Pre-Surgical Checklist for Dogs and Cats
Enter the admission time and this tool works out exactly when food and water stop, builds a morning medication plan and gives you a tick-off list for the night before and the morning of surgery. Clinics can fill it in and send the owner a link, print it or email it. Owners can tick items off on their phone.
- Your pet ate, stole food or was fed by someone else after the food cut-off time. Do not hide it. Surgery may just be moved later in the day.
- Vomiting, diarrhoea, coughing, sneezing or your pet is off colour in the 24 hours before surgery.
- A new medication was started, a dose was missed, or your pet has had a reaction to a drug before.
- Your female dog or cat has come into season.
Edit this checklist (clinic details, fasting, medications, items)
1Patient and procedure
Everything here is printed at the top of the owner sheet.
2Fasting plan
Defaults are set from the species, age group and diabetic status, and reset whenever those change. Change either option afterwards to override. Times are worked back from the admission date and time.
3Medications on the morning of surgery
Type each medication the pet is on. Owners can add what their pet takes; the vet decides what is given, skipped or adjusted. Never change a dose without the vet's instruction.
4Checklist items
Untick anything that does not apply. Edit the wording if you need to. Add clinic-specific items at the bottom of each section. Times update automatically when the fasting plan changes.
By Dr Duncan Houston. askavet.com. Your clinic's instructions always override this sheet.
Pre-surgical checklist
Medications on the morning of surgery
| Medication | Dose | Instruction | Time | Notes |
|---|
No medications listed. If your pet takes anything at all, including supplements or flea and worm products, tell the clinic.
Tell the team on arrival
This checklist was built with the ASK A VET™ pre-surgical checklist tool by Dr Duncan Houston. It is general guidance. The instructions from the clinic performing the surgery always take priority.
Not sure about a medication, the fast, or something that happened overnight?
Chat with a certified vet in the ASK A VET™ app before you leave the house. Keep your pet's surgery notes, medications and recovery reminders in one place.
Ask a vet in the app Use code DRDUNCANQuick answer: how long should my dog or cat fast before surgery?
Most healthy adult dogs and cats should have their last meal the night before surgery, usually no food after midnight, and water taken away early on the morning of surgery, commonly from 6am or two hours before admission. Puppies and kittens under four months, diabetic pets and very small patients need a shorter fast, usually a small meal around four hours before admission. Rabbits and guinea pigs should never be fasted. Morning medications are decided by the vet: some are given as normal, some are skipped, and insulin is almost always adjusted. When in doubt, ring the clinic.
Written and reviewed by Dr Duncan Houston, emergency veterinarian, University of Sydney graduate, who admits and anaesthetises surgical patients every week.
Why fasting before anaesthesia matters
Anaesthetic drugs relax the muscle ring at the top of the stomach and switch off the reflexes that protect the airway. If the stomach is full, food and acid can flow back up the oesophagus and be inhaled into the lungs. That is aspiration pneumonia, and it is one of the most serious avoidable anaesthetic complications. Reflux without inhalation can also burn the oesophagus and leave a stricture weeks later. A sensibly empty stomach reduces both risks, and it also reduces vomiting when the pet wakes up and during the pre-medication phase.
Fasting is not the same as starving. Over the last decade the evidence has moved away from very long fasts. A fast of 18 to 24 hours does not empty the stomach any better than 8 to 12 hours, and in dogs it can actually increase reflux because acid keeps being produced with nothing to buffer it. Long fasts also drop blood sugar in small, young and diabetic patients. That is why modern guidance sits at roughly 6 to 12 hours for healthy adults, with a shorter fast for the patients who cannot tolerate one.
Water is different. Water leaves the stomach quickly and helps keep the patient hydrated, so most clinics only remove it an hour or two before admission. Removing water the night before is unnecessary and can leave a pet mildly dehydrated going into anaesthesia.
Fasting times by patient type
| Patient | Food | Water | Why |
|---|---|---|---|
| Healthy adult dog or cat | Last meal the night before. Midnight is the common clinic rule; 8 to 12 hours before admission is the evidence-based range. | Away 1 to 2 hours before admission, or from 6am for a morning admission | Empty stomach for the airway, without the reflux and hypoglycaemia risks of a very long fast |
| Puppy or kitten under 4 months | Small meal about 4 hours before admission | Available until 1 hour before, or as the clinic directs | Small glycogen stores; long fasts cause low blood sugar |
| Toy breed under 2 kg | Often 4 to 6 hours. Follow the clinic | As above | Same hypoglycaemia risk as young patients |
| Diabetic dog or cat | Vet-directed. Usually a small meal 4 hours before with an adjusted insulin dose, or early-morning surgery slot | Available until admission unless told otherwise | Insulin without food causes dangerous hypoglycaemia; food without insulin causes hyperglycaemia |
| Senior with kidney disease | Standard adult fast unless the vet shortens it | Usually left available until admission | Dehydration worsens kidney function under anaesthesia |
| Rabbit or guinea pig | Do not fast. Hay and usual food available until admission | Do not remove | They cannot vomit, and gut stasis from fasting can be fatal |
| Birds and reptiles | Species specific. Ask the clinic | Ask the clinic | Very different metabolism and crop or gut anatomy |
The tool above applies these defaults automatically from the species, age group and diabetic setting, then lets the clinic override any of them.
Which medications are given on the morning of surgery?
