Watch Out for Tuna
Every once in a while an unusual case comes along. This recently happened; something that I have never seen in 20 years of veterinary practice. Such was the case of “Nikita” 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. We had recently performed a dental on Nikita and she had recovered well and had been doing fine prior to this evening.
Her owner had been feeding her 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. 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, toxoplasmosis titers and had treated her with IV fluid therapy, antibiotics and other medications. Their final recommendation was a consult with a neurologist and an MRI (a radiographic bran/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 were fitting the diagnostic picture. I was very discouraged that she was not responding to her medications. This made the number one rule-out on my list a brain tumor. I sadly told my friend that I felt at this point that she had a very poor prognosis. 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 regime and said good bye to my friend, fearing for 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. He 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.
Dr. Sullivan Saves the Day
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 B 1) injections and began administration promptly.
Within a few hours of the first injection Nikita began to respond. She became less agitated; she calmed down she was able to stand and to 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 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.
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 on each animal that comes into the veterinarians 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 happy at home.