several pharmacologic, pharmacology, and alternative medicine studies, oral
administration of medication or test substances to experimental animals is
needed. It is clinically sound and recommended to administer test substances to
experimental animals along the same route that they are taken or expected to be
taken by humans as general bioavailability; the pharmacology and pharmacology
parameters obtained for the drug will depend significantly on the route chosen
to administer it. The lack of ready access to high-quality oral tubing built
for different species, as well as a widespread lack of technical expertise to
properly use out-of-the-box techniques in this part of the world, has made this
route controversial among medicine scientists. The typical problems and
difficulties associated with the oral administration of test product solutions
were avoided by mistreating either the syringe alone or incorporating it into
the animals' feeds or drinkables. This jury-rigged oral tubing was also used to
ensure that the expected doses were correctly administered in each case.
pharmacology, medical specialties, and drug development trials, oral
administration of materials may be a standard practice. Oral delivery is less
invasive than other widely used body routes, such as blood vessel and
intraperitoneal administration, and may be a more physiological and clinically
applicable option for evaluating the effectiveness of medication for treating
human diseases, since most human medication is taken orally. The intra-gastric
feeding procedure, which includes handling and restraining the animal,
inserting a feeding needle into the esophagus, and injecting the drug directly
into the abdomen through a syringe, is often used to achieve oral
administration in conscious animals. Oral feeding, despite its efficacy, has
been linked to metastasis involvement, abdominal distension, and the production
of granulation inside the cavity after repeated dosing. Furthermore, as seen in
a recent study, the strenuous restraint of warning animals necessary to escape
technical complications triggers stress responses that have a major effect on
physiology and alter experimental outcomes. These intra-gastric feeding
problems can be more difficult if the handler is inexperienced or inept in
Instruments used for stomachic forced feeding,
pilling (including capsule administration), and powdery diet are the most
widely used for oral dosing. Water bottles affixed to the caging are used to
administer liquid and soluble substances directly or as binary compound
solutions for voluntary use.
To avoid the intra-tracheal dosing and any
aspiration chances and to prefer the unconditioned reflex, animals are given
the oral dose in their state of consciousness. For this purpose, we can use the
feeding needles that are curved or may be straight and also the medication
gavage tubes. Advantage of the ball tipped needles that are stainless is that
they are easy to sterilize and clean, but the disadvantage is that it imposes a
greater risk of rupturing the muscle system if it is pushed into the body.
Tissue injury risk or the puncture can be minimized by using the plastic or
rubber feeding needles having narrower and more adaptable rubber, but it
requires the mouth gag to be used in larger animals because they may chew the
needles if not properly placed inside their mouth. For the acute or more
frequent but fixed doses can be accurately given using the nasogastric tubes
for several days to hold a suture. We will require a Elizabethan collar incase
if nasogastric tubes is placed on the left side so that the animal can be
prevented from dislodging the tube. Whereas some animals do not enable us to
use to these collars. Moreover, permanent inborn reflex can occur in cases of
the chronic tube replacements.
Pilling or Bolus Delivery
Pills and capsulesare
issued to rodents weighing more than 150 grams for example cats and dogs as
well as rabbits using balling arms. Pill and the plunger can be hold together
by using the slender, onerous and long metal or plastic tubes having a small
slot at its top and it can be done accurately until the administration of the
pill at the back of the animal's tongue. Hence the capsules can be administered
to the abdomen or the distal passageway of the rodents. Pill can also be
inserted using an alternative method into the hollow conduit tip and making it
a gastric tube through the stomach. After the tube is at its postion we can
force the air bolus into the conduit to dislodge the pill. We can use the
lubricant that is oil based in order to avoid the compromise the integrity of
the capsule in case they are made of gelatin because the water content will
dissolve it. As the tube of the lumen is at risk of blocking by the pill, so
proper tube can be positioned and ensured only after the pill is dispensed.
Medicated Food and Food Treats
Commercially available pre-formulated treats
containing a variety of medications are available for a variety of animals, and
personalized treats may also be made. Pelletized diets are often purchased or
modified to include drugs or substitute ingredients in precise doses.
