Please see a preferably [piggy savvy vet as soon as you can afford to! Have him checked for dental problems (including back teeth), GI stasis (no or very little gut movement), heart problems (which would account for him being cold and lethargic) etc. There is obviously something more serious going on that needs a closer inspection and that cannot be healed with a minimal course of antibiotics and vitamin C on spec.
Bloat, GI Stasis ( No Gut Movement) And Not Eating
Guinea Lynx :: GL's Vet List
Until then, please switch from weighing once weekly as part of his regular health check-up to weighing daily at the same time in order to monitor his food intake. Cheap kitchen scales from the supermarket will suffice.
How To Pick Up And Weigh Your Guinea Pig
Top him up with syringe feed asap. Over 80% of the daily food intake is hay, which you cannot control by eye. A guinea pig can lose a lot of weight very quickly if you just watch him nibble on a little veg or pellets and think that that is enough.
You can use mushed up pellets in an emergency as long as you cut off the tip of the syringe and plunger as shown in the syringe feeding guide. Needle free syringes are available in any pharmacy. Your care at home in this respect is as important any necessary medication and absolutely vital to keep him alive until you can see a vet and have him treated. Your home feed however cannot replace any vet care and heal the underlying problem.
Complete Syringe Feeding Guide
Administering Medications And Syringe Feed
Please save up for your vet fund as part of the weekly food and bedding cost for your piggy right from the start. Vet care is making the biggest overall budget post in any pet's life, but too many people don't factor this in when they buy their pets.
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