Progressive vision loss in any dog in the absence of canine glaucoma or cataracts can be an indication of PRA. It usually starts with decreased vision at night, or nyctalopia. Other symptoms include dilated pupils and decreased pupillary light reflex. Fundoscopy to examine the retina will show shrinking of the blood vessels, decreased pigmentation of the nontapetal fundus, increased reflection from the tapetum due to thinning of the retina, and later in the disease a darkened, atrophied optic disc. Secondary cataract formation in the posterior portion of the lens can occur late in the disease. In these cases diagnosis of PRA may require electroretinography (ERG). For many breeds there are specific genetic tests of blood or buccal mucosa for PRA.

Absent a genetic test, animals of breeds susceptible to PRA can be cleared of the disease only by the passage of time—that is, by living past the age at which PRA symptoms are typically apparent in their breed. Breeds in which the PRA gene is recessive may still be carriers of the gene and pass it on to their offspring, however, even if they lack symptoms, and it is also possible for onset of the disease to be later than expected, making this an imperfect test at best.

Progressive retinal atrophy (PRA) is a group of genetic diseases seen in certain breeds of dogs and, more rarely, cats. Similar to retinitis pigmentosa in humans, it is characterized by the bilateral degeneration of the retina, causing progressive vision loss culminating in blindness. The condition in nearly all breeds is inherited as an autosomal recessive trait, with the exception of the Siberian Husky (inherited as an X chromosome linked trait) and the Bullmastiff (inherited as an autosomal dominant trait). There is no treatment.

Persistently increased blood pressure may also be due to kidney disease or hyperthyroidism. When a cause is not readily apparent, and especially when hypokalemia is identified, hyperaldosteronism should be considered. Diagnostic imaging, usually beginning with abdominal ultrasound, may identify that one or both adrenal glands are enlarged. Imaging may also detect metastasis and usually includes radiographs of the chest in addition to abdominal ultrasound and/or computerized tomography (CT).

The ratio of plasma aldosterone concentration (PAC) to plasma renin activity (PRA) can be used as a screening test for PHA. In cats with unilateral or bilateral zona glomerulosa tumors, the PAC may be very high while the PRA is completely suppressed. In cats with idiopathic bilateral nodular hyperplasia of the zona glomerulosa, the PAC may be slightly elevated or high normal. In the presence of hypokalemia even a mildly elevated aldosterone should be considered inappropriately high. A high-normal or elevated PAC with a low PRA indicates persistent aldosterone synthesis in the presence of little or no stimulation of the renin-angiotensin system.

Unilateral primary hyperaldosteronism due to an adrenocortical adenoma or adrenocarcinoma can be potentially cured surgically. Unilateral adrenalectomy is the treatment of choice for unilateral PHA. Potential complications include hemorrhage and postoperative hypokalemia. With complete removal of the tumor, prognosis is excellent.

Bilateral primary hyperaldosteronism due to hyperplasia of the zona glomerulosa or metastasized adrenocortical adenocarcinoma should be treated medically. Medical therapy is aimed at normalizing blood pressure and plasma potassium concentration. Mineralocorticoid receptor blockers, such as spironolactone, coupled with potassium supplementation are the most commonly used treatments. Specific therapy for treating high blood pressure (e.g., amlodipine), should be added if necessary.

Clinically induced RA has been achieved using different forms of electrical induction.

- Electroconvulsive therapy (ECT), used as a depression therapy, can cause impairments in memory. Tests show that information of days and weeks before the ECT can be permanently lost. The results of this study also show that severity of RA is more extreme in cases of bilateral ECT rather than unilateral ECT. Impairments can also be more intense if ECT is administered repetitively (sine wave simulation) as opposed to a single pulse (brief-pulse stimulation).

- Electroconvulsive shock (ECS): The research in this field has been advanced by using animals as subjects. Researchers induce RA in rats, for example, by giving daily ECS treatments. This is done to further understand RA.

As previously mentioned, RA can affect people's memories in different degrees, but testing is required to help determine if someone is experiencing RA. Several tests exist, for example, testing for factual knowledge such as known public events. A problem with this form of testing is that people generally differ in their knowledge of such subjects. Other ways to test someone is via autobiographical knowledge using the Autobiographical Memory Interview (AMI), comprising names of relatives, personal information, and job history. This information could help determine if someone is experiencing RA and the degree of memory affected. However, due to the nature of the information being tested, it is often difficult to verify the accuracy of the memories being recalled, especially if they are from a distant past. Some researchers have found that the time interval after the head injury occurred did not seem to matter. The effect of the memory loss was the same no matter how long it had been after from the injury.

Brain abnormalities can be measured using magnetic resonance imaging (MRI), computed tomography scan (CT) and electroencephalography (EEG), which can provide detailed information about specific brain structures. In many cases, an autopsy helps identify the exact brain region affected and the extent of the damage that caused RA once the patient has died.

There are some aspects essential to the patient that remain unaffected by RA. In many patients, their personality remains the same. Also, semantic memory, that is general knowledge about the world, is usually unaffected. However, episodic memory, which refers to one's life experiences, is impaired.

Another real life problem with RA is malingering, which is conceived as the rational output of a neurologically normal brain aiming at the surreptitious achievement of a well identified gain. Since it is common for people who have committed a crime to report having RA for that specific event in order to avoid their punishment, the legal system has pushed for the creation of a standardized test of amnesia. However, since most cases differ in onset, duration, and content forgotten, this task has shown to be a rather complex one.