Electronically regulated feeders that can automatically operate themselves
because times are preset for opening and closing, are available in specialized
cages to hold or restrict the number of medicated diets eaten, as well as to
monitor the temporal order and length of feeding sessions. For dogs and larger
animals, similar gating devices with a radiofrequency-emitting collar are
helpful to monitor or document access to prescribed medication feeds.
Worldwide Guiding Principles: A Tool for Harmonization
Globalization of science and moral qualities
have prompted usage of guidelines on security of creatures utilized for logical
purposes around the world, in view of the standards of substitution and
refinement. In any case, while guidelines in individual nations are by and
large dependent on these standards, there are varieties in the way they are
essentially applied. Consequently, worldwide, and worldwide associations have
created core values to fit creature care and utilize and have given
suggestions, which can be comparatively applied regardless of the
administrative structure working in a specific country.
Oversight of Research Animal Welfare in the
The utilization of creatures in exploration in
the United States (US) is represented by various longstanding guidelines and
guidelines. The Animal Welfare Act and Regulations declared by the US
Department of Agriculture, Animal Plant Health Inspection Service, administers
explicitly characterized vertebrate creatures utilized for research, testing,
educating, presentation, and trade. This government law gives explicit
necessities to creature care, which incorporates angles from support and
institutional survey to veterinary consideration and revealing. The Guide gives
a nitty gritty arrangement of execution guidelines incorporating significant
subjects like Institutional Animal Care and Use Committee (IACUC) design and
capacity, word related wellbeing and security, creature climate and the board,
veterinary consideration, and actual plant. The cornerstones of the US
regulations and guidelines are the IACUC, the Institutional Official, and the
central role of the attending veterinarian. All must work together in providing
an animal care and use program that ensures the well-being of animals and the
integrity of science.
The mouse and human genomes are about 85% the
equivalent, and the similitudes have made the mouse a ground-breaking model for
examining human science and sicknesses. Dealing with, blood assortment, and
medication organization are same as rodent.
Table 1.Details of the
M 20-30g, F 18-35g
Rats were first utilized for exploratory
purposes during the 1800s, deliberately reared rats are utilized in creature
testing for various reasons, including their successive multiplication,
hereditary virtue, and similitudes to human science.
Table 2. Details of the
M 300-500g, F 250-300g
Frog or Toad
Guinea pig: hypersensitive test (allergic
reaction) or the screening of anti-asthmatic drugs
expensive, the effect of some drugs
Solid or Liquid Dosage Forms or Substances to be Administered Via Oral
Prior to controlling any substance (remedial or
test) to a creature subject, one should think about the pH, sterility, and
synthetic nature (scent, taste, mucosal touchiness, osmolarity, dissolvability,
light affectability, and risk status) of the compound and settle on proper
choices on the portion to be managed, recurrence of organization, volume to be
directed, the dissolvable (if important), and course of organization.
Name of compound or a concise synthetic
if not by and large known (except if
ØDose (mg/kg) of compound.
ØRoute of organization
ØVolume of organization.
of organization, and spans between rehashed organization Information on
dissolvable/vehicle including pH and other substance attributes.
of compound as well as vehicle including planned impacts and results.
Characteristics of Compound and Solvent (Vehicle)
Know the pH of the
compound AND the vehicle. Focus on pH ~7. On the off chance that the pH is
sequential attempt one of the accompanying:
Cushion to pH 7 if conceivable
Weaken the arrangement
utilizing clean typical saline or PBS
Filtration and other
cleansing methods are required to deliver the compounds maintaining their
sterility. Only those compounds are allowed to be regulated that are mixtures
of pharmaceutical grades.
Voluntary intake of
the compound is sometimes affected by the odor of the compound that can be
Some mixtures that are
prepared in the normal water must be having sucrose in order to improve their
taste that can be very bitter otherwise and effect the intake. These
incorporate yet are not restricted to antibiotic medication, doxycycline, and
metronidazole. 2.5 to 5 grams of the sucrose can provide a satisfactory
improvement in the taste of the solution.
