Why is my male dog peeing inside after a new female dog arrived?

Unneutered male dogs have the highest likelihood of “marking” around the house. However, some male neutered dogs and an occasional female dog will also. Any new dog you bring into the house should be confined to small, safe areas unless supervised for a while until you know their marking/ urination/ defecation/ destruction habits. Best of luck and I hope you enjoy your new dog if you get one! Thank you for using Pet Coach.

Inappropriate urination occurs when a dog regresses to urinating inside the house. This behavior is more common in male dogs that have not been neutered, although it can occur in non-neutered dogs and cats. The first thing to rule out is inappropriate urination that occurs when there is an underlying health problem which is causing a dog to urinate inside the house. It may have lost control of the muscles in its bladder or sphincter, or there may be an infection (UTI) or other condition as drinking too much (seen in many medical conditions) that is making it difficult for the dog to hold it in long enough to get outside. When a medical caused has been ruled out we can think about the second type of inappropriate urination which is behavioral (such as marking). I recommend to take Bakar to the vet with a "fresh" urine sample to first check or rule out medical causes. Hope this helps and thank you for using Petco Pet Education Center, formerly Petcoach.

They may have a continuous disagreement over who is boss. Your male dog may urinate in an attempt to establish dominance over the other. He also may be marking his "territory", i.e. marking her as "his"

Given that Jake is not neutered and you have introduced a new male puppy into the home, he may be urinating on the new puppy to declare his status as top dog in the home. He is letting the new puppy known that he is top of the hierarchy in the home, and that the new puppy is below him in status. This reason is most likely if he physically dominating the puppy (standing tall over him) as he does this behavior. I would consider neutering Jake to help reduce hormone related behavior.

The first thing I think Dallas needs is a vet visit and a urine check. Whenever a dog has an unexplained loss of house training, we need to check for urinary tract infection, bladder stones, diabetes etc. Once a medical issue is ruled out, I would recommend use of belly bands (Male diapers that can be washed), crating when you can't watch him and treats for going outside.

It is possible, but it is also possible he is urine marking because if he was only neutered in the last few months, or merely because there is a new cat present. I would suggest the following article to help; https://www.petcoach.co/article/6-common-reasons-for-potty-accidents-in-dogs/

The best long-term solution is spaying/neutering to prevent any puppies, especially since if a male senses a female in heat they will try to do everything possible to get to that female. Keeping them physically separated with barriers in different rooms, crates, etc can help, but there is still the chance they can get together to mate if one escapes. Spaying and neutering can also help with marking behavior inside the house as it can be hormonal related, You can also use an enzymatic cleaner to clean any accidents and deter them from going potty inside. Reverting back to a "puppy" style of potty training taking them out every few hours can also help remind them of where to go and reduce accidents.