Canine Hypothyroidism

What is thyroid disease in pet animals?

Your veterinarian may have recently discussed thyroid disease in your dog or cat with you. In dogs, low levels of thyroid hormone, or hypothyroidism, tends to affect middle-aged dogs, and we frequently screen for it on yearly or pre-anesthetic bloodwork. Cats, especially older kitties in their teens, are predisposed to the opposite problem, developing high levels of thyroid hormone, often secondary to a benign hormone secreting thyroid tumor.  Managing these diseases is usually done through oral medication and is often successful in bringing thyroid hormone levels in to their desired normal ranges and controlling the symptoms of the disease. 

Why is thyroid disease important?

Thyroid hormones affect a huge number of systems in the body. During growth and development, thyroid hormones play an essential role in normal formation of the neurologic and skeletal systems. Congenitally hypothyroid puppies often show very stunted growth patterns. Thyroid hormones in adults function in increasing metabolism in the tissues, increasing the heart rate, breaking down fat, stimulating red blood cell production, and regulating cholesterol.   These functions are all affected when thyroid hormones are too low or too high, which results in the symptoms that we see in our patients.

Facts about canine hypothyroidism:

Hypothyroid dogs are usually diagnosed during middle age, on average about 7 years old. About 50% of the time it is caused by a condition called lymphocytic thyroiditis, an immune-mediated condition where the body starts to create antibodies to the thyroid tissue. Other causes can be due to a cancer of the thyroid gland, a secondary condition involving the pituitary, or for unknown reasons, what we call “idiopathic.

Symptoms of hypothyroidism include:

  • Lethargy
  • Strong appetite and obesity not responsive to diet or exercise therapy
  • Fatty deposits in the cornea of the eye
  • Neurologic abnormalities
  • Seizures
  • Vestibular disease
  • Peripheral neuropathy
  • Dermatologic problems
  • Hair loss, especially symmetrical hair loss on both sides
  • Poor re-growth of hair after shaving or clipping
  • Dry and flaky or very oily skin
  • Recurrent skin infections

Diagnosis of canine hypothyroidism

We diagnose canine hypothyroidism through a combination of symptoms, physical examination and blood tests to check for circulating hormone levels.

The thyroid glands are located in the neck just behind the larynx (voice box) in dogs and cats, and actively produce thyroid hormones, including thyroxine (also called T4).  Production of thyroid hormones is regulated by the pituitary gland, through a hormone called thyroid stimulating hormone (TSH).  A feedback loop exists between the body and the pituitary gland, with TSH production by the pituitary going up when the body needs thyroid hormone and turning off when thyroid hormone levels are high.

Screening the blood for indicators of hypothyroidism may include the following tests:

  • Complete blood count – may show a mild anemia in hypothyroid dogs
  • Serum biochemistry – often shows high levels of fasting triglycerides and cholesterol with canine hypothyroidism
  • TT4 – evaluates total T4 concentration in the blood
  • Free T4 (fT4) – evaluates only the portion of circulating T4 that is not bound to protein in the blood.
  • This is a more sensitive indicator of disease. Some dogs that are not truly hypothyroid may have a low TT4 but a normal fT4.
  • TSH levels – may be increased as the pituitary produces more and more TSH to try to stimulate an under-responsive thyroid gland
  • Anti-thyroid antibody – a test that may help determine if autoimmune disease is present

Certain kinds of drugs (e.g. sulfa antibiotics, anti-inflammatory, anti-depressant and anti-seizure medication) can cause artificially lowered thyroid levels so it is important to make sure we account for these before making a diagnosis. In addition, some breeds, such as greyhounds, will normally have lower TT4 levels.

Some non-thyroid diseases can also cause circulating thyroid hormone levels in the blood to decrease. Your veterinarian may need to do other tests to rule these diseases out before confirming a diagnosis of hypothyroidism.

