How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Dr. Andy Your Own Question
Dr. Andy
Dr. Andy, Medical Director
Category: Pet
Satisfied Customers: 30046
Experience:  2003 Graduate
Type Your Pet Question Here...
Dr. Andy is online now
A new question is answered every 9 seconds

My dog has suddenly begun to pant excessively, shake as if

This answer was rated:

My dog has suddenly begun to pant excessively, shake as if trying to dry off his fur and rubbing his face and body on the carpet like he itches. He also seems sensitive to touch on his lower back. I have given him generic Benedryl which seems to help, but he is lethargic and has not eaten in over 24 hours. although he does drink water. What is going on with him. He is 3 years old, and is llasa apso and chichuahua mix.


I am sorry to hear how Michie is doing.

Giving the benadryl was fine, as his symptoms could suggest some type of hypersensitivity reaction.


for future reference the benadryl dose:



Benadryl can be given at a dose of 1mg per pound of body weight. Keep in mind, Benadryl tablets and liquids come in different sizes. So, an approximately 25 pound dog can get a full 25mg tablet or a half of a 50mg tablet. I usually avoid the liquid Benadryl in larger dogs (you would have to give too much of it). You can give Benadryl every 8-12 hours.


The panting is usually suggestive of underlying nausea and/or pain.


With that in mind,



To help settle the stomach you could try one of the following drugs.

  • 1. Pepcid A.C. (famotidine) comes in 10mg, 20mg, or 40mg tablets.

You can give it every 12 hours. You give 0.25 to 0.5mg per pound of body weight. So, a 20 pound dog would get 5 to 10mg. A typical cat gets ¼ tablet of the 10mg tablet.


2. Prilosec (omeprazole). It comes in 10mg or 20mg tablets.

You can give in every 24 hours. You give 0.25 to 0.5mg per pound of body weight. So, a 20 pound dog would get 5 to 10mg.


3. Zantac (Ranitidne). It comes in 75mg, 150mg, or 300mg sizes.

You can give it every 8 to 12 hours. You give 0.25 to 1mg per pound of body weight. So, a 20 pound dog would get roughly 1/3 tablet of the 75mg. Even with bigger pets, it is easiest to get the smallest size tablet. Even a 75 pound dog would only need one 75mg tablet.


4. Pepto-Bismol or Kaopectate.

You can give it every 8 hours. The average dose is 1mg per pound of body weight, and that is the TOTAL dose for the day. So, if a pet weighs 30 pounds, they would get a total of 10mg every 8 hours. Pepto comes in various concentrations (262 mg per 15ml for the adult liquid, 525mg per 15ml for the "extra strength", and 75mg per 5ml for the pediatric liquid).

To simplify:

Regular strength Pepto ~ 85mg per teaspoon

Extra strength Pepto ~ 175mg per teaspoon


But, it really sounds like there could be a more serious systemic problem with the lethargy and poor appetite. So, despite the above suggestions and repeating teh benadryl, I do feel it is well worth a veterinary examination at this time.


I just don't know for sure if this is some allergic reaction, digestive problem, musculoskeletal issue, etc...


Good Luck

Dr. Andy






I greatly appreciate when you click "ACCEPT" if you have found the advice helpful or informative, so I may receive credit for the answer. Receiving feedback and bonuses is happily welcomed.

The answer provided is for information only. Unfortunately, I cannot legally prescribe medications or offer a definitive diagnosis without performing a physical examination. If you have any concerns please contact your primary veterinarian, or contact an ER facility if this is an emergency.


Dr. Andy and 2 other Pet Specialists are ready to help you