Analgesic Drugs and Dosages in Rodents and Rabbits  | Agricultural Animals Used in Research  | Birds 

 

An ARP veterinarian must be consulted if a research animal shows unexpected clinical signs suggestive of pain, illness, injury or distress. A veterinarian may be reached 24 hours a day by calling the Animal Resource Program office at 865-1495 (this phone number is posted in the animal facilities). If calling after hours, a recorded message will provide contact information.

Signs of pain and distress in laboratory rodents

Research animals can experience pain during and after many types of experimental procedures. To effectively treat pain in animals, personnel must be able to recognize signs of pain in the species they are working with. Mechanisms of pain perception are similar in all mammals, but the ability to tolerate and cope with pain varies between species. For example, prey species such as rodents may not show obvious signs of pain to avoid signaling to predators that they are ill and would be an easy meal. An animal experiencing mild to moderate pain may display only subtle behavioral signs associated with its discomfort. Moderate to severe pain usually leads to more obvious changes in normal physiology and behavior. Because animals can’t tell us how they feel, we must use close observation to recognize when pain alters normal behavior. Pain assessment scales or systems are often used to increase consistency and reduce subjectivity in pain evaluation. Ideally, these scales or systems should be easy to use, repeatable, and reliable when used by people of varying background and experience. All individuals involved in pain assessment must be trained to use the scale/system and know the trigger points for therapeutic or other interventions.

Common pain-related clinical signs and behaviors in rodents

Hunched posture:  General sign of pain or illness.

Decreased activity:  Painful or sick rodents are usually less active than normal. Rodents with localized pain may show decreased mobility of specific body parts or regions (e.g., lameness).

Facial expression/squinting of eyes:  By itself, squinting of one or both eyes can indicate pain associated with an ocular problem. Bilateral eye squinting along with other changes in facial expression can indicate more generalized pain. See: https://nc3rs.org.uk/grimacescales#posters.

Decreased body temperature:  Rodents that feel cold to the touch are likely severely hypothermic and need immediate veterinary care.

Decreased body weight:  Usually a result of decreased food intake due to pain and/or distress. Body condition scoring may be useful in chronic conditions.

Rough, greasy haircoat:  Painful or ill animals do not groom themselves regularly and will look scruffy and/or dirty.

Decreased nest building or maintenance:  Mice are highly motivated to build nests if provided with adequate nesting material. A decrease in amount or quality of nest building may be found in mice who are in pain, distress or ill.

Decreased response to external stimulation:  Unless well-used to handling, normal rodents attempt to escape when handled. Failure to show this behavior may indicate pain or illness.

Licking or scratching at painful site:  Especially post-operatively, may result in red, swollen or oozing wounds.

Porphyrin (red pigment) staining around eyes and nose:  Nonspecific sign of stress seen in rats only.

Managing Pain in Research Animals

Many different analgesic medications are available to provide effective pain relief without interfering with experimental objectives. Analgesic drugs work in various ways to relieve pain. Some, such as morphine and buprenorphine provide pain relief through their action on the central nervous system. Non-steroidal anti-inflammatory drugs (NSAIDS) such as ketoprofen and meloxicam, relieve pain by decreasing inflammation and, in some cases, direct analgesic action. Long acting local anesthetics such as bupivacaine, provide postoperative analgesia by blocking nerve conduction.

General Principles of Analgesic Drug Use

General anesthesia is required for all procedures likely to cause more than slight or momentary pain. Animals that are likely to experience post procedural pain must receive analgesic medication. Analgesics are often administered before or immediately after surgery (prior to anesthetic recovery) to minimize the development of post-procedural pain. Additional doses of analgesic medication may be given on a predetermined schedule and/or based on a subjective assessment of the degree of pain experienced by the animal. In most cases analgesics should be administered by injection. Analgesic drugs can be placed in drinking water or food for oral delivery but will not be effective if the animal is not eating or drinking or if the medication tastes bad. A detailed analgesic regimen must be incorporated into your experimental design based on a prediction of how much pain will occur after an experimental procedure. This type of regimen insures that all animals will receive some type of analgesic treatment, but it does not relieve research personnel of their responsibility to observe and evaluate each animal after surgery. Animals that continue to show signs of pain or have other complicating problems after surgery need to be assessed individually and treated appropriately.