They include:

  • Diabetes mellitus
  • Adrenal disease
  • Hypoadrenocorticism (Addison’s disease)
  • Hyperadrenocorticism (Cushing’s disease)
  • Renal disease
  • Heart failure
  • Severe infections

Treatment of canine hypothyroidism

Treatment for hypothyroidism involves lifelong oral medication with levothyroxine, a relatively inexpensive thyroid hormone supplement. Generally blood tests are rechecked approximately 4-8 weeks after starting medication and again as needed while the dog’s metabolism adjusts to the therapy. After that, once yearly checks are adequate to ensure that the thyroid hormone level remains in the normal range. The prognosis is usually very good for long-term management, but complete resolution of symptoms may take several months.

Next blog from Dr. Rainwater: Feline hyperthyroidism!

Have You Logged Into Your Pet Portal?

We began using Pet Portals in January this year in an effort to provide our clients easier access to their pet’s medical records. If we have your email address on file, you receive periodic email reminders about wellness services that are due, but Pet Portals can do so much more!

  1. View your pet’s wellness records at any time: You can print a copy to provide to your boarding facility and take on trips with you in case of emergency. Click on the name of the service to read what it means and why we recommend it.
  2. Request appointments: Sometimes, remembering to schedule a vet appointment happens at 10 o’clock at night or is just easier to do online than it is over the phone. When you request an appointment through Pet Portals, you can specify which doctor you wish to see and give a range of potential dates and times that work for you. Our receptionists check the requests frequently and will get back to you by the next business day.
  3. Request medication and diet refills: Your pet’s full prescription history is listed in chronological order on your Pet Portal. When you are ready for a refill, simply click “pick up a refill.” Our technicians will fill the prescription and have it waiting for you at our office by the next business day.
  4. View upcoming/recent appointments: Forget the time of your next appointment? Want to see when you were last in? It’s all there!
  5. Create your own email reminders: Need help remembering to give monthly prevention? Want to remind yourself to schedule a grooming appointment every 6 weeks? You can set up email alerts for anything you like!
  6. Get informed: The “Care Guide” section of your pet portal has information on a range of topics including behavior, wellness, disease, and tests.
  7. Connect with other animal-lovers: Upload pictures, share stories, and read the “tails” of our four-legged friends across the country.

In the coming weeks we will be adding an online store to your Pet Portal which will allow home-delivery of all the products we recommend! More information on that when it’s available!

Log onto your Pet Portal, and click the button. If you need help accessing your Pet Portal, call our office and we can provide a temporary password.

Tell us your thoughts on Pet Portals! Do you like it? Dislike it? What would you change? What do you use it for?

Debunking the Dangerous Breed Myth

Are some breeds too dangerous for Daniel Island?

A dog’s appearance or breed is NOT an indication of potential problems.  Those assumptions are akin to racial profiling – not only unfair to pet owners, but also inadequate for purposes of reducing the risk of aggressive dog activity.

Temperament testing individual dogs is a MUCH more effective way to determine which dogs are safe in a community setting and which dogs should not be allowed.  Giving all dogs, regardless of their appearance, a temperament test enables identifying aggressive individuals of “safe” breeds (i.e. Labrador retriever) as well as determining which individuals of a “suspect” breed could be a problem.  Breed assumptions are very inaccurate, more “wives’ tale” than fact.  In actuality, most “pit bull” appearing dogs are sweet and safe.

Certified trainers can administer the temperament test in about 10 minutes, and the results are far superior to using appearance alone to identify dangerous dogs.  After over 20 years in veterinary medicine, I can personally attest to the fact that individual temperament is not determined solely by breed!!

What is a temperament test?

A good resource on temperament testing of dogs is the American Temperament Testing Society. By reading their website's breed statistics page, you will note that breed is not a reliable indicator for temperament.  I am aware of several area trainers who are certified in AKC Good Citizen Testing and offer these tests locally.

A smart and effective community policy is to require owners of dogs involved in any aggressive incident to have their dogs tested and certified before allowing them to stay.  This policy protects everyone.  When owners are required to present proof of temperament only after a problem arises, no one is targeted for their pet’s appearance, and the cost to the community is nothing.

