Cushing’s Disease in Senior Dogs

Named after noted American neurosurgeon, Harvey Cushing, Cushing’s disease occurs when your dog’s body makes too much of a natural steroid hormone called cortisol. This hormone helps him respond to stress, control his weight, fight infections and keep his blood sugar levels in check.

There are two major types of the disease. Pituitary dependent is the most common, affecting about 80% to 90% of those with Cushing’s, and is caused by a benign tumor in the pituitary gland, a pea-sized gland at the base of the brain. Adrenal dependent affects about 15% to 20% of dogs and is caused by a benign or malignant tumor in one of the adrenal glands that lie on top of the kidneys.

While the disease’s warning signs may be harder to spot at the beginning, symptoms include: increased thirst, hunger, panting and urination, a pot-bellied abdomen, fat pads on the neck and shoulders, loss of hair, thinning or darkening skin, lack of energy, muscle weakness, insomnia and recurrent infections.

To diagnose the disease, your veterinarian will first take a comprehensive health history of your dog and conduct a thorough physical exam, followed by a blood chemistry profile, complete blood cell count, fecal examination and urinalysis.

The most common test is the low-dose dexamethasone suppression test (LDDS). A blood sample is taken to measure your dog’s baseline cortisol level and a small amount of dexamethasone is administered by injection. Blood cortisol levels are measured four and eight hours after the dexamethasone is given. In a dog with Cushing’s, cortisol is NOT suppressed.

Since no one diagnostic test is definitive in every case, your vet may also run an ACTH stimulation test, a high-dose dexamethasone suppression test, and perform an abdominal ultrasound to determine whether or not your dog has Cushing’s, and if so, whether the pituitary or adrenal glands are to blame.

If the disease is a result of a tumor in one of your dog’s adrenal gland, your vet may be able to remove it surgically. But if the tumor has spread to other parts of his body, and he has other health problems, surgery may not be an option.

If your dog has pituitary-dependent Cushing’s, your vet will likely prescribe one of two drugs — mitotane (Lysodren) or trilostane (Vetoryl) — for him. Other medications such as ketoconazole, selegiline or cabergoline may also be used under certain circumstances.

Because your dog must remain on this treatment for life, you must take care to administer the right doses to him at the right times and monitor his behavior and symptoms carefully. You must also be on the alert for any adverse reactions to the drugs. Typical signs of an adverse reaction are lack of appetite, lack of energy, weakness, vomiting, diarrhea and sometimes difficulty walking. Should any of these side effects occur, discontinue the medication and contact your vet immediately.

Otherwise, your vet will schedule regular follow-up visits to examine your dog and run blood tests to ensure the treatment is working and that he’s receiving the correct dose of medication. While schedules vary, be prepared to see your vet several times a year once the maintenance phase of your dog’s therapy has been reached.

And so, working together with your vet, the dog you love can usually go on to lead an active, happy and normal life.

Chronic Kidney Disease in Senior Dogs

Chronic kidney disease, also known as chronic kidney or renal failure, is one of the most common age-related conditions in senior dogs. Unlike acute kidney failure (occurring suddenly, it’s mainly caused by the ingestion of a toxic substance like antifreeze or by an inadequate flow of blood to the kidneys), chronic kidney failure is a progressive disease in which a dog’s kidney function declines over months, even years, before any symptoms appear.

Small breed dogs may show early signs of kidney damage at 10 to 14 years of age, whereas large breed dogs with shorter life spans will show signs earlier. While the damage to their kidneys is irreversible, supportive treatment can often improve a dog’s quality of life and slow the disease’s progression.

In healthy dogs, the kidneys act as filters to excrete the body’s toxic waste products. They concentrate and eliminate the waste in urine and then return water and salts to the body to maintain normal hydration and electrolyte balance. In most cases of chronic renal failure, the kidneys simply “wear out” as part of the aging process, drastically reducing their ability to filter these wastes from the blood. Most dogs, however, only show signs of renal failure when 70 to 75 percent of their kidney function has been lost.

The result is a vicious cycle. A dog’s kidneys become less effective at excreting his body’s wastes and less effective at retaining water, producing large quantities of very dilute (poorly concentrated) urine and building up toxins in his bloodstream. To compensate for the increased fluid loss in his urine, he’ll drink more and more water.

Two of the earliest and most easily recognizable signs of kidney failure are increased thirst (polydipsia) and increased urination (polyuria). Other signs include the need to urinate at night (nocturia), loss of appetite, weight loss, bad breath, oral ulcers, pale gums, weakness, poor hair coat, vomiting, blood in his vomit, diarrhea, black, tarry stool, and behavioral changes. These symptoms tend to worsen as the disease progresses.

