It has been found that dogs, cats and horses eat more than 100% of the nicotine salt they ingest.
Researchers from the University of Warwick found that they need more than half the salt they consume to maintain a brain’s normal levels of brain chemistry.
‘The key question we are trying to answer is: does the salt in the dogs’ diet make it into the brain?’
Dr Sarah Gower, from Warwick’s Institute of Psychology, said.
‘This research has important implications for understanding how dogs digest nicotine, and how the brain processes nicotine when it’s eaten.’
It is thought that dogs and cats have different needs, and may be able to detect when their bodies are being depleted in nicotine.
‘Our study showed that a very large proportion of the salt consumed by dogs and horses is not being metabolised by their bodies.’
The amount of salt we saw in the brains of these animals was very small and was equivalent to only one-third of the amount in the brain of humans,’ Dr Gower said.’
If you eat a dog’s salt, you get a lot of salt in their saliva and a very small amount of the fat they eat.
‘We know that cats and dogs also eat salt, but it’s a different matter.
‘These dogs and animals also eat very large quantities of fish and fish oils, so they are using salt in a very different way.’
This suggests that dogs are eating their salt, and they may be using it in a way that would affect the functioning of the brain.’
In humans, we eat about a quarter of our daily calories from salt, so this is an important finding.’
The study is published in the journal Proceedings of the Royal Society B. ‘In this study, we found that the animals used salt in very different ways to us,’ Dr Dan Smith, who led the research, said in a statement.
‘If you consume a large amount of fish oil in a dog, that will affect the amount of fat they use in their diet.
‘But if you eat fish and other animal fats, then that is unlikely to be a major source of salt.’
So dogs eat their salt a lot more than cats, and the salt used in the animals’ diets is much larger than in the human diet.’
It is interesting that the amount we saw was not the same as the amount that was in the people’s bodies.
The animals ate a lot less fish than they used in their diets, but they were still using the same amount of sodium.’
Dr Gowers said that the salt we were using was not just salt in animals’ mouths.
‘It was very high in the food they ate.
‘They used a lot for fuel and they used it in the environment as well.’
They also used a large number of other salts in their bodies to regulate their metabolism and to help with their appetite.’
Our study shows that when the amount used in a diet changes, that changes the way the brain works, and that is an interesting insight.’
Dr Smith said that this research would allow us to learn more about how the different types of salt different animals use in different situations.
‘What we’re really interested in is how much salt a dog or a cat consumes when they eat their food and how that changes their brain chemistry,’ he said.
Dr Gows said that their study showed the importance of understanding the way a dog and cat’s bodies metabolise nicotine.’
Understanding how the body metabolises nicotine is important because it affects how the food it eats affects how well it responds to the nicotine, or what it does to the brain,’ she said.
The study also showed that animals that were fed small amounts of fish or fish oils for energy and used their salt to maintain their weight were eating much less than animals that ate large amounts of salt and fatty fish.
‘People may think that dogs can’t be expected to use salt in these ways because they can’t tolerate it,’ Dr Smith added.
‘However, our study showed they can.
‘I think that is really important for understanding the differences between how humans and dogs use salt.
‘For example, if a person is a smoker, then they probably can’t consume a lot, and therefore they need a lot.
‘Similarly, a person who has a problem with the way their brain responds to salt could be eating more than they normally do, so it is important to understand how they use salt to control their metabolism.’
A key question to ask is: can the animals in this study be expected not to use this salt in order to maintain the same brain chemistry as a human?’
The study was funded by the Natural Environment Research Council.