Feline Heartworm Disease - What Owners Should Know

Heartworm infection has been a recognized disease in the veterinary world for many, many years but the focus has always been on our canine companions. Spread through the bite of a mosquito, heartworm larvae will continue to mature while migrating to the heart and pulmonary arteries.  In dogs, the juvenile worms mature and develop into adult heartworms. If left untreated, these adult worms will reproduce leading to larger worm burdens within the dog as well as circulating microfilaria ("babies") in the vasculature.  Tests to diagnose heartworms detect either antigen produced by the heartworms, antibodies produced by the dog in response to the heartworms, or a drop of blood, where microfilaria may sometimes be observed.

Cats are an aberrant host for heartworms, so the larvae will migrate to the heart and pulmonary arteries but most often die and do not establish a mature adult infection. The problem for cats arises from the death of these immature worms which sets up a HUGE inflammatory response in the lungs ofan infected animal. Clinical signs may include coughing or dyspnea, vomiting, neurologic signs (from aberrant migration of a larva), or most worrisome - acute collapse and death. The inflammation is often transient, but may last for 6-8 months.  There are some cats (approximately 30% in one study) that may remain asymptomatic and can self-cure.

Due to the atypical infection in cats: very low worm burden, single sex infections, and lack of microfilaria: diagnosis is challenging. The heartworm antigen test lacks sensitivity because of the typical low worm burden and possibility of an all male infection (only the female produces the detected antigen). False negative antigen tests are therefore common; however, false positives are rare, so if positive, an active infection is indicated.  Antibody tests just indicate prior exposure, so these are generally used as screening tests in asymptomatic cats.  In symptomatic cats, combining the antigen and antibody tests give us the best chance of diagnosing heartworm disease. Chest radiographs (x-rays) and echocardiography (ultrasound of the heart) may also be used to aid in diagnosis.

If heartworm disease is diagnosed in dogs, there is an approved drug to kill the adult heartworms (called "adulticide therapy"). Unfortunately, adulticide therapy is not used in cats due to the high risk of death associated with it. Due to this, we often are left with supportive treatment - most commonly with corticosteroids.

Due to difficulty in diagnosing, non-specific treatment, and potential for acute collapse and death as the first (and only) sign of heartworm disease in cats, what is a cat owner living in South Carolina (where the state bird is the mosquito) supposed to do? Prevent the disease from ever occurring is what we recommend! Heartworm preventatives are labeled for use in cats and the two that we recommend are Revolution and Heartgard Plus. 

  • Revolution is a topical flea/heartworm/intestinal parasite preventative, which is often easier to administer to cats. 
  • Heartgard Plus is a flavored heartworm/intestinal parasite chew. 

Both of these products are delivered to the pet monthly, and in the southeast United States, should be done year round.  So, why risk an untreatable and potentially fatal disease for your cat, when you can prevent it completely with regular use of a heartworm preventative?

Find out more on the Know Heartworms website.

Respect Your Elders; Caring for Aging Pets


Dogs and cats have an average life expectancy of 12 - 18 years.  We consider them “senior” at seven years of age. This is the time to become proactive in controlling disease processes which begin now and worsen with time.  We cannot keep our pets from aging, but we can keep them feeling good for longer.

These are the three most effective measures a pet owner can take:

  • Regular veterinary exams
  • Annual lab work
  • Preventive dental care

Starting treatment early is more effective medically and financially. We see patients every six months in order to identify and adjust to individual changes which vary greatly.  Weight control and dietary management of early organ disease are examples of simple changes we can make to help your companion live longer and feel better.

Annual lab work is a powerful tool for identifying problems early. Evaluating liver and kidney function allows us to use medications safely and effectively in individual pets and it enables us to use anesthesia for dental cleanings and other important procedures.

Monitoring thyroid status in aging pets is important.  Some dogs need thyroid supplementation to maintain energy, good immunity and cardiac health. Cats sometimes produce too much thyroid hormone, which makes them feel ill.

We cannot prevent aging changes, but adjusting to them as they occur allows for better quality of life for our valued companions!

Weight loss in Cats

It’s a long hard road, but it’s worth it!

If there are two things I see in otherwise healthy pets that jeopardize their long-term well-being, they are obesity and dental disease. Previously I talked about the obesity epidemic in dogs, and now it’s time to discuss managing your too big kitty. (Also read: Dr. Flood's article on dental health.)

