Health Concerns: Endocrine System
Binky, my 13-year-old cat lives indoors and has been very healthy. Lately, I've noticed that he is looking thin, yet he is eating more than usual and crying a lot. He seems very active but I'm concerned about the weight loss.
Dear Pet Owner:
Weight loss can indicate many problems with your cat and a thorough physical exam with your veterinarian is indicated. Your vet would probably want to run a blood test to check for three common problems found in older cats – diabetes, kidney failure, and hyperthyroidism. Binky sounds like he may be suffering from the last condition – an overproduction of the thyroid hormone. These cats lose weight despite a healthy appetite, vocalize and seem to be hyperactive with a rapid heart rate. The overproduction of hormone is the result of thyroid adenoma or a physical enlargement of the thyroid gland located in the throat area. If blood tests confirm that Binky has hyperthyroidism, your vet will discuss three options:
1) Surgery to remove the diseased organ. This is a permanent fix but can be risky.
2) Irradiation of the thyroid gland with radioactive Iodine which could require an extended hospital stay.
3) Daily medication to regulate the level of thyroid hormone in the blood. Continuous treatment is needed with frequent visits to monitor effects.
Help. My dog has Cushings Disease. What do I do?
Dear Pet Owner:
Cushings Disease, also known as Hyperadrenocorticism, is a disease primarily of dogs that results in excessive production of the body's normal cortisone. It usually occurs in middle age to older dogs with females being more commonly affected. Severity of signs depends on the degree of hormone excess and duration. Clinical symptoms include excessive thirst and urination, muscle weakness and panting. Diabetes sometimes accompanies this disease. Additionally skin changes that include hair loss, pimples, and skin darkening also can occur.
Blood tests that measure blood cortisol are needed for the diagnosis. Ultrasound exams are sometimes performed to visualize and measure the adrenal glands. Most dogs with Cushings Disease have overactive adrenal glands while a small percentage of dogs have adrenal gland tumors.
The current recommended treatment involves giving an oral medicine called Lysodren to reduce the adrenal gland's size and ability to produce abnormally high levels of coritsol. Most pets receive medicine daily for a 10-day period and then need lifelong treatment that is usually two to three times a week. Most pets are monitored with blood tests several times a year. This can be a difficult disease to control and relapses often do occur. Since many organ systems can be affected, the severity of signs vary with each individual and other secondary problems may arise. Dogs rarely die from Cushings Disease but can live a much better life when the disease is under control.
My middle-aged Golden Retriever is gaining weight, has no energy, and has a dull, dry hair coat. My veterinarian wants to test her for hypothyroidism. What is hypothyroidism?
Dear Pet Owner:
Hypothyroidism by definition is a condition that results from inadequate production and release of thyroid hormones from the thyroid glands. The thyroid glands are located under the upper part of the neck on either side of the windpipe or trachea. In dogs, hypothyroidism may be caused by a shrinking of the gland or an inflammation of the gland, which may sometimes be seen in groups of related dogs.
Thyroid hormone helps to run and regulate the functions of the body. So, when the gland is not producing adequate amounts of hormone, many organ systems of the body are affected. The most common findings include a decrease in energy, mental dullness, weight gain despite no change in the amount of food consumed, excessive hair loss and lack of regrowth, a lusterless hair coat, dry flaky skin, darker skin tone, recurrent sin or ear infections, and cold intolerance. Intact animals may have irregular heat cycles or lack of libido and/or infertility. Less common signs of hypothyroidism may involve the nervous system and include seizures, facial paralysis, an enlarged, weak esophagus and paralysis of the larynx, the area where swallowing and voice sounds occur.
It is easy to test for hypothyroidism. A blood sample is commonly drawn from your pet for a chemistry panel in addition to various thyroid hormone levels. It is important to do a chemistry panel to assess the other internal organs as well as to measure the cholesterol and triglyceride levels.
