Please see a vet.

Not good! You should get him to a vet for an X-ray to determine if he did indeed eat the battery. There is corrosive material inside batteries that could cause a lot of tissue damage inside if the battery starts to leak or the battery itself could cause an obstruction. Sometimes you can look in their mouth & see where there are mouth sores from the battery- there could be sores on the tongue, inside of cheeks.  Your dog should see a vet ASAP to ensure he is safe from the acid & an obstruction.

Hi, the pictures are not visible, can you try again? Guinea pigs commonly get trichoepitheliomas which are most commonly benign and the most common spot for them is near the tail/hind end. That being said, any mass on any animal has potential to be cancerous until proven otherwise. Your vet could aspirate some cells with a needle if the mass is big enough or simply remove it which is recommended while it is small. Even though trichoepitheliomas are usually benign, they can get very large and uncomfortable or ulcerated so removal while they are small (to prevent surgical complications) is recommended.

 http://www.merckvetmanual.com/pethealth/exotic_pets/guinea_pigs/disorders_and_diseases_of_guinea_pigs.html

hamsters are not outside pets.  please keep him inside where he’s safe and in a climate-controlled environment.

i personally wouldn’t do it. too much predator risk.

Honestly as long as he is completely safe he will likely enjoy fresh air and sunlight, however, he may get this near an open window!  I like animals to go out but they  must be safe.  An hour should be fine.

i would avoid it.  it’s not worth the risk.

Thank you I have booked him in the vets for first thing in the morning

Spoke to vet explaining everything and he did not seem concerned,could not get him in until 9.00am

He has started eating and drinking now thank goodness . Had an app for this evening vet said he has had a tummy upset .

that’s a VERY speedy decline.  i would be rushing her to emergency vet right now if i were in your shoes.

Apply direct pressure to the wound, cauderizing can be dangerous if you don’t know what your doing!

Hi Elaine, perhaps a bite? Could toxin from it have got into his system? Thats just a wold guess from your description of his symptoms. Maybe you should pop him to your Vet for a firm diagnosis and the correct treatment.

Good luck!

vomiting he vomited 4 times already