Oral Administration: Liquids

By | 2013-07-26

Without a Stomach Tube

Patient Preparation

None required. Technique is appropriate for owners to perform at home.


Small amounts of liquid medicine can be given successfully to dogs and cats by pulling the commissure of the lip out to form a pocket (). Deposit the liquid medication into the “cheek pouch,” where it subsequently flows between the teeth as the head is held slightly upward. Patience and gentleness, along with a reasonably flavored medication, contribute to the success.

Spoons are ineffective, as fluids are easily spilled. A disposable syringe can be used to measure and administer liquids orally. Depending on the liquid administered, disposable syringes can be reused several times, assuming they are rinsed after each administration. In addition, disposable syringes can be dispensed legally to clients for home administration of liquid medication. Mixing of medications in the same syringe is not recommended. However, dispensing of a separate, clearly marked syringe for each type of liquid medication prescribed for home administration is recommended.

Special Considerations

Compounding pharmacies are also available and can mix many medications into palatable flavors to help facilitate the oral administration of medications.

Dogs with swallowing disorders should not be treated at home with liquid medications because this could cause complications associated with aspiration.

With an Administration Tube

Patient Preparation

None required.

Note: This procedure is reserved for in-hospital use only. The technique should be performed only by individuals trained to perform this procedure.


Administration of medications, contrast material, and rehydrating fluids can be accomplished with the use of a well lubricated feeding tube passed through the nostrils into the stomach or distal esophagus. When a feeding tube is placed for long-term use (multiple days) and repeated use (described under Gastrointestinal Procedures later), it is generally recommended to avoid passing the tip of the tube beyond the distal esophagus. The reason for recommending nasoesophageal intubation over nasogastric intubation is based on the fact that reflex peristalsis of the esophagus against a tube passing through the cardia can result in significant mucosal ulceration within 72 hours. This is not a factor in patients receiving a single dose of medication or contrast material.

TABLE The French Catheter Scale Equivalents*

Scale Millimeters Inches
3 1 0.039
4 1.35 0.053
5 1.67 0.066
6 2 0.079
7 2.3 0.092
8 2.7 0.105
9 3 0.118
10 3.3 0.131
11 3.7 0.144
12 4 0.158
13 4.3 0.170
14 4.7 0.184
15 5 0.197
16 5.3 0.210
17 5.7 0.223
18 6 0.236
19 6.3 0.249
20 6.7 0.263
22 7.3 0.288
24 8 0.315
26 8.7 0.341
28 9.3 0.367
30 10 0.393
32 10.7 0.419
34 11.3 0.445

*Multiple types of pediatric polyurethane nasogastric feeding tubes are available in sizes ranging from 8F to 12F that easily accommodate administration of liquids medications and fluids to kittens, cats, and small dogs.

The narrow lumen of tubes passed through the nostril of small dogs and cats limits the viscosity of solutions that can be administered through a tube directly into the gastrointestinal tract. Nasoesophageal intubation can be done with a variety of tube types and sizes (Table The French Catheter Scale Equivalents). Newer polyurethane tubes, when coated with a lidocaine lubricating jelly, are nonirritating and may be left in place with the tip at the level of the distal esophagus. When placing the nasogastric tube, instill 4 to 5 drops of 0.5% proparacaine in the nostril of the cat or small dog; 0.5 to 1.0 mL of 2% lidocaine instilled into the nostril of a larger-breed dog may be required to achieve the level of topical anesthesia needed to pass a tube through the nostril. With the head elevated, direct the tube dorsomedially toward the alar fold (). Pushing dorsally on the nasal philtrum and pushing the nostril from lateral to medially will help facilitate passage of the tube into the ventrome-dial nasal meatus.

Caution: The tip of the feeding tube can be inadvertently introduced through the glottis and into the trachea. Topical anesthetic instilled into the nose can anesthetize the arytenoid cartilages, thereby blocking a cough or gag reflex.

After inserting the tip 1 to 2 cm into the nostril, continue to advance the tube until it reaches the desired length. If the turbinates obstruct the passage of the tube, withdraw the tube by a few centimeters. Then readvance the tube, taking care to direct the tube ventrally through the nasal cavity. Occasionally it will be necessary to withdraw the tube completely from the nostril and repeat the procedure. In particularly small patients or patients with obstructive lesions (e.g., tumor) in the nasal cavity, it may not be possible to pass a tube. Do not force the tube against significant resistance through the nostril.

Gavage, or gastric lavage and feeding, in puppies and kittens can be accomplished by passing a soft rubber catheter or feeding tube into the mouth, tilting the puppy’s or kittens head, and watching it swallow the tube. Most puppies or kittens will struggle and vocalize. They usually will not vocalize if the tube has been placed into the trachea. A 12F catheter is of an adequate diameter to pass freely, but it is too large for dogs and cats less than 2 to 3 weeks of age. Mark the tube with tape or a pen at a point equal to the distance from the mouth to the last rib. Merely push the tube into the pharynx and down the esophagus to the caudal thoracic level (into the stomach). Verify the placement of the tube using the same dry syringe aspiration technique to ensure that the tube is positioned in the esophagus or stomach rather than the trachea. Attach a syringe to the flared end, and slowly inject medication or food.

Depending on the feeding tube type, the end of the tube may or may not accommodate a syringe. For example, soft, rubber urinary catheters are excellent tubes for single administration use. However, the flared end may not accommodate a syringe. To affix a syringe to the outside end of a tapered feeding tube or catheter, insert a plastic adapter () into the open end of the tube.

Special Considerations

Esophageal (versus intratracheal) placement of the feeding tube can be verified with a dry, empty syringe. Attach the empty syringe to the end of the feeding tube. Rather than injecting air or water in an attempt to auscultate borborygmus over the abdomen, attempt simply to aspirate air from the feeding tube. If there is no resistance during aspiration and air fills the syringe, the tube likely has been placed in the trachea. Completely remove the tube and repeat the procedure. However, if repeated attempts to aspirate are met with immediate resistance and no air enters the syringe, the tube tip is positioned properly within the esophagus. If there is any question regarding placement, a lateral survey radiograph is indicated.

Definitive confirmation of proper tube placement can be made by diluting 1 to 2 ml of an iodinated contrast agent with sterile saline, instilling the liquid into the tube, then taking a lateral thoracoabdominal radiograph to confirm entry of the contrast material into the stomach.