RE: Meloxicam dose

Mark Rowland — Wed, 10 Feb 2021 19:25:14 GMT

In exotics I throw metacam at animals at doses that would frighten many but clearance studies have been done. For dogs and cats there's ,loads of research so I would stick to the data sheet.

That said for G pigs the licensed dose is PATHETIC and I would always go much higher.

RE: Meloxicam dose

Gillian Mostyn — Wed, 10 Feb 2021 09:55:45 GMT

I would also follow the data sheets, as you do, and reduce the dose on the second day. (I also sometimes just prescribe oral meloxicam to dogs and tell them to double dose on the first day.)

Your boss is obviously free to dose as they wish, as long as any medications you prescribe are given as per your instructions if animals under your care are hospitalised. Maybe just reiterate to them that in any case of severe side effects or death, they will need to feel able to defend going off license - and have consent for doing so from the owner. Even if the animal's death has nothing to do with the meloxicam dose, not all owners think or behave logically in an emotional situation!

(See the various 'metacam kills' pages on facebook. 'My animal was really ill, in pain and hadn't eaten properly for weeks....I declined bloods but the vet gave it metacam and it killed it' kind of thing....')

RE: Meloxicam dose

Beats — Wed, 10 Feb 2021 08:13:47 GMT

I don't tend to repeat the loading dose daily, and with dogs i give half the loading dose by injection if repeating on daily basis.

Ditto with cats, but as you say is quarter of loading dose when using 2mg/ml injectable metacam.

I have not seen any known complications, however, from vets giving a loading dose daily by injection for 2 to 5 days, and i have found this to be surprisingly commonly done (but i agree doesn't make a lot of sense).

I have noticed that with cats, the initial loading dose appears to control pyrexia better in a fair few cats than subsequent "maintenance" doses of 0.05mg/kg by injection.

Finally, it is worth noting that the 5mg/ml metacam is licensed to give to cats as a one-off injection (with no follow-up maintenance doses) at 0.3mg/lg, so it would be difficult to argue that there is anything wrong with someone giving a loading dose of metacam to a cat at 0.2mg/kg and then a single further injection the next day at 0.1mg/kg.

With respect to the GI tract, I think injectable metacam has much less side effects than oral metacam - I assume this is because diiarrhoea is the most common side effect and this presumably has little to do with the drugs general pharmacological effects on the body and more to do with poor tolerance of the drug when passing through the GI tract. many dogs that become quite ill with a single dose of oral metacam cope quite fine with an injection of it. I would expect any renal effects to be the same or higher with the injection (better bioavailability and more likely to be given to hypovolemic/hypotensive/otherwise-ill patient). What I'm not sure on is GI ulceration - is this more related to level of drug directly in stomach (making oral worse) or plasma levels (likely to be higher with injections and making them worse) - my gut instinct would be oral is worse for this even if injectable does give higher plasma levels from higher bioavailability (and I note that the loading dose for dogs at least is the same on licensed metacam whether this loading dose is given by injection or orally, so the bioavailability may not be that much higher by paranteral versus oral anyway).

I would let your boss do what he wants, but I'd give maintenance doses like you suggest when repeating injectable on subsequent days (or where on daily maintenance metacam already), unless your boss has specifically specified he wishes you to administer a specified higher dose on a specified case and you are content that this is intentionally a higher dose than what you or I would use, as opposed to unintentionally.