A dog chasing his tail.
A dog chasing his tail. Photography ©Mike Watson Images | Thinkstock.

Tail Biting in Dogs — What Are the Causes?

Is your dog biting, gnawing or chewing at the base of her tail? Allergies, injury, infection and stress are among the causes of dog tail biting or tail chewing.

Since dogs cannot talk, they cannot make their needs or desires plain to us in any simple or intelligible way. It’s easy to get frustrated when our dogs engage in behaviors that are repetitive, troubling or destructive. We all take some degree of pleasure, on the other hand, when we see a dog chasing her tail. When an occasional canine tail chase turns into a habit, though, and when that habit ends in tail biting or tail chewing, it can signal a range of potential issues.

What’s even more troubling is the sheer volume of people who not only ask, “Why does my dog keep biting her tail and whining?” but also end that question with “for no reason?” Just because we cannot immediately isolate the source of the odd behavior doesn’t mean that it is purposeless or without foundation. Obsessive or compulsive canine behaviors, like chasing and gnawing at the tail, always have a root cause.

Closeup of a dog tail.
What are the most common reasons for dog tail biting or tail chewing? Photography ©ulkas | Thinkstock.

The most common causes of tail biting and tail chewing in dogs are:

  1. Parasites: fleas, ticks, or worms
  2. Environmental and skin allergies
  3. Hot spots and other secondary infections
  4. Stress, boredom, or confinement
  5. Injury
  6. Impacted anal glands

Let’s take a closer look at each of these issues below.

1. Parasitic infestations

Fleas and ticks are common enough seasonal afflictions for dogs. We’ve all seen a dog scratch at a spot on his body where fleas are bouncing around or a tick has attached itself. With medicated collars, regular baths, and prescriptions, these pests are fairly easy to treat. In the same way that humans are allergic to the saliva of cats or dogs, so too are some dogs allergic, not to the presence of ticks and fleas, but to the saliva in their bites.

A dog with an undiagnosed flea allergy may bite repeatedly at the site of an allergic reaction until they break their own skin to find relief. Tapeworms can also cause such physical discomfort in the area surrounding the anus that a dog feels compelled to gnaw at the base of her tail. Ultimately, it’s the pain she’s causing herself by constant chewing that leads her to whine as well.

2. Allergies

Inflammation of the skin, or dermatitis, caused by fleas and ticks is not the only allergy that can lead a dog to chew at her tail. Environmental allergies — anything from pollen outside to household chemicals inside — can give rise to allergic reactions. Whether the source of your dog’s allergy is mites, mold or contact with other animals, the reactions are most severe in a dog’s early years, between 3 months and 6 years old.

A human’s first instinct to a skin allergy is to scratch at it, and it’s the same for a dog. Interestingly, trying to treat one allergy can lead to the discovery of a different one. If your dog has sensitive skin, something as simple as the shampoos or soaps you use to bathe her can also spur an allergic response.

3. Hot spots

A hot spot is an area on a dog’s body where repeated scratching or chewing leads to the creation of an open wound. Warmth and moisture are the optimal conditions for hot spots to form. Should a stray bacteria find its way to the site before it is properly treated, a secondary infection is a typical result. Recognize a hot spot by the presence of blood, pus, and matted hair.

If your puppy or dog is biting at the base of her tail so frequently that she draws blood, then secondary infections are not the root cause of her problem, only another symptom. A veterinarian can help you determine whether the true reason has to do with hygiene, nutrition, or another factor.

4. Stress and anxiety

Stress, anxiety and boredom can lead dogs into a host of destructive and repetitive behaviors: tearing up your favorite shoes, your most comfortable couch pillows, and so on. Out of necessity, some people crate their dogs when they leave for the day. If dogs spend too much time confined, they may turn their attentions inward and seek relief where they can.

The same applies to dogs who do not get sufficient exercise, interactive play or mental stimulation. Some people may think a dog turns to self-destructive activities like tail biting as ways to get attention, and in these cases, who can blame them?

5. Injury

Any kind of rear or hindquarters injury — a broken or fractured tail bone, for instance — is something a dog cannot inform his owner of, and may go unnoticed under normal circumstances. The intensity of the dog’s pain may lead her to act on or draw attention to it by excessive chewing, biting, or licking at the affected area. Only veterinary X-rays will be able to properly diagnose such an issue.

A dog sitting and looking back.
Anal gland issues may cause dog tail biting. Photography ©Fly_dragonfly | Thinkstock.