If abnormalities are detected, hypothyroidism can be treated with hormonal replacement therapy, mainly a levothyroxine tablet. This tablet may need to be given one or twice daily depending on the pet. Repeating a thyroid level in 4-6 weeks into therapy is recommended to gauge how well therapy is working. Clinical signs of improvement may be noted within a few weeks but some of the skin changes may take months to improve. If the pet had neurologic changes associated with hypothyroidism, some may improve while others may not. Therapy would need to be continued for the remainder of your pet's life. The thyroid medication and regular check-ups with your veterinarian will continue to keep your pet healthy and happy.
My 12-year-old cat has been eating a lot, but still losing weight. My veterinarian says she has hyperthyroidism and needs medicine for life. Is this true?
Dear Pet Owner:
Many older cats develop benign nodules in their thyroid glands that lead to illness. The nodules are benign 99% of the time. This means they do not spread to other locations. Never the less, they cause excess production of thyroid hormone which makes cats very ill. Thyroid hormone is responsible for many things including the overall speed with which the metabolism is regulated. When levels are elevated, cats eat and drink more, sleep less, have rapid heart rates, can become agitated and lose weight. Blood tests can measure thyroid levels. Left untreated, many cats often develop fatal heart and kidney disease.
Three different treatments are currently being employed to normalize thyroid hormone levels. The medication methimazole (Tapazole) can be effectively used to “dismantle the biochemical machinery” that produces the hormone. It needs to be given daily and reduced hormone levels are seen in 2-3 weeks. Regular blood tests to monitor thyroid function and blood counts are required. An alternative treatment requires the affected gland to be surgically removed. It is an effective means but cats often will grow a second thyroid tumor on the remaining gland within 1-2 years. The safest and most effective treatment is to give a single injection of radioactive iodine, which selectively destroys the abnormal tissue. Following treatment, cats will be radioactive and need to be kept in a special facility while the radioactivity diminishes which is a few days to one week.
So, you can see that this is a very treatable disease that we see with increasing frequency in our older cats. These three treatments separately, and in combination, have helped many old sick cats continue to grow old in good health.
My two-year-old Dalmation, Annie, is acting strangely. She has always been an active playful dog, but this week, she has been hiding in my closet. Also, after a few minutes of being outside, she whines to come back in. She is not eating her dog food but she's hungry for treats. Also, her breasts seem puffy like she's nursing puppies but she was in heat about a month ago and she didn't mate. We can't find any puppies but she is carrying around her favorite tennis ball all day. What is going on?
Dear Pet Owner:
Annie is experiencing a condition called Pseudocyesis, or false pregnancy. Female dogs have a reproductive phase, or estrus cycle, about twice a year. During the first two weeks, they are ovulating, and natural chemicals in the body called hormones cause the dog to behave in ways that would attract a male dog and result in a successful mating. This is called ‘heat”. After this initial period, the hormone, progesterone, increases and this chemical helps maintain the pregnancy and the nursing period that follows. This hormone rises even if she did not mate. Some dog's bodies are sensitive to this chemical surge, and physical and mental changes occur that make a female dog look and feel like she's nursing, even if she was never pregnant. Annie's hormones after her heat are making her feel like she's nursing invisible puppies. If you roll her over and gentle squeeze her nipples, milk will probably drip out. She is caring for her imaginary brood in the closet and carrying a tennis ball baby around the house. There are several tricks to help Annie snap out of this behavior. Take away the toys she is mothering and don't allow her in the closet. She will be unhappy at first, so try to lift her mood by playing games outside and making her obey commands for rewards. Best of all, have your veterinarian perform a hysterectomy (spay) so this condition will not recur. Spaying Annie will not only eliminate these behaviors but will also have tremendous health benefits.
My husband and I have a wonderful one-year-old Golden Retriever named Sunny. We adore him but recently I have caught him wetting on a chair near our patio door. He just lifts his leg and lets go. I heard that getting him fixed might stop this problem but when I mention it, my husband winces and says he can't do that to ‘our boy'. Can I convince him or do I have to get waterproof furniture?
