Crossroads Veterinary Services (706) 743-7614 or (706) 224-3200

Small animal internal medicine involves evaluating the major organ systems for signs of dysfunction, performing diagnostics and pursuing various therapeutic options depending on the system affected. There are multiple components of internal medicine; the following is a small list of the major systems affected.

Cardiology

The heart is a four chambered muscle. Its function is to pump blood to all the organs and cells of the body, thus providing them with nutrients and oxygen, and removing waste. The heart itself needs nutrients and oxygen. One nutrient in particular, taurine is crucial. If it is missing, the heart will undergo irreversible changes that impede its function and eventually result in failure. Taurine is an essential amino acid in cats and is present in all commercial cat foods. Home made diets that do not have added vitamins for cats may not contain taurine and may put your cat at risk for developing heart disease. Feeding your cat a high quality food can help prevent this from happening.

Cardiac disease is often heralded by a heart murmur. This most often occurs when one or more of the heart valves is not working well, creating turbulent blood flow. Your veterinarian can diagnose this during a physical examination and make recommendations for further diagnostics. Usually, the first step is to take x-rays of the chest to determine if the heart is already larger than normal.Most of the time, an ultrasound of the heart is recommended. This enables a cardiologist to determine which valve, if any, is at fault, and what changes the heart has undergone to make up for the lack of efficiency the valve has caused. Depending on the results, medication may be prescribed to help the heart function better, and halt or slow down further structural changes. A heart murmur can appear in the healthiest of animals, sometimes in just a few days time. Regular check ups are crucial in catching a cardiac disease early in order to treat optimally.

Hyperthyroidism in Cats

Hyperthyroidism is a disease of older cats, caused by excessive production of thyroid hormones. The usual cause for increased hormone production is a tumor of the thyroid gland. These tumors may be benign or malignant. The reason these glands develop tumors is not yet known. Signs of excessive thyroid production include weight loss despite a ravenous appetite, frequent bowel movements, increased thirst and urination, restlessness, hyperactivity, frequent crying or vocalizing, neglect of normal grooming, a rapid heart beat, abnormal heart rhythm, or a heart murmur. The effects on the heart may be severe and result in congestive heart failure. Other symptoms can include vomiting or diarrhea.

In most cats, a blood test measuring the thyroid hormone level may be all that is needed to diagnose the condition. In some cats with a normal hormone level, but who clinically appear hyperthyroid, further testing may be indicated to confirm the condition. To properly stage the disease, your cat should get a complete examination, including different blood tests and x-rays. This is to ensure an overall healthy pet, enables early diagnosis of concurrent illnesses (many hyperthyroid cats also have kidney disease) and to be sure that the tumor has not already spread to the chest or other internal organs.  

Three major therapies are available to your cat if diagnosed with hyperthyroidism:

1.  Medical management: this is accomplished through treatment with an anti-thyroid drug such as methimazole. The side effects this drug can have are as follows: poor appetite, vomiting, scratching at the face and neck, liver toxicities, bone marrow suppression resulting in low platelet or white cell counts, or anemia.

2.  Surgery: this involves anesthesia and removal of the offending gland. This can be difficult in an older animal, especially if other medical problems are present that make anesthesia even more risky. However, once the surgery is completed, and as long as the tumor doesn't recur or occur on the other side, the condition is cured.

3.  Radioactive iodine treatment: this procedure must be done in a radioactive safe facility, usually a referral hospital. Radioactive iodine, in a quantity safe to the body, is administered to the patient. The thyroid, whose role it is to regulate iodine metabolism, "gathers" the radioactive iodine. The amount of radiation now concentrated in the thyroid, is enough to kill off the cancerous tissue. No anesthesia or surgery or potentially harmful drugs are necessary. The major drawback of this procedure is its cost. 

Kidney Disease

Dogs and cats can get both acute (sudden) and chronic kidney disease. Acute kidney failure usually occurs due to severe dehydration (such as secondary to vomiting and diarrhea), poisoning (such as in anti-freeze), and bacterial infection (such as with leptospirosis in dogs).