6. Impacted anal glands

Finally, another common reason why a dog may be biting at the base of her tail until it’s bleeding is an impacted anal gland. A dog’s anal glands are as important to a dog as our hands are to us, and, socially, they fill similar needs. Just as we shake hands when we meet folks, canine anal glands secrete interesting fluids that dogs smell when they meet each other. This is one reason why dogs are so intent on sniffing at each other’s rear ends at any opportunity.

One obvious sign that a dog is having an anal gland issue is scooting, when he sits up and drags his butt across the ground. Other symptoms include a fouler-than-normal smell originating from a dog’s behind, trouble defecating (you call it constipation), and, in severe cases, blood or pus in the feces.

How have you been dealing with your dog tail biting?

As you can tell, dogs who are giving a lot of attention to chewing their tails — particularly the base of the tail — may be afflicted with a wide variety of problems. Really, it’s quite a rich tapestry of causes that can lead to compulsive tail biting.

But, good news! Whether it’s practicing better hygiene with your dogs, discovering whether they are allergic to some thing or creature around the home, addressing small wounds before they develop secondary infections or simply making sure they get out more, all of these issues are treatable.

Tell us: Have you ever had a puppy or a dog who seemed to fixate on her tail area? Were you or your veterinarian able to isolate the key problem and address it successfully? Share your experiences with dog tail biting in the comments!

This post was originally published on May 1, 2018. 

About the author: Melvin Peña trained as a scholar and teacher of 18th-century British literature before turning his research and writing skills to puppies and kittens. He enjoys making art, hiking, and concert-going, as well as dazzling crowds with operatic karaoke performances. He has a one-year-old female Bluetick Coonhound mix named Idris, and his online life is conveniently encapsulated here.

Thumbnail: Photography ©Mike Watson Images | Thinkstock. 

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56 thoughts on “Tail Biting in Dogs — What Are the Causes?”

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  24. I hafd a German Shepherd. He chased his tail constantly and would bite it and make it bleed. The house would be all blood splattered when I got home. There was nothing physically wrong with him (vet checked). The only thing that would begin to stop him was a Shock Collar. He lived 13 yrs and did this til the day he died. ?

  25. My dog Sam a Snorkie is constantly licking his tail and don’t know what to do. He does have back issues according to our vet.

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  27. Hey! My pitt bull has been chewing his tail alot lately and today he did it to the point of it dripping blood. What can I do to prevent him from doing it again?

    1. Hi Brianna,

      There’s a good chance that there is something bothering your dog, like fleas or other parasites, on his tail. We suggest visiting your vet to see what might be causing the problem. Please let us know how things go!

  28. I”ve been trying to figure it out for years. He spins around in circles trying to get to his tail. He bites and licks it. He also licks his back legs constantly. There has never been any missing fur, raw spots, or blood ANYWHERE, regardless of how much he does it. No worms in his poop. He is on a grain free diet with probiotics and all kinds of good stuff. No chicken ingredients. He does not have ANY fleas or ticks EVER. He doesn’t have anxiety, I’m home with him all day, I take him on walks every day. He has his own fenced backyard. He’s never in a cage.
    So I’m down to allergies or impacted anal glands. He has none of the symptoms of impacted anal glands. No scooting, no foul smell, I sleep with him I would know, and no issues using the bathroom, and his stool is normal. I don’t bathe him too much, maybe once every 3 months cause he stays clean and soft. When I do bathe him I use a completely natural shampoo. I also use a waterless shampoo that’s 100% natural plant based. So what is it??? It drives me nuts I’m constantly telling him to leave his tail alone.

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  30. Pingback: Dog Pulling Fur Out: How to Stop It | My Pet Needs That

  31. I am having a problem with my 16 year old dachshund, we have lived in our car for two years (homeless) and we found a place to live. My doxie has just started to chew at his back and the base of his tail. He can’t have corn or wheat in dog food, and I play with him a lot , go for walks. What else can I do to resolve this problem?

  32. I have a female white shepherd, we rescued her from some terrible people, today i niticed oh her tail about half way down a gravely texture spot in the middle of her tail. Any ideas of what it could be and how to get rid of it? Thank you in advance

  33. I have a white male a Swiss Shepherd and he was biting the base of his tail and it turned out to be something you don’t mention in the article, but is fairly common with the breed, an irritated sebaceous gland. It actually has a name “stud tail” where it makes a dent in the fur. We were able to treat it with hydrocortisone and it has not returned in several years.

