Vet360, December 2016 - Page 13

DERMATOLOGY A big tip: Consider the calendar: If a cat’s pruritus is seasonal, you do not need to perform a food trial. But if the pruritus is not seasonal, you  do need  to perform a food trial. "Blood testing for food allergies is unreliable, inaccurate and a total waste of your client’s money.” We have established a facebook group earlier this year and already have 700 members from all over the world. We would like to invite all Veterinarians who are interest in Veterinary Dermatology to join. With this new platform we will be able to communicate easier and share interesting cases, discuss difficult cases, new treatments, etc. In order to join the SAVDIG, a registered facebook account is required. It is really simple. 1. Go to www.facebook.com 2. Register yourself as a user on facebook under create account. All new users must have a functional email address. 3. During registration please stipulate the region and practice you work at for our demographic purposes. 3. Once you have registered and have a fully functional facebook account please click on the link below or copy this into the URL whilst you are logged into facebook https://www.facebook.com/ groups/300873470265888/?ref=bookmarks 4. You can request to join this group and we will confirm. 5. The facebook page allows each member to upload any photos or post remarks. If you have any struggles or need assistance please feel free to email Cameron Prior on u29072299@tuks.co.za . Cameron is a keen final year veterinary student at Onderstepoort, who has been very helpful in changing the format away from the old web forum site to a newer social media platform to make the group more accessible. Interested parties can also contact Heidi Schroeder (wpsam@absamail.co.za) or Andy Leizewitz (Andrew.Leisewitz@up.ac.za) Food allergy Food allergies can start at any age, so it isn’t unusual to have an older cat that breaks out with pruritus due to food allergies. Dr. Ghubash cautions that, in her opinion, you should be on the lookout for this more in Siamese and Siamese cross-breeds than others. Changing the diet to a veterinary prescription diet for 12 weeks is the only accurate way to diagnose food allergies in Dr. Ghubash's opinion. The reason the over-the-counter (OTC) diets don't work for food trials is because the food companies frequently "cobatch" when they produce their foods. This means that they use the same equipment to produce different brands of specific foods. This can frequently lead to differences in allergen content in each bag on the shelf. Dr. Ghubash points out that there was a study that demonstrated that OTC venison diets had microscopic traces of other proteins in them. As a result, there is no OTC diet that she recommends for a food trial. Think food allergies are off the hook if the cat improves with corticosteroids? Dr. Ghubash says think again as some cats do. Targeted testing You can’t use a blood allergy test to diagnose allergies or atopy. Make the diagnosis and then use the blood tests to tailor your immunotherapy. It’s never wrong to step back and do a biopsy, says Dr. Ghubash. The results might tell you that the animal is allergic. Sometimes you may need multiple samples, and remember to send your samples to a pathologist who is comfortable reading skin histopathology. The results might tell you that the animal is allergic, or that they have a condition only diagnosable via biopsy. Allergies to parasites If the cat goes outdoors at all, rule out flea allergies before anything else, even if you don’t find any fleas or flea dirt and the cat is receiving monthly flea control. Some cats are excellent groomers and can groom any live fleas or their evidence (flea dirt) that were ever there off of their bodies before a reaction is shown. Dr. Ghubash says that, “Regardless of the history, the vast majority of itchy cats that you see are going to be flea-allergic.” You may note a pattern in these cases, with the pruritus being located mostly in the dorsal and lumbar regions. If you see that, think parasites: fleas, Cheyletiella and Notoedres species and Demodex gatoi. A note about diagnosis: it can take months to rule out flea allergy, but Dr. Ghubash would recommend doing that before initiating food trials. “Putting them on once-a-month flea preventives and still letting them go outside is not ruling fle H[\H] 8'HH^\ˈBX[Y[Y\[H][ܜ[\[Y[[‚\YH PSPT M L‚