Three coats' worth of hair, one stomach to process it
The Siberian wears a triple coat built for Russian winters: a dense undercoat, a water-resistant middle layer, and long guard hairs. It is glorious, and it is also a digestive workload. When the coat turns over, particularly in spring, every grooming session sends a wad of undercoat toward her stomach, and appetite is frequently the first thing that falters while that hair works its way through.
Seasonal hair and the hunter's stomach
Hairball nausea in a Siberian has a calendar. If she is blowing her coat, leaving drifts of fluff on furniture and producing a brushful of fur at every session, a day of refused food with occasional retching fits the season. The second breed-shaped cause is her own competence as a hunter: athletic, powerful Siberians who go outdoors catch things, and a mouse or bird eaten yesterday can mean vomiting, loose stool, and no interest in dinner today. Dental pain and ordinary stomach upsets remain possible, of course, and a cat who is off food outside shedding season, with a settled coat and no hunting access, should not have her symptoms waved away as seasonal. Stress is a lesser factor in this generally confident breed, though a house move or a new dog can still cost a few meals.
Evidence gathering for a forest breed
Start with the brush: the volume of loose undercoat coming away tells you how much hair her stomach is currently handling. Look for retching episodes and whether they produce hair, foam, or nothing. Check the litter tray for stool quantity, because swallowed hair slows the whole gut and a cat passing very little may feel too full to eat. If she hunts, note any remains, feathers, or a suspiciously satisfied morning followed by today's refusal. Finally, feel her condition through the coat, since a Siberian's bulk is mostly muscle and fur, and your hands are the only reliable scale between vet visits.
Helping the coat and the gut together
Give her a long, gentle grooming session if she enjoys it, removing loose undercoat before her tongue does, and repeat daily while the coat is turning. Serve her normal food warmed and in smaller, more frequent portions that a nauseous stomach can accept, and keep fresh water in several places to support gut movement. Keep her in during the episode if she hunts, so you can see exactly what she eats and produces. Avoid the temptation to offer rich tidbits to jump-start her appetite, which can turn a hair-related dip into a full stomach upset.
When seasonal becomes veterinary
Call the vet if she eats nothing beyond a day, retches repeatedly without result, vomits several times, passes no stool, or becomes lethargic, and mention any hunting or possible prey at the appointment. Repeated appetite loss every shedding season is also worth a planned conversation, because a managed coat routine may prevent it. Coordinating that routine is a household job, and KinsLe Care Teams lets you assign the grooming, feeding, and appetite watching for her across the family, each completed task marked off so nothing is doubled or missed.