There are currently 5 accredited vet nursing courses in Ireland: St. Johns (1 year level 6 FETAC course after 1 year level 5 animal care course), Athlone, Dundalk and Letterkenny ITs (all 3 year level 7 degrees) and UCD (4 year level 8 degree).
There are basically 3 ways you can get a place on a vet nursing course:
1. Meet the leaving cert requirements as specified by each college (for example for DkIT you need a C3 in higher level biology or Ag. Science, AIT also accept Home Economics) and get the points required for a place.
2. Do a FETAC level 5 Animal Care course and apply to a college whose vet nursing degree is linked to that course and has a number of 1st year places reserved for FETAC applicants.
3. If you are over 23 you can apply as a mature applicant. There are no specific entry requirements for this but as it's a popular career the standard of applicants tends to be very high. Most successful candidates have other relevant qualifications and extensive experience working in the veterinary profession.
N.B. it's very important that you carefully check the entry requirements for each of the courses/colleges that you wish to apply to. They vary between colleges, so you can't assume that what works for one will apply to all.
The level 5 in St. Johns is the Animal Care course (which is also available in a number of other FETAC colleges e.g. Drogheda, Mallow, Killester etc.).
St. Johns also run a Level 6 1 year follow on course in veterinary nursing. Once you complete this you can register with the Veterinary Council as a veterinary nurse, so if you complete that there would be no point in trying to transfer on to a level 7 or 8 course in veterinary nursing in another college.
You would need to contact St. Johns for specific advice about getting a place on their level 6 course. Vet nursing is very popular so they may be filling their places from within their own level 5 course. Likewise, you will need to contact UCD to see what their specific entry requirements are.
You can register as a vet nurse with the Veterinary Council of Ireland once you complete any of these 5 courses, the difference between them is in regards to how long they take and the amount of content. Obviously you will have the time to cover more material and in more depth over a specific 3 or 4 year vet nursing degree. A 2 year animal care/vet nursing course that leads to a vet nursing qualification will primarily focus on the key vet nursing skills and knowledge.
If you want to work in a practice as a registered vet nurse it doesn't really matter which course you complete. If you would like to maybe go on to further study some day then you should consider the level 7 or 8 courses, they also have a lot more places available on a national basis.
Finally, if you are interested in veterinary nursing as a career then it's a really good idea to spend as much time as possible in a veterinary practice that employs registered veterinary nurses (RVNs), so that you can experience the job first hand. The day to day realities can be very different from what people expect and, although highly rewarding, it's generally not a very well paid job so it's important that you're sure it's the right career for you before you commit to it.
Best of luck with it.