First, we have a study on the clinicopathologic findings of IV regional limb perfusion (RLP) of amikacin in chickens. Distal pelvic limb infections, in particular pododermatitis and septic arthritis, are common causes of morbidity and mortality in birds. These conditions are challenging to treat due to repeated mechanical trauma, biofilm formation, difficulty in keeping affected lesions clean, granuloma formation, and extensive scar tissue. Standard treatment methods, such as topical and systemic antibiotic therapy, are often insufficient for treating moderate to severe infections, and treatment failures are common; because of that, RLP has been used to treat cases of distal limb infections in avian species.

However, potentially nephrotoxic drugs, such as amikacin, may increase the risk of nephrotoxicity with RLP because of the presence of the renal portal system and direct venous blood flow from the pelvic limbs to the kidneys. This study tested the safety of repeated amikacin administration (20 mg/kg q24h for 3 doses) via RLP in healthy female chickens. 

Their results showed no changes to plasma uric acid concentrations, nor in renal pathology scores between treated and control birds or between kidneys ipsilateral to the perfused limb and contralateral kidneys. Therefore, they concluded that RLP of amikacin at high doses produced no discernable renal pathology in healthy euhydrated chickens. 

It is important to note that all birds here were healthy and euhydrated, so use caution in clinical patients as they are often dehydrated and have concurrent systemic illness (meaning, do not use until rehydrated!). Sedation or anesthesia were not needed in these birds, but you may need to with more fractious or nervous patients, which may affect renal perfusion. Stress can potentially decrease renal blood flow since renal portal valve opens under sympathetic nervous stimulation, allowing blood to bypass the kidney.

Second, we have a 2022 study on the effects of high-dose, repeated meloxicam administration in chickens. Meloxicam is a commonly prescribed NSAID that has demonstrated pharmacodynamic efficacy at a single high dose of 5 mg/ kg for chickens. This study aimed to characterize clinical, clinicopathologic, and histopathologic effects of multiple doses of meloxicam (5 mg/kg PO q 12 hr x 5 days).

Twenty-one healthy adult Rhode Island Red hens were randomly assigned to a treatment (n=11) or control group (n=10), and received a 15-mg tablet of meloxicam or a nonmedicated feed pellet, respectively, orally twice daily. Following completion of the treatment course, an external physical examination, blood collection for a CBC and plasma biochemistry panel, euthanasia, necropsy, and measurement of meloxicam tissue residues would be performed.

However, during the treatment course, four hens from the treatment group died or were euthanized due to poor condition before the treatment period ended. Within the meloxicam group, 7 out of 11 hens had gross and histologic evidence of varying levels of renal acute tubular injury and gout. Plasma uric acid concentrations and heterophil count were above the species reference intervals in all affected hens in the treatment group. Also, meloxicam was present at detectable concentrations in all tissues submitted. Based on the results of this study, repeated oral dosing of meloxicam in chickens at 5 mg/kg twice daily is not recommended. 

It is important to note that the authors didn’t feel that underlying renal disease was a factor in morbity or mortality of meloxicam group because the ones in the control group were similar age, breed, husbandry, and they had no acute renal disease. The hematologic changes are likely clinically irrelevant, and may be due to stress. Also, uric acid was elevated, but it is not a sensitive indicator for mild/mod renal pathology in birds in clinical circumstances.

Lastly, we have a study on the pharmacokinetics of amantadine after oral administration in orange-winged Amazon parrots (Amazona amazonica). Amantadine is a synthetic amine that increases the release of dopamine in CNS, and via weak antagonism of NMDA receptors, decreases tolerance to opioids.  It reduces nociception associated with chronic pain and can be used alone; however, it may need multimodal treatments to effectively manage pain. It is synergistic with NSAIDs, opioids, and derivatives of GABA, so it can help to decrease opioid use!