Dear Pet Owner:
Sunny's intolerable behavior is fueled by his maturing level of the male hormone, testosterone, which is primarily produced by the testicles, and can be lowered by having your veterinarian surgically neuter, or castrate, him. This is the best thing to do for Sunny's mental and physical health.
There are many health benefits to neutering Sunny. An older male dog may develop bleeding skin tumors near the tail and anus called perianal adenomas, an enlarged prostate gland causing pain and bloody urination, and tumors of the testicles themselves. At best, these conditions can be corrected but require performing surgery on an aged pet with more complications and risk. In a young dog, this is a safer operation with quicker recovery.
Also some uncastrated male dogs will also become increasingly aggressive toward strangers and maybe even toward family members over food or territory. Proper training can lessen these encounters but your dog will be more likely to respond if his male hormones aren't instinctively telling him to rule!
Sunny is being bombarded by sensations from his surroundings. Stuck in your house or yard, he smells the poodle in heat two blocks away. He sees the beagle wandering down the sidewalk. He hears the mail truck stop next door. In the perfect dog world, he could court, cavort, or confront each experience, but in your neighborhood, he is not permitted to respond. Urine marking often ensues. If Sunny is neutered, his testosterone will no longer drive him to react to these events. He will no longer be frustrated by instinctual urges and he will be a more content member of the family.
My veterinarian just diagnosed my cat, Sam, with diabetes. I didn't realize that animals could get the same illnesses as humans or that they could be treated for them. My vet says Sam can live a good life as long as I monitor his blood sugar levels and give him his injections. Is this true?
Dear Pet Owner:
Many diseases affecting humans can affect our pets. One disease that is being detected more frequently in both the human and animal populations is diabetes mellitus, or sugar diabetes. Diabetes produces symptoms and complications in animals that are identical to those found in humans and treatment of this disease in animals is very similar to the treatment used in humans.
Symptoms include excessive hunger and thirst, excessive urination, weight loss, and lethargy. Diabetes is characterized by high blood glucose levels, due to a lack of insulin from destruction of the betacells (Type I), or inadequate insulin production to overcome resistance at the cellular level (Type II). In animals, Type I is more common in middle-aged older dogs with certain breeds at higher risk such as Keeshonds, Golden Retrievers, Poodles, Old English Sheepdogs, Daschunds, and mixed breed dogs, predominantly females. Type I and Type II occurs in cats, commonly adult males, and obesity is a risk factor. Cats can also fluctuate between requiring insulin and being controlled with diet only. However, many cats are not brought to the veterinarian until the diabetes is so advanced as to require insulin.
Excess blood sugar also results in sugar in the urine. Since glucose lost in the urine is in a dissolved state, the body also loses important water. This water loss is the reason that the major symptoms of a human or animal with diabetes is excessive thirst and urination.
While Type II diabetes in humans can be treated with diet, exercise, and medication, most dogs or cats with overt diabetes are best regulated with daily insulin injections. Without treatment, diabetes is a debilitating disease because the body breaks down fat and muscle for energy when it cannot utilize blood glucose. This causes weight loss and can lead to a dangerous condition called ketoacidosis that requires hospitalization and intravenous fluids therapy. Other complications of long-term diabetes are cataracts and neurological problems causing abnormal walking posture in the hind legs.
My veterinarian wants to treat my pet with steroids but I have heard bad things about these drugs and I'm reluctant to administer the pills. What exactly are steroids and what are the consequences of treatment?
Dear Pet Owner:
Steroids can be natural – the glucocorticords and mineralocorticoids produced in the adrenal glands which are necessary for normal bodily functions. Parenteral steroids are those administered by your veterinarian and are either anti-inflammatory or anabolic. Anti-inflammatory steroids are used to treat many disorders or symptoms of disease. These are probably the type being recommended by your veterinarian. Given at the proper dosage and according to the directions, they can be a beneficial part of therapy.
Anabolic steroids are used less frequently and are used for treating muscle wasting, weakness, and weight loss. These are the type abused by weight lifter and sports figures and can cause liver and heart damage.