If your dog exhibits any or all of these signs, see your vet immediately. A correct diagnosis of renal failure requires the following: blood tests to determine the levels of two waste products, urea and creatinine, normally excreted in the urine (elevated concentrations suggest kidney failure), and a urinalysis to measure your dog’s urine-specific gravity (very dilute urine helps confirm the diagnosis).

Once a diagnosis of chronic kidney failure has been made, it’s crucial to provide your dog with round-the-clock access to fresh, clean water — mainly to prevent dehydration due to the large amount of water passing out of his body — and put him on a diet high in moisture, with a reduced amount of high-quality protein and a low phosphorus content. You must also carefully and consistently monitor the amount of food and water he consumes each day, and weigh him at least once a week to insure that he’s getting enough calories to maintain his weight and enough water to maintain the proper levels of hydration in his body.

Many dogs benefit from the administration of fluids under their skin. Subcutaneous (SQ) fluids dramatically increase daily water consumption and help keep their kidneys functioning as efficiently as possible. Your vet or veterinary technician will teach you how to administer these fluids to your dog at home, and while it may sound difficult, most people find the procedure easy and most dogs tolerate it well.

Potassium is often added either to the SQ fluids or to your dog’s diet to safeguard against muscle weakness and heart rhythm disturbances that result from low electrolyte levels. In some cases, IV fluids may also be required.

Because hypertension is a common and dangerous complication of chronic renal failure, your dog’s blood pressure should be closely monitored to help prevent further damage to his kidneys. Left untreated, high blood pressure not only accelerates the progression of the disease but can also damage his retinas, resulting in sudden blindness. And so, certain medications may be added to his regime.

The success of your dog’s treatment for chronic kidney failure depends then, in large part, on you. Your reward for carefully monitoring his diet, water intake and blood pressure, and administering his medications will be an improved quality of life for him and the possibility of a longer, loving future together.

Diabetes in Senior Dogs

Has your senior dog been drinking a lot more water recently, and having to urinate more frequently? Has he begun losing weight despite being hungrier than usual and wanting to eat all the time?

If so, your dog may have diabetes. While the exact cause of diabetes is unknown, genetics, autoimmune disease, obesity, chronic pancreatitis, certain medications, and abnormal protein deposits in the pancreas can play a major role in the development of the disease.

The most common form of diabetes in dogs is Type I (insulin-dependent diabetes), which occurs when the pancreas is incapable of producing or secreting adequate levels of insulin, thereby causing high levels of glucose in the blood. For most dogs with Type I diabetes, insulin therapy in the form of insulin injections is essential to not only regulate their blood glucose levels but to ensure their very survival. And so, if your dog is exhibiting the four classic symptoms of diabetes — increased thirst and water intake, increased urination, appetite gain and weight loss – bring him to the vet immediately.

To make a proper diagnosis, your vet will record all of your dog’s clinical signs, perform a physical examination, and collect both blood and urine samples. Treatment will then depend on the severity of his symptoms, the test results, and whether he has any other health issues that could complicate his therapy. Since every dog responds differently to treatment, your dog’s therapy must be tailored to fit him – now and for the rest of his life.

Your dog’s initial insulin dose will be based on his body weight, and adjustments will be made until the optimal dose has been determined. Insulin injections are usually given twice a day — every 12 hours with meals – and your vet will show you how to administer them. And because regular blood glucose checks are critical to monitoring his blood sugar, your vet will help you set up a testing schedule and show you how to perform the tests yourself at home.

Routine is key to successfully caring for your diabetic dog, and along with his insulin therapy, you must strictly manage and maintain his weight through proper diet and exercise. You should feed him twice a day (when he receives his insulin), keep him on a high-fiber diet to help slow down glucose absorption, and, most importantly, avoid giving him any treats high in glucose.

Because exercise can help avoid high blood sugar levels and may improve the insulin’s absorption into his system, provide your dog with steady, moderate-intensity activities. Too much or too strenuous exercise can cause his glucose levels to become dangerously low, resulting in hypoglycemia. Hypoglycemia can also occur when your dog’s had too much insulin or if he didn’t eat when he received his regular insulin injection. To be prepared for just such an emergency, ensure that either glucose powder or a glucose solution is always within reach.

Although diabetes is a lifelong condition without a cure, it can be managed effectively, keeping your beloved dog healthy and happy for as long as paws-ible.

Cataracts in Senior Dogs

Any opaqueness in the lens of the eye is called a cataract — a small spot that doesn’t initially or significantly affect a dog’s vision. However, most cataracts will progress, cover the entire lens, and ultimately cause blindness. Since the lens is located directly behind the colored iris, as a mature cataract develops, the pupil may appear white. Vision through a mature cataract is like looking through white painted glass. And while cataracts can be the result of injuries or diabetes, most of them are inherited.

