Discriminator does not switch schema

Using Swagger UI v2.2.3

Swagger file:

{
    "swagger": "2.0",
    "info": {
        "title": "Animals yo!",
        "description": "An API for animals",
        "version": "1.0.0"
    },
    "produces": [
        "application/json"
    ],
    "paths": {
        "/animal": {
            "get": {
                "summary": "Retrieves an animal",
                "responses": {
                    "200": {
                        "description": "Animal",
                        "schema": {
                            "$ref": "#/definitions/Animal"
                        }
                    }
                }
            },
            "post": {
                "summary": "Animal",
                "parameters": [
                    {
                        "in": "body",
                        "name": "animal",
                        "required": true,
                        "schema": {
                            "$ref": "#/definitions/Animal"
                        }
                    }
                ],
                "responses": {
                    "200": {
                        "description": "Animal",
                        "schema": {
                            "$ref": "#/definitions/Animal"
                        }
                    }
                }
            }
        }
    },
    "definitions": {
        "Animal": {
            "additionalProperties": true,
            "discriminator": "animalType",
            "required": [
                "name",
                "animalType"
            ],
            "properties": {
                "name": {
                    "type": "string"
                },
                "animalType": {
                    "type": "string",
                    "enum": [
                        "Cat",
                        "Dog"
                    ]
                }
            }
        },
        "Cat": {
            "allOf": [
                {
                    "$ref": "#/definitions/Animal"
                }
            ],
            "required": [
                "huntingSkill"
            ],
            "properties": {
                "huntingSkill": {
                    "type": "string",
                    "description": "Skill of hunting",
                    "default": "lazy",
                    "enum": [
                        "lazy",
                        "clueless",
                        "adventurous",
                        "aggressive"
                    ]
                }
            }
        },
        "Dog": {
            "allOf": [
                {
                    "$ref": "#/definitions/Animal"
                }
            ],
            "required": [
                "packSize"
            ],
            "properties": {
                "packSize": {
                    "type": "integer",
                    "format": "int32",
                    "description": "Size of the pack",
                    "default": 0,
                    "minimum": 0
                }
            }
        }
    }
}

What I expect to see:
Under GET /animals some indication that a Dog or Cat may actually be returned with corresponding huntingSkill or packSize parameters.

Under POST /animals parameters section a text box corresponding to huntingSkill when animalType dropdown is set to Cat, and a packSize text box when animalType is set to Dog

What I actually see:
Basic Animal represented for both GET and POST.

If I change the schema $ref in GET or POST to one of the options then the model will show all fields for an Animal plus the specific type of animal. However the animalType parameter can still be changed to the other type.

Reproduce the behavior in Swagger UI v2.2.3 with the supplied Swagger document, then inspect the GET and POST model and parameter rendering for the Animal discriminator. Done means GET indicates Cat and Dog-specific fields and POST updates its inputs when animalType changes between Cat and Dog.