That's the message coming from local veterinarians after an increase in the number of cats and dogs presenting with poisoning due to the consumption of baited mice.

As a result of the mice plague ravaging rural and regional areas of NSW, vets are seeing a nationwide shortage of Vitamin K, which is used to treat affected animals.

Local vet Dr Kellie Launders said her clinic, Cowra Veterinary Centre, has experienced a 30 per cent increase of Vitamin K prescriptions in the last few weeks.

A total of 36 prescriptions have been distributed in the month of May, compared to 12 in April.

"The Vitamin K tablets are becoming really hard to source, the bigger size seems to be completely out of stock Australia wide, so we're currently on a smaller size so the bigger dogs have more tablets," Dr Launders said.

"As far as I can tell, all the online pet pharmacies are out of stock. We have some regular veterinary supplies out of stock but we are still able to get a little bit.

"I think, in the next couple of weeks, it might be interesting to see how that goes with a lot stocks aren't being able to be replenished for at least two to four weeks."

According to Dr Launders, both cats and dogs are generally given a three week course of Vitamin K to treat poisoning, as well as plasma if major internal organs are affected.

She said her clinic has seen animals present with coagulopathy, where blood takes longer than two minutes to clot, even for routine procedures such as de-sexing.

"Then they are treated immediately with Vitamin K, so that is the vitamin that the rat bait takes out, it is important for clotting," Dr Launders said.

"But that takes 24 hours to work, so depending on where the bleeding is, depends on what we do next.

"If it's bleeding in a really essential part, [the] lungs... under the tongue, if it's going to affect their airway, we act and treat a lot more aggressively by giving them plasma. That will stop the bleeding immediately and then we have time for the Vitamin K to kick in.

"A lot of the current poisons have a problem defect, so they can continue to cause clotting problems for up to three weeks."

Due to the Vitamin K shortage, Dr Launders is urging pet owners to try and keep their animals away from the mice or use alternative methods to poisons such as traps or pet-friendly bait.

"We just really need to try to limit consumption, if that's by muzzling dogs to try and stop them... or keeping them locked up," she said.

"I know a lot of farm dogs are up in cages off the ground so whether they are left in that sort of situation for longer periods of time.

"It is very hard, I do recognise that, especially cats, cats don't appreciate changes of routine.

"But if people can understand that it's happening, and it's happening a lot and often exposure is a surprise, they don't realise that they are eating so many and they don't realise that they are getting toxic doses of poison through mice."

Dr Launders encouraged any pet owners to get their animals to a vet straight away if they suspect bait poisoning.

"Usually the first sign is that they are lethargic, they will go off their food and look a bit sad and that's when they need to act," she said.

"Often we are seeing them at that later stage where they've been noticed to been unwell for a couple of days but by then, they are actively bleeding somewhere.

"Any sign of lethargy with a possible access to baited mice or to bait, they need to take them to their local vet and get them tested."