PI to check tissue
similarity while applying to the mucosal surfaces while directing such
mixtures, for example to the windpipe or to the eyes.
Osmolarity should be
280 osmoles i.e. iso osmolar in case of the parenterally administered
mixtures. For example, the Lactated ringer solution containing dextrose 5% is
itself iso osmolar without help from anyone else, delivers the water and CO2
causing the resultant mixture to be iso osmotic as well. Be that as it may,
alert is exhorted in a got dried out creature.
Some substances are
insoluble in water requiring them to be incorporated into a suspension form. A
model is sulfamethoxazole trimethoprim suspension that is controlled in the
normal water. Regular shaking is required in this suspension to get the
accurate dose on daily basis.
By using a glass cover
foil made up of plastic or rubber or even by using the glass that is hued. Some
antibiotics like the sulfa and trim are incorporated in this way.
PI to report any
substance or a vehicle that is new to be directed to creatures to decide limits
to utilize and results.
Powdered diet, gastric gavage and sometimes
pilling are the most commonly used equipments for the oral dosing even
including the capsule administration.
and water-dissolvable stuffs usually can be administered either by
incorporating into an aqeous solution for the voluntary feeding by the animals
by placing them in their cages or administered directly.
Table 3.Types of Needles
and Gavages that are used for Oral Administration in Animal
Stretchy or Firmly Straight Needles
Ball-Tipped Stainless Steel Needles
Stretchy or firm straight or arched gavage
needles as well as nasogastric pediatric feeding tubes have less possibility
of tissue rupture.
Ball-tipped stainless steel needles can be
easily clean and sanitize though have a great esophageal breach risk, if
their passage is enforced into the animal's mouth.
They may be used for critical dosing in
large animals or may be affixed in place for some days via stay suture or by
using surgical glue drop.
but if they are not located properly in
animal's mouth then they may be crushed by animal.
An Elizabethan collar may be required to
avert animal from removing tube.
and to use for animals with large size then
they require a mouth gag.
Few animals don't gladly bear these collars.
Chronic tube placement might cause frequent
emesis in few animals.
Procedure for Oral Administration in Animals
needles or metal gavage of appropriate size
needles or plastic gavage of appropriate size
(if required) to wrap rats if flexible red rubber feeding tubes are used
Table 4. Suggested Maximum
Administration Volume and Gavage Needle Size
For a mouse of 25gm, 0.25ml would be maximum volume
3.8 – 10 cm (1.5-4”)
For a rat of 250 gm, 2.5 ml would be maximum volume
Figure 1:Metal gavage,
plastic gavage needles and red rubber feeding tubes for rats
To calculate maximum volume to be administered, first of all
weigh the selected animal
Then select gavage needle finest for your use.
For mice and rats, there are flexible plastic and metal feeding needles in
Metal gavage needles are usually easy to use
for mice as they can’t morsel the tube but are at higher risk to harm esophagus
if mouse scuffles.
Curved or straight metal gavage needles are
accessible but their choice hinge on individual penchant and practice.
Flexible plastic gavage needles (for rats or
mice) or red rubber feeding tubes (for rats) are less likely to damage
esophagus. Though animals can morsel them and they also need some training to use
Measure distance from the oral cavity to the
end of xiphoid process that is the sternum’s caudal point, by using feeding
tube or needle on restrained animal’s outside, before performing oral gavage
procedure. This would be the expanse for needle to be introduced into
esophagus. By using a small piece of tape or a permanent marker, mark this
distance on needle.
