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In general the following points should be duly considered while
collecting materials for laboratory diagnosis of bacterial, viral,
parasitic and other diseases.
a. All materials collected should be accompanied with full history of
disease out break viz., morbidity and mortality rates, clinical signs,
duration of disease, species affected, disease suspected etc.
b. The materials from ailing 5-6 or more animals should be collected
at the height of body temperature/ clinical signs.
c. When sero-diagnosis is desired always paired sterile, about 2 ml,
sera should be collected. One serum sample at the time of start of
disease and another after recovery (3-4weeks) from disease.
d. All biological specimens should be transported on ice to the
nearest laboratory though a courier within shortest possible time where
they may be processed and stored on proper conditions. The courier
should be instructed to change ice if long distance is involved.
e. When death is recorded in ailing animal, the post-mortem
examination should be conducted at the earliest to avoid putrification
of the carcasses. Putrified materials are unfit for lab examination.
f. Materials collected for bacteriological examination should not be
kept at subzero temperature (-20 ̊ C) while for virus isolation these
can be stored at -20 to -80̊ C. For most of the diseases keep at 4̊ C.
g. Detailed post-mortem report should be despatched with morbid
materials in 10% formalin. The morbid materials should be sent without
preservative in sterile containers over ice. The transport media used
specially for virological examination of the morbid materials are 50%
Phosphate Buffered Glycerine, Phosphate Buffer Saline (pH 7.3-7.4) PBS
and Hank’s Balanced Salt Solution. In case of non-availability of
transport media, it is always desirable to collect tissues in sterile
containers, sealed and transported on sufficient ice to the nearest
laboratory for storage and processing. Small tissue pieces of ½x2 cms
thick from organs showing the lesions are considered better for
preservation and fixation in 10% Formalin. The specimen bottles should
be sealed, labelled clearly indicating the fixative/transport media
used. Care should be taken to seal and pack these bottles in hard
boxes/polythene bags to avoid leakage during transit. Unbreakable
bottles and sterile polybags may be used for collection and transport of
biological specimens. When viral disease is suspected, antibiotics
(Penicillin 1000 units & streptomycin 10mg/ml) may be used in transport
media and in serum samples despatches for diagnosis. This will inhibit
contamination. About 20 gram each of spleen/lymphnode tissues be
collected for virus isolation. Always 5 to 6 or more animals be
investigated and material collected for lab examine. Less number of
materials sometimes fail to give results/true picture of disease
outbreak. The type of materials to be collected in different diseases is
1. HAEMORRHAGIC SEPTICAEMIA: From sick animals fixed smears from blood
and liver. Heart blood in a sterile pipette/bottle, lymph node and
spleen on ice.
2. ANTHRAX: Flame fixed blood smears of cattle and sheep. From
subcutaneous swelling in horses, swine and dogs. Swabs of blood from ear
vein for cultural examination from dead animals. A small piece from tip
of muzzle (½x1 cm approx.) in saline or without any preservative in
sterile glass test tube or bottle on ice duly sealed. It is not
advisable to open the carcass suspected for anthrax in field. If opened,
it should be properly disposed by burning.
3. BLACK QUARTER : Impression smears from the affected muscle tissue;
exudate from lesions; pieces of affected muscles on ice.
4. ENTEROTOXAEMIA,LAMB DYSENTERY : Contents of small intestine with
and without chloroform separately on ice, kidney, urine.
5. BRUCELLOSIS : Paired serum, blood and abomasal contents of aborted
foetus, placenta with 2-3 cotyledons, vaginal swabs in PBS, separate
bottle on ice, whole foetus if small on ice.
6. JOHNE’S DISEASE : Rectal pinch smears, bowl washings(atleast 10gm
preserved in 10% formalin). In dead animals terminal portion of ileum
with ileocaecal valve, mensenteric lymph gland in 10% formal-saline.
7.GLANDERS : Exudate from skin and lung lesions in vials on ice.
Impression smears from exudate duly fixed.
8. TUBERCULOSIS : (1) Cough material in sterile container from live
animal, (2) Sample of milk in sterile, container (3) Suspected lesions
in 10% Formal-Saline (dead animal), (4) Smears from lesions fixed by
heat and (5) Lymph glands or lung lesions in sterile container for
isolation in 50%buffered glycerine.
9. LEPTOSPIROSIS : (1) Blood, serum (2) Pieces of liver and kidney in
10% formalin (in dead animals) and (3) Milk or urine in vials by adding
1 drop of formalin per 20ml.
10. SALMONELLA SP. : Intestinal swab, heart blood, bile in sterile
container on ice.
11. ACTINOMYCOSIS & ACTINOBACILLOSIS : (1) Smears from pus lesions,
pus in vial on ice (2) Formalin preserved materials from lesions
12. LISTERIOSIS: (1) Aborted foetus, brain, placenta (2) All internal
organs in 10% formalin/on ice.
13. MYCOPLASMOSIS/CCPP/CBPP/CORYZA: (1) Swab from lesions, nasal and
vaginal swabs in PBS on ice. (2) Piece of lung preserved in 10% formalin
for histopathological examination and on ice separately. Paired serum.
14. CHLAMYDIA/PSITTACOSIS: (1) Nasal swab, lung pieces in sterile
container on ice and internal organs in 10% formalin, (2) Fixed
impression smears from liver, lung and foetus, (3) Paired sera.
15. MYCOTIC INFECTIONS: Deep skin scrap in sterile vials.
16. SKIN DISEASES (RINGWORM, MANAGE, MITES : Skin scrapings for
identification of ectoparasites and fungus in vials.