Dog keeps bitting patches of hair out

We currently use Nextra dog worming tablets. She is 10 month old toy cavoodle. She only bites it occasionally and when we stay stop she does but still it's a noticeable patch.   We have moved house a month ago and wondered if it was anxiety. We have a backyard now when we didn't used to.   Any advice would be appreciated.

Hello!  Where exactly is this patch?  (I mean, in terms of the landscape of the dog - I can see it in the pictures).  Because an underestimated cause of self-trauma in animals is actually chronic (the means ongoing, possibly niggling) pain.  Sometimes this is itching caused by fleas, sometimes joint pain as a result of mild arthritis, sometimes the stretch of full anal glands or the grinding of stiff spinal vertebrae or even belly ache, eg pancreatitis.  Furthermore, dogs don't always bite the region that's hurting.  If they've got back-ache, they might luck an easy-to-reach spot in the general direction.  Soon they might have two painful spots; whatever was originally hurting and the inflamed skin.   Allergy is another cause of self trauma and more common in some places than others.  Parasites, for example fleas, can cause or exacerbate skin disease.  Any of these can lead to superficial skin infection, which tends to spread outwards.  Itchy patches can be fast-spreading, persistent or both so we would definitely advise speaking to your vet.

(rewritten for linguistic clarity)  Hello!  Where exactly is this patch?  (I mean, in terms of the landscape of the dog - I can see it in the pictures).  An underestimated cause of self-trauma in animals is underlying chronic pain.  This means ongoing, low-level, niggling pain.  At its mildest, this could be itching caused by fleas, but could also include joint pain as a result of mild arthritis or the stretch of full anal glands or the grinding of stiff spinal vertebrae.  It could also include belly ache, for example in pancreatitis, because dogs don't always bite the region that's hurting; they sometimes settling for licking an easy-to-reach spot in the general direction.  Soon they might have two painful spots; whatever was originally hurting and the inflamed skin a distance away.   Allergy is another cause of self trauma and more common in some spots than others.  Any of these potential causes can lead to superficial skin infection, which tends to spread outwards and can be a cause of itch or pain in itself.  Itchy patches can be fast-spreading, persistent or both so we would definitely advise speaking to your vet.

It's just the rear section on both sides and one centre top. I'll get another photo today. It isn't down to the skin there is a little hair elft or possibly growing back. I'm not sure if she is able to get it down to the skin anyway. She seems very happy at the moment as I've been off work for two weeks and spending time with her. She doesn't walk around injured. Also if it were fleas would it be in different spots not just the same three? I was thinking of changing her worming tablets. Thanks for your advice.

Hello,   No - don't worry, I'm sure she's not in walking agony.  But sometimes e.g. arthritis, rubbing bones, internal pain, creaky back, that sort of thing, they don't really show on the surface, and the first awareness the owner has of it is a licked patch of skin.  We are only just beginning to understand the signs of pain in other animals - it has changed a lot since I qualified.  'Down to the skin' lesions tend not to itch e.g. demodex mites, endocrine diseases:  self-trauma tends to leave a short bit of hair behind (but it sounds as if you know it's self trauma because you've seen it).  Fleas tend to start in one place, usually above the tail, and spread out.  Anal gland damage tends to start either side of the anus.  Tapeworms and other parasites can present as rubbing around the perineum.  However these are all tendencies rather than hard and fast rules, so hopefully your vet will help you to narrow it down!  Best of luck