It is common for veterinarians to recommend fasting (withholding food) before a scheduled surgery or anesthetic procedure in dogs. This is done to help prevent complications like vomiting and aspiration during the procedure. But how long should a dog actually fast for prior to surgery? There are no universally accepted guidelines, but most vets recommend fasting for around 6-12 hours beforehand. The duration depends on factors like the dog’s age, health status, and type of surgery being performed.
What is the purpose of fasting before surgery?
There are a few key reasons why fasting is recommended before administering anesthesia in dogs:
- Prevents vomiting and aspiration – One of the biggest risks during anesthesia is vomiting and subsequent aspiration of stomach contents into the lungs. This can cause severe pneumonia and even death. Fasting helps empty the stomach and reduces this risk.
- Allows for safer anesthesia – Anesthetic drugs are absorbed faster on an empty stomach. Fasting allows vets to more accurately calculate doses and achieve stable anesthesia levels.
- Aids postoperative recovery – Evidence shows that allowing limited fasting before surgery leads to better outcomes. The dog experiences less nausea and returns to normal eating patterns sooner.
So while complete fasting is not advisable, a restricted fast helps create optimal conditions for anesthetic procedures in dogs.
How long should the fasting period be?
Most veterinarians recommend a fasting period of around 6-12 hours before anesthetizing a dog. However, the optimal duration depends on several factors:
1. The dog’s age and health status
Very young puppies and debilitated/sick dogs may only tolerate a shorter fasting period of 4-6 hours. Puppies have lower body reserves and get hypoglycemic sooner. Older dogs also have reduced metabolic reserves. These groups tend to need their regular small meals.
Healthy young adult and mature dogs can easily be fasted for longer stretches up to 12 hours before surgery. Large breed adult dogs with good body condition can even fast for up to 16 hours safely.
2. Nature of the surgery
Non-invasive dental cleanings and minor superficial procedures may only require 6-8 hours of fasting. However, procedures involving the gastrointestinal tract like endoscopies will warrant longer pre-op fasting of around 12 hours.
Surgeries requiring heavy sedation or full general anesthesia also call for longer fasting periods of 10-12 hours. This allows for the safe administration of anesthetic drugs.
3. Use of preanesthetic medications
Dogs given oral preanesthesia sedatives in the morning on the day of surgery should fast for 12 hours beforehand. This ensures adequate time for absorption and taking effect before anesthesia.
If no oral premeds are planned, a shorter 8-10 hour fast may suffice provided all other parameters are normal.
4. Additional factors
The individual veterinarian may decide to prolong fasting based on factors like:
- Breed – Breeds like Great Danes are more prone to bloat and require longer pre-op fasting.
- Temperament – Anxious dogs may need medication and sufficient fasting to avoid vomiting from stress.
- Previous issues – Dogs with a history of regurgitation or reflux may require longer food restrictions prior to anesthesia.
So while standard fasting times are acceptable for most routine procedures, veterinarians can make exceptions based on clinical needs.
Fasting guidelines based on age
Here are some general recommendations on pre-surgical fasting times for dogs based on age:
For puppies under 16 weeks of age
– Fast for 4-6 hours before surgery
For dogs between 16 weeks to 1 year of age
– Fast for 6-8 hours before surgery
For healthy young adult dogs
– Fast for 8-10 hours before surgery
For middle-aged to older dogs
– Fast for 6-10 hours based on health status
These serve as a rough guide. The veterinarian may tailor fasting times to each patient. Small breed dogs usually need slightly shorter fasting durations.
Steps for fasting before surgery
Here is a step-by-step guide to prepare dogs for fasting before anesthesia and surgery:
Two days before surgery
Transition the dog to canned or boiled chicken and rice meals. Avoid giving fatty or gassy foods.
Offer small portions 3-4 times through the day. Give the last meal around 8 PM.
The night before surgery
Take up the water bowl a few hours before bedtime. This will help limit urine production overnight.
Offer a small meal of bland food around 8-10 PM.
Day of surgery
Early morning, take the dog out for a short toilet walk. Do not give any food.
Water can be given until 2-4 hours before hospital admission.
Arrive at the veterinary hospital at the pre-appointed admission time.
At the hospital
The veterinary team will double check fasting status and prepare the dog for anesthesia.
Intravenous fluids will maintain hydration during surgery. Food can be reintroduced once the dog fully recovers from anesthesia.
