Guidelines for sampling

General Analytical

Whole blood
The hematology study sample is whole blood. Whole blood is fragile so we only expose small suggestions to the sample.

  • Letting blood by venipuncture avoiding, if possible, the extraction of small veins as difficult and traumatic extractions stimulate the clotting mechanism.
  • Discard the needle of the syringe and transfer the sample to the tube with the blood thinner sliding down the walls of the tube. Cover and swirl gently shaking the tube with twisting motion to avoid hemolysis. At least 10 movements.
  • The anticoagulant of choice for counting blood cells in mammals and their evaluation is EDTA (red cap). Heparin is not so well preserved cells.
  • Fill the tubes at least halfway to avoid hemodilution. The laboratory sumistra material according to the weight and size of animal pipes, 1 or 5 ml capacity.
  • Book a remnant of the extraction to prepare two or three thin extensions of peripheral blood. Air dry and submitted with the previous sample. If possible, always be set on the blood smear once dry methanol.
  • Protect from scratches smears using a specially designed boxes for shipping or confronted the two cytology slides a piece of cardboard or pads at both ends


Citrated Plasma
The citrated plasma was obtained from the mixture of whole blood with sodium citrate at a ratio that indicates the tube (1:9) blue stopper. Dilution is homogenized and centrifuged immediately, always within 30 minutes of extraction at 2,500 or 3,000 rpm for 12 to 15 min.

  • Separate the plasma carefully with a pipette or syringe new cells trying not to breathe.
  • It is advisable to freeze the plasma prior to shipment to the laboratory. To do this, there are special containers for shipment of frozen samples that may apply at the nearest delegation Laboratory.
  • If the extraction was not smooth and easy, we recommend repeating the sampling with a new syringe, a new tube and a different vein, for the reasons previously cited.

In most laboratory tests are performed in units of Biochemistry, Immunology, Toxicology and immunoassay, the serum sample is required. It is always advisable to take samples from fasting for at least 8 hours. Lipemia interfere with many tests.

  • Serum is obtained by venipuncture and transferring blood to a glass tube, preferably plastic or without anticoagulant.
  • Leave at room temperature until the clot is well formed and centrifuge. Separate the supernatant (serum), ff serogel tubs are not used, introduce it in a tub without aditives, where the sample will be send to the Laboratory.
  • Cool to +4 º C until sent to the Laboratory.


Plasma Heparin / EDTA Plasma
This type of sample is required for some special tests, such as:

ACTH (Frozen Plasma EDTA), Ammonia (Frozen Plasma EDTA), Vitamin C (Frozen Plasma EDTA) Lactic Acid (Frozen Fluorined Plasma)...

It uses a tube with the specific anticoagulant as determined. Once the sample homogenized, centrifuged and separated the supernatant (plasma). Normally, the plasma must be frozen quickly obtained by the lability of the substances analyzed.

Please get in touch with nearest Echevarne center to look up the necessary material to send frozen samples.


Microbiological Study

Urine samples for bacteriological analysis should preferably be taken by cystocentesis or catheter. Samples taken by free voiding be interpreted with caution given that may be contaminated cells and microorganisms from the lower urogenital tract and in any case, it should be left in midstream, that is, discarding the first part of the urine and collecting only the remainder.

Parasitological examination:

  • The stool parasitological intended for analysis must be collected from the rectum, unless the animal is observed in the act of defecation.
  • The stool is placed in a clean container and / or in a container provided by the laboratory containing formalin to preserve Protozoa.

Bacteriological examination (stool):

  • The collection system is the same as above but the sample must be placed in a sterile.
  • If in addition to forwarding the bottle container with faeces a rectal swab is sent to Cary Blair transport medium will extend the sensitivity of culture (preserve anaerobic microorganisms Camppylobacter sp).

Anaerobic samples
A crucial factor for the success of the anaerobic cultures is the transport of clinical samples, the lethal effect of atmospheric oxygen must be vacated until it can be processed.

Appropriate samples for anaerobic culture:

  • - Pus or drainage from deep wounds or surgical
  • Abscesses
  • Woven fabrics obtained after surgery or autopsy
  • Body fluids: pleural or peritoneal aspirates
  • Liquids joint or cerebrospinal fluid
  • The liquid material is preferably obtained by anaerobic culture using a sterile needle and syringe, expelling all the air in them. Avoid the remittance of needles using special syringe stopper.
  • Abscesses, take the sample from the inner face of the capsule trying to scrape. 
  • In case of injury or skin wounds, whenever possible, you should suck the pus present under a flap of skin or deep cavities using a needle syringe. If this is not possible, but taking care to use a swab to take sample of the most profound and avoiding contact with adjacent skin areas.
  • Tissue from autopsy or surgery (about 2 cm in diameter) usually retain an anaerobic environment in the center of the piece, so can be entered and submitted to the Laboratory in a sterile container.
  • Such samples are not refrigerated, and oxygen uptake is greater at lower temperatures. Store at room temperature.

