Tuna is a popular treat for many cats, but is it really safe for them to eat regularly? While many pet owners assume that fish is a natural and healthy choice for felines, an unusual case involving an 11-year-old Burmese cat named Nikita revealed the hidden dangers of a tuna-heavy diet. When Nikita suddenly developed alarming neurological symptoms, we were left searching for answers. What we discovered highlights an important lesson about feline nutrition and why tuna should only be an occasional treat rather than a dietary staple.
A Short Backstory
Every once in a while, an unusual case comes along. This recently happened, something that I have never seen in my 30 years of veterinary practice. “Nikita” is a very sweet, female, Burmese, 11-year-old kitty.
My client called me one morning after being up most of the night at the emergency clinic with Nikita. She had come home the previous evening to find Nikita disoriented, unable to stand, depressed, and not at all her usual self.
I had recently performed a dental on Nikita, and she had recovered well and had been doing fine prior to this evening.
The owner had been feeding the cat tuna because she had had several extractions and enjoyed the tuna in place of her hard kibble. After spending thousands of dollars in 24 hours at the emergency clinic, my client was discouraged by the fact that Nikita seemed worse instead of better and brought her in to see me.
Initial Observations
Nikita was very distressed and became anxious when we lifted her out of her carrier. When we set her down on the floor to see if she could walk, she circled to the left for a few turns and then circled a bit to the right and then sat crouched fearfully against the base of the exam table. She couldn’t really walk at all.
She had also endured a seizure while at the emergency clinic. When I picked her up, her head bent forward at a dramatic angle toward her chest.
I tested her vision and discovered she was totally blind. I examined her eyes with my ophthalmoscope and found that the back of her eyes (the retinas) were extremely reflective; I couldn’t see the normal array of blood vessels or the optic nerve.
Her heart rate was fast, and her reflexes were slow. In contrast to these symptoms, she was well hydrated, and her skin, lungs, and abdomen were normal. She was clearly very agitated out of the box and much calmer and less anxious when inside the box.
The emergency clinic had performed multiple tests, including bloodwork, x-rays, urinalysis, and toxoplasmosis titers. They also treated her with IV fluid therapy, antibiotics, and other medications. Their final recommendation was a consult with a neurologist and an MRI (a radiographic brain/body scan).
I mentally went through all of the possibilities of what the cause could be: metabolic, toxicity, immune mediated, infectious, neoplastic (cancer), and so on. None of these fit the diagnostic picture. I was very discouraged that she was not responding to her medications.
Tuna Was the Culprit
This made the number one rule-out on my list a brain tumor. I sadly told my friend that I felt that she had a very poor prognosis at this point. However, given the unusual condition of her eyes, I told my friend that I wanted to consult with an ophthalmologist about what I was seeing.
My client took Nikita home to spend the night with her and see what happened. I added another couple of medications to her current regimen and said goodbye to my friend, fearing the worst.
I made a phone call to Dr. Sullivan at the Animal Eye Clinic in the University district. He was kind enough to take my phone call in the middle of his busy schedule and listened carefully to what I described. Dr. Sullivan was forthright and honest when he told me that the ocular signs that I was relaying didn’t really fit with a brain tumor or toxoplasmosis, the other disease high on my list. He wasn’t sure without seeing the cat himself what was going on. I hung up the phone feeling very upset that I couldn’t find an answer to this kitty’s problem.
About two hours later, he called me back. “Any chance this cat is eating tuna?” he asked. I scanned through the record and found the notes about her tuna diet. “This could be a thiamine deficiency,” he said, an extremely rare disorder. “You might try administering some thiamine and see what happens,” he recommended. Finally, I had some hope. I researched the condition and gathered all the information I needed to treat her successfully. We arranged for her thiamine (Vitamin B1) injections and began administration promptly.
Positive Results
Within a few hours of the first injection, Nikita began to respond. She became less agitated; she calmed down and was able to stand and eat. At her second injection the next morning, she was no longer blind, was responsive, and no longer had the curvature of her neck. She was also able to stand and walk in a straight line. It was absolutely amazing. We continued the injections until she was fully recovered and replaced the tuna in her diet with regular cat food. Tuna is especially susceptible to the degradation of thiamine in the processing, storage, or feeding stages. Tuna also has mercury and should only be fed once or twice weekly to avoid mercury poisoning.
Conclusion
This unusual case demonstrates the importance of adequate diets and nutrition in our animal companions.
Cats must have taurine and thiamine added to any diets they receive. They are carnivores and need to be fed a meat-based balanced diet. This case also demonstrates the importance of taking an accurate history of each animal that comes into the veterinarian’s office. Without this vital piece of information, we would never have been able to diagnose and treat Nikita’s condition. At the time of this writing, Nikita is doing well and is happy at home.
