Non-Terminal Blood Sampling Techniques in Guinea Pigs

The overall goal of this video is to illustrate the methodology of four different blood sampling techniques in Guinea pigs. The procedures shown are not terminal unless sample volumes or number of samples exceed guidelines for blood collection. In laboratory animals, here we see the cause of the lateral ous vein and the tarsal vein.

The ous vein runs dorsally and laterally over the tarsal joint. A maximum of three samples should be taken from each hind leg, and approximately 100 to 400 microliters of blood can be collected per sample. Necessary equipment include an electric shaver, warm water bath, a clean towel, some cotton wool, a disinfectant such as 70%alcohol, sterile needles, 21 gorge or smaller collection tubes.

And if the aim is to measure blood glucose and AccuCheck sampler, blood sampling from the cepheus or tarsal vein can be done in Guinea pigs without anesthesia. The Guinea pig is restrained by a trained assistant and a septic technique should be used. The hair covering the tarsal area is shaved with an electric shaver and the hind leg washed and warmed in a lukewarm water bath.

In addition to cleaning the leg, this makes the veins dilate and become more visible. The hind leg is extended and stasis achieved by applying gentle downward pressure just above the knee, allowing the vein to become visible immediately prior to sampling. The shaved area is wiped with a disinfectant.

The vein is punctured with a needle or a lancet, and blood can be collected into a capillary or microt tube. When blood has been collected, stasis is alleviated and gentle pressure applied with a piece of cotton wool To facilitate hemostasis, the superficial arteries and veins on the dorsal surface of the Guinea pig ear can be seen here. These vessels can be used for blood sampling when only a very small volume is required.

One example could be for blood glucose measurements. The Guinea pig is gently restrained while leaving the ear accessible. The puncture site must be a septically prepared prior to sampling, but shaving is not necessary.

Slight pressure can be applied at the base of the ear to make the veins more visible. The vein is punctured with a needle or a lancet and blood collected in a capillary tube or immediately analyzed for blood glucose levels using the AccuCheck sample system. When blood has been collected, gentle pressure should be applied to the puncture site to facilitate hemostasis.

This picture illustrates the position of the Guinea pig for jugular blood sampling and the cause of the jugular vein. The procedure is exclusively performed on an anesthetized animal. Necessary equipment include drugs for anesthesia and electric shaver cotton wool, a disinfectant such as 70%alcohol stethoscope, neutral eye ointment, one milliliter syringes, sterile needles, usually 23 or 25.

Gorge Heparin and EDTA can be used to flush syringes prior to sampling in order to prevent coagulation. A variety of anesthetic protocols exist for Guinea pigs. In this case, animals are anesthetized by balanced anesthesia with a mixture of solit tile sine and butif injected subcutaneously in the neck.

This mixture can be diluted with saline to make dosing more accurate. After injection, the Guinea pig should be returned to its cage and left in quiet. Surroundings effect is usually seen after approximately 10 minutes and lasts for 30 to 40 minutes prior to sampling.

The depth of anesthesia is assessed by checking reflexes and neutral eye ointment is given to protect the eyes. The jugular vein is approached with the Guinea pig placed on its back, and the front legs retracted quarterly. The area is shaved and prepared aseptically, the clavicle is palpated, and a 23 gorge needle mounted on a one milliliter syringe is inserted approximately one centimeter lateral to the midline, just cranio dorsally to the clavicle.

The syringe should be kept in a slight upward and medial angle. As soon as the skin is penetrated, slight negative pressure is applied to the syringe as the jugular is situated quite superficially and insertion depth of around three to four millimeters is sufficient. When the sample has been collected, release the tension of the front legs and apply gentle pressure to the puncture side.

The animal can then be returned to a recovery cage, but must be monitored to ensure hemostasis and recovery from anesthesia. When the Guinea pig is fully recovered from the anesthesia, it may return to its pen. The anatomical features of the Guinea pig are slightly different from those of other rodent models, and modulation of sampling techniques is necessary to accommodate for species specific differences and to obtain sufficient quality samples within the shortest possible time.

As both long and short term. In vivo, studies often require repeated blood sampling. The choice of technique should be carefully considered in order to reduce stress and discomfort and to ensure survival, as well as compliance with requirements of sample size and accessibility.

All the described methods have been thoroughly tested and successfully applied for repeated in vivo blood sampling. In studies in our research facility, the Guinea pig represents a niche in experimental animal sciences, but limited data is available on the execution of basic procedures. In this video paper, we've presented four different approaches to non terminal in vivo blood sampling in either conscious or anesthetized animals, provided that sample volumes and number of samples do not exceed the guidelines for blood collection in lab animals.

These procedures are recommended for the use in Guinea pigs when repeated blood sampling is required. In your study protocol.