if there is gunk in there mate and it’s shaking all the time scratching uuntil they bleed
if you smell them does it smell could be an infection maybe need anti biotics could also be ear mites will be muck in there and normally scratching until they bleed on out side id get some advocate for this mate be on the safe side it must be horrible shaking head and scrating
the nails just trim mate leave abit past tithe quick 5mm or so doesn’t hurt them just get them snipped mate
best thing for teeth is bones regular mate if they are bad then plague off works i seen it on a ol