A guinea pig who eats enthusiastically but only from a short personal menu creates a specific worry, because guinea pigs cannot make vitamin C and a narrow diet can quietly underdeliver it even while the pig looks round, bright and well fed. The vet visit goes best when it starts from what your pig genuinely eats, not what the care sheet says guinea pigs eat.
Questions about whether the current diet is enough
Bring a truthful food diary covering a week or two: every vegetable, fruit, pellet and treat offered, what was eaten, what was left, and how much hay disappears daily. With that in hand, ask which of the foods your pig reliably eats actually contribute meaningful vitamin C, and whether the total picture plausibly covers a guinea pig's needs or leaves a gap. Ask how freshness and storage affect what your pig is getting, because vitamin C fades in opened pellet bags and in produce kept too long, so a diet that looks adequate on paper may deliver less in the bowl. Ask too what early signs of shortage they would want you to watch for in this pig, given its age and health, and how quickly a shortfall would matter. If your pig is young, elderly, pregnant or recovering from illness, say so, because demand changes across life stages and the vet's threshold for concern changes with it.
Questions about supplements and fussy eaters
If the diet has a real gap, ask whether a vitamin C supplement is appropriate for this pig, and be guided by the vet on product type and amount rather than choosing from shop shelves or online advice. Ask which form a picky eater is most likely to accept, since a tablet treated as a treat, a liquid given by syringe, and something sprinkled on food each create a different daily reality, and a supplement refused daily is no supplement at all. Ask whether vitamin C should ever go in the drinking water, because it degrades in light and can put some pigs off drinking, and ask how you will know the plan is working: what improvement or stability to expect, when to review, and whether weight checks or a repeat diary would help. Also ask how to widen the menu itself, because the sustainable answer is usually a pig who eats more foods: gradual introduction alongside favourites, offering new vegetables in tiny amounts repeatedly, and not letting one refused item vanish from rotation forever.
Questions about what else pickiness might mean
Persistently picky eating is not always a personality trait, so ask what else the vet would consider. Dental discomfort is a classic hidden cause, with pigs favouring soft or easy foods while avoiding items that need work; ask whether the teeth, including the back teeth that cannot be seen at home, should be checked. Ask about pain, gut discomfort, stress from a cage mate who guards food, and simple learned habit, since a pig whose favourites are always topped up learns that refusing earns an upgrade. Describing exactly how the pickiness plays out, what is refused, what is demanded, and whether appetite overall is strong, helps the vet separate a fussy-but-healthy pig from one whose menu is narrowing for a reason that needs treatment.
An honest diary of offered versus eaten foods is the evidence that makes all of these questions answerable in one visit, and KinsLe's Pet Passport keeps that diary with your guinea pig's records so diet, weight and vet advice stay connected over time.