Here's why:
* Mercury: Tuna, especially larger varieties like albacore, can contain high levels of mercury. This heavy metal can be toxic to dogs, especially over time.
* Salt: Canned tuna is often high in salt, which can be harmful to dogs, potentially leading to dehydration or other health problems.
* Allergens: Some dogs are allergic to fish, including tuna. Even if your rat terrier hasn't shown a reaction before, they may develop one later.
Alternatives:
* Cooked chicken or turkey: These are excellent sources of protein for dogs.
* Fish specifically formulated for dogs: There are commercial dog foods and treats that contain fish, but these have been carefully formulated to be safe for canine consumption.
Always consult your veterinarian: Before feeding your dog any new food, it's best to check with your veterinarian. They can advise on appropriate feeding amounts and any potential health concerns.