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AHVMA Journal • Volume 58 Spring 2020 35
Scientific Report
Abbreviations
ADLs Activities of daily living
CBD Cannabidiol
NSAIDs Nonsteroidalanti-inammatorydrugs
OA Osteoarthritis
THC Tetrahydrocannabinol
Abstract
The objective of this 90-day pilot clinical trial was to
assess the impact of a full-spectrum product containing
hemp extract and hemp seed oil on dogs with chronic mal-
adaptive pain. A total of 37 dogs diagnosed with chronic
maladaptive pain primarily as a result of osteoarthritis
were enrolled in the study. The dogs were given an initial
physical examination that included systematic pain palpa-
tion, mapping of pain patterns, informal gait analysis,
metabolic prole, and owner interview. The same palpa-
tions and mappings were performed during each biweekly
assessment to identify trends, chart progress, and inform
dose adjustments. The metabolic parameters were repeated
at the end of the study. Of the 32 dogs that completed the
study, 30 dogs demonstrated improved pain support. Of
the 23 dogs in the study that were taking gabapentin at the
time of enrollment, 10 dogs were able to discontinue the
gabapentin, and an additional 11 dogs were able to have
their daily dose reduced with the addition of the cannabi-
diol (CBD) oil. Conclusion: The addition of a hemp-
derived CBD oil appears to positively affect dogs with
chronic maladaptive pain by decreasing their pain, thereby
improving their mobility and quality of life. The reduction
in gabapentin dose may be the result of changes in analgesia
and/or sedation with the addition of the hemp oil extract.
Introduction
Laws in the United States surrounding cannabis have
undergone tremendous changes over the last several
years. In 2018, the US government enacted the Agriculture
Improvement Act of 2018, which removed hemp from
Schedule I of the federal Controlled Substances Act. Hemp
Author contacts:
Lori Kogan, PhD
Department of Clinical Sciences, College
of Veterinary Medicine and Biomedical
Sciences, Colorado State University
Fort Collins, CO
Lori.Kogan@colostate.edu
Peter Hellyer, DVM
Department of Clinical Sciences, College
of Veterinary Medicine and Biomedical
Sciences, Colorado State University
Fort Collins, CO
Robin Downing, DVM, MS
The Downing Center for Animal Pain
Management, LLC
Wi ndso r, CO
The Use of Cannabidiol-Rich
Hemp Oil Extract to Treat
Canine Osteoarthritis-Related Pain:
A Pilot Study
Lori Kogan, PhD, Peter Hellyer, DVM, Robin Downing, DVM, MS
36 AHVMA Journal • Volume 58 Spring 2020
is a form of Cannabis sativa L with low levels (<0.3%) of
tetrahydrocannabinol (THC). The federal act authorized
the states to seek approval from the USDA to have primary
regulatory authority over hemp production within the state
by preparing and submitting a state plan of regulation to
the secretary of the USDA (1). Subsequently, the state of
Colorado (the location of the current study) passed a bill
in May 2019 stating that “Colorado leads the nation in
public policy supporting the hemp industry and is poised
to continue that leadership with the passage of the federal
‘Agricultural [sic] Improvement Act of 2018’” (2).
Due to the myriad of laws concerning cannabis and only
recent changes in the legal status of hemp, there is little
empirical research regarding the veterinary use of cannabis
products (3). Yet many pet owners are increasingly willing to
try cannabis products to help their pets with a wide array of
medical and behavioral issues (4, 5). Some of the benets of
cannabis products reported by pet owners include improved
mobility in animals with osteoarthritis (OA) as well as
reduced anxiety, pain, and occurrence of epileptic seizures
(5, 6). When pet owners were asked to compare cannabis
products to other forms of medication or therapy, the major-
ity (93%) reported that cannabis products work better than
other treatments (only 7% felt that cannabis does not work
as well) (6). When asked about side effects, these pet owners
most frequently reported sedation and overactive appetite.
