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Why is my pet itchy?

Why is my pet itchy?

Okay so I can’t tell you why your specific pet is itchy without seeing it and talking to you but I can tell you about how we start to figure out why your pet is itchy.

The most common cause for chronically itchy pets are environmental allergies, flea allergies, and food allergies.


There are some important things we need to rule out when your pet is losing hair or itchy. Sarcoptes mites (seen at the left) can cause severe itchiness, some endocrine diseases can cause hair loss (which can look like an itchy pet), and yeast infections and bacterial infections can also cause itchiness. If your pet is itchy please bring them in for an examination as we will need to take a skin scraping to look for mites, a skin cell sample to look for bacteria and yeast, and we may need to run some blood work to screen for endocrine disease like hypothyroidism.

Once we have ruled out those diseases we are back to environmental, food, and flea allergies. Lets talk about each individually and how we tell the difference.

Flea Allergies

When dogs are itchy on the back half of the body we are highly suspicious of flea allergies but cats can be itchy on their head and neck with flea allergies because that is just how cats are! If your pet is really itchy make sure to bring them in for an examination because if they have a flea allergy we can give them a short term medication to make them more comfortable and also get them on the best flea preventions.


The best way to manage flea allergies in the long term is to always keep your pet on flea prevention. Every month. For life. Sometime pets need flea prevention every two weeks instead of every month because their flea allergies are that bad. I prefer flea preventions you give by mouth, like Nexguard (always given with Heartgard for heartworms) or Tri-fexis because even water proof flea preventions you put on the skin lose a little of their effectiveness during bathing.



For cats I love Revolution because you get fleas, heartworms, and ear mites all in one (and a few intestinal worms too!). There is no oral flea prevention in cats ☹.

Your pet can still have flare ups on any flea prevention as they all take several hours to kill a flea that has bit them. If they do have flare ups make sure you wash all machine washable fabric items in hot water, thoroughly vacuum all floors, and consider having your home treated by professional company, and…Keep all your pets on flea prevention. Every month. For life.

Environmental Allergies

The next most common allergy is environmental allergies. We start to notice environmental allergies bugging your pet from about 6 months to 6 years, most commonly 3 to 6 years old. Our most common allergens that cause those allergies are house dust mites, pollen from grasses, trees, and weeds. Your pet will need a diet trial to rule out food allergies and they should be kept on flea prevention at all times to rule out flea allergies. There are chronic medications for itchiness but the best treatment is finding the specific allergens.

>We can determine what environmental allergen are bugging your dog by submitting a blood sample or a dermatologist can place them under sedation and inject the allergens under the skin. Only intradermal testing, allergens placed under the skin, is accurate in cats. With either method we get what allergens are irritating them and then make mixture of these to give them at low doses. We can give these allergens by mouth or under the skin. It takes months to respond but works in about 70% pets and it is much safer than keeping them on some of our short term itchy treatments.

Food Allergies

Food allergies are the third most common and they often start from 4 months to 12 years. They occur throughout the year and they can cause itchiness all over the body. The most common allergens that dogs are sensitive to are beef cow’s milk, chicken, chicken eggs, and lamb. The most common cat allergens are fish, milk, milk products, beef, and lamb. Your pet can have a corn or grain sensitivity although it is not as common as allergies to the protein source in their food.

No matter what your kind of food your pet is allergic to they need a diet trial with a balanced food made of either a protein they have never had before, rabbit, duck, or kangaroo (seen to the right)

royal caniniams


Or a balanced food with a protein that has been broken down to the point the immune system does not recognize it as an allergen. These foods are called hydrolyzed protein diets like Hill’s z/d or Royal Canin HP for cats or dogs.

hillsroyal canin cat


If your pet stops being itchy with their diet trial they may need their new food for life or we may do some further experimenting by adding protein sources to this food to see what foods they can tolerate.

royal canin doghills senstitive dog food


These are not complete descriptions of pet allergies or complete treatment plans for your pet but it gives you a little window into the things we are thinking about when your pet is itchy. Allergies can be a lot of work but with Sierra Veterinary Clinic and pet parents working as a team we can get to the bottom of your pet’s itchiness so they can get back to enjoying life.

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Wednesday, 18 July 2018

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