"Dogs’ livers break down naltrexone MUCH faster than peoples’ livers. So, it takes a bigger dose than you would think necessary to get blood levels that are equivalent to what you have when people take the doses that are recommended for them. If I had a large dog I would dose them with a normal ‘human’ dose two times every evening, with the second dose being given around two and a half hours after the first. If possible, dose titration to effect would be desirable." - That Crazy Pharmacist
Yes Dogs can take LDN as well. So can you cats, horses, cows, llamas, or whatever pet you have! The dosage varies from animal to animal as it varies from human to human. It is common for that average human to take it at 4.5 mg but is slightly different for animals. Ask you vet what the best dosage your pet can take LDN at.