& Management / Disease
Investigation & Control / Treatment &
Care / Techniques:
- All the equipment and consumables required should be prepared and
placed ready for use before the bird is removed from its
- A clean, sterilised tube should be used for each individual bird.
- Check that the tube is patent (not blocked) before use; with
transparent tubes a visual inspection can be used.
- Prepare a syringe with the required medication, fluids or formula.
- Connect a flexible feeding tube (for
example: a urinary catheter, giving set, lamb feeding tube or stainless steel feeding
needle) firmly to the syringe ensuring that the tube is of a type that will not cause damage to the mucosa, with a smooth and
- Note that the end of the syringe must fit the tube used, e.g. a
catheter-tipped syringe is required to fit a lamb feeding tube. (B13.15.w10)
- If tube feeding or giving fluids, check the temperature of the
feed/fluids (should be warm but
not too hot) - squirt a small amount onto your wrist to check the
- Fluids may be warmed by placing them in hot water until they are just
warm to the touch (100°F/38°C). (D135.5.w5)
- Empty the tube of air by expelling a little fluid from the syringe. (D135.5.w5)
Volumes for rehydration or
The volume of fluids or food mixture which may be given at one
time by gavage is limited. Different authorities suggest different limits:
- Recent publications from oiled wildlife responders in the USA suggest
that 50 mL may be given per kg body weight (i.e. about 5% of body
weight), although smaller volumes should be given initially, for example
only half this volume, with the amount increased from 2.5% of body
weight (25 mL/kg) to 5% of body weight (50 mL/kg bodyweight) gradually
over several gavages. (D133.5.w5,
- In recent Australian publications it has been suggested that most
birds can accept about 10 - 20 mL per kg bodyweight at one time, the
smaller volume for birds without a crop and the larger volume for birds
with a crop; for most seabirds it is suggested that 15 - 30 mL can be
given per kg bodyweight. (B363.App5.w18,
- A British publication gives the following "Rule of Thumb": maximum up to 2% of bodyweight at one
time. Generally assume 1 ml of liquid to weigh 1 gram, therefore give up to
2 ml per 100g
bodyweight, i.e. 20 ml per kg bodyweight. (B156.15.w15)
- A recent chapter on seabirds in another European publication suggested
that for gavage feeding, up to 30% body weight could be given in up to
four feeds daily, but stated that "it is rare to force feed more
than 20% body weight in two feeds." (B197.15.w15)
- Examples have also been given:
- Restrain the birds body and head, holding the bird in a vertical
position with the neck extended.
- One person can hold the bird while a second person carries out the
- Experienced personnel may be able to carry out gavage
single-handed, particularly for smaller birds. (B13.15.w10)
- With large, aggressive birds, particularly piscivorous (fish
goggles should be worn to protect the eyes. (V.w5)
- Externally measure the distance from the mouth to the intended delivery site (crop or stomach).
Determine how much of the catheter (tube) should still be exposed once
the tip has reached the crop (base of the neck). (D135.5.w5)
- Palpate the crop to ensure that it is empty before giving food by
- Apply gentle pressure at the commisures of the bill and open the bill.
- Apply gentle pressure to stabilize the tongue.
- Extend the bird's neck upwards and forwards. (D135.5.w5)
- Visualise the glottis (opening to the trachea) at the base of the
- The feeding tube must NOT be placed into the glottis.
- Bring the tube in from the left oral commissure, moving it backwards
and across the mouth, past and to the right of the glottis, sliding it
into and down the oesophagus on the right side of the neck and to the crop or stomach.
- Confirm the tube is in the oesophagus/crop by visual inspection and/or
gentle palpation of the neck. (D9)
- It should be possible to see, looking inside the bird's mouth, that the tube goes down behind the
- If the tube is in the oesophagus then two cylindrical structures
should be palpable in the neck - the tube and the trachea. (B115.5.w6,
- If there is only one palpable cylindrical structure in the neck
this indicates that the feeding tube has been inserted into the
- A slight bulge should be visible/palpable in the neck; the end of
this should move if you move the tube up and down slightly. (D135.5.w5)
- Damping the feathers on the right side of the neck may assist in
visualising the tube. (B13.15.w10)
- Note: Particular care is required to ensure that the
feeding tube has been properly positioned into the oesophagus when
tube-feeding long-billed birds. (B336.16.w16)
- Connect the syringe of fluids/food formula to the feeding tube. (B115.8.w4)
- Slowly deliver the fluids or feed formula, monitoring for fluid appearing in pharynx. Stop
if this occurs, and continue at slower rate. (D9)
- If the bird regurgitates it should be released to allow it
to clear its oral cavity. (B13.15.w10,
- Quickly remove the tube. (B115.8.w4)
- The bird should be allowed to shake its head and neck if food
is being regurgitated. (D135.5.w5)
- Clean out the bird's mouth. Gently stroke down the bird's
- When the syringe is empty, pinch or fold over the tube and remove it quickly.
- Stop just before the syringe is empty, to avoid pushing air into
the gastrointestinal tract. (D135.5.w5)
- The tube is pinched or folded over to prevent dripping and
possible aspiration of fluid/food. (D135.5.w5)
- Note: If a bird has regurgitated at the previous feeding, reduce the
quantity and/or give more slowly. (B115.5.w6)
- Keep the bird's head extended while returning it to its
- Avoid disturbing the bird for at least 20-30 minutes to reduce the
risk of regurgitation.
|Appropriate Use (?)
