Christmas pudding could have killed my little dog
Published 22/12/2015 | 00:00
I usually write about crises happening to other people's pets, but last night, I had a pet drama in my own home.
I was sitting in front of the computer in my home office, taking part in one of my monthly live Facebook "Question and Answer" sessions. These are fairly intensive, needing my complete focus for several hours while I do my best to answer people's concerns about their pets. I was interrupted by a shout from my daughter next door in the kitchen: "Dad, quick, Kiko's eaten something". I rushed through to find our little terrier Kiko in her basket, happily devouring the remnants of a small Christmas pudding. It was a special gluten-free one which had been wrapped up in Christmas paper, to be given to a friend the following day. Kiko had been in the kitchen on her own and she must have sniffed out the pudding. She'd jumped onto the table, grabbed the package and opened it with her teeth before munching its contents.
Of course it was annoying that she'd done this: dogs should know better than to jump up onto counters and tables to steal food. But that was not what bothered me: it was the fact that she had eaten something that could kill her.
Raisins can be highly toxic to dogs, and Kiko had just eaten twenty or thirty of them in the Christmas pudding. Her life was at risk, and I needed to take immediate action to save her.
For many people, it seems unbelievable that raisins can be poisonous. After all, many dogs have been given foods containing raisins as treats without any adverse consequences. There are two reasons for this: firstly, like all poisons, the effect depends on the dose taken, so large dogs may be able to eat significant numbers of raisins without problems. And second, the toxic ingredient in raisins is not always present, so a dog could eat raisins on three or four occasions without problems, then fall seriously ill the next time.
The precise toxic agent is still a mystery, and has never been definitively isolated. The poisonous nature of grapes and raisins has been deduced by circumstantial evidence. Over the past twenty years, many dogs have developed severe, fatal kidney failure, and the only common factor has been that they have eaten a large quantity of grapes or raisins in the previous few days. Despite attempts to analyse samples of the fruit that has been eaten, a specific toxic agent has never been identified. The best guess is that the poison is a type of mycotoxin (i.e. a poison produced by moulds or fungi on the grapes). Incidents of kidney failure following grape consumption have been most common in years where there have been high levels of rainfall, leading to damp grapes which will have been more likely to develop mould and fungal growth.
But why should dogs be affected, and not humans? Cultured dog kidney cells in the laboratory are known to be the most sensitive of all species to some other types of mycotoxins that are known to damage kidneys. The presumption is that dog kidneys are also more sensitive to damage by this new, unidentified mycotoxin, so that they are badly affected while other species are spared.
So when do owners need to worry?
If a dog steals a mince pie, is a visit to the vet needed?
The best way to make a judgment on this is to review the lowest recorded amounts of grapes or raisins that have caused kidney failure in dogs in the past, and so to work out the probable toxic dose depending on a dog's weight.
To start with grapes: the lowest dose to cause a problem has been 20g grapes per one kilogram of dog body weight. Each grape weighs 2 - 5g, so that means that the toxic dose is around 4 grapes per kg. This means around 20 grapes for a 5kg terrier, or 120 grapes for a 30kg Labrador.
Next, raisins: the lowest dose to cause toxicity has been around 3g/kg. Each raisin weighs around 0.5g, making a toxic dose around 6 raisins per kg. This works out at around 30 raisins for 5kg dog, or 180 raisins for a 30kg Labrador.
Bearing in mind that this is the dose that has definitely caused serious kidney failure, it's sensible to say that if a dog consumes even half of this dose, action should be taken.
This takes me back to Kiko. She is a small dog, weighing 5kg, and she had eaten 20 - 30 raisins in the Christmas pudding. This was right on the threshold of a toxic dose, so I decided that it was safest to take pre-emptive action. I took her to my clinic last night, and gave her an injection to induce vomiting. I did this within half an hour of her eating the raisins: if I had left it any later, it would have been too late.
I felt sorry for Kiko as she retched, emptying the half-digested Christmas pudding onto the ground, but I was very glad that I'd been cautious. If the raisins had been left in her stomach, they'd have passed on into her intestines within a few hours, and she could have absorbed a fatal poison into her bloodstream. If that had happened, there would have been little that I could have done to help her.
If your dog eats raisins over Christmas, don't wait around: call the emergency vet. Prompt action can be lifesaving.
Have a Happy Christmas, everyone!