Exudates and secretions

  • Take the sample in a sterile swab and send to the Laboratory refrigerated transportation Stuart or Amies to the sample does not dry out.
  • The type of sample will be from natural openings or body surface area, for example:
  • Eye discharge, obtaining the sample prior to administration of local analgesics, eye drops or antibiotics. To search for Chlamydia sp evert the eyelid and conjunctiva rubbing with a swab.
  • Mammary secretion: As collected by voiding urine free, discard the first drop, probably contaminated by the regional flora of the skin and to sample half of lactation.
  • Throat swab, the swab touch with any body exudate, swollen membranes or trying to avoid contact with oral mucosa or tongue.
  • Nasal. It introduced the swab as deep as possible. If biopsy is performed to send a portion intranasal mass for microbiology.
  • Ear swabs, etc.
Tracheal washings 

Send aspirate in a sterile container with a hisopo. The best ideal is to perform cytology and microbiology at the same time.

Blood cultures
The blood culture is performed when suspicion of bacteremia or septicemia. Strict asepsis is required because a small contamination can produce a wrong result. Sampling Prior to blood collection, the puncture site should be shaved and cleaned with soap. Disinfect with 70% ethyl alcohol and then apply iodine solution. Leave to dry for one minute to exercise its action. Is not recommended the removal of blood through catheters as these devices can harbor bacteria that have colonized giving rise to false positives.

Inoculation of the bottles:

  • Remove the outer covering of the bottles (not unscrew the cap).
  • Disinfect the rubber stopper with iodine solution and let dry at least one minute.
  • Inoculate the bottle with the recommended amount of blood and move the jars to the blood and the medium was mixed.
  • Do not place the jars in the refrigerator.

Blood Volume:

Depend on the size of the animal. Contact the Laboratory to receive the appropriate bottles depending on the size of the animal, the volume of blood removed or if it is taking an antibiotic treatment.

Body Fluids: Pleural, Ascitic, Articulate, LCR.
Maintain the highest aseptic precautions and send to the Laboratory in a sterile tube. It will always be a more representative sample than a swab.

Culture Mycological
The skin lesions for microbiological analysis: mushroom cultivation and direct observation be drawn from the edges of the lesion and contain both hair and skin flakes.

Liquids and Cytology Study


  • The cytology samples may be obtained by a swab, by scraping or by fine needle aspiration.
  • If you get a swab, roll the swab on a clean slide and dry, never arastrar.
  • If performed by curettage, requires a scalpel blade to pass over the site of injury up several times. The material obtained on the blade will be deposited on the slide.
  • The samples obtained by needle are expelled at the end of the slide.
  • Take another clean slide and placed on its narrow end above the excavated material to 45 †. Make an extension of the material forward along the slide until the cell layer becomes thinner and runs out of material.
  • Let dry for 20 or extension 30 min.
  • Sending slides are preferably carried out in specially-designed containers (hard plastic). Other forms of transport but are not adequately protected if there is an increased risk of rupture.

Liquids or effusions
Type of analysis performed in a liquid:

  • Counting of cells, preferably send in a tube with EDTA
  • Cytology, serving the previous sample
  • Microbiology: as above

Bone Marrow
There are several ways to prepare areas of bone marrow although we recommend the combined technique: some crushing and one for a full study extensión.Para Please send whole blood with EDTA and possible extensions of fresh blood (see blood smear preparation ). If it was not possible to send blood sample, please send us the results obtained prior to hematological bone marrow extraction.

Samples from Autopsies
Sometimes for a complete post-mortem study is necessary to complement microbiology and histopathology. The treatment of the samples is different, for this reason here are some indications in the process of obtaining the samples:

  • Samples selection. The clinician performing the necropsy sending to the Laboratory the organs as it deems best suited to gross lesions and clinical manifestation.
  • The samples for bacteriological examination should be as aseptic as possible. The pieces of different organs will be introduced in sterile containers, separated and correctly identified.
  • For the pathological examination can be sent different organs in the same package.
  • Size of the pieces. It is recommended that parts are not very large because it is easier to produce an incorrect cooling anin terms of histopathology, formalin does not penetrate deeply into the central portions.
  • The size of the parts should not exceed 2 cm in diameter. If they are major pieces to various portions of the tissue being studied.


Pathology samples (biopsies)

  • Immersion of the tissues obtained in 10% formaldehyde in distilled water (9 parts water and 1 part formaldehyde). Please note that the purest form of liquid formaldehyde is in 37-50% concentration. It is with this concentration that we prepare the 1:10 dilution.
  • Fixer volume should be about 10 times that of the sample volume. Please use a sample container proportional to the size of sample to accommodate whole prep.
  • Endoscopic biopsies must travel in small volume containers (tubes, eppendorfs) and these must be correctly identified.
  • The bone biopsies should be fixed by immersion in formaldehyde just like any other tissue.
  • Muscular tissue biopsies should be attached to a physical support (plastic, wood, styrofoam) using needles or suture stitches to prevent hyper-contraction of myofibers.
  • Avoid mixing large pieces with small pieces in the same container. Small pieces  could go unnoticed.