Why Do Dogs Smell When Nervous

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You are out with your dog and he has an altercation with another dog, is startled by something on the road, or even goes crazy about a squirrel and suddenly he smells horribly. Was he nervous, agitated, or anxious? What you smell is the emission of his anal glands. Commonly referred to as shooting the glands, at times the emitted oils will spray onto objects within range and saturate his backside. While his smell is undoubtedly unpleasant, what he experienced is perfectly normal and may likely happen again in a similar situation. Some breeds are more prone to emitting the offensive odor, and all dogs have odors given certain situations. If the odor emission does become a problem, consult with your veterinarian regarding options to help your pup stay odor free or at least less offensive.

The Root of the Behavior

All dogs have two anal sacs, also known as anal glands, located at around the four and eight o’clock position of the anus. They are pea-sized sacs filled with an oil-like fluid that is excreted when a dog has a bowel movement. When he pushes out his feces, it presses against the glands and expresses them, releasing the oil. The oil has a very pungent fishy smell and serves several purposes. It covers the feces during the bowel movement and allows your dog to mark his territory with his stool. In addition, it serves as a communication between your dog and other animals that may encounter his poop. When dogs smell each other’s butts, it is to smell their anal glands. Dogs can spread their smell simply by wagging their tails too. Each dog can be identified by his smell. Dogs that are nervous around others tend to put their tail between their legs in an effort to hide their smell and remain somewhat anonymous. Researchers also believe it makes it easier for your dog to have a bowel movement in that the oil in the anal glands provides lubrication to the anus.

Bowel movements are not the only way his anal sacs are expressed. If he becomes excited, scared, or nervous his sphincter muscles will contract just as they do when he has a bowel movement and express the glands. He will immediately smell like rotting fish. If you are not sure if that horrible smell is emanating from your dog, you can look for other signs of fear that he may express including a hidden tail, licking of his lips, excessive drooling, stiff fur on his back, and a crouched or lowered posture. Also, when your dog is afraid, not only can he express his glands but dogs sometimes also urinate and defecate, making the smell even worse. Many owners are dismayed when they pick up their precious pup from the veterinarian or groomer, expecting a freshly cleaned fur-baby, and he stinks. While he undoubtedly had a bath, he also most likely expressed his glands because he was afraid of the grooming experience.

Encouraging the Behavior

A dog cannot control his anal glands any more than you can control a hiccup, so hoping to stop him from expressing his glands is futile. Typically, a dog’s glands are expressed often enough during a bowel movement that his expressing during fear does not occur that often. The scent is also transient, so while it can be ghastly, it does not last long. If he is often expressing his glands, you can express them yourself by inserting your finger into his anus. Most people ask their veterinarian or groomer to handle the deed as they are trained to perform the task efficiently without harming the dog or the glands. You can also increase the fiber in his diet in an effort to have his bowel movements express the glands more efficiently. 

A dog’s glands can get impacted and infected if they are not expressed often enough. A dog suffering from impacted glands will often scoot his bottom on the ground or lick and nip at his anus in an effort to relieve the discomfort. Dogs of any age or breed can suffer from impacted or infected glands, but the problem is more common in small breeds such as Lhasa Apsos, Miniature Poodles, Toy Poodles, and Chihuahuas as well as medium size breeds such as Beagles, Cocker Spaniels, and Basset Hounds. If you suspect your dog’s glands are impacted or getting infected, it is important to take him to the veterinarian for a complete exam. An infection will require treatment with antibiotics and perhaps compresses to relieve the pain while he heals. An abscess may need surgery to remove the damage and infected tissue as well as to drain the fluid. Dogs who frequently deal with infections should have their glands checked often to avoid further problems.

Other Solutions and Considerations

Dogs can smell for more than just expressed glands. A dog’s coat contains yeast and bacteria, and when his fur gets wet they are released and stink. His breath can also smell, especially if he has a gum or dental infection. Dogs with skin folds, such as Bulldogs, Pugs, Pekingese, Spaniels and Shar-Peis can have dermatitis in their folds that has an odor. Ear infections also have an odor that is unpleasant to the human nose. And of course, an especially gassy dog can cause odors. In some of these instances it is important to see a veterinarian to ensure that the source of the odor is treated properly.


When a dog is startled, he may accidentally express his anal glands, which excrete an oil that smells like rotten fish. This reaction is perfectly normal and the odor will dissipate rather quickly. If you notice he is expressing his glands often, you can increase the fiber in his diet in an effort to make his bowel movements more effective in expressing them naturally. However, if he is scooting his bottom on the ground, biting or licking his anus, or straining during his bowel movements, you need to take him to the veterinarian for an exam.