Last updated on February 18th, 2023 at 06:02 pm
Rescue dogs adopted from shelters can be awesome pets. In some cases, however, new owners have found that their rescue dog’s behavior was worsening a few weeks after adoption. Shelter staff members usually offer some information about a dog’s personality and behavior. However, a shelter is not a normal place for a dog to live. Therefore, a dog’s true personality may be hidden until after being adopted. Dogs who are quiet and reserved may later lash out when frightened. Conversely, dogs who bark a lot at the shelter may later quiet down after leaving the noisy chaos of shelter life.
Additionally, new perspective owners can usually visit and hang out with the dog they are considering multiple times. This gives a prospective owner a chance to interact with a particular dog and try to bond. However, it is unlikely a dog’s true personality will emerge immediately when adopted. And, in some cases, a rescue dog’s behavior might actually get worse.
Most rescue dogs eventually do well in a loving home environment. However, some struggle to integrate well and need more time to settle in. A rescued dog who has suffered a lot of trauma will be terrified of anything new. Therefore, he should be introduced to everything and everyone in his home very slowly.
Rescue Dogs Need to Learn How to Be Dogs Again
The first 12 weeks of a puppy’s life are the most formative weeks. During this time, a puppy will learn from his mother and litter mates how to appropriately interact with his pack. He will socialize, hang out, and play with his siblings. His mother will discipline him if he gets too rambunctious. In rather words, this is the time a puppy learns how to be a dog.
Unfortunately, pups who do not get this opportunity may adopt unhealthy or challenging behaviors in order to cope. Puppies who are taken away from their mothers too soon (before 8 weeks) or raised in puppy mills do not have the opportunity to grow up normally. They will be forced to find their own ways of dealing with life. To learn more please see my post about puppy mills and how you can help.
Even if a dog has had a healthy puppyhood, the stress of being abused later in life can alter his behavior as he tries to survive. Additionally, dogs who spend long periods of time in a shelter or are rehomed can be traumatized. As a result, these dogs can become very stressed and act out due to their fear and anxiety.
Dogs can and do recover, however. In time they can re-learn or learn for the first time, how to live happily in a loving and caring home. But go slow! Do not overwhelm your new dog with too much cuddling or too many people. Let him settle in first and get to know he can trust you and be safe in his new home.
Common Rescue Dog Behaviors Which May Get Worse Before They Get Better
Just like humans, dogs will develop certain behaviors to protect themselves. Most of the negative behaviors stem from feelings of fear, stress, or extreme anxiety. Therefore, punishment is absolutely the worst way to handle a frightened dog. This will only make the behavior escalate. Here are some of the more common ways in which rescue dogs may behave when fearful:
- Cowering when petted
- Hiding under furniture
- Trying to run away
- Whimpering
- Growling if cornered or approached
- Snapping or biting when growling is not heeded
- Barking excessively
- Lunging
- Chewing or destroying things
- Digging
- Circling
- Staring
- Acting despondent
Healing and training a dog is not a linear process. Therefore, you may see great progress in the beginning, but something could cause your dog to regress. So, don’t be discouraged if your dog has some relapses. Many of these behaviors will disappear over time as your dog feels more relaxed and safe. See my post, Is My Rescue Dog Depressed? for some more insights. Some of the more psychologically damaged dogs may need to be treated by a veterinarian specialist.
If your rescue dog’s behavior gets progressively worse over time, you will need to figure out why. Perhaps something or someone in your household may seem frightening to your dog, so he is reverting back to his prior coping strategies. Loud noises, other pets, or someone who resembles a person in his past could feel threatening. If your rescue dog’s behavior is really unacceptable such as biting or attacking, get some professional help soon!
Growling, snarling, lunging, and biting are behaviors often seen in dogs who were abused or trained to fight other dogs. In this case, your dog may need some serious intervention. Let the shelter know and ask them for resources, as they will want to help. Your local vet or a professional dog trainer may be able to assist as well.
The First Three Months are Critical
The majority of dogs who have been in shelters or rescued are like wilted flowers who will bloom and come back to life with tender, loving care. But it will take some time. Be sure to read my post Rescue Dogs are Not Broken! if you need some encouragement.
It is really important to give your new pup plenty of space. And pay attention to his body language. If he cowers when you try to pet him, don’t. If he growls while eating or is backed into a corner, step back and respect his need to be left alone. Most importantly, do not overwhelm him by being overly affectionate or taking him to several new places. He will primarily need to know that he is safe, will not be harmed, and will be allowed to eat and rest in peace.
On average, it takes about 3 months for a newly-adopted dog to settle into his new home. The phases of this period are often referred to as the 3-3-3 rule by shelter staff and trainers. In the first 3 days, he will get oriented and learn where he will sleep, eat, and potty.
For the next 3 weeks, your rescue dog will begin to get used to his daily schedule, which you should keep as consistent as possible. Meals, walks, and bedtime should always be set for the same time each day as much as possible. During the first 3 months, your dog will begin to know you and how he will be treated. This period will be critical to the bonding process when you can begin to build trust. It will take him a while to fully relax, and you may need to teach your dog how to play if he has never learned.
Don’t Give Up Too Soon
If we think about our own relationships–marriage, friendship, career networks, and extended family–we will probably recall that these bonds and connections did not happen overnight. They were developed, tested, and experienced over a long period of time. We spent time together, shared experiences, relied on one another, and worked out our differences. The same is true in building a relationship and bonding with a newly adopted dog.
For some dogs with really challenging pasts, it may take more than three months and up to a year or more to fully begin to trust humans. Some coping or obsessive behaviors may never go away completely, but most can recover significantly over time and become wonderful pets and happy dogs. Be sure to see my very comprehensive post How to Comfort and Heal a Rescue Dog for a complete guide to raising your new rescue dog and dealing with behavioral issues.
Final Thoughts
Remember to give your new rescue dog plenty of personal space and time to recover and heal. He has gone through a lot and healing will not happen overnight. Even so, most shelter dogs are thrilled and grateful to be freed from their past situation and in a caring home and healthy environment. Just try to be patient and keep your expectations low.
In time, your dog will most likely adjust, heal, and bond with you. Watching a sad dog come to life and be joyful is a tremendously rewarding experience!

Deanna Euritt is a dedicated dog enthusiast with over three decades of experience in raising and training a diverse range of dogs, including many rescue pups. Her practical expertise is rooted in real-life experiences, where she has successfully navigated the challenges of nurturing rescue dogs into confident, well-adjusted companions. Residing in Northern California, Deanna’s days are filled with adventures along trails and beaches with her beloved dogs, Charlotte and Georgia. In her writing, she offers insightful, compassionate advice to fellow dog lovers, leveraging her extensive personal journey in the world of dog care and training. Visit us on Pinterest, Facebook, LinkedIn and FlipBoard (+ icon below) See our full story — About Us.