Episode 4 - Food For Thought

In Episode 4 of the Skin Flint Podcast, we invite specialist Hilary Jackson to join us to discuss a large and very important topic - diet. Hilary was on the faculty at North Carolina State University, before returning to Scotland where she works as a clinical director at the Dermatology Referral Service in Glasgow. She has clinical and research interests in canine atopic dermatitis and immune mediated skin disease and has published and lectured widely on these subjects and other aspects of veterinary dermatology.

 

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Intro

John Redbond introduces producer Paul Heasman and specialist Sue Paterson for this podcast focusing on diet in relation to pet skin. Sue introduces today’s interviewee as Hilary Jackson, the leading dermatologist on food allergy who has worked in the US and UK and recently finished editing the BSAVA dermatology manual.

Chapter 1: A Balanced Diet

02:21   Sue welcomes Hilary, who introduces herself as in clinical practice in Glasgow with a specialist interest in allergic skin disease in dogs and cats; Sue clarifies her as a world authority on the subject having published a lot of research in the area before

 

03:20 Sue asks why it is important to feed a dog a balanced diet - Hilary clarifies this goes beyond simply considering food allergy, with the skin requiring a quarter of the protein in a dog or cat’s diet. The balance of minerals and fatty acids are also important for skin health. Hilary says any owner should consult a veterinary nutritionist to feed any diet, particularly if home preparing and issues arrive when people go ‘off piste’

04:16 Sue then enquires about what sort of problems Hilary sees as a dermatologist related to insufficient diets or foods the individual pets are allergic to. Hilary replies saying dull hair or poor growth can be a sign of an insufficient balance in the diet and generally itching (or ‘pruritus’ as it is technically known) is the indicator for allergic response to food.

 

Chapter 2: Food Allergies

05:37 Sue asks when a food allergy could start in pets and Hilary suggests they can start at any age; however dermatologists see a lot of young dogs with this. They can go on to develop other allergies to things in the environment but generally if allergy is seen under 12 months it is a food allergic response.

 

06:35 John then asks what sort of foods owners should look out for with allergies, and Hilary says it is very much dependent on what the dog has been fed, so the vet needs to take a careful diet history of what they have eaten, then this will be one or a combination of those foods (likely protein). This will have developed over time, not be from a sudden change as is often thought.

 

07:35 John then asks what signs should be looked for with food allergy and Hilary says unfortunately no signs point between either food or environmental allergy, but the signs for both are itchy ears, itchy faces, paw licking, leg nibbling, tummy rubbing or sometimes scooting and rubbing the back end. With a food allergy occasionally intermittent vomiting, loose stools or diarrhoea could be a sign as this is an internal problem.

 

08:44 Sue asks if this is a pedigree problem related to specific breeds and Hilary says she sees it in all dog but some studies have suggested Boxers, West Highland White Terriers and Labradors can be more prone, but it is often dependent on the area you live.

 

09:49  Sue and Hilary together clarify any dog can get a food allergy and this isn’t related to the quality of the protein at all.

 

Chapter 3: The Right Diet for Allergies

11:05 John asks if there is an easy way of finding the protein they are allergic to, perhaps a blood test, but Hilary says blood tests have been shown to be unreliable so the only way is to feed an elimination diet for 6-8 weeks, consisting of something they haven’t eaten before, before going back to the original foods to find what was causing the reaction.

 

12:41. Hilary clarifies what a novel protein is: anything which is novel to that patient. This can be difficult to find as lots of different protein find their way into the diets, plus cross reactivity means you couldn’t feed (e.g.) turkey to a patient who had eaten chicken previously.

 

13:42 John asks about a vegetarian or vegan diet as an option and Hilary says this can be used as an option for elimination foods; also something called hydrolysed food, where the molecules of the protein are broken down so small that the patient does not react.

 

14:40 Sue clarifies a vegetarian diet should be a pre-made proprietary diet, rather than a home-made mix of vegetables, to ensure the nutritional content is adequate, before then asking about hydrolysed diets (could you feed a chicken allergic dog a hydrolysed chicken diet?). Hilary suggests this isn’t always the case depending on the degree of hydrolysis, so the ultra-hydrolysed foods should be used in these instances.

 

17:00 Sue asks if ‘undeclared proteins’ (proteins not on the labels but which are present in the food) are something avoided with a hydrolysed food and Hilary suggests the hydrolysed diets do well on this.

 

18:07 Sue asks whether an owner with a beef allergic dog should avoid all ruminants in case of cross reaction; Hilary agrees that to be safe this would be the best option - and there can also be less logical cross reactions such as fish and chicken!

 

18:53 John asks if an owner should really be asking their vet which diet to use, given all the variables and Hilary suggests there is a lot of misinformation in pet shops on food, stating the word hypoallergenic actually means very little, as it is so dependent to on what the individual pet is allergic to.

 

19:42 Sue asks how long a pet should be fed a diet before you would expect to see a change with Hilary recommending a minimum period of 6 weeks as the skin takes a lot longer to settle down from this, than say diarrhoea would.

 

20:30 Sue then asks how to cope with a dog itching excessively whilst waiting 6 weeks for the skin to settle and Hilary agrees that its welfare is most important - so some anti itch medication may be used in the short term whilst waiting for the skin to settle down from the diet change.

 

21:23 John asks if you would stay on the new food long term, if it works and Hilary shows how this can be very complicated based on other variables (e.g. the seasons changing and a different environment) so the only way to know for sure is to go back and feed the original food and see if the problem returns - which she indicates could take a week.

 

Chapter 4, the Skin and Gut Microbiome

23:38 Sue asks about the gut and the skin microbiome, whether feeding yoghurt (for example) could improve these symptoms. Hilary says we’re still uncertain - but in people it has been recommended. Hilary and Sue both talk around some of the studies on how these could be related, but stress the research is in its early stages so people shouldn’t jump to feeding a raw diet, for example, based on this.

 

26:14 John asks if this is suggesting a healthy microbiome in the gut means a healthy microbiome on the skin, but Hilary says we do not have evidence for this yet; we do however know more about how the balance of the microbiome on the skin is very important to the health of the skin now, and its response to allergy.

 

27:16 John enquires as to whether supplementation would be a good way of improving the coat and response to allergy, and Hilary says the skin barrier (which keeps the bad out and good in) can be improved with supplementation in theory, with a skin barrier fortifying diet or essential fatty acid supplementation.

 

29:00 Sue summarises that we must be aware of what we are feeding our pets, especially if we have a pet with a food allergy and Hilary suggests more premium diets would be better for consistency on this. Sue wraps up by reiterating the vets are the best place to go to find out more on a potential allergy in their pet.

 

Outro

31:20 John bids farewell to Sue and Paul, who all wrap up the conversation before John puts them on the spot with another silly question.