Guinea Pig Nutrition and Health Quiz

Rodent Suborders

• Guinea pigs, chinchillas, porcupines, and capybaras belong to the Hystricomorpha suborder (porcupine-like)
• Squirrels, chipmunks, and beavers belong to the Sciuromorpha suborder (squirrel-like)
• Rats, mice, hamsters, and gerbils belong to the Myomorpha suborder (rat & mouse-like)

Guinea Pig Biology

• Scientific name: Cavia porcellus
• Common names: Guinea pig, cavy
• Stocky build, large head, short legs, unfurred short ears
• Head and body length: 200-400 mm
• Weight: 500-1,500 g
• Live in groups of up to 10
• Inhabit burrows
• Most active at night, feeding on plant materials
• Full elodont and hypsodont dentition (i.e., continuously growing and erupting teeth with a long anatomic crown)

Guinea Pig Breeds

• Multiple breeds, including: American or shorthair, Abyssinian, Peruvian/Silkie, Nude, Crested, Sheba, Teddy, Texel, Himalayan, Merino, Rex, Dutch, Coronet, Roan, Agouti, Dalmatian, Alpaca, Lunkarya, and Tricolour

Guinea Pig Dentition

• I 1/1, C 0/0, P 1/1, M 3/3
• All teeth grow continuously
• Malocclusion of molars and premolars is common

Guinea Pig GI Tract

• Fully glandular stomach
• Large cecum
• Produce two types of fecal pellets: nitrogen-rich (intended for cecotrophy), and nitrogen-poor
• When food is continually available, ~40% of the feces are reingested, 90% of which occurs at night
• When food is limited, guinea pigs ingest feces during parts of the day when food is unavailable

Guinea Pig Feet

• Description of feet (images provided)

Guinea Pig External Genitalia

• Single pair of inguinal nipples
• External genitalia (images provided)

Guinea Pig Normal Parameters

• Adult body weight: male (900-1200g), female (700-900g)
• Life span: 3-7 years
• Rectal temperature: 100.2-103.1°F
• First estrus: 68 days
• Estrus cycle: 15-17 days
• Gestation: 63 days average
• Fertile: 4-5 years

Guinea Pig White Blood Cells

• Lymphocytes are the predominant WBC in guinea pigs.
• These range from 45%-80% of the WBC count.

Guinea Pig Kurloff Cells

• Specialized natural killer cells
• Contain large mucopolysaccharide intracytoplasmic inclusions
• Population shifts during pregnancy (from lungs/spleen to thymus/placenta)

Guinea Pig Nutrition

• Requires vitamin C in the diet
• Use commercial diets, cabbage, or kale, within 90 days of milling
• Vitamin C in water must be changed daily
• Do not feed antibiotic-containing diets
• Picky eaters, reluctant to eat new feeds
• Begin to discriminate between food and nonfood within a few days of birth
• Introduce experimental feeds early and gradually

Guinea Pig Vitamin C Deficiency

• Deficient in L-gluonolactone oxidase
• Necessary for conversion of glucose to ascorbic acid, which interferes with collagen, osteoid, and dentin formation.
• Clinical signs: swollen, painful joints, reluctance to move, delayed wound healing, hemorrhages, impaired bone/teeth formation, and death
• Histology: disruption of epiphyseal cartilage and new bone spicules, bone marrow fibrosis

Guinea Pig Vitamin C Deficiency Prevention & Treatment

• Daily vitamin C source (10mg/kg, 30mg/kg - pregnant sows)
• Treatment: >50 mg/kg daily, injection vs. oral, continue until improvement is seen

Guinea Pig Metastatic Calcification

• Common in pigs over one year
• Usually incidental necropsy finding
• Typically no clinical signs (but +/- muscle stiffness)
• +- renal malfunction
• Widespread tissue mineralization (kidney, stomach, heart, liver, uterus, colon, etc.)
• Can induce by feeding excessive phosphorus or calcium

Guinea Pig Foods to Avoid

• Avocado (all parts), Allium vegetables (onions, garlic, leeks, chives), animal protein (meat, poultry, fish, eggs, dairy), processed foods (bread, pasta, chips, crackers), butter, raw potatoes, hot peppers, and certain parts of tomatoes (unripe tomatoes, leaves, and stems as they contain tomatine)

