Author: Brittany Kleszynski, DVM

What is Feline Hyperthyroidism?

Brittany Kleszynski, DVM

Middle-aged and geriatric cats are frequently diagnosed with hyperthyroidism. Pet parents often first notice a change in their cats’ behaviors or significant weight loss, which can be clues that this disease may be present. With early detection, necessary treatment can be implemented to prevent secondary complications.

What is it?

Hyperthyroidism occurs when a cat’s thyroid gland produces too much thyroid hormone (T3 or T4). Usually, a benign enlargement of the thyroid gland, commonly referred to as an adenoma, is the cause. Rarely, a malignant thyroid tumor may be present. It is unknown what causes this enlargement to occur.

Thyroid hormone affects many of the organ systems, especially the heart and kidneys. If too much thyroid hormone is secreted, your cat’s metabolic state kicks into overdrive and can cause systemic damage.

What are the clinical signs?

Weight loss despite a ravenous appetite is often the first sign that pet parents notice. Hyperactivity, increased thirst, increased urination, and an unkempt hair coat are also common. When a cat presents to the veterinary hospital, he or she may have an increased heart rate, increased blood pressure, and a palpable enlargement of the thyroid gland. If the thyroid hormone is increased severely, some cats may also have abnormal heart rhythms.

Hyperthyroidism causes increased perfusion of the kidneys (due to the high blood pressure), so kidney disease can also be masked in untreated hyperthyroid cats.

How is it diagnosed?

If your cat’s veterinarian suspects that hyperthyroidism is present based on a thorough physical exam, he or she can formulate a diagnostic plan. Blood may be collected to check overall health. A urinalysis may also be submitted to check for any concurrent illnesses. An abnormally high T4 level is supportive of hyperthyroidism. In rare instances, some hyperthyroid cats have T4 levels within the normal range.

How is it treated?

There are several treatment options that your pet’s veterinarian may recommend, including a diet change, medications, surgery, or radioactive iodine therapy. Sine iodine is essential in producing thyroid hormones, a low-iodine diet may decrease T4 levels. This is usually reserved for very mild cases of hyperthyroidism or in patients where other treatment options are contraindicated. Most often, cats are started on a medication to prevent the thyroid from producing hormones.  Less commonly, surgery to remove the thyroid glands or radioactive iodine treatments to destroy the thyroid gland is used. Your veterinarian can work with you to choose the best course of treatment for your pet.

Are there any complications?

Cats with hyperthyroidism are at risk for heart disease and high blood pressure. If high blood pressure is left untreated, cats can develop retinopathies that may lead to blindness. Treating hyperthyroidism may unmask kidney disease in some patients, which may require additional treatment. With surgery and radioactive iodine therapy, some cats may actually become hypothyroid and require thyroid hormone supplementation. Regular veterinary care, despite the therapy chosen, is needed to ensure cats are well-managed and living happy, healthy lives.

Understanding Feline Diabetes

Brittany Kleszynski, DVM

Diabetes mellitus typically affects overweight, middle-aged to older cats. Unlike their canine counterparts who develop insulin-deficient diabetes, cats develop insulin-resistant diabetes primarily. This means that either an insufficient amount of insulin is being secreted by the pancreas or the body is not using secreted insulin appropriately to maintain normal blood glucose. The result is persistent hyperglycemia (high blood glucose). There may be a couple reasons why this occurs.

In diabetic cats, a type of protein hormone known as amylin is concurrently secreted with insulin. When there is insulin resistance, even more insulin and amylin are secreted. As a result, amyloid plaques can build up within the pancreas and cause significant inflammation which further reduces effective insulin secretion. The resulting inflammation can actually be so severe that the pancreatic beta cells become damaged and cease to secrete insulin altogether. This is quite rare, however. The other phenomenon that is likely occurring includes inability of target tissues within the body to respond appropriately to insulin. These target tissues are usually muscle, liver, and adipose. They use glucose for energy, maintain glucose homeostasis, and ensure appropriate lipid metabolism.

Clinical Signs

Cats tend to be stoic and therefore, many of the clinical signs associated with diabetes may not be obvious. Having to change the litterbox more frequently is one of the first signs that a pet parent notices. This is due to polyuria (frequent urination) that results from the body trying to get rid of the excess glucose in the blood. Naturally, a cat will also develop polydipsia (excessive thirst) to compensate for fluid loss in the urine and to dilute the high glucose concentration within the blood. Polyphagia (increased appetite) may also accompany these signs.