Despite the interest by pet owners, however, the lack of
scientic studies has made veterinarians reluctant to
initiate cannabis-related conversations with their clients. In
addition, state laws legalizing medicinal and/or recreational
forms of cannabis do not apply to animals. The laws sur-
rounding the use of cannabis products, including hemp prod-
ucts, in veterinary medicine are complex and evolving. One
study found that 85% of veterinarians rarely or never initiate
conversations about cannabis (3). Similarly, very few advise
(73% either never or rarely), recommend (83% either never
or rarely), or prescribe (91% either never or rarely) cannabis
products, with a lack of knowledge being the most common
reason (3). With the changing laws, however, clinical trials
are now permitted. This paper outlines one such study.
Many pet owners and veterinarians working with animals
suffering from OA-related pain desire an alternative to tra-
ditional medications (nonsteroidal anti-inammatory drugs
[NSAIDs], gabapentin, etc). NSAIDs, as well as other drugs
such as gabapentin, are sometimes inadequate in relieving
OA-related pain and come with potential side effects, espe-
cially for geriatric patients (7). The facts that the endocan-
nabinoid receptor system is involved with pain modulation
and cannabis has antihyperalgesic and anti-inammatory
properties have made cannabidiol (CBD) an attractive option
to explore for the reduction of canine pain (8, 9). CBD is a
component of cannabis, which is derived from the hemp plant
and is low in psychoactive THC. One clinical trial conducted
with dogs suffering from OA found that CBD oil increased
the canine subjects’ comfort and activity levels and decreased
their pain without side effects (7). This study emphasized,
however, that different strains of cannabis contain differ-
ent amounts of cannabinoids, including CBD, making the
results difcult to generalize (7). For this reason, the current
study was undertaken to continue the exploration of canna-
bis products’ effects on dogs suffering from OA-related pain.
This pilot study had 4 objectives: (1) to determine if this par-
ticular hemp-derived CBD product could positively inuence
pain relief and overall function in dogs experiencing chronic
maladaptive pain from OA; (2) to determine if it would
be well tolerated and accepted by the enrolled dogs; (3) to
observe any potential effects on the doses of pain-related
medications already in place for the dogs; and (4) to identify
an appropriate dosing range to facilitate improved pain man-
agement in dogs suffering from chronic maladaptive pain.
Materials and Methods
A total of 37 dogs were enrolled in this 90-day pilot study.
All of the enrollees suffered from chronic maladaptive
pain, primarily as a result of OA. All but 5 of the dogs
were patients of a specialty clinic in animal pain manage-
ment in Colorado prior to participating in the study. Of
the 37 enrolled dogs, 32 dogs completed and had their
nal assessment at 90 days, and 5 dogs did not complete
the study due to their medical conditions or their owners’
life/schedule changes. Specically, changes in 1 owner’s
schedule precluded her ability to participate in the
reassessment appointments; 1 dog was diagnosed with a
bleeding splenic tumor and was euthanized; 1 dog devel-
oped an iris mass and the ophthalmologist recommended
withdrawal from the study; 1 dog was diagnosed with
an osteosarcoma and was withdrawn; and 1 dog’s pre-
existing liver and kidney disease progressed, and she was
therefore withdrawn from the study.
38 AHVMA Journal • Volume 58 Spring 2020
To minimize the potential for inconsistencies among
multiple observers, all enrollments and assessments were
conducted at the same hospital by the same veterinarian
(RD). Independent observations from the owners played
an important role in how these patients were managed,
providing feedback on the efcacy of increasing the hemp
oil extract and decreasing the gabapentin dose. Descrip-
tive statistics and paired t tests were conducted in SPSS
(IBM SPSS version 25) for changes in pain, ALKP, and
ALT. Statistical signicance was set at P < .05.
Eligible canine subjects and their owners met the follow-
ing criteria: dogs with chronic pain from OA for at least
3 months in duration; owners who desired trying a CBD
product to manage their dogs’ pain; owners who could
commit to a 90-day study with dogs’ medical assess-
ments every 2 weeks; owners who were willing to keep an
informal journal of their dogs’ activities of daily living
(ADLs) using the Cincinnati Orthopedic Disability Index
(se e Appendix 1 p. 44) as a guide during the duration of
the study to better understand the impact of the CBD prod-
uct; and owners who agreed not to use any medications or
supplements during the 90-day course of the study unless
approved by the veterinarian performing the assessments.