Feline obesity increases the risk of skin disease, cardiovascular stress, respiratory stress, urinary obstruction (especially male cats), diabetes mellitus, joint disease and hepatic lipidosis to name a few problems.  Any of these will be much more expensive and stressful to treat than getting weight off your cat!

Realize that weight loss in cats is very different from dogs, and if done improperly, can kill them.  This is because if cats either lose weight too quickly or stop eating due to the stress of a diet change, they can mobilize too much fat at once which accumulates in the liver causing a dangerous condition called hepatic lipidosis (fatty liver disease). This condition often requires hospitalization and in some cases, surgical placement of a feeding tube.

If you are interested in starting a weight loss plan for your kitty, here is an algorithm to use in conjunction with regular monitoring.

  1. Start with a visit to the veterinarian to determine body condition, ideal weight and establish a weight loss plan. We recommend doing some routine bloodwork (serum biochemistry and complete red and white blood cell count) at this time to ensure that the liver and kidneys are healthy prior to starting the weight loss plan.  This bloodwork should be rechecked at least once during the weight loss process.  Your veterinarian will also calculate the number of calories the pet should be fed, advise you on diet options (see below) and give you an exact amount to feed daily.
  2. Buy a baby scale. These are readily available from online sources for about $50 or less. You can also use a postage scale (office supply stores sell these) or cooking scale, as long as it goes up to about 20 pounds.  You will use this to weigh your cat weekly, instituting a weight loss goal of approximately 0.5 – 2% body weight loss per week. In other words, a 15 pound cat with an ideal weight of 8 pounds needs to lose between 1.2 and 4.8 ounces per week (given 1 pound = 16 ounces).  This means that it will take this kitty at least 6 months to safely lose weight, so be patient.  If weight loss is too rapid, dietary intake will need to be increased. If too slow, then either intake or type of food may need to be adjusted.
  3. Decide on a diet.  There are many options for dietary weight loss in cats. Generally, if cats are healthy, a high protein diet (at least 40% dry matter) will be selected. Both prescription and over-the-counter options are available. Many feline practitioners also advocate a switch from dry to wet food, due to the higher protein and water content and lower carbohydrates. Be prepared to try more than one diet; some cats will be very picky about what they want to eat and you may have to try several types of before you find one that works well.  Always transition cats slowly to a new food over at least 5-7 days.
  4. Meal feeding. If your cat is free fed dry food, even a weight loss food, it is unlikely that he will lose weight.  It is important to get your cat on a feeding schedule. In very hungry cats, feeding small meals 3-4 times daily may work better than twice daily.  However, do not go above the daily calorie amount recommended by your veterinarian.
  5. Exercise.  Just like anyone else losing weight, your kitty needs more exercise. Commit to adding at least 15 minutes per day to their routine, which you can break up into 5 minute bouts if that works better.  Laser pointers, bird toys, making them “fetch” for low-calorie treats or pieces of kibble, feeding toys and providing vertical climbing space such as cat towers can all be helpful. Do not encourage jumping on or off furniture for overweight cats, as that can put them at risk of joint injury or bone fractures. Check out The Indoor Cat Initiative (through Ohio State University) for ideas on improving the life of your indoor cats.

As always, contact your veterinarian along the way with any questions or concerns!

We Love our Technicians!


Next week (October 10-16th) is National Veterinary Technician Week! We are looking forward to our in-clinic celebrations and are taking this opportunity to explain who technicians are and what they do.

LVT stands for Licensed Veterinary Technician.  Depending on the state, the same credential can be seen as CVT (Certified Veterinary Technician) or RVT (Registered Veterinary Technician).  Regardless of the acronym, a veterinary technician can be compared to a human hospital's RN and the title is awarded to those who have completed the following:

  • Associates or Bachelors Degree in Veterinary Technology from a nationally credentialed institution
  • Successfully completing National and State Board Exams
  • Licensure (Certification or Registration) by the state licensing board
  • 10 Hours of Continuing Education every 2 Years (SC requirement)

In a private practice, such as Daniel Island Animal Hospital, the LVT plays a vital role in patient care and the day-to-day operations of the hospital. We rely on their education and experience to support our doctors with cases ranging from wellness to emergency. Here are some of our technician's responsibilities:

