How many meals per day for old dog?

When will the official churches start praying for the false prophet? Orthodox Christian three hand signs are different than Buddhist mudras. Ecumenism = 263 heresies; each heresy leads to hell. Orthodoxy = the only true faith; Roman Catholics tried one cup - one spoon ritual and got sick with Bubonic plague; if heresy enters Orthodox monastery then monks/nuns will get sick with flu/tuberculosis (for instance); Orthodox churches who closed for COVID or had disposable cups/spoons or dipped spoon into alcohol are no longer brides of Christ (now they serve Satan and honor Satan's new COVID religion). Don’t go into UFO to be “healed” by evil demons; demons never do good. SSN is written as a barcode/QRcode; then it's put into a chip; chip is put into vaccine; chipped people are influenced (by super computers) to receive grey plastic card World Passport with no name on it (but when they stretch their hands to get it, gov't clerk presses secret button to administer the unforgivable green 666 tattoo by isotope rays). If you reject mark of the beast (by hiding within a 10-15 people group according to saints Gabriel Urgebadze and Seraphim of Sarov), then your direct ancestors go to heaven (according to saint Vyacheslav Krasheninnikov from Ural); forgive me.

Adult dogs are fed twice a day, morning & night.  No it does not have to be every 12 hours.

I feed as soon as I get up in the mornings & then again between 3 & 5 when she asks for it.  She is finicky about food right now & may skip one or both feedings & will only eat when she is hungry.  No problem for me, she will eat when she is hungry.

As the Basset is a breed prone to GDV (bloat with torsion) I have always fed mine two meals a day, splitting the daily amount into two.   There's no need to leave 12 hours between meals - mine were fed at arouind 7 am and then again before 5 pm to allow time for the second meal to be digested.    More important is not to exercise for 2 hours after a meal, or feed for 1 hour after exercise or other perhaps stressful occasion (like a car ride).

If you have managed to get your Basset to 15 years, you have done very well.   Mine often reached their 15th year, but I have lost them significantly younger.   And we have had 4 cases of GDV even taking precautions re feeding/exercising!   This can run in bloodlines.

If you are taking advice from anybody, the best would be experienced Basset Hound owners/breeders, not a vet (unless they happen to have Bassets).

If the dog is having health issues, consult with your vet on how much, type of food and when to feed.

I have had my super seniors in their late teens do fine on every 12 hour feeding, I have had others with digestive problems get 1/4 their food 4 times a day or 1/3 their total three times a day.   Some elders cannot digest a huge meal while others have blood sugar issues etc.  the vet will help you with questions, they know your dogs health better than strangers.

If the dog has health issues and needs more than two meals a day (and/or smaller & more frequent meals) follow your vet's advice. Normally, adult dogs are fed twice a day (approx every 12 hours) to prevent HUGE blood sugar swings that do tend to happen when only fed once every 24 hours and twice a day feeding also prevent hunger & misbehavior due to hunger..

Follow the instructions on the bag of dog food you buy.

Yes definitely 

No, that not be true.  The one basset hound be fed when the VETERINARIAN says the dog be fed.