Guinea Pig Husbandry

• Nervous animals, may refuse to drink or eat after change in location, feed, or husbandry
• Minimal or nonexistent effect of environmental change when two animals are kept together
• Live in family units centered on an alpha male
• Males, especially strangers will fight
• Non-breeding females do not develop dominance problems

Guinea Pig Behaviors

• Freeze reaction (tonic immobility) following noise, shock, or environmental change (may last 20 minutes)
• Scatter reaction (scatter in all directions, stampeding, running in circles, trampling young) in response to sudden movement or noise. The prey or pinna reflex can be observed
• Neophobic (afraid of new things, especially food and water). Changes in appearance, taste, or texture of food or water may deter consumption. Early exposure to a variety of foods, especially vegetables, is beneficial.

Guinea Pig Research Uses

• Immunology
• Complement and red blood cell donors for diagnostic testing
• Respiratory anaphylaxis
• Airway research
• Dermatology
• Infectious disease
• Tuberculosis, typhus, Brucelosis (as research subjects)

Guinea Pig Breeding

• First breeding: 2-4 months
• Estrus cycle: 15-17 days
• Breeding life: 18-20 months
• Courtship by boar: sniffing, circling, licking, nibbling, mounting
• Lordosis by sow

Guinea Pig Dystocia

• Causes: incomplete relaxation of pubic symphysis, large or malformed fetus, abnormal presentation, uterine inertia, and pregnancy toxemia
• Therapy: oxytocin, C-section
• Prevention: first breed sows prior to 6 months of age and avoid obesity

Guinea Pig Pregnancy Toxemia

• Occurrence: last 2 weeks of gestation/within days of parturition
• Pregnancy not an essential factor
• Predisposing factors: obesity, fasting, 1st or 2nd pregnancy, and dietary or other stress
• Known causes: uteroplacental ischemia, aortic compression caudal to renal arteries, placental degeneration/DIC, and fasting/anorexia
• Lesions: hemorrhage & necrosis at placental sites, fatty changes in liver, adrenal gland enlargement, necrosis of renal proximal tubules, and proteinuria

Guinea Pig Mothering

• Sows are not attentive mothers
• Neonates must nurse "on the run".
• If not nursed for 24 hours, sows may not return to nursing
• Preweanings will nurse from different sows, stripping milk needed for younger animals

Guinea Pig Young

• Precocious young (walking, eyes open, teeth)
• Wean at 3-4 weeks

Guinea Pig Partial Alopecia

• Sows (late gestation, common, resolves after parturition, ovarian cysts may cause bilateral symmetric flank alopecia)
• Weanlings (moth-eaten appearance, guard hairs emerging, thinning, barbering, dominance behavior in groups, and self-barbering due to stress)

Guinea Pig Caging

• Solid bottom with bedding
• Wide-slotted floors acceptable
• Messy animals (defecating in food and water crocks). Water bottles and J-feeders recommended
• Housing recommendations based on weight

Guinea Pig Housing

• Animals weighing up to 350 grams require 20 x 20 cm² of floor space, animals > 350 grams require 30 x 25 cm²
• Nursing females with litters need a minimum of 700 sq cm
• Minimum height for cages is 17 cm
• Unweaned guinea pigs should not be housed with adult animals other than their parents.

Guinea Pig Pododermatitis

• Causal factors: Obesity, rough wire flooring, poor husbandry, trauma predisposing to secondary bacterial infections
• Move to solid, clean environment
• Local treatment
• Crusty, painful lesions slow to heal

Guinea Pig Handling

• Various handling techniques (images provided)

Guinea Pig Injections

• Various injection procedures (images provided)

Guinea Pig Physical Examination

• Easy to hold and restrain, may nip if young
• Healthy guinea pigs are dense and alert, Fatigue, lack of interest, and light body weight often indicate illness.
• Sick guinea pigs could show weight loss, hunched posture, abnormal gait, drawn-in abdomen, scruffy fur, or labored breathing
• Respiratory and GI conditions are common (ocular or nasal discharges or diarrhea)
• Examine feet for sores or broken nails

Guinea Pig Teeth Examination

• Teeth may overgrow; examination is difficult due to small mouth
• Nasal speculum attached to an otoscope handle is helpful for checking cheek teeth in awake guinea pigs
• Mouth, ears, and eyes should be examined for swellings

