Poor kid. Well, it sounds like the rabies vaccine probably was the catalyst. The problem is that now he's not eating and drinking, so giving him meds to help with a reaction to the vaccine won't be feasible.
Probably the fastest way to see results is going to be having him seen in Corpus Christi and injectable medications administered to make him feel better. If you wish to try this on your own, I can give you some recommendations. I would start at the bottom and work your way up. First, try some medication to help calm his stomach and once that is handled then try medication to help with the rabies vaccine reaction.
The first step is to administer a dose of regular pepcid (famotidine) every 12-24 hours to calm the stomach, in case it is bothering him. You will want to give 0.5mg/pound of body weight (a 10# ***** would receive 5mg, a 5# ***** would receive 2.5mg, etc). For this, you can visit any human pharmacy and buy the OTC brand name Pepcid, or you can use the cheaper, off-brand “famotidine” that’s available. Either will be useful.
2 hours following a dose of famotidine, the time needed for the medication to begin working, you can offer a bland diet. To make this, you’ll combine white or brown rice, boneless, skinless chicken breast and sufficient water for cooking in a stock pot. Boil on medium until it turns to mush and the breast is easily flaked. To avoid more nausea, start with small amounts to begin with and offer the amount every 2-4 hours. A few teaspoons to start is typically sufficient and you can work your way up every 2-4 hours in incremental increases until you’re sure no vomiting will be seen. If your companion requires a more palatable food, try adding in pureed baby food in chicken, turkey and similar flavors. Avoid those that contain onion or garlic in the ingredient panel. Start small and work your way up.
Once he's feeling better, you can give 1-2mg/pound of body weight of benadryl by mouth every 8-12 hours. This should help with any reaction the vaccine might have caused. In any case, it certainly won't hurt if the stress of travel alone was simply too much for him.
I’ll be standing by if you have other questions. Let me know if I can help further.
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