scott@vtx-cpd.com

You’re absolutely right that exposure and sensitisation are central to the development of atopic dermatitis (AD), but we don’t necessarily need patients to be over a year of age before we can make a diagnosis. While the typical age of onset is between 6 months and 4 years, we do occasionally see very young dogs, even as early as 14–16 weeks, presenting with clear clinical signs of AD, sometimes quite severely affected.

It’s all about pattern recognition and ruling out other causes of pruritus, particularly ectoparasites. Using Favrot’s criteria can really help guide your reasoning in younger patients. When you’re confident there’s no ectoparasitic burden, an atopic process should remain high on your list, especially with classic signs such as itchy ears, face, paws, axillae, or ventrum.

As for your question on brachycephaly and conformation, there isn’t evidence that these features directly reduce the age of onset or cause AD. However, we do see AD more frequently in these breeds, likely due to a combination of genetic restriction (small breeding pools) and environmental influences. Conformational issues can certainly exacerbate AD by worsening secondary factors like skin barrier disruption or chronic inflammation, but they don’t inherently cause immune sensitisation earlier in life.

Now, onto diets, and yes, it’s a real minefield! Owners often want to “add a little something” for flavour, but unfortunately, that completely defeats the purpose of a diet trial. I often explain it with a simple analogy: giving a dog on a strict elimination diet “just a little treat” is like giving someone with a peanut allergy a fun-sized Snickers every day, they’ll never improve! That usually gets the message across.

When possible, I prefer clear, controlled diets with known ingredients, either home-prepared single protein diets (e.g. kangaroo, rabbit, ostrich, with butternut squash or sweet potato if tolerated) or a commercial hydrolysed diet. Hydrolysed diets are generally best for practical use, but they must be fed with absolutely no additional treats or toppers. For clients struggling with palatability, making a simple meat gravy or puree from the chosen protein and freezing it in small portions can help, just make sure the pet actually likes it before committing to a full batch!