The owners of the enrolled dogs consented to have the
data generated during the study anonymously aggregated
for evaluation, statistical analysis, and publication at a
future date. Likewise, they consented to a review of
their dogs’ complete medical records to ensure that all
inclusion criteria were met. This study was classied
as exempt by the institutional review board at Colorado
State University.
Several specic pain-directed medications and therapies
were excluded during the 90-day study. With the limited
study population and in order to create as consistent a
“baseline” as possible, the use of NSAIDs was restricted
from all participants. The intention was to have NSAIDs
available only as a “rescue” therapy for individuals whose
pain could not be relieved with the CBD product under
investigation. In addition, none of the patients enrolled
in the study were taking tramadol or amantadine at the
commencement of the study, and to minimize extra-
neous variables, the addition of tramadol or amantadine
during the course of the study was disallowed. Finally,
to limit some of the inherent variability in a study of this
nature, study participants were limited to a single physi-
cal medicine modality. Because several participants were
receiving medical acupuncture for neurologic support
(rather than for pain management) at the time of enroll-
ment, the decision was made to not withdraw acupuncture
support from their treatment protocols in order to avoid
compromising these patients.
Specic pain-directed medications that were permitted
during the 90-day study included gabapentin and poly-
sulfated glycosaminoglycan (a). Most of the dogs enrolled
in this study were under the care of a veterinary pain
management expert and were already taking gabapentin
as part of a multimodal pain management strategy. Taking
into consideration the phenomenon of rebound pain in
response to an abrupt withdrawal of gabapentin, it was
determined that dogs already taking gabapentin would be
able to continue their dosing, but any new prescriptions of
gabapentin were disallowed during the course of the study.
Specic pain-directed therapies that could possibly be
permitted during the 90-day study pending approval
included medical acupuncture, therapeutic laser, and
nutraceuticals. These therapies were evaluated on a case-
by-case basis. Although these therapies can alter the
degree of pain and may have affected the results, the
intent of the study was to determine the role of the hemp oil
extract as an adjunct in the management of chronic pain.
In this group of patients, chronic pain was managed using
a multimodal approach, and the authors were interested
in determining the role of the hemp oil extract in the
presence of other therapeutic modalities.
The initial assessment of the dogs enrolled in this study
included a full physical examination and informal gait
analysis. The physical examination consisted of a sys-
tematic pain palpation and mapping of pain patterns. The
same palpation and mapping were performed during each
biweekly assessment to identify trends, chart progress, and
inform dose adjustments. A metabolic prole, including
a CBC, serum chemistry prole, and a screening thyroid
prole, to evaluate organ system function and to provide
a baseline for future comparison were performed on each
enrollee. These same metabolic parameters were repeated
at the end of the study. The informal gait analysis consisted
AHVMA Journal • Volume 58 Spring 2020 39
of observing the dog, with the owner as the handler,
at a slow walk, a fast walk, and a trot. The dogs were
in an inside hallway approximately 40 feet in length,
moving rst away from and then toward the observer
(RD). Lameness was noted as to limb and severity. In
addition to identifying lameness, the purpose was to
gain insight into each patient’s ability and willingness to
move at various speeds and to note any changes over the
course of the study. No force plate or lm analysis was
conducted. Informal assessment of the dogs’ ease and
willingness to move was one aspect of evaluating their
quality of life. Initial assessment also included a detailed
interview with each dog owner to discuss the dog’s ADLs
and quality of life as well as the owner’s desired outcome
goals for the dog.
At the initial evaluation and enrollment, qualied dogs
received a CBD oil product at a dose of 0.25 mg/kg
delivered on food QD for 3 days and then morning and
night (approximately every 12 hours). The product
given was a certied organic, cold-pressed hemp seed oil
infused with 1,000 mg of full-spectrum hemp extract
derived from organically grown hemp plants, cultivated
in Colorado. Full-spectrum extract includes cannabinoids
(such as cannabidiolic acid, CBD, cannabigerol, canna-
bichromene), avonoids, terpenes, and other constitu-
ents within the cannabis plant (see Cannabinoid Prole
in Appendix 2 p. 45).
