I have not heard back from you but did want to leave my thoughts about Rocky for your return.
First, I have to say that I am concerned to hear about your lad’s situation. While worms could cause weight loss, this doesn’t explain why he isn’t eating/drinking properly for us nor his dehydration. Therefore, you can certainly worm him if its been over a month since his last wormer, but this isn’t likely the root case for his weight loss inducing anorexia.
Instead, in this case, we’d be more wary of a potential bacterial or viral gastroenteritis, pancreatitis, parasites/protozoa infections, general dietary indiscretions, and ingestion of harmful items (ie toxins, plants, non-edible items). We could see anorexia secondary to metabolic and organ issues but we’d hope for those to be less likely at his age.
With this all in mind, bloods +/- an xray would be ideal to help us narrow our concerns. Though there are some supportive are steps we can also try. First, since nausea is a common side effect of the above and what puts dogs off their food, do ring his vet for an anti-nausea treatment (ie Cerenia, Metoclopramide, Zofran, etc) +/- appetite stimulant. Otherwise, we can at least try him with an antacid. Common OTC pet safe options would be Pepcid (More Info/Dose @http://www.petplace.com/article/drug-library/library/over-the-counter/famotidine-pepcid), Zantac (More Info/Dose @ http://www.petplace.com/article/drug-library/library/over-the-counter/ranitidine-hcl-zantac), or Tagamet (More Info/Dose Here @ http://www.petplace.com/article/drug-library/library/over-the-counter/cimetidine-hcl-tagamet). Whichever you choose, we’d give this 20 minutes before offering food to allow absorption. Of course, do double check with your vet if he has a known health issues or is on any medications you haven't mentioned.
Once that is on board, we can start tempting him to eat (as I am sure you have been). Favorites are allowed or you can consider starting him on a light/easily digestible diet. Examples you can use are cooked white rice with boiled chicken, boiled white fish, cottage cheese, or scrambled eggs (made with water and not milk). There are also OTC vet diets that can be used (ie Hill’s I/D or Royal Canin’s sensitivity) too. The aim of these diets is that they will be better tolerated/absorbed by the compromised gut. Therefore, it should get more nutrients in and result in less GI upset.
Though if he cannot be tempted, then we’d want to start syringe feeding. To do so, we can water down calorie rich diets (ie Hills A/D, Royal Canin Recovery diet, even canned puppy food) or use a liquid diet (ie Clinicare, Dogsure). As well, there are paste supplements (ie Nutrical) that can also be used. And these will all get more in per bite even if we cannot get much in.
As well, if he has been dehydrated already, we do keep an eye on his water intake. If he won't drink water, then you can try to encourage him to drink low-sodium chicken broth. As well, wet foods (as mentioned above) are 35% water, so getting him to eat will help us deal with water intake as well.I f he continues not to drink, you may wish to offer unflavored pedialyte via syringe feeding. While we cannot do this if they are vomiting, it may be an option for this situation. A typical maintenance rate for hydration in an animal 48mls per kilogram of weight a day. If you do give syringe pedialyte, this should obviously be divided up into multiple offerings through the day rather then all at once. This value will give you the total he needs for the day and is a good starting point to give you an idea of his daily requirement. If he does vomits if you give pedialyte, I would discontinue this as a therapy. (since we don’t want him vomiting because of our intervention).
Overall, worms could cause weight loss in a young dog but tend to make them eat more not less as your lad. Therefore, they aren’t likely our main suspect and we’d need to consider those others I noted. Therefore, we do want to start the above supportive care now but need to consider having bloods or an xray checked to help narrow down the cause for his anorexia and get this cleared for Rocky as quickly as possible.
Please take care,
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