A very obvious sign unique to undiagnosed diabetic cats is something referred to as a plantigrade stance. This is a late manifestation of diabetes where persistently increased blood glucose causes nerve damage in the rear legs. Instead of the cat walking only on the rear paws, the entire bottoms of the back feet will be touching the ground. This neuropathy usually resolves after blood glucose returns to more normal levels.

Diagnosis

Diagnosing diabetes in cats may be more challenging than in dogs. Cats tend to be stressed during their veterinary visits, which results in a mild hyperglycemia in an otherwise healthy patient. For this reason, an essential part of an office visit for a suspected diabetic cat is a fructosamine test. This test provides information as to what the blood glucose levels have been over the past 2-3 weeks rather than at one point in time. An increased fructosamine level with a high blood glucose would confirm diabetes. However, a normal fructosamine level with a mildly increased blood glucose is probably just indicative of a stress response. Your pet’s veterinarian will be able to further explain these tests and their significance related to your cat.

Although a urine sample is important in the diagnosis of diabetes, it can be quite difficult to obtain these samples from cats. Cats usually need to have urine collected via cystocentesis, which is a minimally invasive procedure where a small needle is inserted through the abdomen directly into the bladder. Abnormalities within the urine such as glucose, white blood cells, bacteria, and protein can be detected using a microscope. Cats have a high renal threshold for glucose, which means it takes more glucose in the blood for it to spill over into the urine. With mild hyperglycemia or early diabetes, glucose may not yet be present in the urine. Many diabetic patients that have glucose in the urine are at increased risk of developing urinary tract infections. Your pet’s veterinarian may recommend a urine culture if test results are not obvious.

In diabetic cats, it is common to see hypercholesterolemia (high cholesterol) and hypertriglyceridemia (high blood triglycerides). With chronic undiagnosed diabetes, kidney and heart diseases can also develop.

Management

Although the majority of cats will require daily subcutaneous insulin injections, some cats can be managed with weight loss and a diet change. A high-protein, low-carbohydrate diet can help diabetic cats maintain better control of their blood glucose. With time, some cats may actually return to a non-diabetic state. There are certain diets specifically formulated for diabetic cats with the proper carbohydrate and protein ratios. Using a wet food formulation can also provide an extra source of hydration for diabetic cats and increase palatability. Your pet’s veterinarian can recommend the best diet to meet your cat’s individual needs.

When a cat is initially diagnosed, they may need to visit a veterinarian every few weeks until the diabetes is well-regulated. Bloodwork and urinalysis at regular intervals thereafter are needed while managing this chronic disease.

Complications

Because glucose regulation is important for normal physiology, diabetes can result in damage to many bodily systems, including the heart and kidneys. As mentioned above, it is very common to see hypertension in diabetic patients as well as protein loss through the kidneys. Other complications include nerve damage, damage to the eyes, and other infections.

Lastly, diabetic ketoacidosis is a severe complication that occurs in an energy-starved state when fats are broken down for energy instead of glucose in the absence of insulin. When kidneys do not filter these ketones out, they build up within the bloodstream and cause an acidic state. This metabolic disturbance is a medical emergency and requires overnight hospitalization with appropriate fluid therapy and electrolyte monitoring.

Prognosis

With the proper diet change and weight loss, some cats can revert back to a non-diabetic state. However, recurrence of diabetes can occur in these patients. Diabetes care requires a life-long commitment and regular veterinary checkups to aid in glucose regulation and promote the best quality of life for the affected cat. It is also important to note that diabetes can increase the chance of secondary complications and risk of developing infections over time.

Leptospirosis in Dogs & Zoonotic Risks

Brittany Kleszynski, DVM

Leptospirosis is a zoonotic disease, which means it can transfer from animals to people and may cause similar sickness in both species.

What is it?

Leptospirosis is an infection caused by a type of spirochete bacteria. Dogs most commonly contract this disease by coming into contact with infected urine of other dogs and wildlife. It may be transmitted by contaminated surfaces in the environment as well. The spirochetes cause infection by penetrating mucus membranes or damaged skin and then spreading to tissues via the bloodstream. They replicate rapidly within many different organ systems, and the body works to clear the infection via antibody production. However, even when antibodies are present, the spirochetes can persist and replicate within the kidneys for several years, remaining infectious when eliminated in the urine.

What are the clinical signs?

Infected dogs often have fevers early in the disease process. Other clinical signs may include muscle pain, lack of appetite, vomiting, uveitis (eye inflammation), hematuria (blood-tinged urine), fever, increased thirst and urination, or petechia (small skin hemorrhages). In advanced stages, outward signs of liver and kidney disease may be seen, including the presence of icterus (yellowing of the mucus membranes and sclera) and poor perfusion or inflammation of the blood vessels.

