From the vet:
The main studies in the past few years are in rabbits, but drugs studied in Guinea Pigs and rabbits previously show very similar uptake with oral administration, which makes sense since the digestive tracts are so similar. A dose for a dog is 0.1-0.2 mg per kg of body weight, which is what was used to base the 0.07 mL dose previously used for your Guinea Pig. Since 2012, formularies for Guinea Pigs have stated the need for greater than 0.5 mg/kg for rodents, with does as high as 1-2 mg/kg for rats and mice. These were based on work with laboratory animals.
In rabbits, two studies done in 2009 showed that the dog dose was ineffective and a dose of 1 mg/kg minimum was needed to achieve behavioral evidence of pain control in rabbits:
- Behavioral Effects of Ovariohystorectomy and Oral Administration of Meloxicam in Laboratory Housed Rabbits. Research in Veterinary Science; 2009, March
Single and Multi-dose Pharmicokinetics of Meloxicam After Oral Administration to the Rabbit. Journal of Zoo and Wildlife Medicine; 2009, December
- Pharmicokinetics of Meloxicam in Rabbits After Oral Administration of Single and Multiple Doses. American Journal of Veterinary Research; 2013, April
Pharmikokinetics of Meloxicam Administered Orally to Rabbits for 29 Days. American Journal of Veterinary Research; 2014, February