A cat that has suddenly taken to shaking his/her head incessantly could have a medical condition that could range from minor to serious and require veterinary attention. Whether the issue is an underlying ear infection or a more serious condition, you will want to get to the bottom of it quickly and consult your veterinarian so that you can begin treatment and your cat can start to feel some relief.
Ear Infections and Ear Mites
Cats do get ear infections, just as dogs do. In fact, of all the reasons for head shaking in a cat, an ear infection is going to be the most likely cause. When you bring your cat to the vet for head shaking, your vet will first visualize your cat's ear canals with the aid of an otoscope. This allows them to evaluate any potential inflammation within the canal as well as to determine whether the tympanic membrane, also know as the ear drum, is intact or not. This step is important as some ear medications can be toxic to the inner ear.
Once your vet as been able to check the status of your cat's ear drums, they will take samples of the discharge from your cat's ears. From there, they will microscopically evaluate these swabs. On the scope, your vet may see two different types of bacteria: either cocci (circle-shaped) or rod-shaped bacteria, budding yeast, or ear mites. Ear mites (Otodectes cynotis) are a type of ectoparasite that, while not entirely common, is certainly more commonly seen in cats than in dogs. They can cause an intense itching sensation that would most definitely lead your cat to be head shaking for relief. Depending on what is seen on the microscope (and depending on whether or not your cat's ear drums are intact) your vet will determine what medicine to give to treat the underlying infection or ear mite infestation.
Just like us, cats can be the unfortunate sufferers of allergies. In cats, allergies can arise either from contact, inhalation, food, or insects (especially flea bites) and most often manifest as intense itching around the head, neck, ears, and can include head shaking. Your vet may prescribe medications to give some itch relief but will also want to try and figure out the allergen. They may want to put your cat on a different, monthly topical flea prevention, regardless of your cat's risk for them. They may also want to switch your cat's diet to a prescription, hydrolyzed food to perform a strict food trial. Food trials are incredibly strict – nothing can pass your cat's lips except the prescribed food for six to eight weeks. This includes treats, people food, and flavored supplements. If you're able to stick with it, though, and if it is what your vet prescribes, successfully completing a food trial will definitively diagnose whether or not your cat suffers from a food allergy.
Cats can sometimes develop ear polyps, also called feline inflammatory polyps. These are benign growths that originate in the mucous membranes of the cat's middle or outer ear. The symptoms of an ear polyp will vary depending on where it is located, but can include coughing, sneezing, head tilt, drooping eyelid, ear infection, or nasal discharge. Polyps can only be effectively treated by surgical removal.
Cats, being natural predators, are prone to getting insect bites, mostly on the face and paws. Some cats will have a reaction localized to the site of the bite that can include swelling, inflammation, itching, hives, and also head shaking. If your vet suspects that your cat was the recipient of an insect bite, they might give antihistamines or steroids to treat the inflammation. On rarer instances, your cat may experience an anaphylactic reaction and this requires immediate veterinary attention.
An aural (ear) hematoma, sometimes referred to as 'pillow ear' isn't so much a reason for head shaking as much as it is something that can happen as a consequence of excessive head shaking. There are a number of small blood vessels within the ear pinna (flap) and if a cat (or dog) shakes their head hard enough, for whatever reason, they run the risk of bursting one of more of these blood vessels. When this happens, the pinna fills with blood and takes on a puffy, pillow-like appearance.
If your cat suddenly develops an aural hematoma, your vet will be able to discuss treatment options with you and determine which would be best. If your vet thinks your cat would be a good candidate for it – it isn't causing too much discomfort– they may elect to drain the fluid off. The fluid is likely to build back up again because there is now an empty space, so additional steps your vet may take to try to prevent reaccumulation of fluid include giving steroids to reduce inflammation, bandaging the ear, or using cold laser therapy. Your cat's ear may crinkle down as it heals if your vet elects for this treatment option. This is merely a cosmetic concern and won't be of any medical concern for your cat. Plus, some may argue that is adds some character. If your cat has a more extensive hematoma, your vet may elect for surgical intervention. If this is the case, your vet will make an incision to drain out the fluid, then will use a pattern of suturing to tack the pinna together such that it cannot fill back up before it has a chance to scar in and heal. Crinkling of the ear is a less common treatment complication if your vet elects for a surgical repair.
There can be several reasons for a cat to be shaking his/her head. A true ear infection may not be the culprit, but even if it were, over the counter ear drops might not be effective for the type of infection your cat has and could cause side effects such as deafness if the ear drum is damaged, so don't delay in scheduling an appointment with your regular veterinarian to get your cat's head shaking checked out.