Canine Behavior/Dog attack


QUESTION: I have two female dogs, Mya who is about 4 and Gertie who is about 2. They have lived in the same house since Gertie was a puppy. They have always gotten along. Mya got loose and got hit by a car, thankfully the car was not going very fast and she walked away with only a few cuts by her face. As soon as Gertie noticed the blood she attacked Mya to kill. My cousin was the only one here and she witnessed the attack and wound up getting bit herself trying to break them up. We separated the dogs for a few nights, and tried reuniting them yesterday. Both were on leashes and we inched them closer to each other, all seemed well but out of no where Gertie attacked again. We are all clueless of why this happened. Do we have to keep them separated forever?

ANSWER: I'm so sorry that Mya got out and struck by a car. And then to come home and have her "sister" be ugly toward her is definitely not a very good day.

I need a bit more information before I can really comment - and in all likelihood my final comment will be that you need a professional who is well versed in canine body language and behavior to observe the dogs in order to really determine what's going on here.

But, if you'd like my input, here are some questions I need answered before I can chime in.

1. What does "attack to kill" actually mean? Most skirmishes between dogs are loud and look like nothing but teeth and fur flying around in a blur, but there's often little to no actual contact - at least no actual damage done. Mya had just been struck by a car and you believe she was hardly injured (externally), so what damage did Gertie do to her in that first bad encounter?

2. Did anyone witness the car striking her? Had anyone looked her over before Gertie got to her to assess what external injuries actually occurred so we know for certain what damage Gertie did?

3. What breed of dogs are Mya and Gertie?

4. Are either of them spayed? If not, how near a heat cycle are each of them?

5. Has Mya been examined by a vet to determine the extent of damage done by the car strike as well as the fight with Gertie?

6. Was Mya limping badly? Was her face/fur obscured by blood when she first came back to the house and Gertie snapped at her?

7. Did your cousin actually witness the start of the fight? Did Gertie literally launch herself at Mya from more than a foot away, open mouth, making a biting contact?

8. Is is possible that Gertie came up to Mya to sniff and check out what was going on with the blood and it was Mya - heavily shaken and in pain - who snapped first in a "get away from me!" manner which Gertie didn't respond well to?

9. Where did you attempt to reunite them? In the house, in the front yard, at a local park?

10. Was there tension on the leash when you were inching them closer?

11. What was their body language telling you while you were trying to get them closer together? Were heads and tails high (higher than the spine), ears pricked forward, staring at each other? Were heads and tails lower (even with spine or lower), ears back, eyes looking away from each other? Was anyone licking their lips or yawning or doing full body shake-offs (like when they're wet), turning their head to look away from the other dog, turning their head far enough to sniff their own hip or genital area?

It is entirely possible that it was Mya who actually snapped first. I know I would be short fused if I'd just been in a car accident and then had my sister come right up to me and try to kiss me on the cheek. I'd probably push her away too. And then, Gertie is defensive the next time they try to meet - or both are defensive.

Is Mya still healing from the accident? If she's still in pain, then she's still going to be short fused.

Generally dogs don't attack each other out of nowhere, especially dogs that have lived and gotten along well for 2 years. So, while it's very likely that you and your cousin didn't see what triggered Gertie's attack when you attempted to reunite them, it's quite likely that there was an exchanged look or body language that Gertie was responding to. Often the one who overtly snaps first is not really the one who threw the "first punch".

I look forward to your reply answering the above questions in detail. I will offer some thoughts and suggestions for helping them get past this once I have that response. And if you feel you need assistance in order to implement the suggestions correctly and safely, then I strongly encourage you to enlist the aid of a local professional skilled in positive reinforcement training and behavior modification - avoid anyone who uses choke, pinch, or electronic collars at all. This is not a time for squirt bottles, leash corrections or noise makers. We want to help these two feel safe with each other again and that will only happen with a positive, nurturing and reassuring approach.