  • Surgical Preparation, Induction, and Monitoring
  • Dental Cleanings
  • Radiology
  • Patient Medical Histories
  • Specimen Collection and Laboratory Tests
  • Prescription Filling
  • Client Education
  • Hospital Patient Monitoring and Care
  • Injection and Fluid Administration
  • IV Catheter Placement
  • Patient Restraint
  • Nail Trims and Anal Gland Expressions
  • Inventory Management
  • OSHA Compliance
  • Controlled Drug Monitoring and DEA Compliance

In cooperation with our doctors, assistants, receptionists, and manager, our compassionate and knowledgeable technicians help keep patient care and client service standards top-notch. We strive to make your trip to our hospital a positive experience for pets and people alike!

Thank you Missy, Bethany, Jen, and Mara - you guys ROCK! Happy Vet Tech Week!

If you are interested in becoming a veterinary technician, you can find more information through these resources: American Veterinary Medical Association (AVMA),  National Association of Veterinary Technicians (NAVTA), Trident Technical College (TTC)

Caring for Wildlife

What to do if you find a sick or injured animal:

(Contact information applies for Charleston, SC area residents)

  1. Do not put yourself in danger.
  2. Leave baby birds, bunnies and squirrels alone for a few hours and watch from afar.  Usually mom is just nearby hunting or readying a new nest, and will return for the offspring.  Wildlife mothers do not abandon their young.  If you have witnessed a cat or dog moving the baby, or the mother does not return after three hours, then pick up the young, keep it warm and covered, and take it to an animal hospital or animal rehabilitator as soon as possible (see list below).  Do not try feeding the baby.
  3. If you think you can safely get a smaller, slow-responding, ill or injured animal into a box or carrier which closes firmly, take it to an animal hospital yourself.  Call before you go, as not all veterinarians work with wildlife.  Pet Vet in Mt. Pleasant (843.884.7387) is open during business hours and routinely treats wildlife.  Nights and weekends, the Animal Emergency Hospital of Mt. Pleasant (843.216.7554) will accept wildlife.
  4. For birds of prey (eagle, hawk, kestrel), call the The Center for Birds of Prey in Awendaw (843.971.7029).
  5. For wildlife pests invading your yard or home, call Wildlife Solutions (843.571.5556) or another private company to humanely trap and remove them (they do charge for services).  Contacting a rehabilitator to arrange transfer and follow-up care will prevent the animal being stressed or injured after it is trapped (see list below).
  6. For alligators over 5 feet long, call the SC Wildlife Department (843.825.3387).
  7. If smaller alligators or feral cats become a pest, call City of Charleston Animal Control (843.720.3915).

State Licensed Rehabilitators:

Keeper of the Wild, Inc.(non-profit)

Mammals and Rodents:

Janet Kinser, Director (843.636.1659) St. George, SC

Song Birds:

Sarah Landgrebe (843.849.6149) Mt. Pleasant, SC

Shore Birds:

Holly Reynolds (843.886.4933) Isle of Palms, SC

Turtle and Tortise Society (non-profit)

Turtles and Tortises:

(843.871.6606) Ladson, SC

These rehabilitators, and the veterinarians who work with them, are not funded by the state. Public donations are greatly appreciated.

Who's Walking Whom?

A very wise board certified animal behaviorist once said to me, "Every labrador puppy should come out of the womb wearing a gentle leader."

What I've come to learn is that most breeds (and owners) could benefit from this playfully unorthodox way of thinking.

