Laravel empty and white page

I have a page in Laravel and the view by id was working but now I only get a blank page and it stops showing the title of the page and only says localhost: 8000

Why is this happening?

This is the page that gives you click to appear by id:

@extends('layouts.app')

@section('content')
<link rel="stylesheet" href="{{ elixir('css/petsbook.css') }}"> 
 <meta name="csrf-token" content="{{ csrf_token() }}">

         <script  src="https://code.jquery.com/jquery-3.3.1.min.js"></script>

<div class="col-md-6 col-lg-6 col-md-offset-3  col-lg-offset-3">
    <div class="panel panel-primary ">
     <div class="col-lg-6 col-lg-offset-3">
    <div class="wrapper">

      <form id="form">
          <input class="input"  type="text" name="search" id="search" class="form-control pull-left" placeholder="Search Exercise...">


      </form>
  </div>
</div>

    <div class="panel-body">

    <h1 class="hidden">List of Exercise </h1>  
    <ul class="list-group">
    @foreach($pets as $pet)
        <li class="list-group-item" id="data"> 

        <a id="name" href="/pets/{{ $pet->id }}" >  {{ $pet->name }}</a></li>
    @endforeach
    </ul> 


    </div>
    </div>
</div>


<h1 class="hidden">The search </h1>  

<script type ="text/javascript">
    $(document).ready(function()
    {
        $.ajaxSetup({
            headers:{
                'X-CSRF-TOKEN' : $('meta[name="csrf-token"]').attr('content')
            }
        });


        $('#form').on('input',function(e)
        {
            e.preventDefault();
            data = $(this).serialize();
            $.post('/getSearch', data, function(search)
            {
                $('#data').html('');
                $.each(search, function (key,val){
                    $('#data').append(''+
                    '<li class="list-group-item" id="data"> <a id="name" href="/pets/{{ $pet->id }}" >'+val.name+'</a></li>'+



                '');

                });

            });
        });
    });

</script>



@endsection

This is the one that appears in Blanco:

@extends('layouts.app')

@section('content')
<link rel="stylesheet" href="{{ elixir('css/petsbook.css') }}"> 



     <div class="row col-md-9 col-lg-9 col-sm-9 pull-left ">
      <h1 class="hidden">Exercise </h1>  

      <div class="show" >

        <h1>{{ $pet->name }}</h1>

      </div>

      <div class="row  col-md-12 col-lg-12 col-sm-12" >
                <p class="lead">{{ $pet->description }}</p>
      </div>


</div>


    @endsection

This is my controller:

<?php
namespace App\Http\Controllers;
use App\Pet ;
use App\Family ;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Auth;
class PetsController extends Controller
{
  /**
     * Display a listing of the resource.
     *
     * @return \Illuminate\Http\Response
     */
     public function index()
     {
         //
         if( Auth::check() ){
             $pets = Pet::where('user_id', Auth::user()->id)->get();

              return view('pets.index', ['pets'=> $pets]);  
         }
         return view('auth.login');



    }


     /**
      * Show the form for creating a new resource.
      *
      * @return \Illuminate\Http\Response
      */
     public function create( $family_id = null )
     {
         //
         $families = null;
         if(!$family_id){
            $families = Family::where('user_id', Auth::user()->id)->get();
         }

         return view('pets.create',['family_id'=>$family_id, 'families'=>$families]);
     }

     /**
      * Store a newly created resource in storage.
      *
      * @param  \Illuminate\Http\Request  $request
      * @return \Illuminate\Http\Response
      */
     public function store(Request $request)
     {
         //

         if(Auth::check()){
             $pet = Pet::create([
                 'name' => $request->input('name'),
                 'description' => $request->input('description'),
                 'family_id' => $request->input('family_id'),
                 'user_id' => Auth::user()->id
             ]);


             if($pet){
                 return redirect()->route('pets.show', ['pets'=> $pet->id])
                 ->with('success' , 'You have an other pet');
             }

         }

             return back()->withInput()->with('errors', 'Error creating new pet');

     }


     /**
      * Display the specified resource.
      *
      * @param  \App\pet  $pet
      * @return \Illuminate\Http\Response
      */
     public function show(Pet $pet)
     {
         //

        // $pet = Pet::where('id', $pett->id )->first();
        $pet = Pet::find($pet->id);


     }

     /**
      * Show the form for editing the specified resource.
      *
      * @param  \App\pet  $pet
      * @return \Illuminate\Http\Response
      */
     public function edit(Pet $pet)
     {
         //
         $pet = Pet::find($pet->id);

         return view('pets.edit', ['pet'=>$pet]);
     }

     /**
      * Update the specified resource in storage.
      *
      * @param  \Illuminate\Http\Request  $request
      * @param  \App\pet  $pet
      * @return \Illuminate\Http\Response
      */
     public function update(Request $request, pet $pet)
     {

       //save data

       $petUpdate = Pet::where('id', $pet->id)
                                 ->update([
                                         'name'=> $request->input('name'),
                                         'description'=> $request->input('description')
                                 ]);

       if($petUpdate){
           return redirect()->route('pets.show', ['pet'=> $pet->id])
           ->with('success' , 'Yey An other Pet');
       }
       //redirect
       return back()->withInput();



     }

     /**
      * Remove the specified resource from storage.
      *
      * @param  \App\pet  $pet
      * @return \Illuminate\Http\Response
      */
     public function destroy(Pet $pet)
     {
         //

         $findpet = Pet::find( $pet->id);
         if($findpet->delete()){

             //redirect
             return redirect()->route('pets.index')
             ->with('success' , 'The Pet is not longer here');
         }

         return back()->withInput()->with('error' , 'we can not say  bye bye Pet');


     }

     public function search(Request $req)
    {
        $pets= Pet::all();
        return view ('search', compact ('pets'));
    }


    public function getSearch (Request $req)
    {
        if($req->ajax())
        {
            $find= Pet::where('name', 'LIKE','%' .$req->search. '%' )->get();
            return response()->json($find);

        }
    }


}

I do not understand what could have happened, Thank you.