Hi Boris and Pinkangel,
Hope this helps.
Antibiotics are ideally injected into the intraperitoneal space rather than through oral route or baths. Oral route administration is quite a hassle especially if the axolotl is inappetant and refuse to feed on a 'medicated worm'. Manipulation of the jaw to drench can also result in nasty fractures. Baths are ok but its difficult to titrate to a level effective yet safe to treat a systemic illness (more for minor external sores).
Inject with a tuberculin 25-gauge needle (dog/cat insulin needle is fine) intraperitoneally, just in front of a hind leg, approximately parallel to the body and about midway between the dorsal and ventral surfaces: that is, dorsal to the bladder and ventral to the kidneys and too caudal to hit the liver or spleen. Attached is a link with a picture of where the shot should be given.
http://www.axolotl.org/health.htm
I would recommend use of amikacin +
piperacillin. Alternatively,
gentamicin or enrofloxacin can also be used but they have more serious side effects.
If your vet intend to use a nephrotoxic drug such as
gentamicin, i highly recommend the axolotl be supported with fluid therapy for a day or so beforehand. The fluid therapy will aid in renal perfusion and minimise the side effects. You can basically soak the axolotl in amphian ringers solution or Holtrefeter's Solution. These baths aid in osmo-regulation. Although axolotls are fully aquatic, they can become dehydrated. Dehydration occurs in illnesses whereby the osmo-regulation is compromised, leading to celluluar and interstitial fluids being drawn out and excreted. Attached is a link for recipes for the fluid support baths.
http://www.axolotl.org/requirements.htm
The axolotl should also be weighed. You can use just the usual scales for small animals. Subtract the reading from water + tub from that of water + tub + axolotl. That would give you axolotl weight.
Use a dose of 5mg/kg of body weight of antibiotics. Because you are dealing with a small volume, you can constitute a solution of 5mg/ml in physiological saline and give a volume of 0.1ml.
The animal should get 3 shots of amikacin or
gentamicin, each separated by 48 hours or 5-7 shots of enrofloxacin, each separated by 24 hours.
You can continue fridging the axolotl during the recovery and can still provide fluid support.