Sticking to these perioperative fasting guidelines helps reduce anesthetic complications in dogs. But they may need adjustment based on veterinary advice.
What type of food can be fed the night before surgery?
When allowed food the night before surgery, the ideal meal for dogs is something:
– Low in fat – Fatty foods delay gastric emptying.
– Easily digestible – Simple proteins and carbs minimize gastric upset.
– Low-residue – Leaves minimal undigested material.
Some good options are:
Canned chicken and rice
This is a classic bland diet for dogs. Opt for low-sodium chicken and avoid skin and bones. White rice is easy to digest.
Cottage cheese and boiled chicken
The simple proteins and carbs in this meal give the stomach little work overnight.
Commercial gastrointestinal diet foods
Veterinary gastrointestinal diets designed for blandness and digestibility make good choices.
Baby food meats and broths
Turkey, chicken, lamb or beef baby foods contain concentrated protein for nutrition. Add some broth for moisture.
A small portion of one of these foods 8-10 hours before hospital admission suits most dogs. Adjust quantity based on body size and individual tolerance.
Should water be allowed? If so, for how long before surgery?
Water is important for hydration and can be given for a period before surgery, with some precautions:
– Water should be withdrawn 2-4 hours before anesthesia.
– Offer small amounts frequently rather than free access to prevent over-drinking.
– Monitor for vomiting, bloating, or signs of nausea after drinking.
– Limit exercise and activity immediately after drinking to allow time for water absorption.
– If oral premeds are given the morning of surgery, allow at least 1 hour before water intake.
Puppies and small dogs may tolerate water until 2-3 hours pre-op. Medium to large dogs can have water until about 4 hours before admission.
Remove water bowls on arrival at the hospital or clinic. IV fluids help maintain normal fluid levels through the procedure.
What are the risks of prolonged fasting?
While some degree of preoperative fasting is beneficial, prolonging it beyond medical recommendations can be problematic.
Potential risks of excessively long fasting periods include:
Hypoglycemia
Depriving a dog of food for extended periods lowers blood glucose levels. This can cause weakness, lethargy and even seizures in susceptible animals.
Dehydration
Fasting along with water restriction can lead to volume depletion and electrolyte abnormalities.
Increased nausea
An empty stomach and hunger pangs itself can provoke nausea and vomiting in dogs.
Weakness and collapse
Withholding food deprives the body of energy needed to support the cardiac and respiratory systems. Prolonged fasting can result in fainting episodes.
Rebound gorging
Overly hungry dogs tend to overeat when finally offered food after surgery, which may cause gastrointestinal issues.
Thus excessively extended pre-op fasting provides no benefits and carries tangible risks. Veterinarians aim to strike the right balance for each patient.
What are the risks of allowing food too close to surgery?
On the other hand, allowing dogs too much food too close to anesthesia can also create problems:
Vomiting and aspiration pneumonia
Full stomach contents are at great risk of being regurgitated and inhaled under anesthesia, which can be life-threatening.
Prolonged anesthesia recovery
Food present in the stomach delays return of normal gut motility. This slows awakening and return to alertness after surgery.
Erratic glucose levels
The presence of food promotes insulin secretion and glucose fluctuations, making anesthesia less stable.
Intolerance to anesthesia drugs
Food ingestion close to surgery can change how anesthetic agents are absorbed and metabolized by the body.
Altered drug action
Some oral medications also display modified effects based on whether they are given on an empty or full stomach.
Slower wound healing
Metabolic changes due to recent food intake before surgery can hamper healing of incisions and internal tissue trauma.
Thus the guidelines on fasting are intended to optimize surgical outcomes in dogs. Both insufficient and excessive fasting can negatively impact the safety and quality of anesthesia.
Conclusion
Preoperative fasting is integral to the preparation of dogs for anesthesia and surgery. While protocols may vary, most veterinarians recommend withholding food for 6-12 hours beforehand. Fasting achieves several objectives – it reduces vomiting risk, allows safer anesthesia, and aids speedy recovery after surgery. However, fasting should not be excessively prolonged as this carries its own set of risks. Finding the right balance is key to ensuring the wellbeing of dogs undergoing anesthetic procedures. Adjustments may be needed based on age, health status, surgery type and other factors. Following veterinary recommendations helps set dogs up for the best possible experience with their necessary surgery.