Pain assessments of each participant were conducted
every 2 weeks during the 90-day study and consisted of
a systematic pain palpation and pain pattern mapping,
informal gait analysis, and review with each dog’s owner
of the previous week’s ADLs and owner observations as
recorded in the owner’s log. The CBD dose was adjusted
as needed in response to the new assessment. CBD dose
escalations of 0.5 to 0.75 mg/kg approximately every
12 hours were prescribed at each reassessment until the
patient’s pain score on palpation was 0 to 1 on a scale of
10. Each modied dose of the CBD product within that
dose escalation range reected a volume that was easy for
the owner to measure. The primary goal was to achieve
acceptable comfort without inducing sedation. Although
sedation is a known potential side effect of CBD ingestion,
the sedation may be occurring as a result of low levels
of THC in the formula, not the CBD (10).
Each patient’s overall pain severity was scored using a
0 to 10 scale, with 10 representing the worst possible pain.
This overall pain score alongside the pain map was used to
guide CBD oil dose adjustments. The pain map recorded
anatomic locations that were reactive to systematic pal-
pation. This pain palpation technique has been described
in detail (11). In addition, for the dogs taking gabapentin
for chronic maladaptive pain at the time of study enroll-
ment, once their comfort level was stable following
CBD dose escalations, gabapentin dose reductions were
attempted. Gabapentin dosing varied from 10 to 40 mg/kg
delivered every 8 to 12 hours, depending on the needs
of the individual patient to achieve adequate pain
relief without inducing sedation. At times, deescalating
the gabapentin dose changed the dosing interval from
every 8 hours to every 12 hours or from every 12 hours to
every 8 hours, depending on the total dose per day, ease of
achieving the required dose based on currently available
strengths of gabapentin, and ease of dosing with respect to
the owners’ schedules. The gabapentin dose was reduced
by 20% to 40% of the total daily dose based on the reduc-
tion amount that would provide the easiest dose delivery
(for instance, reducing a dog’s dose from 1,200 to 900 mg
per day, which would reduce the daily dose by 300 mg).
The new dose was maintained until the next assessment.
If a dose reduction was too great (dened as increased
pain noted in the following pain reassessment), the dose
would be increased to the previous level. These dose
reductions were a way to assess the ability of the CBD
oil to reduce the required dose of gabapentin to support
the dog’s comfort level.
Results
A total of 32 dogs completed the study, with only 2 dogs
deemed by their owners and supported by the veterinary
assessments to have achieved no measurable improvement
in pain with the addition of the CBD oil. The nal CBD
dose used in the 2 “non-responders” was 2 mg/kg every
12 hours. These dogs’ overall mobility and comfort did not
change during the course of the 90-day study, with their
overall pain scores remaining at 1/10. It is unclear why
they seemed to show no changes with the addition of the
CBD product. The 30 remaining dogs represent a variety
of breeds with an average weight of 23.2 kg (range: 5–50 kg)
and average age of 10.9 years (range: 2–16.6 years)
(Table 1). All 30 dogs demonstrated improved pain
40 AHVMA Journal • Volume 58 Spring 2020
support, with their pain scale score decreasing from
an average of 3.2 ± 2.2 (mean ± standard deviation) to
0.97 ± 0.81, or an average change of −2.23 ± 2.3 (Table 2).
Of the patients, 7 patients had no change in their over-
all pain scores, starting and ending the study with pain
scores of 1. These 7 dogs started the study with gabapentin
as a part of their pain management protocols, and their
gabapentin doses were reduced and comfort was retained.
Of the 23 dogs that were taking gabapentin at the time of
enrollment, 10 dogs were able to discontinue taking
gabapentin after the addition of the CBD oil to their pain
management protocols. Of the 13 dogs in the study that
were taking gabapentin when they were enrolled and were
unable to discontinue gabapentin by the end of the study,
11 dogs were able to have their daily dose of gabapentin
reduced with the addition of the CBD oil; 5 enrolled dogs
received no gabapentin during the course of the study.
