Prevalence

• It's not known how many cats develop hypertension, according to veterinary information company Doctors Foster and Smith, but it is growing thanks to higher rates of obesity among pets. In about 20 percent of pets with conditions like kidney disease, hypertension can develop--and kidney disease itself is very common in cats; it's estimated 35 percent of older cats will get the disease versus 10 percent of dogs.
  
  

Risk Factors

• Like humans, if your cat is overweight, he can develop high blood pressure. The condition can also arise as the result of a primary disease, like diabetes. Hypercalcemia can result from thyroid diseases or tumors, as well as a poor diet that's too rich in meats, according to Dr. Wendy C. Brooks of Veterinary Information Network--a clearinghouse for information geared toward animal medical professionals.
  
  

Symptoms

• As with humans, your cat may be hypertensive and you won't even know it. According to Doctors Foster and Smith, there are often no clinical signs. It can present itself with headaches, weakness and vision problems. If your cat develops hypercalcemia, the strain the condition places on his kidneys can cause him to urinate more often than usual and to be extremely thirsty.
  
  

Process

• If your cat has high blood pressure, the arteries that carry the oxygenated blood through the body become smaller, which makes it harder to push the blood through a smaller "tube," according to Doctors Foster and Smith. The pressure needed to force the blood through goes up, hence "high blood pressure." Hypercalcemia is really "too-high calcium levels" in the blood. Calcium is necessary for healthy bones, but when the message to your bones misfires, causing them to release too much calcium into the body, your bones become brittle. Your kidneys come into play because they try to get rid of the excess calcium through urine, causing frequent urination, thirst and, over time, inflammation, pain and kidney failure.
  
  

Treatment

• One way to help your pet get his high blood pressure under control is to get him moving and change his diet. In addition to weight loss, meds to relax the arteries may be prescribed, according to Doctors Foster and Smith. If hypertension is the result of an underlying problem like diabetes, that must be treated first. Hypercalcemia can also be caused by conditions like Addison's disease or endocrine system tumors, which can be treated with meds or surgery. If hypercalcemia is a primary condition, your pet's diet should be evaluated and balanced.