Is CBD Safe and How Does it Vary Between Dogs and Cats? Facts, Dosages, and Cautions – Part IV: A Practical Guide to Responsible Use

Part 4 – Safety, dog vs. cat differences, and other considerations

Bioavailability and species

Dogs absorb CBD much better than cats. In a 12-week study with the same dose (2 mg/kg BID), the mean Cmax in dogs was 301 ng/mL; in cats, it was only 43 ng/mL (Graph 5). This explains why felines sometimes need more mg/kg or liposomal formulas.

Graph 5 shown above: "Oral bioavailability: dogs vs. cats"

Safety profile

• Most trials report mild and reversible effects: drowsiness, soft stools, hypersalivation (cats).

• Elevations in ALP/ALT are common but have not been correlated with functional liver damage.

• Maximum tolerated doses: dogs >30 mg/kg; cats 30 mg/kg without severe toxicity.

A key question for any owner is: Is CBD safe for my pet? So far, scientific literature suggests that CBD has a fairly good safety profile in dogs and cats when used at common "therapeutic" doses (e.g., 1–5 mg/kg). In multiple studies, including prolonged treatments of several months, most pets did not experience significant adverse effects . Unlike THC, CBD does not produce intoxication or noticeable discoordination at normal doses, so the animal does not "get high" or lose lucidity. In fact, in a long-term study in dogs (6.5 months receiving 4 mg/kg daily), CBD was well-tolerated and considered safe, with the caveat of a consistent increase in blood alkaline phosphatase (ALP) . This increase in liver enzymes (ALT or ALP) is a frequent finding but so far has not been linked to functional liver damage – it simply indicates that the animal's liver is metabolizing the compound. However, as a precaution, regular blood tests are usually recommended if the animal will receive CBD for a prolonged period .

The mild side effects that have been reported include: transient drowsiness or lethargy (in some animals, CBD can cause relaxation and increased sleep, especially at high doses), diarrhea or soft stools (possibly due to the product's carrier oil) , occasional vomiting, or signs of dry mouth/hypersalivation. In cats, as we saw, salivation, licking, or momentary restlessness may occur after oral administration due to taste. These effects are usually temporary and manageable by reducing the dose or administering with food. Important: CBD is not psychoactive or intoxicating for pets, so there should be no severe disorientation, hyperactivity, or anything of the sort – if this occurs, it is possible that the product contains more THC than desired.

Speaking of THC, beware of unregulated products! A safety risk is giving pets cannabis oils of unknown origin or marijuana directly, which can cause severe toxicity (ataxia, nervous depression, urinary incontinence, etc.). Always use high-purity CBD products derived from hemp with <0.3% THC, preferably those formulated specifically for pets. This ensures that the THC content is minimal or nil, avoiding scares. In reviewed studies, all used hemp extracts practically free of THC and no dog or cat showed signs of intoxication .

Another consideration is quality and exact dosage: given that the CBD market for pets is poorly regulated in some places, there is variability in the actual CBD concentration in commercial oils or treats . It is advisable to purchase products from reliable companies that provide laboratory analyses (certificates of content). Start with low doses and see how your pet reacts. Every animal is different: some dogs show improvement with 1 mg/kg, others may require 4 mg/kg; and greatly exceeding recommended doses is usually not helpful and could increase adverse effects.

Other emerging indications

• Inflammatory Bowel Disease (IBD): CBD improves the intestinal barrier and modulates the microbiota in murine models; clinical trials in canines are anticipated.

• Atopic dermatitis: A series of 8 cases showed a significant reduction in pruritus with 2 mg/kg BID of CBD oil.

• Supportive oncology: Owners report improved appetite and rest in dogs with advanced cancer; evidence is still anecdotal.

Good practices for use

1. Certified product (<0.3% THC) and clear CBD mg labeling.

2. Initial dose: 1–2 mg/kg BID (dogs), 0.5–1 mg/kg BID (cats) and adjust.

3. Monitoring blood biochemistry every six months if used chronically.

4. Avoid mixing with NSAIDs or anticonvulsants without veterinary supervision (metabolic interaction).

In summary,

the accumulated scientific evidence (based on the review of 20 sources we have carried out) indicates that CBD can offer several therapeutic benefits for dogs and cats: from reducing anxiety and stress, alleviating chronic pain and inflammation, to helping as an adjunct in epilepsy and perhaps improving certain gastrointestinal conditions. All this by acting through the endocannabinoid system and other neuroimmune pathways in our four-legged companions. While it is not a "magic cure" and does not replace traditional veterinary care, CBD is emerging as a valuable tool within a comprehensive approach to animal health. As more studies are conducted, we will better understand optimal doses, precise indications, and any limitations. For now, interested owners should consult their trusted veterinarian, who can guide them on its responsible use. With knowledge and caution, CBD could improve the well-being of many pets that today suffer from anxiety, pain, or other ailments, providing them with a more comfortable and peaceful life.

Bibliography – Part 4

1. Deabold KA et al. AJVR 2019

2. Marker‑Katz A et al. Animals 2022 (dermatitis)

3. Comprehensive safety review, Ann. Rev. Anim Biosci 2025

4. PK and safety study (2019): Pharmacokinetics and tolerability of CBD in dogs and cats. Found greater CBD absorption in dogs than in cats (Cmax dogs 301 ng/ml vs. cats 43 ng/ml) and more taste effects in cats (drooling, licking), but overall both tolerated it well without serious clinical abnormalities .

10. Long-term tolerability study (2023): Long-term CBD supplementation in healthy dogs. Concluded that 4 mg/kg daily for 6.5 months was well tolerated in dogs, observing only reversible ALP elevation . Reinforces safety with prolonged use.

11. Owner surveys (2020-2021): Several international surveys show the growing use of CBD in pets and the largely positive perception of its effects (pain relief, anxiety, seizures) , although they also point out the need for more scientific information (many veterinarians and owners ask for more efficacy data ).

12. Molecular mechanisms: Basic research detailing how CBD interacts with receptors: modulation of CB1/CB2 , agonism at 5-HT1A (anxiolytic) , activation of TRPV1 (analgesic and anticonvulsant) , inhibition of FAAH elevating endocannabinoids , and activation of PPAR-γ (anti-inflammatory) . These mechanisms explain its multi-site effects in the pet's body.

13. Safety in cats (2021): Safety of escalating cannabinoid doses in cats. Showed that healthy cats tolerated up to 30 mg/kg of isolated CBD (and also THC up to 41 mg/kg in another group) with only mild and transient effects . This indicates a wide safety margin, although such high doses are not used in practice.

14. Effects on oxidative stress and pain: Studies in rats and animal models (referenced in reviews) show that CBD has neuroprotective and antioxidant properties that could protect against neural damage in chronic epilepsy , and activates antinociceptive pathways in the brain that contribute to its analgesic effect (e.g., synergistic opioid and endocannabinoid circuits) .

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