I await your reply.
Jody, APDT
Los Angeles Behaviorist

---------- FOLLOW-UP ----------

QUESTION: Hello Jody,
      I am trying to get all the facts straight, I need to ask my cousin some questions still. I messed up their ages previously, they are both 3, Mya is a collie-retriever mix, my uncle found her abandoned in the woods when she was a puppy. Gertie is a springer spaniel-mix, we got her 6 months after Mya. I am sorry for taking so long to answer your questions, I will have all the answers by morning. Both dogs are safe, and Myas injuries have been checked out, she is just hesitant to move from room to room and in and out of the house. Gertie is staying at a family member's house. Thank you so much for your concern, I will get back to you shortly.

ANSWER: I appreciate the update. I think it's good that they are staying in separate houses until we can work through this. That allows each to fully relax and recover emotionally from their spat.

I look forward to your full reply.

Jody, APDT
Los Angeles Behaviorist

---------- FOLLOW-UP ----------

QUESTION: Mya is a golden/collie. Gertie is boxer/springer spaniel.
Mya ran her head into pickup truck
Bleeding from nose and had a scrap on her neck. it was bleeding.
Gertie was not on a leash in front of house and sniffed mya then bit onto her neck whipping her around. sounded awful.
mya ran off to neighbors when cousin separated the dogs.
reunited dogs in house 1 hour later and gertie grabbed a hold of mya by the neck again.
Uncle picked up gertie by her collar and gertie did not let go of mya for about 30 seconds. both dogs were in the air.
separated both dogs for 2 days. then they met outside the house. both on leashes. Mya kept her head down and was very timid about being near Gertie. At first Gertie did not even care about Mya then she walked over to mya and sniffed her. head went up and tail went up and then she bit mya and would not let go.
Both dogs are spayed.
Mya was not limping at all.
There was definite contact by Gertie onto mya.
There was no tension on Gertie with leash. Mya was right next to me on a leash.
It is believed that Gertie threw first punch in every bad encounter.
completely the opposite of her disposition. Neither dog has ever been aggressive.

That sounds like Gertie was seriously trying to cause harm to Mya. A bite/hold/head whip as you describe is considered a kill bite. You see it in many wild animals on the nature shows - grab the neck and then break it by whipping the head around, while also cutting off blood flow to the brain.

The fact that she did this twice is definitely a concern. This may fall somewhat outside my personal expertise. It's not that Gertie "smelled blood", but it may be that Gertie saw Mya as weak and injured and this triggered something in her. Given that she's never shown any signs of aggression nor predation (at least you've mentioned nothing about predation behavior such as chasing/killing lizards, birds, squirrels or other small animals), this is definitely an odd behavior and if you were an in-person client of mine, I'd be consulting with someone more educated and experienced than myself.

I think the decision to permanently re-home Gertie away from Mya is a sound one. Once Mya is completely healed from the accident and the encounters with Gertie, it may be possible to reunite them under heavy supervision from a professional who uses positive reinforcement and learning theory based techniques. But, you may never be able to trust Gertie alone with Mya again. So, rehoming, especially if it's with someone you know so you can continue a relationship with Gertie if you want one, is a very good solution here.

As to what a CAAB or vet behaviorist would do (from your other posted question)... they would meet with you and both dogs. They would observe both dogs separately from each other, get a thorough history of both dogs, as well as their relationship with each other. They would observe the dogs in the same space (tethered and out of reach of each other), and if they feel it's safe, they may observe them engaging with each other. They would discuss the possible reasons for the sudden aggressive behavior change that Gertie displayed as well as whether or not they believe it can be worked through. If they believe it can be worked through, they will design a protocol custom to you and your dogs to help you reunite them safely. They will work with you to implement the protocol and continue to check in with you, usually for 6 months (anywhere from weekly to monthly contact) following the consultation to make sure things are going well, and/or help you refine the protocol to best benefit both dogs.

Or, they may, after the consultation and observing the dogs, tell you that these two dogs have permanently damaged their relationship and it's not worth inflicting that much stress on each dog in an effort to reunite them, when they would both live quite happily and comfortably in separate homes. It's certainly not fair to Mya to force her to deal with Gertie's aggression if it's going to continue. And it's not fair to Gertie to put her in a position where she feels a need to be so aggressive, especially as that's so counter to her normal nature.