How is it diagnosed?

When leptospirosis is suspected, dogs should be placed in isolation to avoid the spread of disease while a diagnosis is confirmed. Your veterinarian will likely check bloodwork and a urine sample for signs of infection. There may be increased kidney and liver values, changes in white blood cell counts, and low platelets depending on the stage of disease. A SNAP test or serum titers can be performed to check for exposure to and antibodies against leptospirosis, respectively. Performing PCR on the urine can detect an active infection and is most useful in diagnosis.

How is it treated?

Antibiotics can be administered to eliminate the acute and carrier phases of infection. In some cases, infected dogs may need to be hospitalized on fluid therapy to help flush the kidneys and to replenish any fluid losses that may have occurred through increased urination or vomiting. Affected dogs will need to be isolated until the infection has fully cleared.

Is it preventable?

Vaccinations can be given annually to protect at-risk dogs. In addition, reducing exposure to puddles or other areas where wildlife urine may be present can help prevent this infection.

Ocular Issues in Dogs

Brittany Kleszynski, DVM

We will discuss several common eye conditions in dogs, including allergies, infection, and corneal ulcers.

Allergies can result in clear, serous discharge from the eyes and mild redness on the sclera (the white part of the eye). Usually these signs are seen bilaterally. A dog may paw at his or her eyes frequently to itch them, similar to how we itch our eyes when dealing with environmental allergies. Unfortunately, allergies are difficult to cure since it is hard to pinpoint exactly what the culprit is within the environment. However, there are medications that your pet’s veterinarian may prescribe to provide some relief.

An eye infection is usually bacterial in nature and will cause green-yellow discharge from the affected eye. This clinical sign is referred to as conjunctivitis. Infections can arise from close contact with another pet, a foreign object within the eye, or immunosuppression. It is common to see redness and squinting in some cases as well as frequent pawing.

Corneal ulcers are the most severe of these issues, and they can result in extensive damage to the eye if not treated promptly. Sometimes a foreign object can penetrate the corneal epithelium and expose the underlying tissue layer. These can also develop from scratches on the cornea that continue to worsen. The eye can be stained with an eye-safe fluorescent dye to check for scratches and ulcers. Your veterinarian may prescribe topical and oral medications if an ulcer is diagnosed. If left untreated, the eye can worsen and may require surgery.

If you are concerned about an eye problem in your dog, it is best to schedule a visit to see your veterinarian. He or she can perform testing and determine an appropriate treatment to help your pup feel better!

Why are Wellness Exams Important?

Brittany Kleszynski, DVM

Wellness exams every 6 months to one year can help your pet stay healthy. At these visits, thorough physical exams are performed and any concerns can be addressed. During the physical exam, your pet’s eyes, ears, nose, mouth and teeth, lymph nodes, skin and coat, heart, lungs, abdomen, joints, and temperature are checked. A thorough exam allows your pet’s veterinarian to catch any abnormalities that may have developed and inform you of the findings. Based upon these findings, diagnostic testing may be recommended.

Bloodwork can provide a great deal of vital information about the health of your pet. There are two large blood panels that are commonly performed during a wellness visit if deemed appropriate. They are a Complete Blood Count (CBC) and a serum chemistry.

A CBC provides information on your pet’s cell counts, including red blood cells, white blood cells, and platelets. This test detects signs of infection, anemia, low platelets, dehydration, stress, and blood parasites, just to name a few. A serum chemistry panel provides a look at internal organ function, including kidneys and liver. This test can also provide clues as to whether or not certain metabolic or endocrine diseases may be present.

Heartworm antigen tests are also a common component of wellness visits. Heartworm disease is a preventable disease and identified with a few drops of blood. This test is done yearly but may be recommended more frequently if your veterinarian deems it appropriate. Year-round heartworm prevention is important in both cats and dogs.

Urinalysis may also be performed at a wellness visit, especially for geriatric patients. Urinary crystals, urinary tract infections, and signs of endocrine or kidney dysfunction can be identified.

A wellness exam provides a wealth of information and establishes a relationship between you, your pet, and the veterinarian. Because pets cannot speak and tell us something is wrong, wellness and preventative care is essential to catch any abnormalities early on and help pets live long, healthy lives.

What is Feline Respiratory Disease Complex?

Brittany Kleszynski, DVM

Feline Respiratory Disease Complex is very common among cats, particularly those that are immunocompromised or unvaccinated. This disease is highly contagious and can spread rapidly in shelter environments or in multi-cat households. Although it is typically self-limiting, disease progression can occur and lead to pneumonia in some cases.

