature by 1 to 2 months old
  • Estrus (heat) cycle length (days): 15-17; estrus phase of estrus cycle 6 to 11 hours long; ovulation is spontaneous; non-seasonally polyestrus
  • Gestation (days): 59-72
  • Litter size: usually 2 to 5, ranges from 1 to 13 pups
  • Birth weight (g): 60-100
  • Age eyes open (days): birth
  • Weaning age (days): 14-28
  • Breeding life: 3-4 years
  • Separate adults before birth: no
  • Food consumption per 100g body weight per day (g): 6
  • Water consumption per 100g body weight per day (ml): 10
  • Zoonotic diseases (diseases transmittable to people): allergies to dander and urine; bacterial infections (rare), including Bordatella, Salmonella, Yersinia, and Streptococcus; dermatophytes (ringworm); sarcoptic mites (mange)

SPECIAL  CONSIDERATIONS

  • Any painful condition can cause decreased appetite, and serious secondary illness can occur as quickly as 24 to 48 hours after the GP stops eating.
  • Typically do not eat for 12 to 24 hours after giving birth.
  • Lack the digestive enzyme l-gluconolactone and thus cannot synthesize vitamin C like other animals can, so they require a dietary source.
  • Hindgut fermenters and coprophagic (eat their own feces); the droppings they eat are called cecotrophs and they are taken directly from the anus; this occurs several times a day
  • Digestion of fiber occurs in the cecum and ascending colon; these portions make up ~65% of the gut
  • Normal digestive tract bacteria are gram positive cocci, anaerobes and lactobacilli
  • The menace reflex is a useful test in most animals for determining the ability to blink and see, but it cannot be used in GPs because they will not blink
  • GP eyes have a limited tear film, small third eyelid, and few blood vessels in the retina
  • Female GPS older than 1 year normally have multiple cysts on their ovaries; the cysts get larger and more numerous as the GP gets older
  • Two glandular areas produce marking scents: the special skin along the midline of the lower back, and the fold around the anus (circumanal fold); both areas are more developed in males; GPs deposit scent from the circumanal fold by dragging their bottoms over a surface; males scent mark when their environment changes, when they conflict with another male, and during courtship; in addition to glandular secretions, urine and bacteria are responsible for components of the scents used in marking
  • Obligate nasal breathers, so upper respiratory disease (nasal congestion without pneumonia) can cause severe difficulty breathing
  • Urinary stones in GPS are usually made up of calcium carbonate or calcium phosphate, and thus show up on an x-ray
  • In female GPs the opening to the urethra is not located in the vagina, but in a small bump in front of the vagina called the urethral papilla
  • Male GPs have a tiny pouch, the intromittent sac, located next to the urethral opening within the glans penis