1. Medication Administration in Cats and Dogs
CTVT pages

2. Routes of Medication Administration
Oral (PO)
Aural
Sublingual
Topical
Via feeding tube
Topical ophthalmic
Esophagostomy
Transdermal
Gastrostomy
Intranasal
Jejunostomy
Inhalation
Orogastric intubation
Nebulized or volatilized
Nasogastric intubation
Intratracheal
Rectal (PR)

3. Parenteral Routes: administered with a needle and syringe
Intradermal (ID)
Subcutaneous
(SC or SQ)
Intramuscular (IM)
Intravenous (IV)
Intraosseous (IO)
Intraperitoneal (IP)
Intra-arterial (IA)
Epidural/subdural
Intracardiac (IC)
Intramammary

4. Route Depends on Many Factors
Patient Factors
Health conditions
Symptoms
Absorption rate of drug required
Temperament
Ease of administration for client
Drug Factors
Type of medication/fluid
Formulation of drug
Cost
Systemic vs. local effect desired

5. Other Factors to Consider
Does this medication require that special precautions be followed during administration (i.e. gloves, mask)?
Examples?
Potential side effects?
Pain from injection
Vomiting/GI upset/constipation

6. Comparison of Common Parenteral Routes of Drug Administration
Intramuscular
90°
Intravenous
25°
Subcutaneous
45°
Intradermal
10°–15°
Epidermis
Dermis
Subcutaneous tissue
Muscle

8. Mini A&P Review of Skin Layers
The skin is made up of three layers: the epidermis, dermis, and subcutaneous layers
The epidermis is several cell layers thick and does not contain blood vessels. Its thickness varies greatly from region to region in any animal and varies from species to species.
The dermis is composed of blood vessels, lymph, nerve fibers, and accessory organs of the skin (glands and hair follicles).
The subcutaneous layer (hypodermis) is composed of connective tissue and contains a large amount of fat.
Muscle lies underneath all of these layers

9. Before the Injection Gather supplies Needles Syringe
Medication to be injected
Proficient person to restrain the animal
For venipuncture only:
Cotton ball with alcohol
Hydrogen Peroxide (optional)

10. Syringes are available in various sizes (even more than this)

11. Needles Needle gauge is determined by:
Consistency of drug
Route of administration
Patient size
At least two needles are required
One to draw up the medication
One to administer the medication
Why is this?

12. Process for Changing Needle
Draw up exact amount of drug
Can use smallest needle available
Aspirate all drug into the syringe (out of the needle)
Hub loss-
Remove needle and replace with appropriate needle
Carefully ensure all air is out of the syringe by slowly depressing the plunger.

13. Injectable Drugs Supplied as: May be stored in: Sterilized solutions
Powders that must be reconstituted with sterile solution
May be stored in:
Vials (single or multi-dose)
Ampules
Fluid bags

15. Intradermal Injections
Common use of ID route:
Desensitize skin
Allergy skin testing
Skin is usually shaved before performing an ID injection
Drug is not dispersed throughout the body

16. Intradermal Administration

17. ID Injection Procedure
A fold of skin is lifted or skin is pulled taught and a 25- to 27- gauge needle attached to a syringe is inserted with the bevel up into the dermis.
If allergy testing: A 0.1 ml volume of allergen is injected.
If locally anesthetizing skin: dose of drug
The injection site will look like a translucent lump if the injection is performed correctly.

18. Subcutaneous Injections
Easiest route to perform technically
Common use of SQ route:
Vaccine administration
Fluid administration
Pain medications, antibiotic injections, Insulin
Absorption rate is slow compared to other routes
May be slower in obese animals
Some substances are harmful if injected SC
Example:

19. Subcutaneous Administration

20. SC Injection Sites
Preferred site for most SC injections is the dorsolateral region from the neck to the hips.
The dorsal region of the neck and back should be avoided for drug administration.
Cat vaccines: the _______________________ should be avoided because of the incidence of vaccine-induced tumors.
Feline vaccinations should be administered in as distal a portion of an extremity as possible.

21. SC Injection Sites

22. SC Injection Procedure
Fold of skin is tented and the needle is inserted at the base of the tent.
Insert needle as if walking INTO the tent
Aspirate
Why?
After injection, briefly massage skin to facilitate drug distribution.

23. Skin Tent

24. Intramuscular Injections
Appropriate route for injection of small volumes of medication.
Common uses of IM route:
Anesthetics/sedatives
Convenient route of administration for fractious animals
Pain medications
Heartworm treatment
Generally, more painful for animals than SC or IV.
Why?

25. Intramuscular Administration

26. IM Injection Sites Drugs are most often administered in the:
Lumbosacral musculature lateral to the dorsal spinous processes
Semimembranosus/ semitendinosus muscles of the rear leg
In the hind limb: needle should enter the lateral aspect of the muscle and be directed caudally
Why?

27. Avoid the sciatic nerve!

28. IM Injection Sites
Deep IM injections in the third to fifth lumbar region of the ___________________ are used to administer adulticide heartworm treatment (Immiticide®).

29. IM Injection Procedure
Isolate the muscle between the fingers and thumb.
A 22 to 25 gauge needle attached to a syringe is embedded in the muscle at a ______ angle.
As with a SQ injection, the needle hub is checked for blood before administration of medication to make certain a vessel is not inadvertently penetrated.
How did we do this?
Once in the muscle, inject the medication slowly.
Massage the site for a few seconds after the injection to help distribute the substance if possible.
Exception:

30. Complications from IM Injection
Tissue trauma
Pain at injection site
Nerve damage

31. Intravenous Administration
Drugs and/or fluids may be injected directly into a vein or through an IV catheter.
IV route produces an immediate response
Usually given slowly
Common use of IV route:
Inducing anesthesia
Chemotherapeutic agents
Anti-convulsant drugs
Irritating drugs
Emergency/resuscitation drugs
Large amounts of _________ needed
Requires new needle for administration

32. IV Injection Sites CAT DOG
Cephalic
Medial saphenous
Femoral
Cephalic
Lateral saphenous
Note: The jugular vein is used to administer injections in small animals IF an intravenous jugular catheter is in place.

33. Cephalic Vein

34. Femoral/Medial Saphenous Vein (cat)

35. Lateral Saphenous Vein (dog)

36. IV Injection Instructions
Expel all air bubbles from the syringe prior to inserting into the vein.
Restrainer should occlude the vessel with digital pressure or use a tourniquet.
Grasp the extremity and pull the skin taut in a distal direction.
Swab the skin and hair with an alcohol-soaked cotton ball (go with the fur).
Insert a 20- to 25- gauge needle, bevel up into the vein.

37. IV Injection Instructions (cont’d)
Usually blood enters the hub of the needle at penetration of the vein (flash), BUT, placement is confirmed by aspirating.
What should we see?
Venipuncturist: communicate to restrainer “I’m in”
Restrainer: release pressure from the vein
Inject the medication into the vein.
If large volume of drug or movement of needle:
Communicate with restrainer and remove needle
Apply firm pressure to the injection site until hemostasis/coagulation occurs

38. If Using a Tourniquet
Most common: Nye Tourniquet or Penrose drain/rubber material
Can be very dangerous if used improperly
Goal is to visualize and palapte vein.
Must be able to remove before injecting!

39. Possible Complications with IV Injections
Injecting drug outside of vein
Hematoma formation
Intra-arterial injection of drug
Hitting a nerve (pain, lameness, paralysis)
Air-embolus
Phlebitis
Septicemia