Currently, no medications are effective in treating mature cataracts. Treatment requires the surgical removal of the discolored lens material, and once it’s removed, the cataract won’t recur. The name of this procedure is phacoemulsification ultrasound technology.

Phacoemulsification ultrasound technology is used to break up and remove the lens material. It’s then replaced with an artificial lens inserted into a pocket formed by the original lens capsule that remains permanently in the eye. If, however, a weakness in this capsule is detected during surgery, replacing the lens may not be possible. Cataract removal without lens replacement results in a dog’s vision being somewhat blurry, but it’s an improvement over what he was able to see before the operation.

If your dog is having difficulty navigating stairs, if he’s sniffing for treats rather than seeing them, or if he’s not able to fetch or retrieve as well as usual, he may have a cataract in one or both of his eyes. If you either suspect or actually see that your dog has cataracts, consult your vet or a veterinary ophthalmologist to discuss whether or not he’s a candidate for surgery.

Since the surgery is performed by a veterinary ophthalmologist on an OUTPATIENT basis, your dog can go home with you the same day, but must return for his first post-op examination the following day. Upon admittance to the hospital on the morning of his surgery, the hair will be clipped from the area around his eyes and from one of his front legs (to administer the anesthetic). Prior to the operation, which takes approximately one hour per eye, an electroretinogram test will be conducted to confirm the retina is functioning properly, and he’ll be closely monitored for a few hours following the operation.

When he returns home, he’ll be wearing a firm plastic collar to keep him from rubbing at his eyes and to avoid injuring them. It’s also vital to keep your dog quiet and to avoid all direct nose-to-nose contact with other animals during the first two weeks post-surgery. And while gentle leash walking is acceptable, bathing and uncontrolled exercise are not. Most dogs experience improved vision immediately, and their vision typically continues to improve over the next three to seven days.

Post-operative care involves eye drops as well as oral medications. The first two weeks involves multiple eye drops four times a day, which is usually reduced to once a day long- term therapy by the two-month recheck. Periodic follow-up examinations are then scheduled with the veterinary ophthalmologist on a six-month to a yearly basis to ensure your dog remains pain-free and sighted for life.

Cognition and Anxiety Issues in Senior Dogs

As dogs change from adults into seniors, behavioral changes are sure to follow. Because of this, protective pet parents must become proactive pet parents to ensure their cherished companions receive the extra care they require.

For senior dogs without a specific disease or injury, these are some of the most common behaviors associated with their overall physical and cognitive decline:

Confusion and disorientation: Many dogs may appear lost or confused in familiar surroundings, including their own home. While they may seem distressed the first few times this happens, they generally calm down once it’s become a common occurrence.

Changes in responsiveness: Dogs may appear to not recognize family members and may respond poorly to basic commands.

Vocalizations, restlessness and/or new sensitivities: Some dogs may begin to perform repetitive behaviors or vocalizations such as whimpers or howls, become more restless or develop separation anxiety even if they’ve never had it before, and/or become more sensitive to loud noises like thunderstorms.

Reduced activity: Not only will most older dogs slow down physically, they may also eat less, groom themselves less, and become less affectionate.

Changes in the sleep-wake cycle: Many senior dogs experience disturbances in their sleep cycle, leading them to sleep during the day and stay awake at night when they may pace and/or vocalize.

Changes in house training: Many seem to lose their house training skills causing them to have frequent accidents inside and/or forget to go when they’re outside.

To provide the best possible care for your senior dog, start by having him thoroughly examined and tested by your vet. The results will reveal whether his new behaviors are due to a treatable condition or to canine cognitive dysfunction syndrome, i.e. normal cognitive decline.

If your dog does suffer from cognitive dysfunction syndrome, your vet may prescribe a medication like selegiline hydrochloride to help ease his symptoms. If he’s been diagnosed with separation anxiety, your vet may prescribe an anti-anxiety medication for him. In addition, specially formulated food for senior dogs can help with joint problems and many other common aging issues he might have.

If some of your dog’s behaviors have become highly disruptive, consider working with an experienced animal behaviorist. The behaviorist may be able to help him relearn a few basic commands, improve his housetraining skills, create hand signals for him if he’s now hard of hearing, and suggest solutions for a variety of other problems.

Find new or modified ways of keeping your senior dog active, stimulated, and healthy, including short walks, indoor training and gentle playtime. Any activity is better for his brain and his body than no activity at all.

Remember too, that as your dog ages, he may be in pain, and because of this, do your best to be patient and gentle with him. Find ways to make him more comfortable, such as providing him with a heated dog bed that may soothe his joints and make it easier for him to sleep through the night. Take him outdoors to potty more often during the day and before bedtime, and/or provide him with an indoor doggy litter box. But most of all, remember he’s the same dog you’ve always loved and who’s always loved you, and that, with all the resources at your disposal, your time together can still be quality time.