What is it?

Feline Respiratory Disease Complex refers to several viruses and bacteria that cause upper respiratory infections. These include herpesvirus, calicivirus, mycoplasma, chlamydophila, and bordetella. Although the majority of feline upper respiratory infections are caused by viruses, secondary bacterial infections commonly worsen clinical signs. The disease is spread via droplets in the air or close contact with contagious cats.

What are the clinical signs?

The most common clinical signs include sneezing, coughing, nasal discharge, and conjunctivitis.  Eye discharge can range from serous to thick in consistency. Thicker, white discharge usually indicates a bacterial cause, whereas serous discharge is more common with viruses. In some cases, mouth lesions are seen depending on the causative agent. If the disease is chronic or has progressed to pneumonia, respiratory changes and a fever may be present.

How is it diagnosed?

Usually the disease is diagnosed based on clinical signs consistent with an upper respiratory infection. However, virus isolation and bacterial culture may be done to determine the exact cause to better target treatment in non-resolving cases.

How is it treated?

Treatment depends on severity of disease. Even if a viral agent is suspected, antibiotics to protect against secondary bacterial infections are often prescribed. Eye ointment or artificial tears may also be given by your pet’s veterinarian. In severe or chronic cases, cats may need to have subcutaneous fluids administered to counteract dehydration. It may take up to two weeks for clinical signs to fully resolve. Your pet’s veterinarian can provide the most appropriate treatment recommendations.

Cats infected with herpesvirus and calicivirus will have latent lifelong infections. If the cat becomes immunocompromised or stressed, they may begin shedding the virus and become contagious to other cats. They may also have recurrence of clinical signs throughout their lives during times of stress.

Is it preventable?

A core vaccine for cats called FVRCP is the best protection against upper respiratory disease. FVRCP protects against Feline Viral Rhinotracheitis, Calicivirus, and Panleukopenia. Feline Viral Rhinotracheitis is actually caused by herpesvirus as mentioned above. Although cats who have received this vaccine are still susceptible to infection, the risk is greatly minimized. If a cat who has been previously vaccinated comes into contact with these causative agents, the respiratory infection is not nearly as severe and does not last as long compared to unvaccinated cats.

Understanding Diabetes Mellitus in Dogs

Brittany Kleszynski, DVM

Diabetes mellitus is a disease that most commonly affects middle-aged dogs. It occurs when the pancreas does not produce the insulin that is needed to regulate blood glucose levels. Therefore, a dog’s blood glucose will be persistently high, which increases the risk for additional complications. Although the exact mechanism of this disease is not known, it is thought to be an inappropriate attack on the pancreas by the patient’s own immune system. Thus, it is referred to as an autoimmune disease.

Clinical Signs

The most common clinical signs include increased thirst, excessive urination, and weight loss despite an increased appetite. Pet parents may notice they are refilling the water bowl more frequently or that their dogs need to be let outside more often.

Diagnosis

Your pet’s veterinarian will first obtain a thorough patient history. If diabetes is a likely diagnosis, blood and urine samples will be collected to check for evidence of increased glucose levels.

Management

Diabetes management consists of daily insulin injections. These injections are given with a meal in order to reduce the risk of an episode of low blood glucose. Typically dosing occurs twice daily, but the dosage and frequency will vary based on individual needs. Your pet’s veterinarian can provide guidance on injection techniques as well as how to check blood glucose at home if necessary. A specially formulated high fiber diet may also be prescribed to help regulate glucose.

Complications

Persistently increased blood glucose levels can have negative effects on many body systems, including the kidneys, heart, and eyes. It is not uncommon to see diabetic dogs experience hypertension that may need additional management. Most diabetic dogs will also develop cataracts, which can lead to blindness.

Prognosis

Proper insulin dosing at home coupled with regular veterinary checkups can help manage diabetes and prevent additional complications. It is important to know that it may take several months after initiating treatment for a dog’s glucose to become regulated. Your veterinarian will determine an appropriate type of insulin and dosing schedule to meet the individual needs of the patient. Managing diabetes requires strong vigilance by the pet parent, but most dogs can go on to live long, happy lives with appropriate treatment and monitoring.

Acute Canine Pancreatitis

Brittany Kleszynski, DVM
What is it?