Of the 30 dogs deemed to benet from the addition of
CBD oil to treat their chronic maladaptive pain, all ended
the study with an overall pain score ranging from 0/10 to
2/10 (Table 2). Of these 30 dogs, 6 dogs experienced an
improvement in their overall pain scores of 5 or better:
2 dogs’ scores reduced from 8/10 to 1/10; 2 dogs’ scores
reduced from 7/10 to 1/10; 1 dog’s score reduced from 6/10
to 1/10; and 1 dog’s score reduced from 5/10 to 0/10.
Among these 30 dogs, the dose of CBD needed to achieve
a positive effect ranged from 0.3 up to 4.12 mg/kg BID.
The 2 dogs in the study requiring the highest dose of the
CBD product were both Cavalier King Charles spaniels
(not related to one another), and neither of these dogs
experienced any changes/elevations in liver enzymes. It
is unclear why some patients responded to a very small
dose of the CBD product (0.3 mg/kg per dose), whereas
the majority required dosing in the range of 1 to 2 mg/kg
per dose. This wide dosing range suggests that practi-
tioners must approach CBD use for chronic pain in dogs
with the intention of following these patients carefully
during their initial treatment in order to ne-tune the CBD
dose to meet the needs of the individual. As an analogy,
it is a well-known phenomenon in human pain manage-
ment that individuals can have very different requirements
of opioids to control pain. Further studies of CBD use
in dogs for chronic pain may facilitate a better understand-
ing of variable needs among individuals. The majority,
Table 1. Patient Characteristics of Dogs
With Chronic Pain Enrolled in CBD Trial
Patient # Breed Age (years) Sex Weight (kg)
Existing patients
1Border collie 8.9 FS 25
2 German shepherd 8.2 FS 31
3Rhodesian Ridgeback 11.9 FS 38.6
4Rhodesian Ridgeback 2FI 38
5Labrador retriever 12.8 MN 34
6Labrador retriever 12.8 FS 25
7Maltese 13.3 FS 5
8Labrador retriever 13.5 MN 40
9American pit bull terrier 10.3 MN 28.5
10 Australian shepherd 13.3 MN 10.4
11 French bulldog 5.75 MN 13.6
12 Bichon frise/cocker spaniel 14 FS 9
13 Scottish terrier 16.6 MN 11.8
14 German shepherd 12.9 MN 43.2
15 Shepherd/chow 12.1 FS 21
16 Great Dane 9 FS 50
17 King Charles spaniel 8.1 FI 8
18 Beagle 13.25 MN 10.2
19 King Charles spaniel 8.8 MN 10
20 American pit bull terrier 6.3 FS 27.3
21 Australian shepherd 11.4 FS 2 7.6
22 Peke-a-poo 15.5 MN 8.2
23 Beagle 9.8 FS 10.5
24 Labrador retriever 8.4 MN 41
25 Border collie X 13.7 FS 27
26 Dachshund (standard) 10.2 FS 5.5
New patients
27 Shiba Inu mix 14.25 FS 11
28 Pit bull 5.25 FS 27
29 Australian shepherd 13.25 FS 26
30 Labrador retriever 11.6 FS 33
Patients were either existing or new patients to the clinic for the treatment
of chronic pain.
Abbreviations: FI, intact female; FS, spayed female; MN, neutered male.
AHVMA Journal • Volume 58 Spring 2020 41
or 19, of these dogs ended the study with a dose ranging
between 1.2 and 2 mg/kg BID.
Among the study’s dogs taking gabapentin that expe-
rienced a dose reduction (but not a withdrawal of gaba-
pentin), the nal doses varied from 20% to 60% of the
original dose. The dogs taking gabapentin at the time of
enrollment had been taking gabapentin for a time that
ranged from 3 months to 10 years.
The only clinically meaningful change in blood param-
eters obtained was an increase in ALKP (Table 3). Inter-
estingly, there was a slight decrease in ALT between the
beginning and end of the study, but it was not statistically
signicant (Table 4).