  34. My old dog used to do this, likely because he suffered from skin allergies. One of my current dogs also has skin allergies, but no tail to chew. Anyway, I didn’t realize it could be a result of anal gland issues. Anal glands are apparently very similar to a skunk’s “stink sacs” – and they seem like it feels awful for the dog when they’re not clearing out correctly. :/

  35. My 4 y.o. small medium dog (unknown breed, possible Schipperke mix) just started doing this two days ago after we were gone longer than expected (about 13 hours) and he got into some party trash from the night before. (Low-heat homemade Mexican food.) When we got home, we found multiple accidents (expected and excused) and he was trembling when we refilled his water bowl. (He has slept contentedly that long before; the differing factor was the trash.) Just now we were able to get a look at the spot and it is swollen, red, and glistening as if it is weeping; however we gently applied a baby wipe as a compress and he seemed to find it soothing, and nothing appeared to come away on the wipe. He hasn’t had a bath in a while and is 14 days overdue for his flea drops. Can I treat his wound (and HOW?), bathe, and apply flea stuff and then see how he is? Or should i take him straight to the vet in the morning? He has seemed lethargic, sleeping more than usual but does wag his tail and interact with us. He is eating less, but does occasionally perk up and accept the pumpkin I’ve been offering him. (That has been a reliable tummy remedy for him in the past, but the length of illness and the tail biting are new.) Sorry this is so long; trying to provide the right details.

    1. I did take him to the vet and it turned out to be a ruptured anal sac. He’s on antibiotics and pain meds and wearing the cone of shame. I need to throw in a professional wash with gland expression a little more frequently, since I don’t feel competent to do that myself. I guess the trash incident was just a coincidence.

  36. I adopted an abused ranch dog and brought her to the suburbs. She is very timid toward men especially. She scooted her butt first meeting. Treated her for worms and tapeworms and tested negative for heartworms and all. Had vet check her for anal gland issues and he said nothing wrong. She bites at her butt, scoots sometimes and chases her tail at night. I am worried she may have spinal chord injury from ranchers or missed anal gland tumor or problem. Not sure where to turn or if it’s just a mental dog. I walk her 3x a day. I was told she is 2+ years. She has every shot, flea/tick, heartworm med. Beautiful shiny coat. Her poop is inconsistent. Most times OK ( not hard, not soft) sometimes loose, rarely firm.
    I’ve taken her to petco vet, and house call vet and adopted her from merced co. Animal shelter thru rescue group. Thinking a tail injury might be what the culprit is? Not sure what to do.

    1. Hi there,
      We suggest continuing to work with vets. These articles might provide some insight as well. Hope your dog feels better!

    2. Yoi should get better food. The poop should be firm because thats what releases the anal glands and lets them express. They are like big pimples that fill and need too empty once and a while. If they cant release because of loose then they get backed up and thats why the dog scoots. Hes trying too get them too empty. My pit bull had these issues but better food equals firm stool which puts pressure on the glands so they can empty. Id take him to the cet and get them manually expressed then change the diet. Youll know when they express. It smells like bad fish sort of.. usually dark grey in color

    3. What breed? Typically ranch dogs such as heelers, border collies, etc need jobs to keep them busy. She could be practicing these actions due to being bored. Try fetch, agility, lure coursing, etc. if all checks out at the vet of course.

  37. I have a six month shih tzu who keeps chasing the tip of his tail and making it bleed. He is up to date with flea and worm medication. Any suggestions please.

    1. Michaela Conlon

      Hi there Merle,

      Thanks for reaching out! The article suggests addressing this issue whether it’s by practicing better hygiene with your dog, discovering whether he is allergic to some thing or creature around the home, addressing small wounds before they develop secondary infections or simply making sure he gets out more. If any of these adjustments do not change your dog’s habit, we suggest taking your dog to the vet to find out the problem and how they can help.

  38. paul a sheinberg

    if you’re losing sleep, hire a private dog trainer. in a session or two they should be able to help you minimize the anxiety. PS-many dogs are anxious the first 4-6 weeks you adopt them and then they slowly get better on their own. it takes them a while to adjust.

  39. My dog at bedtime especially will start chasing his tail and then proceed to bite his foot and yelp. He also will nip at my wife’s clothing, but not at me.
    Any help in understanding this behavior and actions correcting it will be a big help.
    We are his third owners and his anxiety issues have been apparent since we adopted him about a month ago. While some behavior issues are to be expected considering he has been attacked by pit bulls and lack of stability in ownership, we are losing sleep over this.

  40. I found that a small amount of coconut oil in one of my dogs food is helping his skin. I also use a Seresto collar on him. I do not use front line because it does not work. When was really bad I got a holistic skin aid from /www.nayhotzesmedicinemusings.com you have to ask her for it because due to pricing issue she can not list i on her site .. She does not charge as much as her supplier thinks she should . I am using this on a foster dog with manage and it is helping

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