Yesterday the dogs and I had a nice walk in the country - dry and intermittently sunny weather and lovely autumn colour on the trees.
When we stopped for tea I shared a few scraps of my fruit loaf with the dogs, which got me thinking about dogs and raisins. From time to time there are dire warnings about feeding raisins to dogs 'because they are toxic and cause kidney failure'. But thinking about raisins, I don't think they are toxic in the sense of poisonous for dogs - the problem surely is that they act like a diuretic, soaking up fluid from the body so that the kidneys can't function properly. Raisins are the largest of the dried fruits used in cooking (especially cake-making), so most people have them in their cupboards. They are dried - but rehydrate easily when they come into prolonged contact with fluid, drawing fluid into themselves. So if dogs eat them in some quantity, they are going to collect fluid from the body on their journey to the stomach, which may lower the fluid in the body to a dangerous level that causes the kidneys to stop functioning. Presumably pre-soaked raisins would not have the same effect, because they wouldn't be able to absorb any more fluid from the body. So cooked raisins - for example, in my fruit loaf - shouldn't be dangerous because they have already absorbed water from the dough or cake mixture. And the odd one or two dried raisins shouldn't be a problem - all my Cavaliers have loved them as occasional treats and had no ill effects. The reported cases have always eaten a lot of raisins in one go.
Birds have a similar problem with bread - you should always pre-soak dry bread that you put out for the birds, as dry bread sitting in their stomachs absorbs too much body fluid, as well as causing acute discomfort as it swells in a tiny tummy.
Have no idea if these thoughts have any medical validity - they just kept me nicely occupied sitting in the sun yesterday!
Kate, Oliver and Aled