The Risk of Fostering


I have been fostering animals for over 12 years, am an animal behavior guru, active in the rescue community and a veterinarian. I know many animal professionals, rescuers, and fosters and have noticed that there is a difficult, terrible, bone-chilling topic that is not frequently talked about in dog rescue: the risk of fostering. For the purposes of this post, I am talking about a foster animal injuring or killing a resident dog or cat. In the Twin Cities alone over the last year and a half, I know of five different instances of a foster dog killing a resident dog and one instance where a foster dog killed a resident cat. I have to assume there are more instances that I don’t know about, because this isn’t a topic people openly talk about.

Unfortunately, the reverse—a resident dog killing a foster animal—can also happen. Understand—it is not ONLY a risk for fostering. Altercations can happen anytime you have two or more animals together. It certainly happens between owned animals as well. But I do believe it is typically a bigger risk while fostering for several reasons:

1) The dogs simply don’t have history or trust built up because they just met each other.

2) The foster dog is often coming from a high-stress environment (i.e. animal control, a shelter, or boarding) and in some cases they are not given time and opportunity to decompress and let those stress hormones leave their body.

3) The foster dog may not yet feel comfortable in their environment and so even being in a home—which is typically less stressful—doesn’t feel safe.

4) The foster doesn’t know the foster dog well (how they will react, if they will escape from their crate, if they resource guard, etc.) and may not be able to accurately predict situations which may be triggers for the dog.


The potential of our pet getting hurt or killed in our own home—when we are only trying to help—is absolutely terrifying. It literally makes me sick to think about it and this is the main reason we are so careful integrating dogs into our house.


There will be complications you cannot possibly foresee.

No matter how careful you are, you are human and you will make mistakes. And a death can happen even if you have done EVERYTHING correctly.

The vast majority of the time, the mistakes you make don’t result in anything (other than anxiety for the handler). Dogs are extremely adaptable and will surprise you with how forgiving they are. However, there is always the risk (which may be bigger or smaller, depending upon the dispositions of the dogs involved) that a fight may break out.

It is important that you do not to blame yourself—even if it is something that could have (somehow, theoretically) been prevented. As long as you were making the best effort you could to minimize the risk and set the dogs up for success—you did what you could. And if you forgot to close a door, latch a crate, or pick up a high value toy—it is a heart-wrenching mistake and your guilt will probably be immeasurable. But it’s a mistake and it isn’t your fault.

Deadly mistakes can happen to the best dog handlers. Experienced trainers, people who professionally handle dog introductions for a living (like at a dog day-care), and veterinarians are not exempt.


Serious altercations often happen during what could be considered surprising times: like when dogs crowd each other to get through a door, over a dropped piece of food during meal preparation, when one dog stepping on the other dog, being together during times of high arousal/excitement (i.e. when someone rings the doorbell and both dogs run to it barking), or when dogs are left at home together but separated with barriers (kennels, crates, doors) that they are able to escape from or chew through. I always try to recognize times when the dogs aren’t feeling secure or when aggression could be a possible outcome, but there is no way that you can protect dogs from everything. Without risk there is no potential for the dogs to grow. Sometimes for me, that means allowing, facilitating, and monitoring what could potentially be difficult situations (i.e. allowing Frankie to climb up on the couch with Jonah again even when I know that has been hard for Jonah in the past)

There are many types of aggression that can be at play in these situations, including:

  •  Predatory
  • Resource guarding/Territorial
  • Fear (flight or fight)
  • Pain-induced
  • Redirected
  • Aggression secondary to a medical issue (brain tumor, hypothyroidism, etc.)

For the people whose animals are killed, it is devastating and isolating. It doesn’t seem like there is anyone you can talk to who would understand the mix of emotions you are feeling: guilt, anger, sadness, grief, shame, disbelief, responsibility, embarrassment and more guilt. You feel like you let your animal down, your foster dog down, the rescue down, you let your family down, hell—you probably even feel like you let down the random people you talk to about your dogs with down (at work or on Facebook).

With many people, guilt and other emotions result in radio silence. Fosters might not talk about it because they feel responsible (“If I had only..”), because they are worried about being judged by the rescue community (“The Smiths have fostered for years and THEY have never had any issues…” or “What did they do?! I met [the foster dog] and he was FINE with other animals…”), because they are worried about giving fostering or a certain breed a bad name (“no one will want to foster dogs if they know there is a risk involved…”), because their grief and guilt is so strong, or for any number of other reasons.

The rescue probably won’t talk about it because of a lot of the same reasons, and because rescues try to keep things positive (it helps get animals adopted), avoid bad press, and don’t want their name to be attached to a resident animal’s death. I believe a reputable rescue will react IMMEDIATELY once they are told their foster dog has killed and they should do so in a professional, sympathetic, and non-judgmental way.

That means they need to send a representative to the foster immediately to either remove the foster dog from the house or to be with the foster dog while they are euthanized.

I also believe, unless it is a case of gross foster negligence (i.e. the foster intentionally put a new foster dog that they know is aggressive with small dogs in with their small dog), that the rescue should quietly let the foster know they will pay for the resident animal’s care (if they were taken to a veterinarian).  One thoughtful rescue offered to pay for the individual cremation of the resident dog. Truly, both the rescue and the foster home are in mourning. Instead of this being a divisive time and laying blame, it can be a time for mutual grieving, unity and support.

The rescue may also keep quiet because they are worried about being judged by the community on what happens to the foster dog that killed the resident animal.