Pancreatitis is inflammation of the pancreas resulting from overstimulation. Onset generally occurs after ingesting large quantities of food high in fat and carbohydrates. One function of the pancreas is to secrete digestive enzymes that aid in breaking down food. When a dog is fed table scraps or high-fat treats, the pancreas becomes overstimulated and releases excessive amounts of these enzymes. Because there are so many extra enzymes released, they begin digesting the pancreas itself. This causes intense inflammation and major discomfort within the affected dog.

What are the clinical signs?

Signs of pancreatitis may include sensitivity in the upper abdomen, lethargy, diarrhea, vomiting, and lack of appetite. Some dogs may appear anxious due to discomfort.

How is it diagnosed?

Your veterinarian will perform a physical examination and take a brief history. A sample of your dog’s blood may be collected to run a test which looks for levels of enzymes above the normal range.

How is it treated?

Pancreatitis may require hospitalization in an intensive care hospital. Continuous intravenous fluids to replace fluid loss from vomiting and to help increase perfusion to the pancreas may be necessary. Special diets may be given as well as medications for pain and nausea during hospitalization.

What is the prognosis?

With early intervention and supportive care, the prognosis is generally good. However, without treatment, pancreatitis may worsen.

Mammary Tumors in Pets

Brittany Kleszynski, DVM

In honor of breast cancer awareness month, I thought it would be great to provide a little information on mammary tumors in dogs and cats! First, what is a mammary tumor? Dogs and cats have glandular tissue surrounding each teat that extends from the underside of the thorax to the abdomen. The cells in this mammary tissue can undergo mutations and become abnormal as a pet gets older. Most commonly this is due to stimulation by the hormone progesterone in an intact female. Spaying a dog or cat at an early age (between 4-6 months) reduces the risk that she will develop mammary cancer later in life.

It is important to note that mammary tumors in dogs and cats behave very differently.  In dogs, if a mammary tumor is diagnosed, around 50% will be benign and around 50% will be malignant. Of those that are malignant, roughly half will spread to other parts of the body. On the other hand, out of the cats who develop mammary tumors, around 80% will be malignant.

These masses often go unnoticed by the pet parent due to their location and size, which is why most mammary masses are diagnosed at a veterinary visit during a physical exam. A sample of the mass can be taken using a needle and examined underneath the microscope. This is an inexpensive and convenient way to start ruling in or out potential causes of the mass.

If abnormal cells are seen, further testing can be done to confirm a diagnosis. If cancer is suspected, it is important to determine whether or not it has spread using additional diagnostics. These can include full bloodwork, thoracic radiographs, and sampling nearby lymph nodes. In animals where the cancer is localized to the mammary tissue, surgical removal is the preferred method of treatment with potential follow up with radiation or chemotherapy. If the cancer has spread, chemotherapy and radiation therapy are generally considered. If surgery is performed, a sample of the tissue, known as a biopsy, can be sent for complete analysis and identification. Pathology reports will provide more specific information about the tumor type, behavior, and the best treatment recommendations.

Overall, prognosis tends to be better for pets with masses less than 3 centimeters in size. If the cancer has already spread by the time of diagnosis, the survival time is further limited.

Common Causes of Skin Allergies in Pets

Brittany Kleszynski, DVM

Below are three of the most common causes of allergic skin disease in pets.

Fleas

The most common pet allergy is caused by fleas. Fleas are parasites that feed on a pet, and their saliva can trigger an allergic reaction, resulting in hair loss, redness, and intense itching. Hairless regions near the base of the tail are commonly seen in dogs and cats. Cats will sometimes experience hair loss around their chins as well. If your veterinarian suspects a flea allergy, he or she will check for evidence of live fleas and flea dirt. Your veterinarian will be able to make recommendations as far as an effective topical or oral flea preventative product as well as ways to rid the environment of fleas and their larvae. It can unfortunately take several months to resolve a flea infestation.

Environment

Another allergy we commonly see in pets is environmental. This is medically referred to as atopic dermatitis. Something in the environment, whether it is grass, pollen, dust, etc, causes a pet to become itchy after multiple exposures. Hairless regions or redness on the paws and inguinal regions are most common since these are the areas allergens touch when a pet is walking or laying down. These allergies can be a little more difficult to conquer. If further testing beyond a primary care veterinarian is necessary, a dermatologist can perform additional allergen testing and make treatment recommendations.

Food

Some pets also develop food allergies after being on the same diet over time. These allergies develop as the body becomes sensitized from repeat exposure to a certain ingredient within the food. Typically the allergic component is the protein. Resolving a food allergy involves strict diet trials over several months. Recurrent ear infections can also be suggestive of possible underlying food allergies.

As always, if you notice changes to your pet’s skin or coat, it is best to schedule a veterinary visit to get to the bottom of it!

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