Guinea Pig Incisor Malocclusion

• Uncommon discrepancy in jaw length due to loss or fracture of opposite incisor
• Lack of dietary material for gnawing can cause overgrowth
• Malocclusion may be secondary to premolar-molar malocclusion
• Comprehensive oral exam is recommended
• Options include: tooth-height reduction every 3-6 weeks, or less, with appropriate dietary adjustment; or extraction of involved teeth

Guinea Pig Caries

• Tooth demineralizing process, bacterial waste products initiate
• Associated with dental plaque accumulation and availability of easily digestible carbohydrates(eg,starch/sugars).
• Rodent caries lesions similar to human lesions; extraction indicated if lesions extensive/symptomatic in anelodont teeth
• Coronal reduction, occlusal correction, and provision of more natural diet may correct (in elodont teeth like guinea pigs/chinchillas) if teeth still erupting/functional

Guinea Pig Anaesthesia

• Preanesthetic evaluation recommended for all dental procedures requiring general anesthesia
• Small size of rodents necessitates a different approach (minimization of stress, potential for ketosis in GP's, potential for hypoglycemia requiring supplemental dextrose in prolonged procedures)

Guinea Pig General Care

• Fasting before anesthesia is not necessarily required, but care is necessary for possible regurgitation, particularly in guinea pigs
• Heated surfaces are good for control of heat loss, and avoiding prolonged food deprivation to prevent hepatic dysfunction

Guinea Pig Genitourinary Disease

• Urolithiasis (stones) common, especially in older, female guinea pigs
• Stones can lodge in ureters or urethra, causing obstruction, which is life-threatening
• Clinical signs: dysuria, vocalization when trying to urinate, and potentially hematuria. Diagnosis via abdominal radiography, finding radiopaque stones usually composed of calcium carbonate/phosphate/oxalate.
• Treatment: surgical removal of stones is common but can be complicated if severe inflammation is present.
• Secondary infection is possible
• Diet changes (high calcium: high oxalate/high fiber in some cases) can be a cause

Guinea Pig Ovarian Cysts

• Cystic rete ovarii identified in 76% of female guinea pigs, between ages 2 and 4 years
• Develop spontaneously; range from 0.5 to 7 cm in diameter
• Single or multilocular
• Both ovaries often affected
• Clinical signs: abdominal distention, anorexia, fatigue, depression, and bilateral symmetric hair loss in flank region

Guinea Pig Respiratory System Disease

• Bordetella bronchiseptica: Gram-negative aerobe, epizootic pneumonia with high mortality, sporadic deaths (winter more common). Clinical signs: lethargy, rough hair coat, nasal discharge, sneezing, sudden death, and potentially metritis/abortion in pregnant sows
• Other concerns: otitis media, torticollis (head tilt), tympanic bulla may be present in severe cases, bronchopneumonia with consolidated lungs and large accumulations of neutrophils and intraluminal debris

Guinea Pig Respiratory System Disease - Transmission and Prevention

• Transmission: direct contact, fomites, aerosolization; avoid housing rabbits with guinea pigs.
• Antibiotic therapy: Doxycycline or fluoroquinolones (marbofloxacin, ciprofloxacin, enrofloxacin, all PO) are often used.

Guinea Pig Antibiotic Dosages

• Antibiotic dosages for guinea pigs

Guinea Pig Cervical Lymphadenitis

• Streptococcus zooepidemicus: suppurative or caseous lymph node abscesses are common. Potential for bronchopneumonia, pyothorax and/or sepsis.
• Transmission: direct contact & aerosol
• Treatment: surgical drainage, antibiotics.
• Differentiation: cavian leukemia

Guinea Pig Streptococcus equi subsp zooepidemicus

• Nasopharynx as latent infection. Direct transmission possible to head and neck through oral cavity abrasions (eg, molar malocclusion to cause suppurative lymphadenitis)
• Treatment: surgical excision of affected lymph nodes and systemic antibiotic treatment. Sensitive to chloramphenicol, azithromycin, and some fluoroquinolones
• Considerations for differentiation: cavian leukemia

Guinea Pig Lymphosarcoma (Cavian Leukemia)