So what happens to a foster dog that kills?

This specifically is hard for me because I know that NO MATTER what the rescue does, people will not be happy with the outcome. There will always be people who think that no matter what the dog should be saved and there will always be people who no matter what think the dog should be put down. It is difficult because animal behavior is not black & white. It is a spectrum and often situation-dependent. My take on the matter is that the foster parents should ALWAYS have a say in what happens to the foster dog (remember, they know the dog best, probably love the dog, and their family was the one harmed) and the foster family’s opinion should be taken extremely seriously by the rescue.

I will say this even though it is a difficult and sometimes unpopular stance: Euthanasia is a viable and responsible option. Euthanasia is something I take extremely seriously as a veterinarian and I never recommend it lightly. Sometimes, euthanizing is the only responsible thing to do (as in the case of dogs that kill people (level 6 attack) or level 5 bites). Euthanizing for behavior seems harder than euthanizing for anything else. Because (often) the dog seems happy and is physically healthy. Once the situation is over (and the resident dog is dead)—it is common for people to attempt to justify the behavior.  You might think “well, he was from an abusive home (or a hoarding situation, or a neglect case, or a dog-fighting ring)” or “he wouldn’t have done this if I had ___ (been home, latched the gate, taken more time introducing them).” And those things may all be true, but they don’t negate the fact that the foster killed another animal. They probably have bad bite inhibition (where the dog chooses to hold back and doesn’t use a lot of force during a bite) and the foster dog’s interactions with other animals (if any) will all have to be closely monitored to prevent another disaster.

Is it a possibility that the foster could co-exist with animals and never cause them any issues? YES. It could happen. But you don’t know that. You already know that the dog will kill under certain circumstances and I would argue that this would make them more likely to resort to serious aggression in similar (or potentially very different) instances.

That said, there are situations where I don’t necessarily think euthanasia of a dog that has killed other animals is the answer. Some of the things I consider when thinking about the outcome for a dog that has killed animals are:

  • Are the dog’s triggers easily predictable? Do they frequently occur?
  • Has the dog ever bitten a human before?
  • Does the dog have a human who is dedicated to their management, rehabilitation, and training? Is the human capable, vigilant, and realistic?
  • Does the dog have someplace safe and without any other animals that he can decompress from the altercation? Stress hormones can take weeks to completely leave the dog’s body after a traumatic event.  It is not responsible to immediately put the dog back into a home where they can interact with other animals (even if that dog has done well with those animals in the past) or the public. It isn’t fair to the dog and they really need to be set up for success.
  • Is the rescue reputable?  Will they do the right thing by the dog even if it means having to euthanize the dog down the road? Can I trust this rescue to disclose the dog’s bite history to potential adopters or other handlers?  If this answer is EVER “no” then I have to recommend that the dog be euthanized for public safety.
  • What are the dog’s other challenges? Do they have multiple physical and mental health problems?

Euthanasia does NOT mean that you have failed the foster dog. In some cases, this is the only thing that you can do to keep them safe and to keep other animals safe. Some dogs are too dangerous or unpredictable to live in the community.

This is a complex, emotional, and difficult issue to talk about. I can remember exactly where I was and what I was doing when I was told by my friends that their resident dog had been killed.  It can scar families forever–but not talking about it and keeping everything quiet isn’t going to help. People need to be aware of how to properly introduce foster dogs to try and minimize the risk to resident animals. Families in this situation need to know that they are not alone, it is not their fault, and the rescue community supports them.



This post is dedicated to the resident dogs and cats that have lost their lives to a foster dog specifically:



We miss you and your family loves you very much. We know your buddy Casey misses you, too.



Melvin was our sweet boy, our pet from puppy-hood. We loved him through fourteen years of always being the senior dog of the household. We miss him terribly, no other will ever be like our little man, he told us when it was time to get up, he told us when it was time for bed, and when it was time to eat. In his younger years he was faster than grease lightening! and always pranced with a certain pride. He knew he was ours, and we were his. Melvin the Great !” -Melvin’s mom



Sasha- the best Beagle lab- was a lover of life, and lived the happiest ten years a dog could live. She is deeply missed, but her legacy will live on.” -Sasha’s mom




This post is also dedicated to a beloved foster dog that killed a resident dog. He is now living in an animal sanctuary. His foster mom is still in touch with his sanctuary and regularly talks with them to see how he’s doing.


Hercules , we still love you.” -Hercules’ foster mom (and Melvin’s mom).





All photos of dedications property of the dog owners. Thank you to ari-stock for the image of the Rottweiler paws.


2 responses to “The Risk of Fostering

  1. I love this post. “This specifically is hard for me because I know that NO MATTER what the rescue does, people will not be happy with the outcome” – YES. And this statement is not only true when a foster dog kills a resident dog (or vice versa) but other decisions related to difficult situations too. The most/best we can do is act as responsible members of the dog and human community while also doing our best to honor each of the animals we are doing all of this for. Great post. Thanks for writing.


  2. My heart is still heavy for euthanizing my foster dog. He was unpredictable yet extremely loving and smart. I miss him terribly but I could not trust him and he was so miserable when he arrived from being passed around from rescues/shelters…because I loved him I gave him eternal peace but it is by far the most painful experience I’ve had in rescue these past fifteen years…rescue is not for the weak at heart. He left happy and extremely loved. Thank you for this article – you’re absolutely right – no one talks about this for all the reasons you mention.


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