There are two Issues going on that are affecting ZigZag’s defensive behaviour. I would call rushing at dogs to grab the face defensive rather than antagonistic.

ZigZag is a 7-year-old Frenchie.

One issue is his physical state. The other is the loss of their older dog, Bonzo, some months ago.

Possible pain and feeling physically vulnerable

Poor ZigZag has had and is still suffering from medical conditions. These include two herniated discs he’s had treatment for and he has a redundant oesophagus. He’s on medication including painkillers.

Even if he’s not currently in pain, his system will be programmed to expect pain if bumped into. Feeling ‘delicate’, he will have learnt over the years to avoid physical interaction with other dogs.

The new puppy

The problem is fitting in their new puppy, now 11 weeks old. She’s an English Bulldog named Purdy.

It’s a big ask to expect a puppy to steer clear of an older dog.

So far the couple have mostly used management – keeping the puppy behind a pen or barrier. ZigZag has lunged at the bars a couple of times.

When unsupervised, the dogs’ view of each other is now blocked or they have an airlock of another room between them.

Separation

Since the passing of Bonzo, ZigZag has developed separation issues when the lady goes out or even leaves the room. 

Now she will change what she does. Instead of shutting doors when leaving the room and doesn’t want him to follow her, they will now use gates.

She will get ZigZag very happy to see her walk out through a gate – in easy stages and using food. She won’t go out of sight to start with. (Unfortunately leaving her with the man is no substitute for the lady).

The role of stress

I suspect there is another issue connected with missing Bonzo that upsets ZigZag. He is now often unwilling to walk when out. He is a lot more nervous on walks. This ‘ordeal’ twice a day may well affect his state of general stress.

His stress levels will in turn affect his feeling of security when the lady leaves him. Stress will affect also his resilience to puppy Purdy.

This case is a good example of taking a holistic approach.

The main issues – symptoms of other things

We looked at the two problems head-on, separation from the lady and integrating Purdy. Both need working on starting at the ‘start’.

The starting point is that where ZigZag is confident and happy.

Tolerating Purdy’s proximity

They will now be more proactive. They will work on each dog individually but in the presence of the other dog.

The ‘starting point’ will be with either a gate or pen between the dogs. ZigZag on a loose lead as a precaution so he can’t rush at the pen.

Now, using clicker and food, ZigZag will learn to look at puppy. He will learn to go near puppy calmly, and to come away from puppy if he feels uncomfortable with the proximity.

From the puppy’s side they will capture and mark every time she looks at ZigZag. This without approaching the bars whenever she’s calm, or sits, or looks away. I suggested a squeaker for Purdy but this proved too exciting, so they will click her also. If there is confusion they can try a kissy sound. 

A programme

The man can be in the pen with Purdy and chosen sound; the lady outside it with ZigZag and the clicker.

Alternatively, the lady can work with one dog only with the barrier between them – that dog on lead.

They can slowly graduate to removing the barrier – both dogs on leads.

Rushes at dogs

When out on walks they will protect ZigZag from unwanted attention from other dogs. They will work on his not feeling the need to rush at them. This may mean walking in different places for now.

His walks will be more of his own choice. If he doesn’t want to move on, they will turn around.

Everything should come together for ZigZag to feel comfortable near Purdy. Each element is interwoven.

The lady is an experienced dog owner with a lot of knowledge. This has prevented things from getting out of hand. Living in our own situation, we can’t always see our options objectively and need a little help.

A month later: Zigs and Purdey now playing together in kitchen and garden. Purdey on a long line as does not know when to stop but Zigs is being very tolerant of her. Especially when she lifts him up under his belly with her head! Today zigs had toy and was pushing it at her to get her to play! 
NB. For the sake of the story and for confidentiality also, this isn’t a complete report. If you listen to ‘other people’ or find instructions on the internet or TV that are not tailored to your own dog, you can do more harm than good. Click here for help