Complete Care for Your Aging Cat - Amy Shojai [23]
Immunity
The immune system is composed of the spleen, thymus, bone marrow, and lymphatic system (including lymph nodes), plus specialized cells and chemicals. They collectively work to protect the body against foreign invaders such as bacteria and viruses. For instance, the bone marrow makes the various immune system cells, while the spleen both filters and stores blood and immune cells. How well the immune system works to large degree is dictated by genetics, but also influenced throughout life by nutrition, stress, and exposure to pathogens.
“The immune system changes by seven years in all cats,” says Dr. Carey. The thymus gland helps new immune cells mature, but cell replication slows down with age, and the thymus regresses as the cat matures. The immune system also produces chemicals such as interferon and interleukins, which help control the immune system’s response. As cats age, the immune function declines. Because of lowered immune protection, geriatric cats are more susceptible to diseases. They get sick quicker, and have more difficulty recovering.
Cats may be affected by viral infections that suppress the immune system, such as feline leukemia virus and feline immunodeficiency virus. Allergy is also considered an immune disorder in which the system overreacts to a “harmless” organisms or substances, such as pollen or dust.
Golden Moments: Tweety’s Drive to Survive
Tweety was one of a litter of seven kittens. Barb Crandall of Eagle River, Alaska and her husband had always wanted a Persian. “She was the most playful one, ducking and hiding, and looked like a little bunny rabbit,” says the elementary school teacher. “She’s gold and silver, very pretty, with the flat Persian face—looks like she’s been hit by a Mack truck.” She was named Tweety (the family’s male Persian is named Tasmanian Devil or “Taz”) because Barb is a fan of Looney Toons.
Tweety has always been a very loving cat, but very mysterious. “She likes to cuddle. She’ll let us turn her upside down to pet her tummy,” says Barb, “then puts her paw on your arm to say that’s enough. And at night she loves to curl up with us, and she’ll sleep between my husband Tom and myself.”
Until two years ago Tweety had been a very healthy, happy cat. Then she developed what they thought was an allergic reaction—to what, they didn’t know. “She broke out around the nose and chin area with black crusty-type material,” says Barb. The veterinarian treated her with a cortisone injection, the rash healed, and Tweety was fine for six months.
“All of a sudden, she broke out again,” says Barb. The skin surrounding her mouth, nose and chin developed black crusts, and her ears completely crusted over with scabs. “It was a real mess.”
They went back to Dr. Jeff Johnson, a veterinarian practicing at Four Paws Animal Hospital in Eagle River. He prescribed anti-inflammatory medications and Clavamox, an antibiotic to fight infection. Despite all efforts to diagnose the problem over the next six months, it remained a mystery. Keeping Tweety comfortable began to be more difficult.
About this time, Barb invited her good friend Lynn Alfino to move in while Lynn developed her writing career. Lynn arrived shortly before Christmas 1999, and because she worked at home, she spent a great deal of time with Tweety and Taz. “When I arrived I found a really sick kitty,” says Lynn. All sorts of medicines, from liquids to pills, were tried. “Barb tried to put pills inside food but Tweety doesn’t buy that.” All the medicine had to be liquefied.
“We changed her to a prescription food,” says Barb, “and that didn’t work. We changed the litter, that didn’t work.” Skin biopsies didn’t show anything, either. “We racked our brains trying to figure out what had changed in her environment,” she says. “We finally did the allergy testing, a blood test, and that didn’t show any huge spike—only