During the course of the study, the dog owners shared their
subjective impressions of their dogs’ responses to the CBD
oil. These impressions included observations of increased
energy and stamina for daily activities. Quotes from clients
include: “She’s more like a puppy”; “He is acting like a
much younger dog”; and “I haven’t seen him play like this
for a long time.” Additionally, several of the dog owners
reported noticing that their dogs were more attentive, ani-
mated, and mentally engaged after starting the CBD oil.
During the study, gabapentin was decreased (n = 11) or
eliminated (n = 10) for 21 dogs. Many of these dog own-
ers reported that their dogs subsequently slept less, which
translated into more interaction time with the family. Our
results could not differentiate the reason for less sleep in
these patients: a reduction in gabapentin-induced sedation,
improved analgesia from the hemp oil extract, or both.
Overall feedback from 94% of the owners (n = 30)
indicated they felt their dogs’ quality of life had improved
after starting the CBD product.
Discussion
Increasing interest in hemp-derived CBD products for
pain relief in dogs, coupled with minimal research dem-
onstrating safety and efcacy to date, prompted this
pilot study to examine the potential role of a CBD oil as a
strategy for managing chronic maladaptive pain in dogs
with OA. Of the 32 dogs that completed the study, 30 dogs
demonstrated benets from the addition of this hemp-derived
Table 2. Starting and Ending Numeric Rating Score, CBD Dose, and Gabapentin Doses in a Clinical Trial
of Dogs Receiving CBD for the Treatment of Chronic Pain
Pre Post Change
Numeric Rating Score* 3.2 ± 2.2 0.97 ± 0.81 −2.23 ± 2.3
CBD dose (mg/kg) 0.31 ± 0.04 1.67 ± 0.09 1.36 ± 0.88
Gabapentin dose (mg/day)** 1,846 ± 1,756 710 ± 1,112 −1,263 ± 1,314
*NRS (t = 5.35, df = 29, P <.001); **Gabapentin (t = 5.12, df = 29, P = .001).
Data are presented as mean ± standard deviation.
Abbreviations: df, degrees of freedom; NRS, Numeric Rating Scale.
Table 3. Changes in Liver Enzymes (ALKP)
in Dogs With Chronic Pain Receiving CBD
in a 90- Day Trial
Starting ALKP (U/L) Ending ALKP (U/L) Change in ALKP (U/L)*
133.3 ± 118 264 ± 233.2 130. 8 ± 135
*ALKP (t = −5.22, df = 28, P = .001).
Biochemistry values were obtained before beginning the clinical trial
and at 90 days.
Abbreviation: df, degrees of freedom.
Table 4. Changes in Liver Enzymes (ALT)
in Dogs With Chronic Pain Receiving CBD
in a 90- Day Trial
Starting ALT (U/L) Ending ALT (U/L) Change in ALT (U/L)*
93.5 ± 69.3 91 ± 60.4 −2.5 ± 43
*ALT (t = .31, df = 29, P = .76).
Biochemistry values were obtained before beginning the clinical trial
and at 90 days.
Abbreviation: df, degrees of freedom.
42 AHVMA Journal • Volume 58 Spring 2020
CBD oil. Outcome benets included decreased pain scores,
improvements in mobility, and improved quality of life
as dened by their owners.
A total of 23 dogs in the study were taking gaba-
pentin as part of a multimodal pain management proto-
col. Of the total, 10 dogs (43.5%) were able to discontinue
their reliance on gabapentin with the addition of CBD
oil. Of the 13 dogs who continued to take gabapentin,
11 dogs were able to reduce the gabapentin dose neces-
sary to retain comfort to 20% to 60% of the original
dose. These results strongly suggest that a CBD prod-
uct, at an appropriate therapeutic dose, may provide a
gabapentin-sparing effect for dogs experiencing chronic
maladaptive pain.