Gentle Leader 101:

  1. IT's NOT A MUZZLE. Anything your dog can do without a gentle leader (GL), your dog can do with one. Meaning, he can eat, drink, catch a ball, chase a tail... you get the picture. ;)
  2. A GL is a head collar for your dog. In short its a horse halter, doggie style.
  3. Consistent withpositive reinforcement training techniques, the GL offers a "gentle"  approach to gain complete control of potentially rambunctious 4 legged friends. Provided that the head collar is fitted properly (which can be a little tricky) and proper usage techniques are being practiced, the collar can offer immediate relief to frustrated owners of pullers, squirrel chasers, collar escapees, and other dogs that seem to have a mind of their own! :)
  4. As a training tool that promotes the human/animal bond, the GL plays a two-part role in the unique relationships that we share with our 4 legged family members. First role being that it almost immediately offers humans better control of  their dogs, therefor allowing them to enjoy walks with their canine companions. Secondly, the dogs are never punished or encounter abrasive interactions from their humans, therefor making walks that much more exciting and rewarding for them.
  5. Not only is the GL a great training tool, it is also great in giving owners who would otherwise be reluctant to walk their pets the confidence to enjoy walking them comfortably. The GL is great for individuals who suffer from joint ailments like knee or hip replacements, the elderly who are nervous about large dogs pulling them down, and children who may not otherwise have the strength to control an overly excitable puppy.

In short, I think the take home message here  is that....Gentle Leaders are AWESOME!!!

Read more about Gentle Leaders on the Premiere website. We carry this product in our hospital and are happy to help fit your dog's Gentle Leader properly.

About the Contributor: Jen Krack is a Certified Animal Behavior Technologist earning her B.S. in Animal Behavior from Purdue University. She has been a part of the veterinary field for 10 years and is currently a technician at Daniel Island Animal Hospital.

Dental Health for Pets

Why is dental health important?

Like us, your pets need regular dental care to keep their teeth in the best possible condition. The rate and amount of plaque which forms on a pet’s teeth is determined by genetic predisposition even more than diet.  Some breeds and certain individuals are especially prone to early periodontal disease, but all pets develop dental tartar eventually.

Plaque is made of food debris and bacteria, and if not cleaned off in this soft stage, will harden into dental tartar/calculus. The calculus is like cement, holding bacteria against the teeth, leading to an infection of the gums called gingivitis. As gingivitis worsens, it can result in infection of the periodontal ligament, tooth roots, and surrounding bone. Left unchecked, these lead to tooth loss, bone infection and a very painful and potentially debilitating condition for your pet.

Dental home care can significantly reduce the accumulation of dental calculus and may decrease the frequency and/or severity of necessary dental cleanings.  Small breed dogs and Greyhounds are at particular risk for extensive calculus accumulation and home care is especially important for them.

How do I take care of my pets teeth?

There are multiple approaches to providing dental home care. For pets at high risk for dental disease, we recommend that more than one strategy be used.


Finger brushes, pet specific tooth brushes or even children’s soft bristled brushes can be used along with an enzymatic toothpaste. Human toothpastes are not recommended.  Pet’s teeth need to be brushed 1-2 times daily to derive maximum benefit. If they are not brushed at least 3 times per week the pet derives little benefit from brushing.  Using enzymatic toothpaste as a treat and then gradually increasing your pet’s comfort level with having a tooth-brush or your fingers in their mouth can help train them to accept regular brushing. Providing a treat after brushing (such as a chew or their regular meal) can also help reinforce the behavior.

Dental Chews:

In order for a chew to be effective, your pet needs to work on it for at least 5-10 minutes. Although not as effective as brushing it can help to decrease bacteria in the mouth and help clean the teeth.  Hard plastic chew toys should be avoided as they can cause tooth damage. Caution must be used with rawhides and bones as both can lead to intestinal obstructions and other GI problems if not chewed completely.

 T/D Diet:

This is a special diet made by Hills Science Diet pet food company. It can be given as a main diet or as an after-meal treat. The structure of the kibble forms a mesh that helps to clean teeth as it is chewed.

Water Additives:

The product we recommend and carry is called AquaDent.  It has a dilute antibacterial ingredient called xylitol to help decrease the amount of bacteria in the mouth. Many owners report an improvement in their pet’s breath with its use and it can definitely decrease the rate of calculus accumulation, especially in cats. ***Xylitol is extremely toxic to pets when given in large amounts, such as the concentration found in many sugarless chewing gums. However, at the low levels in these products it is reported to be safe for dogs and cats.

October (2010) is Dental Health Month at Daniel Island Animal Hospital. $30 off dental cleanings and 10% off dental products. Call for an appointment - space is limited!