This is the question owners get wrong most often, usually by guessing. The rule is simple: list every medication and let the vet decide. In general terms, most heart, thyroid, anti-seizure and behaviour medications are continued as normal with a small amount of water because stopping them is riskier than giving them. Some anti-inflammatories are skipped on the morning of surgery because the vet may give a different one, or because of the anaesthetic's effect on kidney blood flow. Insulin is almost always reduced or timed around a small meal, and the exact plan depends on the clinic's schedule. Sedatives and anti-anxiety medications are sometimes given deliberately before admission for stressed patients, and sometimes withheld so they do not stack with the pre-medication.
Bring every medication in its original packaging, including flea, tick and worm products, supplements and anything bought over the counter. Fish oil, turmeric, aspirin-based products and some herbal supplements can affect bleeding or interact with anaesthetic drugs, and the clinic cannot plan around what it does not know.
The night before surgery
- Feed the last meal by the cut-off time, then remove all food, including the other pets' bowls, the bin, chews, treats and anything reachable on the bench.
- Keep cats indoors overnight with a litter tray. A cat that hunts a mouse at 4am has broken the fast and you will not know.
- Walk the dog and give a proper chance to toilet in the evening.
- If the coat is filthy or heavily matted, a wash or brush the night before helps, but do not wash a pet on the morning of surgery. Wet skin drops body temperature under anaesthesia.
- Find the carrier or lead now, not at 7am. Put a blanket or an unwashed t-shirt with the household smell into the carrier for cats.
- Check the admission time, the address and that your phone will be on and reachable all day.
The morning of surgery
- No breakfast, no treats, no chews, no dental sticks, no "just a little bit" to hide a tablet unless the vet told you to. If a tablet has to be given, use a small amount of water or the smallest smear of food the vet approved.
- Take the water away at the time on your sheet.
- Give medications exactly as listed in the plan. Write down the time you gave each one.
- Take the dog for a toilet walk before you leave. Note the time and whether they passed urine and faeces; you will be asked.
- Dogs on a fitted lead or harness, cats and small pets in a secure carrier. Clinic waiting rooms are busy and stressful.
- Arrive on time and allow 15 to 20 minutes for admission paperwork, a weigh-in and a quick check-over.
What to bring to the clinic
- All medications in their original packaging, plus a written list with doses and the time of the last dose.
- Vaccination and previous medical records if this is not your regular clinic, and any recent blood test results.
- Pet insurance details and a contact number that will actually be answered during the day.
- The usual food if your pet is staying overnight, especially for pets on prescription diets or with sensitive stomachs.
- For cats and small pets, a blanket or item from home. Familiar scent measurably reduces stress in hospital.
- A note of your last-ate, last-drank and last-toilet times. The tool above has a section for this.
Common mistakes before surgery
- Hiding that the pet ate. Owners worry they will be told off, so they say nothing. The result is an anaesthetic on a full stomach. Clinics would much rather move the surgery to later in the day.
- Fasting a rabbit or guinea pig. Old advice that still circulates. It is dangerous for them.
- Fasting for 24 hours "to be safe". Not safer, and it increases reflux and low blood sugar risk.
- Skipping medication without asking. Missing a heart or seizure medication is often more dangerous than the anaesthetic.
- Giving the full insulin dose to a fasted diabetic. This causes hypoglycaemia in the car on the way in. Always follow the vet's adjusted plan.
- Letting the cat out overnight. Cats eat things you do not see.
- Washing the pet that morning. Wet or damp coats lower body temperature and delay recovery.
- Turning the phone off. Surgeons find things. They need to reach you to discuss a change in plan or a cost.
When to call the clinic before admission
Ring the clinic, or the emergency service after hours, if your pet has vomited, has diarrhoea, is coughing, sneezing, breathing differently, has had a seizure, has collapsed, has eaten after the food cut-off, has come into season, has a new lump, wound or lameness, or if any medication has been started, stopped or missed. None of these necessarily cancels surgery, but every one of them changes the anaesthetic plan, and the vet needs to know before the pre-medication is drawn up.
Pre-surgery FAQs
Can my dog have water before surgery?
Yes. Water is usually left available until 1 to 2 hours before admission, or removed from 6am for a morning admission. Do not take water away the night before unless the clinic specifically asks.
My dog ate this morning. Is surgery cancelled?
Not always. Tell the clinic straight away. Depending on what was eaten and when, surgery may be moved to later in the day, or rebooked. What matters is that the vet knows.
Should I give my pet's tablets on the morning of surgery?
Only as the vet has instructed. Most heart, thyroid and seizure medications are continued with a little water. Some anti-inflammatories are skipped. Insulin is almost always adjusted. If you do not have an instruction for a medication, ring and ask before giving or withholding it.
How long should a puppy or kitten fast before surgery?
Much shorter than an adult. Under four months, a small meal about four hours before admission is typical, because young animals have small energy reserves and a long fast drops their blood sugar. Follow the clinic's exact time.
Do rabbits need to fast before surgery?
No. Rabbits and guinea pigs cannot vomit and their gut must keep moving. Fasting them causes gut stasis, which can be fatal. Bring their hay and usual food with them.
Should I bath my dog before surgery?
If needed, the day before, not the morning of surgery. A damp coat lowers body temperature under anaesthesia and slows recovery. Never bath a pet after surgery until the vet clears the wound.
Why does the clinic ask when my pet last went to the toilet?
A full bladder or bowel complicates some procedures, and the timing helps the team judge hydration and plan when to walk the pet after surgery. Note the time before you leave home.
Can I share this checklist with my clinic or family?
Yes. The "Copy share link" button puts everything you have entered, including which items you have ticked, into the link. Anyone who opens it sees the same sheet and can keep ticking.