The dosing range for hemp-derived CBD oil suggested
by this study reects a similar range to that articulated
by Gamble et al (study doses of 2 and 8 mg/kg, with anec-
dotal evidence suggesting efcacy as low as 0.5 mg/kg),
implying that any potential variability among different
hemp plant genetics may be overcome by demonstrating,
via independent analysis, the presence and concentration
of the active CBD molecule (7). Due to the variation in
concentration from product to product of CBD content
and constituents such as terpenes, cannabinoids, and a-
vonoids, it is essential to publish an analysis of the product
being tested in order to describe that specic cultivar.
Interestingly, ALKP, but not ALT, increased signicantly
during the 90-day trial. In a study to investigate CBD
hepatoxicity, 8-week-old male B6C3F1 mice were gavaged
with CBD in an acute and subacute toxicity model. In
both models, mice developed signs of hepatoxicity with
evidence of cholestatic changes (12). The doses used in
that study were signicantly different from doses used
in the current study. Nevertheless, it is worthwhile to note
the potential for hepatotoxicity as a result of an accidental
overdose. There was no evidence of clinical hepatic dis-
ease in dogs in this study that received CBD; however, the
changes in ALKP suggest the need for longer-term safety
studies. The dog who was withdrawn from the study due
to progressing systemic disease was determined via
abdominal ultrasound to have a very advanced liver tumor
that clearly predated the start of this 90-day study. His rapid
decline in activity and quality of life prompted the ultra-
sound, which revealed the terminal neoplastic disease.
This study had several limitations. It was an open study
with no placebo control group, and because a single
individual assessed all patients in the absence of a con-
trol group, there was a potential for bias. In addition,
the sample size was relatively small. Although the study
subjects were understood to be similar in that they were
all suffering from OA, OA and its resultant pain create
individualized experiences among patients. In addition,
the pain assessment and scoring of canine pain are sub-
jective by nature. The investigators attempted to limit the
subjectivity by having the study dogs evaluated and the
owners interviewed by a single individual (RD) through-
out the study. Future studies incorporating more objec-
tive assessments of pain, such as force plate analysis, are
needed to quantify the amount of functional improve-
ment associated with CBD products. Longer-term studies
are needed to determine if CBD, in combination with
other analgesics used to treat chronic pain, has deleterious
effects on liver function.
In summary, this study provides the foundation for
future research into the benecial use of CBD products,
delivered at therapeutically relevant doses, to mitigate
chronic maladaptive pain in dogs with OA.
AHVMA Journal • Volume 58 Spring 2020 43
Acknowledgments
communicating with dog owners and manuscript formatting.
Endnote
a. Adequan®
References
.
.
US veterinarians’ knowledge, experience, and perception
regarding the use of cannabidiol for canine medical conditions.
Front Vet Sci
for pets: gaps in our knowledge. Toxicol Commun
Cannabis in veterinar y medicine: cannabinoid therapies for
animals. In: Gupta RC, Srivastava A, Lall R, eds. Nutraceuticals
in veterinar y medicine. Switzerland: Springer International
use and perceptions of cannabis produc ts. J Am Holist Vet Med
Assoc
osteoarthritic dogs. Front Vet Sci
effect of the nonpsychoactive cannabinoid, cannabidiol,
Br J Pharmacol.
9. Nagarkatti P, Pandey R, Rieder SA, Hegde VL, Nagarkatti M.
Future Med
Chem
synthetic cannabinoids, and cannabidiol in dogs and cats.
Vet Clin North Am Small Anim Pract
NAVC Clinician’s Brief.
of a cannabidiol-rich cannabis ext ract in the mouse model.
Molecules
44 AHVMA Journal • Volume 58 Spring 2020
Appendix 1
AHVMA Journal • Volume 58 Spring 2020 45
Cannabidiolic acid (CBD-A)
Cannabidiol (CBD)
(–)-trans-∆⁹-tetrahydrocannabinol (THC)
∆9-Tetrahydrocannabinolic acid A (THC-A) ∆8-Tetrahydrocannabidol
Tetrahydrocannabivarin (THCV)
Cannabidivarin (CBDV)
Cannabigerolic acid (CBG-A)
Cannabichromene (CBC)
Cannabinol (CBN)
Cannabigerol (CBG)
Appendix 2