Measurement of distance from oral cavity to
process in Ra
Figure 1: Metal Gavage
Needle Showing Distance to be inserted
Figure 2: rubber
feeding Tube-tube is marked at the correct distance from mouth to xiphoid
Figure 3: Metal Gavage
Needle Showing distance to be inserted
Figure 4: V hold
restraint of Rat for passage of metal gavage needle
Figure 5: Gentle
restraint of Rat for Passage of Red Rubber Feeding Tube
Figure 6: gentle
restraint of Mouse for Passage of Metal Gavage Needle
With accurate volume of compound to be administered,
pre-fill the syringe and gavage needle or tube. In order to ensure accurate
dosing and to avert the animal from tasting possibly bitter mixtures, wipe the
outside of needle or tube to remove any of mixture that may be coating the
outside of needle or tube.
MICE: Softly take out the animal from cage and inflexibly
restrain animal in an upright position. Catch a good scruff of skin over the
mouse’s shoulders, in this way front legs are stretched out to side and neck
and head are restrained. Make sure that animal can breathe freely by watching
if the chest is moving.
RATS: Softly take out
the animal from cage. For using a plastic or metal gavage needle, detain rat in
an upright position by using either a crossover or v-hold to restrain the head
and neck. Make sure that animal can breathe easily. For using a red rubber
flexible feeding tube, rat can be smoothly controlled or by wrapping in a towel
by hand however they are sitting flat on a counter or table.
Plastic or Metal Gavage Needle: Glide gavage
needle’s end into left side of mouth of animals in front of
first molar and behind front teeth, along with the roof of animal’s mouth
slowly to animal’s left side. Animal usually “gags” at this stage, when gavage
needle is at the end of mouth. With mild pressure from gavage needle, slightly
lean the head back towards spine. This will let esophagus to be in a straight
line with stomach. When passing the gavage needle, there should be no
resistance and gavage needle should glide down the esophagus with gravity
alone. Gavage needle might requisite to be a little perverted clockwise as it
passes the epiglottis then into esophagus. Till pre-marked line touches the
mouth, keep passing needle into esophagus.
Red Rubber Feeding Tube (for rats only): In
order to prevent front feet of rat to grab hold of feeding tube, hold rat on a
counter or table or cover the rat lightly in a towel. The feeding tube is
glide down into left side of the rat’s mouth, above the tongue to back of the
throat, in a straight line with the stomach. Until pre-marked line touches the
mouth, keep passing the needle into esophagus. Gently restrain front limbs of
rat as rat may habitually try to twitch tube by its front paws.
Make sure that animal is breathing easily when
feeding tube or needle is at pre-measured distance. And inject a small test
dose of approximately 0.05 ml. Gradually introduce the solution for 2 to 3
seconds to reduce liquid approaching back up the esophagus, if having no change
in breathing exertion. To inject viscous or oily ingredient, then smallest
possible volume should be used, and introduce more gradually that is over 5 to
10 seconds, then take out needle slightly, thus none of the matter is brought
back up the esophagus into back of the throat. Gulping any oily matter into
lungs may lead to death of animal.
Figure 7: Advancing the
Gavage Needle down the esophagus of the Rat
Figure 8: Advancing down the
Gavage Needle to Esophagus of the Mouse
remove gavage needle from esophagus and relieve the restraint, if the animal is
not breathing properl
Take out the feeding needle gently, in opposite
direction from insertion when the entire substance has been administered then
return animal to its cage.
In order to observe
for possible problems, observe the animal for at least ten minutes. If there
were any problems like extreme struggling or evident aspiration, observe the
animal until it is behaving naturally before leaving the animal for the day.
important aspect of many research projects and clinical trials is the
administration of substances to animals via various routes for example oral
route. To ensure that experiments involving the experimental administration of
substances to animals are adequately prepared and performed, several
considerations must be addressed by the study staff, veterinarians,
institutional animal caregivers, and members of the animal ethics committee
involving dosing of the drug regarding the weight of the animal and the route
specified in the administration that shows maximum safety and efficacy and also
handling of the animal during the administration to ensure voluntary and safe
administration of therapeutic agents to the animal. Experimental refinement and
minimization of adverse effects on animals regarding administration can be
improved by close attention to detail of the medicine on the label and
consideration of the route of administration for successful and accurate
experimentation to ensure a minimum margin of error in the result obtained