- Tube feeding is an excellent way to initially improve gastrointestinal motility in a debilitated animal,
and provide longer term hydration and nutrition.
- Definitive amounts of medication can be administered.
- Medication can be delivered directly to crop or stomach.
- Fluid medications often are more readily absorbed.
- Effective for routine administration of fluids to mildly dehydrated
- The tube touching the roof of the mouth and passing slowly over the base of
the tongue should
stimulate reflex closure of glottis. (J2.12.w3)
- If used for providing nutrition in a bird which is not taking food voluntarily,
careful calculation of nutrients being provided is essential to ensure
that sufficient nutrition is being provided to meet the bird's needs..
- A gag and/or metal tube is required for species with a strong beak and
good cutting edges , such as psittacines (Psittacidae - Parrots and allies (Family)),
to prevent the bird from biting down, severing the tube and swallowing
the free end.
- Check patency of tube before each use.
- Cleaning followed by sterilisation in Milton for 30 minutes (D139)
or another sterilisation fluid is required if a tube is to be reused. (D139)
|Complications/ Limitations / Risk
- This route of fluid administration is not effective in severely dehydrated or severely debilitated
- There is an increased risk of regurgitation and aspiration.
- Such individuals have reduced absorption from the gastro-intestinal tract.
- Parenteral fluids (intravenous or intraosseous) are preferable in
- Not suitable for use if the individual is vomiting or has reduced
gastro-intestinal tract mobility.
- Not suitable if the individual is unable to maintain its head carriage
normally as there is an increased risk of regurgitation and aspiration.
- There is always a risk of damage to the mucosa.
- Extra care is required to avoid perforating the oesophagus if a metal crop tube is
- In birds with sharp edges to the bill care must be taken that the bill
does not close onto a non-metal tube and cut it, allowing the tube to be
- There is a risk of improper tube placement, into the trachea, and
delivery of fluids/food/medication into the lungs, often with fatal
- Particular care is required to ensure that the feeding tube has
been properly positioned into the oesophagus, when tube-feeding
long-billed birds. (B336.16.w16)
- Risk of regurgitation and aspiration. N.B. vomiting/regurgitation is more likely if
the food is cold rather than warmed.
- Overheating of fluids or food mixtures must be avoided. Take care to ensure food does not contain "hotspots" which may burn
the bird's internal tissues, particularly if the feed has been heated in a microwave - also
note that feed continues to
heat after leaving the microwave. (D9)
- Fluids or food mixtures which are too hot can scald the oesophagus and
- If too cold a mixture is used, regurgitation is more likely. (D9)
- Tube may become blocked.
- Feed mixtures made from e.g. ground up pellets often swell after being mixed with
water. Care must be taken that the mixture is sufficiently thin to pass through the tube.
- Limited to individuals or small groups or animals.
- Often more than one individual is needed to accomplish the procedure.
- Only a limited volume of fluids/food can be delivered at one time.
- Parasitism, diseased mucosa and nutritional deficiencies such as Vitamin A
Deficiency may adversely affect absorption of drugs given
by this route.
- Not all drugs are absorbed if given orally.
- If tubes are not properly cleaned and sterilised between birds then
pathogens may be transmitted from one bird to another.
|Equipment / Chemicals required and Suppliers
- Appropriate sized tube, e.g. 0.5 to 1.0 cm diameter in waterfowl, of
- Syringes of appropriate sizes and with the correct tip to fit the
tubes to be used.
- Appropriate fluids, liquefied / suspended food or medication.
- Sterilising solution if tubes are to be used with more than one
- Gag if appropriate (e.g. for large psittacines (Psittacidae - Parrots and allies (Family))).
|Expertise level / Ease of Use
- Procedure should only be
undertaken by an individual with appropriate clinical training and practical experience.
- Application of the procedure single-handed (same person holding
the bird and carrying out gavage) should only be used by persons
who are familiar with both handling birds and carrying out gavage.
- Not generally expensive,
unless expensive medication / food / fluids are being given.
|Legal and Ethical Considerations
||In some countries there may be
legislation restricting the diagnosis and treatment of disease in animals to licensed
veterinarians. For example in the UK: "The Veterinary Surgeons Act 1966 (Section
19) provides, subject to a number of exceptions, that only registered members of the Royal
College of Veterinary Surgeons may practice veterinary surgery." (see: LCofC1
- RCVS Guide to Professional Conduct 2000 - Treatment of
Animals by Non-Veterinary Surgeons).).
Use of Drugs
- Many drugs are not registered for use in particular bird species and care should
be taken in their use, with proper regard for possible toxic effects. Consideration should
be give to relevant legislation regarding the use of drugs.
- In the UK, guidelines regarding the use of drugs are set out in the Royal College
of Veterinary Surgeons Guide to Professional Conduct 2000: (see: LCofC1
- RCVS Guide to Professional Conduct 2000 - Choice of Medicinal Products).
||Debra Bourne MA VetMB PhD
||Dr Virginia Pierce (V.w73)
B13.15.w10, B13.17.w16, B14,