• Retrovirus (Type C Oncornavirus), widespread
• Transplacental transmission
• Dormant until aged or stressed
• Lymphoblastic cell infiltration; usually in liver, spleen, lymph nodes

Guinea Pig Streptococcus pneumonia

• Epizootic outbreaks with high mortality
• Transmission: asymptomatic carriers (GPs, rats, man); direct contact
• Fibrinosuppurative lesions, pneumonia, pleuritis, pericarditis, and peritonitis

Guinea Pig Chlamydial Conjunctivitis

• Caused by Chlamydia caviae; young animals (4-8 weeks old) most susceptible
• Clinical signs: mild inflammatory conjunctivitis; yellow-white discharge; conjunctival hyperemia; chemosis; severe conjunctivitis with profuse purulent ocular exudate
• Treatment: Doxycycline (5 mg/kg PO, twice daily for 10 days).

Guinea Pig Pulmonary Neoplasia

• Bronchogenic pulmonary adenoma common tumor in >3 year old guinea pigs (approximately 30% in one study)

Guinea Pig Bacterial and Parasitic Enteritis

• Various bacteria and parasites (Yersinia pseudotuberculosis, Clostridium perfringens, Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes) can cause enteritis in guinea pigs
• Often contracted via fecal contamination(of food) . The intestine and regional lymph nodes may become abscessed.
• E. coli often causes wasting, depression, and death in weanling guinea pigs. Intestines may containthe yellow fluid.
• Treatmnt: based on culture and sensitivity analysis; Supportive therapy indicated

Guinea Pig Cryptosporidium sp

• Protozoan, frequently cause subclinicalenteritis
• Common cause of enteric disease
• Signs: lethargy, rough hair coat, weight loss, diarrhea / "greasy coat"
• Transmission: contaminated food/water,fomites
• Colonizes anterior ileum, histological lesions include fusion, atrophy, and metaplasia of villous epithelium; eosinophilic infiltration of lamina propria
• Diagnosis: Identify organisms in epithelial cells, mucosal scrapings, and fresh fecal smears
• No effective treatment

Guinea Pig Dermatophytosis

• Trichophyton mentagrophytes is a common cause
• Asymptomatic carriers are common
• Zoonotic
• Treatmnt: topical (enilconazole/miconazole shampoo) or systemic (itraconazole/terbinafine) for 2-3 weeks until negative cultures(2 week interval), or up to several months, in some cases

Guinea Pig Acariasis

• Caused by burrowing mites (Trixacaris caviae) or fur mites (Chirodiscoides caviae)
• Signs: neck, shoulders, inner thighs alopecia, crusting, intense pruritis, self mutilation, debility/death, few to no clinical signs for fur mite.
• Treatment: ivermectin or selamectin (topical/spot-on) and fipronil (whole body wash) , repeated 2-3 times at 7-10 days interval

Guinea Pig Lice

• Caused by chewing lice (Gliricola porcelliis and Gyropus ovalis)
• Signs: occasional alopecia, mild pruritis, nits on hair shafts
• Transmission: direct contact
• Treatment: topical solution (imidacloprid and moxidectin).

Guinea Pig Alopecia (nonpruritic)

• Common condition (in sows during late gestation)
• Associated with ovarian cysts
• Resolve after parturition

Guinea Pig Lymphocytic Choriomeningitis (LCM)

• RNA Arenavirus
• Clinical signs: asymptomatic, rear limb paralysis, CNS disturbances
• Eradication: colony depopulation

Guinea Pig Antibiotic-Induced Enterotoxemia (Hemorrhagic Typhlitis)

• Overgrowth of enterotoxin-producing enteric bacteria, ex. Clostridium difficile
• Often follows antibiotic use, dietary changes, or stress
• Clinical signs: anorexia, rapid weight loss, dehydration, diarrhea, and death
• Gross findings: enlarged cecum filled with blood and gas; loss of cecal epithelium, extensive hemorrhage & necrosis of mucosa and submucosa
• Treatment: supportive
• Antibiotics not effective or may be harmful in some cases

Test your knowledge on the nutritional needs and health issues of guinea pigs, particularly the role of vitamin C and dietary restrictions. This quiz covers essential topics such as common deficiencies, recommended food sources, and specific health consequences of improper nutrition. Perfect for pet owners and veterinary students!