I would strongly encourage you to continue to supervise Gertie, especially with children. Dogs and children are very different, and just because she's now demonstrated aggression toward a dog doesn't mean that she would ever be aggressive toward a child. But, and this is a very serious and important BUT... she has now demonstrated a capacity for aggression. This means she is not to be trusted to the same extent. If her aggression was triggered by Mya's injuries, or the adrenalin pumping through her (the smell of fear) after being struck by a car, then if a child falls down and scrapes a knee and begins crying and is scared because they hurt themselves, this could also trigger Gertie in the same way that Mya triggered it.

***I would also strongly encourage Gertie to have a complete physical, including a neurological and thyroid exam. (The thyroid is going to be a blood panel and you want a complete thyroid panel, not the mini one). Changes in Gertie's brain health or blood chemistry could be a contributing factor to sudden onset aggression. That's a very real possibility and should not be discounted. In fact, if an exam diagnoses something and it's treated, then you may even be able to reunite the dogs, though Mya may be less than fully trusting for a while. A CAAB is likely, and a vet behaviorist will definitely request a complete physical, including the blood work, by your regular vet to be completed before a session with them. They'll want the medical records of both dogs for review before meeting with you so they have that information handy during their evaluation.

I hope this is helpful. Even if you decide to make the re-homing permanent (a totally valid option), Gertie should still be checked out to make sure she's not dealing with any health issues that should be treated.

Jody, APDT
Los Angeles Behaviorist

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Jody Epstein, MS, CPDT-KA


IF YOU BELIEVE YOUR DOG IS ILL OR INJURED, PLEASE CONTACT YOUR LOCAL VETERINARIAN IMMEDIATELY. THIS IS NOT THE FORUM TO ADDRESS URGENT MEDICAL ISSUES. I AM NOT A LICENSED VET AND HAVE NO DIAGNOSTIC SKILLS. ***I have been answering questions on All Experts for over 8 years now. I enjoy being able to offer assistance in this forum. I do need to be clear, though. If you’re looking for free advice about a specific behavior question, you MUST submit your question to me via All Experts. If you bypass All Experts and write to me directly through my website, I will ask you to submit via All Experts. On the flip side, if you’re local to Los Angeles and you wish to speak to me privately about an in person consultation, please go through my website. I appreciate your assistance in keeping my volunteer work on the volunteer site.*** I can answer questions about the following canine behavior issues: obedience, timid/fearful & fear-based aggression, nuisance behaviors, families that are expanding with either new human or new animal members and many other issues. If you have potty training questions please first read my trio of blogs at If you still have questions after reading the blogs you can post your specific questions here. PLEASE be as specific as possible when asking a question. Give me a detailed example of the situation - dog's behavior, body language, circumstances surrounding the issue, what the consequences are (another dog's response, your response), etc. I can only provide insight if I can get a picture of the whole scenario. If I ask for further details, please provide them. In person I would normally observe for at least 90 minutes to assess the situation and the dynamics before offering tools and suggestions to modify it. In writing it is ever so much more difficult. Thank you for your participation in the process.


I have been a professional obedience trainer for 9 years, and specializing in behavior modification for 8 years. I have owned dogs my entire life. I own my own dog training and behavior modification business called Nutz About Mutz.

I am a Certified Profession Dog Trainer - Knowledge Assessed (CPDT-KA), #2133301 ; I am a member in good standing with the Association of Professional Dog Trainers (APDT), #77763 ; I am an AKC certified Canine Good Citizen evaluator (CGC), #71253

Publications ; ; Multiple articles in the local pet magazine Pet Press (found across Southern California)

I have a masters degree (MS) in Animals and Public Policy, with a minor in Animal Behavior, from Tufts Cummings School of Veterinary Medicine. I also have 3 years of graduate education in Animal Behavior and Learning from UM-Missoula and UL-Lafayette. I continue to educate myself to canine-specific behavior through extensive reading, online interactive workshops, vidoes and attending canine behavior conferences, workshops and seminars. Beginning in March, 2017, I will be the Behavior & Training Manager at Second Chance Center for Animals in Flagstaff, AZ.

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