Dpony goes a long while between shoeings,so not a good example,but
Shoes £60 every 12-16 weeks
Feed £5.99 every 12 weeks
Insurance [she is old so accident cover only] £130
Worming 4 x times a year £60
Hay £2.80 a bale,winter only
Supplement for joints £25.99 a tub x 3 times a year.
Newboy is high maintenance,
Insurance £300
Special feed £35 a bag on special offer 
Shavings as can't have straw £7.49 a bale
Hay and worming as above,but he has his feet trimmed instead,about £20 I think.
I haven't included jabs as she hasn't needed them yet,or lessons for the girls,or pony club membership or rally fees,or gymkhana/show entrance fees or the trailer to take them to pony club/shows,or the 4 x 4 to pull the trailer,or riding hats,boots,body protectors,replacement tack,spare leadropes,grooming kit,rugs,buckets,lunge lines,hoof picks,haynets,jodhpurs.I scour ebay and rarely buy anything new,but costs still spiral.I read somewhere that horse ownership is like standing in the shower ripping up £50 notes.It's a good job the girls love riding.