Disease

Humane considerations overwhelmingly support the practice of spaying — the surgical removal of a female cat’s ovaries and uterus — when an animal is about six months of age. Perhaps the most compelling argument in favor of this procedure (also known as ovariohysterectomy) is the reduction of feline overpopulation. One study has found that 85 percent of cats that are dropped off at shelters are eventually destroyed. It is estimated that as many as three to four million unwanted cats and kittens are put to sleep annually in the U.S.

Cytauxzoonosis — often a fatal infection in domestic cats — is a disease caused by the parasite Cytauxzoon felis, which is transmitted by the bite of a tick. Most affected cats are young adults with exposure to the outdoors and vague clinical signs of lethargy and anorexia. Treatment for cytauxzoonosis is usually imidocarb diproprionate, but a combination of atovaquone and azithromycin (A&A) has also been utilized as a treatment. (neither form of therapy has been prospectively evaluated for efficacy, however). Eighty acutely ill cats with Cytauxzoon felis infection were treated at various veterinary clinics. Of 53 cats treated with A&A, 32 (60 percent) survived to discharge.

While most cats will go through life without experiencing a serious problem with their ears, owners should know that a variety of conditions — including congenital defects, infections, trauma, and age-related changes — can be extremely painful and may compromise an animal’s hearing. Most feline ear disorders are readily treatable and will not result in permanent hearing loss, notes James Flanders, DVM, an associate professor of surgery at Cornell University’s College of Veterinary Medicine. However, some conditions may render a cat partially or totally deaf, especially if they remain unrecognized and untreated.

Feline dermatophytosis, commonly referred to as ringworm, is a fungal infection that is frequently observed in cats. The condition occurs worldwide, most commonly in warm, humid climates that are hospitable to the peculiar type of fungus that causes it. In the U.S., the disorder is especially problematic year-round in the deep South, says William Miller, VMD, a professor of dermatology at Cornell University’s College of Veterinary Medicine, and its prevalence can rise markedly in cooler areas of the nation with the arrival of hot and muggy summer weather. The clinical signs of ringworm include areas of hair loss, broken and stubbly hair, patches of scaling, crusty or inflamed skin and alterations in hair color.

A common single-celled organism called Toxoplasma gondii is a parasite that infects many animals, including rats — in which it causes a peculiar and unexpected transformation. We all know that the average rat will avoid cats at all costs, and they become particularly nervous when exposed to cat urine. That is, unless they’re infected with Toxoplasma.

A cat’s physical well-being depends largely on the efficiency of its endocrine system, an array of small organs that manufacture chemicals called hormones and deliver them into the animal’s bloodstream. Once they reach their respective target destinations, hormones interact with tissues to enable bodily processes and to ensure their effectiveness. Among the components of the endocrine system is the pancreas — a relatively tiny organ located near a cat’s stomach and small intestine. Perhaps the most important function of the pancreas is the manufacture of a hormone called insulin. After a cat has consumed fats, carbohydrates, and proteins, these dietary components are broken down into a vitally necessary chemical substance called glucose — sometimes referred to as “blood sugar.”

Every so often, your otherwise fastidious cat will do this alarming and somewhat disgusting thing. She’ll awake from a peaceful nap, rise up on her paws, retch convulsively for a moment or two, and spit up what may appear at first glance to be a damp clump. What the animal has disgorged — in the middle of your kitchen floor or, worse yet, in the middle of your prized Persian rug — is a trichobezoar, a wad of undigested hair that is commonly referred to as a hairball.Despite the term, disgorged hairballs are not always round. They are often slender and cylindrical, shaped more like a cigar or sausage than a ball.

Red and swollen gums, bad breath, declining appetite and weight loss are among the conspicuous indications that your cat is suffering from a disorder centered in its mouth, most likely in its teeth and gums. The animal may not appear to be in pain, but that’s because cats are generally very good at concealing illness, possibly because they don’t want to signal a potential predator that they are weakened and are thus vulnerable to attack. But a cat with dental disease is likely experiencing significant discomfort, since the sensory nerves that cause humans to experience dental pain are present in the cat as well. Feline dental problems are not at all uncommon, with approximately 90 percent of all cats experiencing some type of dental disease at one time or another.

Cats’ eyes are complex arrangements of delicate structural components that need to operate harmoniously in a normal, healthy animal to enable keen vision. Unfortunately, things sometimes go wrong with one or more of these components as a result of disease, aging, traumatic injury or genetically acquired defects. Cataracts can seriously impair a cat’s vision and even cause blindness. Compared to the frequency of its occurrence in humans and dogs, however, this ocular disorder is rarely seen in cats, says Thomas Kern, DVM, associate professor of ophthalmology at Cornell University’s College of Veterinary Medicine. Nevertheless, all cat owners should be able to recognize the physical and behavioral signs of this disorder and understand the special needs of a visually impaired feline.

Each year, numerous cats are brought into to veterinary clinics throughout the U.S. showing the telltale signs of respiratory distress: labored breathing, chest constriction, wheezing and coughing. In most cases, the animal will be diagnosed with asthma, a mechanical constriction of the airways, or bronchi, the narrow network of tubes that lead directly from the trachea to the lungs. The narrowing of the airways occurs when a cat’s immune system overreacts to the presence of an allergy-producing substance, such as cigarette smoke, dusty kitty litter or pollen and responds to the presence of the allergen by releasing stimulants that cause a swelling of the tissue (mucous membrane) lining the bronchi. But while asthma is by far the most common cause of feline respiratory difficulty, veterinarians will often refrain from diagnosing it definitively until they have reviewed the results of a microscopic examination of the patient’s feces. Why? Because such a procedure could reveal the presence of lungworms in the animal’s respiratory tract — a situation that would produce asthmalike clinical signs but would require a significantly different approach to treatment.

Whether happily playing with its favorite toy, vigorously pursuing a tiny mouse, or frantically fleeing from a dangerous predator, all of your cats activities rely on the controlled transmission of electrical signals among the billions of nerve cells (neurons) that are jammed into its little brain. In a normal cat, the transmission - or firing - of these signals is well controlled within the central nervous system. These neurons either fire or are inhibited from firing according to an animals shifting needs and desires. In the brains of cats affected with the disorder known as epilepsy, however, this elegant process goes awry.

Urethral obstruction (UO) is a relatively common medical condition in male cats that usually requires emergency treatment (see related article on page 3 of this issue). Standard treatment - which involves medical stabilization of cardiovascular and metabolic derangements, correction of electrolyte abnormalities with IV fluid administration, and relief of the obstruction by urethral catheterization - may require a number of days in the hospital at considerable expense. The study ("A protocol for managing urethral obstruction in male cats without urethral catheterization," Journal of the American Veterinary Medical Association, 2010) involved a clinical trial involving 15 male cats with UO where standard treatment had been declined by owners due to cost issues.