What are some of the factors that owners should think about when they want to decide the type of facilities to leave their pets in?

Quantity of pets boarded in facility and ratio of amount of staff to amount of pets boarded. That is one indicator of the amount of attention your dog may receive
If the facility staff takes the initiative to discover about your pet’s preferences (e.g. Food, toilet preferences (grass or pee tray for dogs, type of litter for cats)), pre-existing health issues (e.g. Arthritic pets may have special exercise requirements, pets allergic to certain foods may have specific dietary requirements), vaccination and parasite prevention status;
Kind of space that pet will be kept in (cage or room). E.g. A little cage is not appropriate for a major dog; Are cats and small pets kept in a separate space from dogs and each other?
For dogs, just how many times per day will they be walked and fed? Based on your dog’s nature, activity level and temperament with other dogs, daily playtime with other dogs may be ideal;
Whether there are staff on the facility during the night to watch your pet;
How often the facility is disinfected. In case a pet is available with an infectious disease or external parasites during boarding, will there be an isolation facility designed for quarantine?
Is there transport facilities to bring your dog to the vet if needed? May be the pet sitter/boarder willing to bring your pet to your regular vet if you so choose to?
If our pet requires daily medication or treatments, do let your potential pet sitter/boarder know and ensure they are confident in administering them.
* In case a pet sitter/boarder fulfills all the above standards well, they will have the ability to provide more attentive care to your pet, but these services may come at reduced to ensure these services are given consistently to the required standards.

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What are a few of the characteristics they have to look out for in a pet sitter?

Experience with the species of pet you have. E.g. Handling rabbits requires specific ways to prevent injury to the spine;
Ability and patience of the pet sitter to bond with YOUR pet (every pet differs);
As above, the questions that the pet sitter asks you to comprehend your pet’s needs and lifestyle.
If the pet sitter involves your home to clean up after and feed your pet daily, how often can he/she come across?
What exactly are some precautions/measures that owners should take before sending their pet to a pet sitter/boarding facility?

Go to the facility and speak to the people who’ll be looking after your dog beforehand. Observe the cleanliness of the facility, ventilation, security of the cages, rooms and general areas (e.g. Do rooms and main entrances have closed doors/gates or are there potential routes for pets to flee?). Bring your dog along to go to the facility before hand if allowed. This helps those to familiarise themselves with the surroundings so you can find less stress when they are left there for boarding;
Ask the staff all the questions you will need answered and build-up good rapport with them. They will be your pet’s only guardian when you are away which is important to truly have a good degree of rely upon them;
Speak to other pet owners with first hand experience with the precise pet sitter/boarder for reviews;
Vaccinations (including for kennel cough) should depend on date, or vaccine antibody titre blood tests (e.g. VacciCheck) must have been done before year to ensure sufficient protective antibody levels against common infectious diseases. In case your vet recommends that vaccinations do not need to be achieved yearly predicated on a risk assessment, communicate this to your dog sitter/boarder and invite them to verify this with your vet if needed. A pet sitter/boarder that goes through the difficulty of verifying these information is more likely a responsible person who cares for the well-being of your dog;
Parasite prevention should get monthly, including for ticks, fleas and heartworm, and maintained while at boarding. Ensure to give your pet sitter/boarder sufficient doses of preventatives needed through the stay. Recognise that it’s inevitable that any pet in a higher density pet area reaches threat of getting some external parasites, however they shouldn’t get fully infested if the staff are vigilant at checking your pet regularly;
Inform your vet that your dog will be at a pet sitting and boarding facility, and that they may contact the vet in the event that medical assistance may be needed. Consult with your vet about payment options for the vet bills under these situations;
If your dog has any condition that is not assessed by the vet, or if it has not been to the vet going back six months or longer, a check-up at the vet is preferred, about 3-4 weeks prior the beginning of boarding. This allows your vet can attend to and recheck and medical issues, and means that your dog sitter/boarder doesn’t have to worry about and focus on any sudden medical ailments that might have been managed earlier. This also helps to reduce stress that your pet may face during boarding;
If your dog requires medications while at boarding, ensure that sufficient quantities are brought along for the pet sitter/boarder.
The type of instructions should owners leave with the pet sitter before each goes on vacation?

Pet’s preferences for resting area (pet bed vs floor), ambient resting temperature (air conditioned room?), dietary and exercise requirements, toilet preferences (grass or pee tray for dogs, kind of litter material for cats)), any medications to get and specific signs to consider that indicate the necessity for veterinary attention (e.g. A puppy with a sensitive gastrointestinal system may need medical attention despite having isolated bouts of vomiting or diarrhea that the pet sitter/ boarder may not be as concerned about in other pets);
Contact name and range of next-of-kin that can make decisions for you when your dog has a potential emergency and you are not contactable;
Contact details for your vet (including for after hours emergencies), ideally one who has all or almost all of your pet’s medical history. If you do not have a normal vet, ask your boarding facility if indeed they have a vet they use and the number of services that the vet provides (e.g. For laboratory diagnostics, hospitalisation, emergency and after hours care).
With regards to food, should owners supply the sitter/boarding facility with food for his or her pets to ensure that there are no unwanted side effects from an abrupt diet change?

Owners should bring the same food that their pets eat at home along for the stay during boarding. A little diet change, as well as stress in a fresh environment, may be enough to make your dog sick. If your dog has very strict dietary requirements, make certain to communicate this to your dog sitter/boarder.
When the owner gets their pet back from the sitter/boarding facility, any kind of precautions that they should take?

After receiving your pet back from boarding, check your dog thoroughly for any external parasites such as ticks and fleas. If present, it is important to remove these parasites from your pet’s body immediately to ensure that it generally does not commence to live within your home, as well as your pet should be taken to your vet for an assessment as these parasites will not only cause skin irritation, nonetheless they can also spread life threatening blood-borne diseases. As always, make sure that your pet is behaving normally with normal appetite, defecation and urination habits. Any deviation off normal behaviour or signs such as vomiting, lethargy, diarrhoea, requires veterinary attention.