Can Dogs Eat Tuna? Preserved, raw & more
Everyone knows that as part of a balanced diet, fish is associated with a multitude of health benefits for us humans.
The same goes for our four-legged friends. Some types of fish are excellent sources of protein and healthy fats.
With tuna, especially in canned form, being one of the most commonly consumed types of fish on the market, many pet owners naturally wonder if it is a safe addition to their pup’s diet.
Can Dogs Eat Tuna?
This is not a question with a simple answer. Tuna is safe to feed your adult dog, but only in very small amounts as an occasional treat. It should not be a major ingredient in your dog’s diet. It is important to note that tuna should not be given to pregnant bitches or young puppies. Tuna should not be offered regularly or given to pregnant bitches or puppies as it contains mercury. Overeating tuna or fish that are long-lived or high on the food chain (such as marlin, swordfish or shark) causes mercury to build up in your dog’s body, which can lead to mercury poisoning – discussed in detail below.
What is mercury and why is it in fish?
Mercury is a naturally occurring chemical element that we tend to associate with the liquid metal in old-fashioned thermometers. It exists in several forms, and one compound called “methylmercury” is of particular concern. Methylmercury is produced through the action of certain types of microscopic organisms that live in watercourses such as lakes, rivers and the ocean. It is found where there are sources of nutrients for living things in the water. Importantly, methylmercury is not readily removed from a living being’s body after consumption, which is why a process called ‘biomagnification’ of mercury takes place in the aquatic food chain.
While there is little mercury in the bacteria, The plankton eating these bacteria will consume more mercury, the creatures eating the plankton will consume more mercury, and so on until you reach the big predatory fish. These consume large amounts of mercury over time. In general, piscivorous fish such as sharks, swordfish, marlin and tuna have higher levels of mercury in their tissues. Mercury concentrations are highest in long-lived predatory marine species such as tuna, swordfish and whales.
Why is mercury a problem?
We care so much about mercury because we do poisonous to the body, a problem for dogs and humans alike. Since the body cannot effectively get rid of mercury, it is builds up in our tissues over time and as more mercury is consumed, tissue levels become higher. Our dogs are generally much smaller than us, so they tolerate less mercury than we do. Mercury accumulates in tissues, leading to problems such as tissue degeneration in the brain, kidneys, and muscles to be the most vulnerable.
Signs of mercury poisoning
While mercury toxicity is extremely rare, it can cause the following clinical signs in dogs:
- Sudden blindness
- excitement
- Abnormal Behavior
- abnormal chewing
- Reduced coordination
- seizures
- Altered kidney function (drinking and peeing more often; lack of urine production)
- hair loss or skin changes
Signs of poisoning usually do not appear until several weeks after the poisoning. These symptoms are not unique to mercury poisoning, meaning many other diseases can cause them. If your dog is showing any of these signs, or you are concerned he may have been poisoned, you should speak to your veterinarian or their emergency services immediately. Your vet will need to run tests to determine the underlying cause of the problem.
What types of tuna can I give my dog?
Assuming you’ve decided to give your dog a small amount of tuna as a treat, the next question is what kind of tuna? There are several species of tuna. Bluefin tuna has the highest mercury content and should be avoided entirely. Depending on the way it was preserved, there may be other health considerations for your pooch besides the mercury content.
Canned tuna in brine
Canned tuna with brine should not be fed to dogs (or cats). The reason for this is the high salt content, which can harm your puppy.
Canned freshwater tuna
Of the available types of canned tuna the kind preserved in fresh water is the best option for your dog. This is because there are no added flavors or oils that could upset your dog’s stomach or cause unnecessary problems. Always check the tuna’s label to make sure it doesn’t contain added salt. Some companies add salt to improve palatability for us humans; it is not safe to give to your pup.
Canned tuna with sunflower oil
While a small amount of sunflower oil shouldn’t harm your pup and may even help his coat, extra fats in the diet add significant calories and can cause an upset stomach. For this reason, It is best to avoid pickled tuna in sunflower oil. Again, some of these products contain added salt that can harm your dog.
Tuna prepared with herbs, spices or sauces.
While adding extra herbs or spices when cooking can greatly enhance the food for our human taste buds, many foods that we are safe to enjoy are toxic to our canine friends. For this reason, Any tuna you feed your dog should be prepared simply.
tuna steak
Various species of tuna contain higher levels of mercury. Tuna steak is often a bluefin variety with the highest mercury levels. This should always be avoided. Other types of tuna steaks tend to have lower levels of mercury. Any tuna steak should be thoroughly cooked to avoid the risk of parasite transmission. It’s not appropriate to feed your dog a whole tuna steak, but a small spoonful of plain tuna steak as a treat on the rare occasion should be safe.
Raw tuna
Tuna should never be fed to your dog raw. Unless fish is sushi quality (which comes at a high price), it can contain parasites that can lead to serious illnesses.
How much tuna can I give my dog?
No scientific studies examine this, and for this reason there are no medically accepted guidelines for dogs. It’s best to limit the amount of tuna your pet eats to an occasional treat, and only feed a small amount at those times (think a small spoonful, not a can). The actual amount your pet can have depends on their size. Smaller dogs should be fed less tuna, and less frequently than larger dogs.
No dog should ever be fed an entire can of tuna in one go, and no dog should be fed tuna every day. IIf you feed your dog some tuna, wait a few weeks before giving it back. If you are unsure, it may be best to avoid feeding tuna altogether. Search for dog friendly instead Fish based treats or ask your veterinarian for dietary advice. If you feed your dog other mercury-containing fish as treats, do not feed them tuna as well, as this will lead to higher mercury build-up.
Can I give tuna to my pregnant dog?
It is not advisable to give tuna to a pregnant bitch. This is because mercury can cross the placenta and cause developmental disorders in growing puppies, particularly in the brain and nervous system.
Can I feed tuna to my pup?
It is not advisable to feed tuna to a growing puppy. Again, this is because mercury may be causing problems with your pup’s neurological development. The nervous system of young animals is particularly vulnerable to mercury exposure.
What other types of fish are dogs safe to eat?
The best fish species to consider for your dog are short-lived ones. Long-lived species like tuna and swordfish build up higher levels of mercury over time. Therefore, feeding short-lived fish reduces the risk of high levels of mercury building up in your dog’s body. Some examples are salmon, whitefish, tilapia and pollock. When feeding your dog fish, you need to make sure it is thoroughly cooked. Raw fish can contain parasites that can make your pup nauseous, but it can also contain harmful bacteria like listeria and salmonella.
These can make your pup sick and lead to health problems for you and your family. Young children, pregnant women and people with weakened immune systems are most at risk. Fish should be prepared for your dog on its own, as cooking it with oil or with herbs or spices can cause health problems for your pup, especially if you use herbs like garlic, which are toxic to dogs. Make sure you remove all bones from the fish before feeding your dog, as fish bones can be dangerous and can result in an expensive and unwanted trip to the emergency room for your four-legged friend.
Final Thoughts
Feed your adult dog a small amount of tuna occasionally. The best option is probably canned tuna that has been preserved in spring water. However, tuna should never be a staple in your dog’s diet and should not be given to pregnant dogs or puppies.
Mercury toxicity is very rare, but since we don’t know the safe amounts of mercury-containing fish to feed our pets, it’s best to be cautious. If your dog shows signs of toxicity, contact your vet immediately.