Analgesic Drugs and Dosages

Dosages for several commonly used analgesic drugs in a variety of species are provided on this page.  The effectiveness of an analgesic drug will vary depending on species, strain, sex, age and other parameters. Please consult an ARP veterinarian for more information on alternative analgesic drugs and what to expect when using analgesic drugs in animals.

Analgesics for Rodents and Rabbits

Drug Name and Indications
Mouse
Rat
Hamster
Rabbit
Bupivicaine-local anesthetic; injected or dripped onto incision site Maximum total dose of 4 mg/kg given once at the end of surgery Maximum total dose of 4 mg/kg given once at the end of surgery    
Buprenorphine HCl-mild to moderate pain 0.1 - 0.5 mg/kg SQ q 4-6 hours 0.05 - 0.1 mg/kg SQ q 6-8 hours 0.05-0.5 mg/kg SQ q 8-12 hours 0.01-0.05 mg/kg SQ, IM or IV q 6-12 hours
Buprenorphine SR-Lab - extended release 0.5 - 1 mg/kg SQ; may be repeated once, 72 hours after first dose 1.0-1.2 mg/kg SQ; may be repeated once, 72 hours after first dose.    
Carprofen-mild to moderate pain; nonsteroidal anti-inflammatory drug 5 mg/kg SQ q 24 hours 5 mg/kg SQ q 24 hours 5 mg/kg SQ q 24 hours 4 mg/kg SQ or 1.5 mg/kg PO q 12-24 hours
Ethiqa XR - extended release buprenorphine 0.05 ml/20 gm BW SQ; may be repeated once after 72 hours. 0.1 ml/200 gm BW SQ; may repeat once after 72 hrs. Do not keep rats on wood chip bedding.    
Ketoprofen-mild pain; nonsteroidal anti-inflammatory drug 2-5 mg/kg SQ once 2-5 mg/kg SQ once   3 mg/kg SQ q 12-24 hours
Meloxicam-mild pain; nonsteriodal anti-inflammatory drug 5 mg/kg SQ q 24 hrs x 3 1-2 mg/kg SQ or PO q 24 hours x 3   0.2 mg/kg SQ q 24 hours

Analgesic effectiveness must be evaluated in each animal due to variations in response between individuals and strains. For more information or analgesic guidelines in other species please consult an ARP veterinarian.

 

Analgesics for Agricultural Research Animals

**Note: Most of the drugs listed below have required meat and milk withdrawal times that must be observed if used in animals intended for human consumption.

Drug Name
Cattle
Sheep
Horses
Swine

Aspirin

480-960 grains per mature cow PO every 12 hours

     

Buprenorphine*

 

0.005-0.01 mg/kg IV or IM every 4 hours

 

0.005-0.02 mg/kg IV or IM every 6-12 hours

Butorphanol*

0.01 mg/kg IV or IM every 4-6 hours

0.01 mg/kg IV or IM every 4-6 hours

0.01 mg/kg IV or IM every 4 hours

 

Flunixin meglumine*

0.5 -1.1 mg/kg IV every 24 hours

1.1 mg/kg IV every 24 hours

1.1 mg/kg PO or IV every 12-24 hours

1.1 mg/kg IV or SQ every 24 hours

Ketoprofen

   

0.5 mg/kg IV every 24 hours

 

Phenylbutazone

   

2.2-4.4 mg/kg PO or IV every 12-24 hours

 

*These drugs have required meat and milk withdrawal times that must be observed if used in animals intended for human consumption.

Analgesic effectiveness must be evaluated in each animal due to variations in response between individuals and breeds. For more information or analgesic guidelines in other species please consult an ARP veterinarian.

 

Analgesics for Birds (Including Poultry) Used in Research

 

 

 

*Note: The drugs listed below are not approved for use in birds intended for human consumption.

Drug Name
Dosage
Route
Butorphanol 1-3 mg/kg IM every 4-6 hours
Carprofen 1 mg/kg SQ every 8-24 hours
Flunixin meglumine 1-10 mg/kg IM every 24 hours
Ketoprofen 1-2 mg/kg IM every 8-12 hours
Meloxicam 0.5 mg/kg IV or IM or PO every 24 hours

 

 

 

Analgesic effectiveness must be evaluated in each animal due to variations in response between individuals and breeds. For more information or analgesic guidelines in other species please consult an ARP veterinarian.

 

 

 

 

 

 

 

The information and drug dosages presented in this website are intended as a resource for Pennsylvania State University research investigators. No guarantee of drug efficacy or safety is made nor must information obtained from this site be substituted for professional veterinary advice.