Made with Blender 3.4

Rigify

To get Zoo and human rigs download the add-on:
Download Rigify AnimBox

Install and enable it:

Use these animals for reference: Zoo Tycoon 2

Download the Dromedary Camel
Unzip the file
In Blender : File -> Import -> Wavefront OBJ

Shift+D To Duplicate
Grab X and drag the mouse to the left

Click on the first object and rotate: Rotate Type: Z-90

Make a screenshot (PNG/JPG/GIF) of these two to be using as a reference

Make New Blender File

Important To align everything correctly press 1 on numeric keypad to go to front orthographic view

Shift+A Add : Image -> Reference

Select the image you made

Shift+A Add : Mesh -> ICO Sphere

Scale and Grab X the mesh and position it a on the main body

It is important that you use X while Grabbing the object. That ensures that the mesh remains on the same coordinate system.

Shift+Duplicate the object and repeat Scale and Grab to align all the meshes along the side view of the animal

When you rotate the camera you will see that all the balls are divided by the reference. This is a good sign. The balls are all aligned on the Z-line.
We will have to duplicate the legs and move them to the side. But we need the front facing part for this.

Select all the ico spheres In the outliner (you can search for 'Ico' and do A
Rotate Z 90

Now pick up the empty reference mesh (Grab and X move mouse) and move it to the right to align with the rotated balls.

Turn on wireframe to look through the balls

Scale the upper ball to fit in the front view

Duplicate a few time to create the humb

Pressing numpad 3 reveals that we have now gaps

Fill them in this Right Orthographic view

Switch between numpad 1 and numpad 3 to view both right and front orthographic views.

Select and Shift Select all the front leg balls
It should look like this

Go to front orthographic view ( 1 )
And Grab and X move the mouse to align the right hand leg.

Shift+Duplicate the leg and Grab and X move the mouse to the left

Repeat the process for the behind leg(s)

The Reference image will be preventing you to see the wire balls but you will see the center points of the balls
And use these points to align the legs on the same level as the front legs

Grab the Empty Reference Image and drag (X mouse) to the left and rotate the camera to look at the model

A lot can be done to shape this better before going to sculpt and refine everything.
The mouth and the rest of the head is way off and the humb does not have a smooth curve

But for demonstration purposes we will be using this model to rigify

Join all the balls together
Search in the outliner for 'ico' and select All.
Go to the layout editor and press Ctrl-J to join them all

Rigify : AnimBox

Position the animal on so that the 3D cursor is between the front legs.

Click open the tool-tabs
Go to RigBox -> Rigify Samples -> Rigify Zoo metarigs and select Dog

Drag and Scale the Armature to closely fit in the mesh

Select wireframe mode and drag the three head-bones to their places:

In Object Mode Select the Mesh First and the shift-click the armature.

It should look something like this:

Pose -> Parent -> Automatic Weights:

Pose Mode : Rigify : Generate Rig

Generated Rig looks like this:

Delete original Armature:

go to Object Mode :
Select Mesh
Shift Select Armature
go To Pose Mode

(same as before) Pose -> Parent -> Automatic Weights but now with the generated rig:

Now we do something weird.
We are going to add another Zoo Rigify Rig:

go to Rigify Zoo and click on the Dog

Then click on the armature of the dog and select 'Walk'

Right click on the RIG-armature Animation (the armature of the dromedary)

Set Action: to dog_rig_Walk

And now delete the dog rig we added

The dog_rig_Walk animation should still be on the RIG-armature

Go To Pose Mode and select dog_rig_walk

Press spacebar to start the animation