My dog is on z/d. How do I test for her specific food allergies?

Without a full diet history it is impossible to prescribe a diet. Hills z/d is a hydrolyzed formula where all the proteins have been broken down (akin to being pre-digested) into small pieces so the immune system should not react to them and so should resolve the food intolerance symptoms, it is easily digested and highly absorbable by even the most sensitive bowel. A similar, hydrolyzed option is royal canin hypoallergenic or anallergenic and many pets find these extremely palatable. Some cases can do well on a 'novel protein diet' of home prepared food based on a protein source which she has never eaten before. This should be formulated only by a specialist nutritionist - tufts university clinical nutrition team are available by phone or appointment to help with this but it can be extremely expensive and time consuming to feed such a specific and strict diet and commercial brands are often more successful in resolving symptoms in the long term

For food allergies, the best test is a food trial in which your dog doesn't eat any of a particular food for 3 months, and then if the allergy symptoms go away, you feed the old food again, and if the symptoms come back with the old food, it means she was indeed allergic to the food you were testing. As far as environmental allergies, there isn't a clear conscience on what the best test is. It can either be a blood test or a skin test. I think most dermatologist still recommend the skin test as best, but it does require going to a dermatologist and having her off steroids for some number of days (the amount depends on the particular dermatologist). I would also recommend checking with a dermatologist to make sure it's ok for her to be on steroids when you do the blood testing if you go that way. The results of either type of test for environmental allergies are used to make shots to help the body learn to react less to the allergens. This takes several months to a year. Wishing you the best of luck!!

Thanks for using Petco Pet Education Center, formerly Petcoach! If she has not improved after doing an appropriate food allergy trial, then other possibilities in terms of allergies should be considered which include environmental allergies and flea allergies. This is possibly due to allergies. It really comes down to figuring out what is causing her allergies so that they can be treated or the specific allergen avoided. A secondary infection is likely and also needs to be addressed. There are many things that can cause allergies though in most cases they can be broken down into 3 big categories: flea, food and environmental allergies. Allergies are usually worked up in a stepwise fashion starting with flea allergies as this is the easiest and cheapest to take care of. If not on a flea preventative, then it would be a good idea to get started on one. If already on one then it would be a good idea to change to something else (there are many new products out in the market). If not improved in 1-3 months then it is time to move on and check for environmental allergies, as you have already checked for food allergies, which require blood and/or skin tests. Allergies can be very frustrating to deal with at first but so rewarding at the end when we are able to treat them effectively!

I would try hills z/d ultra or royal canin anallergenic (an even more restricted version). Ensure also she is not receiving any additional treats, flavored tablets, bones, table scraps or raiding any garbage bins. She may also require prescription medication to resolve the current flare up. A home prepared diet may be an option but would have to be formulated with the help of an expert nutritionalist and can only comprise of novel ingredients (foods she has never eaten before such as kangaroo/venison/sweet potato etc - these are very difficult to supplement sufficiently and are very expensive to maintain in the long term)

And thank you for your question! Hills Z/D is a great allergy diet. The way it works is that it is a hydrolyzed protein diet meaning that the proteins that normally cause allergies are too small to trigger the allergy with the hydrolyzed formula. Hill's Derm defense is a great food as well. The way that Derm defense works is that it strengthens the Skin Barrier and it has multiple antioxidants and phytonutrients period before switching to Derm defense I would suggest speaking with your veterinarian who previously placed Louie on Z/D to see if this would be a good switch. Some other things that help with allergies would include omega-3 fish oil supplements and essential 6 Spot On by dermoscent. Help this guide you in the right direction. Please do not hesitate to contact me with any further questions or concerns you may have

For an ideal diet trial for a suspected food allergy, it is typically recommended to feed a hydrolyzed protein diet (proteins are broken down to the point where they can't trigger the immune system) exclusively for 6-8 weeks. After that point, some dogs are rechallenged with their original diet to see if signs recur or started on a novel protein diet (one protein source/one carbohydrate source). If signs of a food allergy are still present, some dogs need to remain on the hydrolyzed diet indefinitely. The hydrolyzed diets are prescription based and include Royal Canin Ultimano, Royal Canin HP, Science Diet Z/D ultra, and Purina HA. There are many pet food companies online that can also dispense these diets with a prescription from your vet (chewy.com is one example). If the cost of a hydrolyzed diet is still not feasible for a diet trial, talk to your vet about starting Rico on a novel protein diet. Many of these are still prescription based, but I have also been impressed by the Dick van Patten Natural Balance limited ingredient line, which is available over the counter. With any diet trial, it can take 2-3 months to determine if it is effective and you need to be strict in that Rico would only receive his dog food with no other treats or table foods. I hope this helps! :-)

According to this peer reviewed study published in April 2017, only 3% of dogs with food allergies react to RC Anallergenic diet. The same study lists some alternative diet options. https://www.ncbi.nlm.nih.gov/m/pubmed/28090706/