from django.db import models
from django.contrib.postgres.fields import JSONField

class Animal(models.Model):
    data = models.JSONField(verbose_name=_('data'), blank=True)

class Sell(models.Model):
    count = models.IntegerField(verbose_name=_('data'), blank=True)
    animal = models.ForeignKey('Animal',
                               on_delete=models.CASCADE,
                               related_name="sales_set",
                               related_query_name="sold"
   )

animal = Animal(data={'type':'dog', 'bread':'Husky', 'count':20})

Animal.objects.annotate(animals_sold=Sum('sales_set__count'))
.filter(data__contains=[{'count__gt': F('animals_sold')}])

Animal.objects.annotate(animals_sold=Sum('sales_set__count'))
.filter(data__contains=[{'count__gt': F('animals_sold')}])