Galahad’s mom left him early Sunday morning. The 14-year-old feline had eaten and interacted with her as usual.
When she returned home around 4 that afternoon, he did not come out to greet her as he normal would. She could hear him vocalizing and found him behind the sofa, a spot her never went to.
He was panting heavily and when he stood to come to her, he staggered and fell. Mom immediately rushed him to the ER.
Galahad had been a patient before, so the admitting doctor quickly reviewed his record. He had been seen for a breathing issue in the past (chronic nasal congestion), so with the heavy panting, it seemed like he was relapsing. Maybe his nose was occluded with mucous making it hard for him to breathe and forcing the open mouth breathing? Lung X-rays revealed no problem there.
Monday morning he transferred to my (Perry Jameson) care. He had some congestion while breathing but was not distressed. When standing, he seemed unstable and on closer examination, I noted he was blind. I realized he had not had a respiratory event but rather a neurologic one.
Cats with seizures and strokes will often be thought to be in respiratory distress by how they react. Panting is a common side effect and unusual for cats in general.
Upon further evaluation, I realized that Galahad had suffered a stroke. He also had bled into the back of his eyes, which resulted in the blindness. The first cause we consider is hypertension. His systolic blood pressure was 220 mmHg when it should be less than 160 mmHg, confirming my suspicion.
Veterinary patients do not have hypertension as much as humans do. It is not even something we check during routine annual examinations because it is so uncommon. Rarely does it occur as a standalone condition but almost always as secondary to another disease process.
The most common disease is chronic renal failure. The kidneys filter toxins from the blood and eliminate them from the body via urine. If the body senses the kidneys are not removing these toxins efficiently, it will raise the blood pressure to improve blood flow to the kidneys. At mild increases, this is beneficial. Over time, however, the increased blood pressure will damage the kidneys, causing renal failure to progress more rapidly.
Another cause in cats is hyperthyroidism. It is estimated that more than 80 percent of cats with hyperthyroidism also will be hypertensive. Fortunately, normalizing the thyroid hormone levels will usually correct the blood pressure.
Get a weekly recap of South Carolina opinion and analysis from The Post and Courier in your inbox on Monday evenings.
Several other hormonal diseases may result in hypertension as well. These are most commonly associated with tumors of the adrenal or pituitary glands.
The elevated blood pressure may cause vessels to rupture and bleed, as it did in Galahad. Symptoms of this are commonly associated with the eyes and brain. Retinal detachment resulting in sudden blindness is the first symptom many cats with hypertension have. Seizures, trouble walking and altered mental function may be seen if hypertension causes bleeding in the brain.
If the heart has to pump blood against this increased pressure, the heart muscle may hypertrophy. This is not a good thing as in other muscles, and can result in heart failure or fatal abnormal heart beats.
When should your pet’s blood pressure be checked?
- When renal disease has been diagnosed: Maintaining a normal pressure is one of the few methods we have to slow the progression of the disease.
- When hyperthyroidism and hyperadrenocorticism have been diagnosed: Even though correction of the hormonal excess often relieves the hypertension, the blood pressure may still need to be normalized. It is terrible to have a patient suddenly lose vision and then realize this was totally preventable had the hypertension been normalized.
- When cardiac disease has been diagnosed: In cats we want to determine if the hypertension has caused the cardiac changes (especially hypertrophic cardiomyopathy). In dogs, even mild elevation in blood pressure may worsen a leaky heart valve.
Blood pressure in cats and dogs is not as easy to measure as in humans. We cannot just listen for changes in blood flow with a stethoscope. We must use a special ultrasound device. They have no idea what is happening, so the effect of stress has to be considered when interpreting the results.
We decrease the impact of stress by taking the measurements in a quiet room away from other animals and people. Multiple readings are taken, usually about 6, and average them together.
It is too early to know what will happen to Galahad. Hopefully, he will regain his vision (most do) and have no long-term neurological deficits.