In the case of long-term use (9 months to years), inappropriate dosing, or undiagnosed pre-existing disease, steroids can cause damage to the liver, kidneys, or adrenal glands. In the face of long-term usage, many veterinarians will recommend periodic blood testing.
Some individual pets may be overly sensitive to steroids. Increased urination and thirst and an increased appetite and occasional behavior changes might be noticed while your pet is being treated with steroids. Notify your veterinarian if you notice any of these signs in your pet.
My cocker spaniel has been to the vet for a hind leg lameness. The doctor says it is a torn ligament and may require surgery. She has a bandage on the leg now. How can I best take care of her?
Dear Pet Owner:
First a word about bandage care. Keep the bandage clean and dry – this means that if it is raining and your dog needs to go outdoors, cover the bottom of the bandage with a plastic bag, restrict your dog's activity and notify your veterinarian immediately if you notice any of the following – a wet bandage, a bandage that has a foul odor, excessive chewing of the bandage or crying in discomfort, irritation or swelling at any point where the bandage meets the dog's body, or any slipping or movement of the bandage from its original position. Should you see any of these signs the bandage may need to be changed before your next scheduled veterinary appointment.
The ligament your dog has torn is undoubtedly the anterior cruciate ligament. The cruciate ligaments are found in the dog's knee and rupture from traumatic injury is one of the most common causes of hind limb lameness in dogs. It is generally an acute injury meaning it has a sudden onset. The cruciate ligaments cross from the end of the femur to the top of the tibia and prevent motion of the joint from front to back. When the anterior ligament is ruptured or torn it creates an instability in the joint as well as inflammation (a precursor to arthritis). Treatment involves bandaging to stabilize the joint and medication for the pain. For smaller, younger dogs this conservative management will suffice and 85% can improve or are normal by six months.
For larger dogs, surgery is recommended and speeds the rate of recovery. In surgical repair a heavy-gauge implant is placed in the same plane as the torn ligament to restore stability. During surgery, the joint is also examined for any additional damage to the menisci (cartilaginous cushions inside the stifle joint).
Recovery from the surgery can be lengthy. Up to three months of restricted activity is often advised and a return to complete athletic functions is rare. No matter the method of treatment, arthritis is a common side effect and of those dogs repaired, 20-40% will rupture the opposite ACL within 1-1 ½ years.
Drugs that protect the cartilage of joints (glucosamine/chondroitin) may help limit cartilage damage and degeneration and may be recommended as alternative therapy.
It's almost a year since my five-year-old Schnauzer, Robin, was diagnosed with diabetes. I glucose-test her urine every morning and evening. Although she shows no ketones in her urine, sometimes she tests negative for sugar. Lately, she's tested positive. How can I regulate her sugar faster?
Dear Pet Owner:
Diabetes Mellitus is a condition seen in many mammals, including dogs and cats, in which the pancreas does not produce enough insulin. Insulin is needed to help control blood sugar levels and fat breakdown, providing energy to the body's cells. With diabetes, the lack of insulin causes too much fat waste products, known as ketones, and sugar to circulate in the blood stream. Diabetic dogs and cats lose weight, drink and urinate excessively, and feel weak or very ill. If untreated, these animals can die.
You didn't mention how you are treating your dog. Usually, insulin injections are given once or twice a day. Several forms of insulin are available. Another type of dosage schedule might work better for you. What your dog eats also affect blood sugar levels. Special dog foods useful in controlling diabetes are available from your veterinarian and feeding the same foods at the same times every day may prevent sugar fluctuations. Is your dog spayed? Diabetic female dogs often go wildly out of control around their heat cycle. Sometimes, other medical conditions can make diabetes difficult to control. Ask your veterinarian to do a blood test to look for liver disease or an overactive adrenal gland.
Despite your high urine sugar test results, it seems you are managing Robin's diabetes successfully. If her weight is stable, she looks good, acts well, and doesn't over-drink, you may be trying too hard to fine-tune her sugar. Ask your veterinarian to perform a fructosamine blood test, which measures sugar levels over a several week time period. If this is normal, relax a little and congratulate yourself on enabling your pet to enjoy a happy year.