Guinea Pigs

 

About Guinea Pigs

Guinea pigs are valuable research animals because of the variety of experiments in which they can be used. They are often used to test lotions and ointments because their skin resembles human skin. Long use of the guinea pig in bacteriological and serological research has resulted in a sizeable accumulation of information on blood values, cell counts, elementary analyses and physical constants. Guinea pigs have been used frequently in nutritional research and in immunology experiments.

 

Guinea pigs became known to research scientists after sailors brought them to England from Peru as pets. The Dunkin-Hartley strain, developed by the British, is the most widely used in laboratories. It is almost always an albino with short, smooth hair. A second type of guinea pig, the Abyssinian, has short, rough hair that grows in rosettes. The present day Peruvian type of guinea pig, with long hair, is seldom used in research.

 

Of all of the commonly used lab animals, guinea pigs are one of the most nervous and high-strung species. The guinea pig needs to be approached quietly and confidently. It will seldom scratch a human when it is picked up if it is supported well. If it does become alarmed, however, the whole colony can detect the fright and become apprehensive. To pick up the pig, grasp behind its head and in front of its forelegs with the thumb and forefinger. With the remaining fingers, hold the pig behind its front legs and rib cage. Use the other hand to support the hindquarters.

 

Good sanitation is extremely important in the guinea pig colony. The animals are very susceptible to paratyphoid infections. Cages need to be cleaned often to keep the animals as free of microorganisms as possible.

 

Like monkeys and human beings, guinea pigs need daily doses of vitamin C to prevent the development of scurvy. Scurvy can develop within seven to ten days without dietary vitamin C. Normally a daily intake of 10 milligrams of ascorbic acid will be adequate to keep the guinea pig free from scurvy. 

 

Custom Diets

Both purified diets and grain-based diets can be formulated for Guinea Pigs.

 

Purified diets can be formulated with varying fat ratios (for example, S:M:P of 1:1:1), and varying percentages and types of protein (soy alone, casein alone, or soy-casein mix), and variations in cholesterol and fiber content (cellulose, pectin, psyllium); or, whatever other variations your research may require.

 

Listed below are some vitamin C modified grain-based diets for guinea pigs. Vitamin C Deficient Guinea Pig Diet 5710-6 (57HV) is formulated without ground wheat, ground corn, alfalfa, animal fat, molasses, and vitamin C. These items are replaced by non-nutritive fiber, casein, soybean oil, and dextrin. The resulting level of vitamin C is below detectable levels. Because the alfalfa has been removed, this diet has lower palatability than the standard Guinea Pig Diet 5025. Therefore, TestDiet^® also manufactures a Modified Guinea Pig Diet without added vitamins. Vitamin modifications can be made on any LabDiet^® product for any species of laboratory animal. Just call us and let us make a modified diet to your specifications. .

 

Similar adjustments can be made in any nutritional component of a LabDiet^® grain-based food. For example, Guinea Pig Diet 5025 can be made without soybean protein or without milk protein (Product Code Number 5711-3 [57TN]). For either modified product, the standard Guinea Pig Diet 5025 may be used as the control diet, thereby eliminating the need to purchase and store a separate control diet.

 

Hundreds of custom diets have been formulated for guinea pigs; we can repeat or modify any existing diet or create new formulas for your specific research requirements.

 

A few examples of custom guinea pig diets—

Description	TestDiet® Formula # or Product #
Vitamin C Deficient Guinea Pig Diet	57HV
Modified Guinea Pig Diet 5025 with no added Vitamin C	58X1
Modified Guinea Pig Diet 5025 without Milk Protein (casein)	57TN

 

Care, Feeding, & Physiology

Care and Feeding
	Number of Adults	Number of Young		Cage Dimensions*
				Length	Width	Height
Breeding/Lactation	1 male	6-8		75 cm	60 cm	30 cm
Growing	3 females
Experimental	12	Variable		75 cm	60 cm	30 cm
Feeding Recom- mendations	Daily Feed Usage		Water Requirement		Begin Dry Food Consumption
	Adult male	35 gm	Ad libitum		4-5 days
	Pregnant female	35 gm
Environmental Data	Room Temp.	Humidity	Light	Litter Material
	20-25 °C	45-55%	10-12 hrs/day	Shredded beet pulp, coarse shavings, or commercial bedding
Biological Values

Blood Chemical Composition	Water	Calcium	Sodium	Chloride	Phosphorus	Potassium
	93-95 gm/100ml	5.3 mEq/L	145 mEq/L	105 mEq/L	5.3 mg/100ml	7.4 mEq/L
Values are for plasma, except where noted	Magnesium	Cholesterol	Glucose	Serum Protein	Albumin	Globulin
	2.3 mg/100 ml	21-43 mg/100ml	96 mg/100ml (whole blood)	5.4 gm/100ml	3.2 gm/100ml	2.2 gm/100ml
Oxygen Consumption and Body Temperature	Observed Weight	Temper- ature	Oxygen Consum- ption	Breathing Rate	Heart Beat
	460 gm	38.6 °C	0.76 mlO2/gm/hr	90/minute (69-104)	280/minute (260-400)
Hematological Values	Whole Blood Volume (T-1824 dye)	Clotting Time	RBC Life Span	RBC Diameter	RBC Rate of Sedimentation
	75 ml/kg	60 sec.	—	7.1 microns	0.5-1.5 mm/hr
	Blood pH	RBC	Hematocrit	Platelets	Hb
	7.35	4.5-7.0 106/mm3	42 ml/100ml	522-900 103/mm3	12.35 gm/100ml
Total and Differential White Blood Cell Counts	Leucocytes	Neutros	Eosinos	Basos	Lymphos	Monos
	10.0 103/mm3	4.2 103/mm3	0.4 103/mm3	0.07 103/mm3	4.9 103/mm3	0.43 103/mm3

Life Cycle Information
	Weight Adult Male	Weight Adult Female	Weight at Birth	Breeding Age Male	Breeding Age Female	Estrus Cycle
	1000-1200 gm	850-900 gm	100 gm	3-5 months 500 gm	3-5 months 500 gm	Post-partum or 16-18 days
	Gestation	Weaning Age	Litter Size	Rebreed After Parturition	Breeding Life Male	Breeding Life Female
	59-67 days 63 days avg.	10 days 250 gm	1-6 3-4 avg.	Immediately	5 years or longer	4-5 years
	Mating Data: Colony: 1 male, 3-10 females

*	Refer to the "Guide for the Care and use of Laboratory Animals" — NIH Publication No. 85-23, Revised 1985.
	Prepared by the Institute of Laboratory Animal Resources, National Research Council, 2101 Constitution Avenue, N.W., Washington, DC 20418