Chronic disease: the typical presentation of a cat with chronic kidney disease is that of an older cat, who has progressively started eating less or is more finicky, is losing weight, and appears to be drinking and urinating more than usual. Some cats don't have any signs at all, until their bodies crash and they get extremely sick.  Dogs can also be affected by kidney disease, with similar signs. The process at work is slow deterioration of the kidneys. The kidneys clear out the poisons (nitrogenous waste) that the cells of the body make as they metabolize the nutrients we ingest in our diet. A cat and dog, as obligate carnivores, need more protein, and so produce more waste. These waste products if not removed from the body, will make an animal nauseous, vomit, anorexic, or all of the above. Your veterinarian can diagnose this disease with help of blood tests and a urinalysis. Luckily, we are all born with about 75% more functional units in our kidneys than we actually need. This means that the kidneys can be deteriorating for some time before signs start to appear. Regular geriatric screenings of kidney function will allow your veterinarian to keep track of a progressing kidney condition, and try to slow the process down. This is the most important part, because the functional units of the kidneys do not regenerate: once they are gone, they are lost forever.

Thanks to diet changes and the help of some medications, disease progression can be slowed down significantly. However, once past the critical point, an IV catheter may be necessary to administer fluids to help the kidneys flush out the waste. At this point, the prognosis for long term recovery depends on how well the kidneys respond to the fluids. After removal of the IV catheter, owners often are taught how to give fluids under the skin, in order to continue “flushing” the by products of protein metabolism. Your veterinarian can also do this for you if you wish.

Kidney disease in cats often occurs with hyperthyroidism. The hyperthyroid condition promotes a greater blood flow to the kidneys, which helps them function more optimally despite their deterioration. Owners will often find that treating the thyroid condition results in renal (kidney) failure. Treatment at this point becomes a balancing act, aided by blood tests to monitor the progression of both diseases.

Yet another problem that often happens to patients with renal disease, is that a normal kidney make hormones that help regulate blood pressure. Without properly functioning kidneys, the hormones are no longer made in the proper amount and the blood pressure starts to rise. If it gets high enough, it can cause the retina in the eye to detach, thereby causing blindness. Your veterinarian can monitor your cat's blood pressure and prescribe anti-tensive drugs to help prevent the blindness.   With close monitoring, through physical exams, blood work, diet changes, and medication, your cat can live longer and happier, despite an irreversible condition. Let your veterinarian help you help your pet!!!

Constipated Cats

This problem can occur more easily in older cats than many people realize. As cats get older, they often get more finicky and so won't always eat what's best for them. As obligate carnivores, their diet is lower in fiber than that of most other animals. Finally, as an animal ages, it becomes stiffer and arthritic, less likely to go looking for water it may need and want, because of the soreness. These are all predisposing factors to a cat getting constipated. Once the problem is present, your veterinarian will most likely have to help your cat get rehydrated through the use of fluids, usually subcutaneously. The administration of one or more enemas will be necessary. In the most obstipated of cases, your veterinarian may need to anesthetize your cat in order to manually remove the hardened feces. The signs a cat will present with can be any combination of straining, frequent visits to the litter box, decreased stool production in the litter box, crying in the litter box, vomiting, decreased or lack of appetite.

Diabetes Mellitus

What is Diabetes Mellitus?

Diabetes mellitus is the correct term used to describe the medical condition that is commonly known as "sugar diabetes". "Diabetes" is a general term used to refer to a variety of disorders characterized by increased urine production (or polyuria) and increased water intake (or polydipsia). Diabetes mellitus is a complex metabolic disorder of carbohydrate, fat, and protein metabolism caused by a deficiency of the hormone, insulin. The pancreas is a small but vital organ that is located near the stomach. It consists of several types of cells. One group of cells called acinar cells produce the enzymes necessary for proper digestion. Another group, called beta-cells, produce insulin. Simply put, diabetes mellitus is a failure of the pancreas to regulate blood sugar.There are essentially two forms of diabetes mellitus. Both types are similar in that there is a failure to regulate blood sugar, but the basic mechanisms of disease differ somewhat between the two groups:

• Type I, or Insulin Dependent Diabetes Mellitus

• Type II, or Non-Insulin Dependent Diabetes Mellitus

·         in this form the beta-cells are present but the amount of insulin they produce is reduced or there is a delayed response in secreting it, or the muscle, fat and other tissues become "resistant" to insulin's effect ·         this form is only rarely diagnosed in dogs and cats ·         up to 40% of cats with Type II diabetes mellitus will regain the ability to control their blood glucose level and require no further treatment but this may take months to years, during which period treatment is required

Why is insulin so important?

Insulin is required by muscles, fat tissue and the liver to utilize the carbohydrates, proteins and fats ingested in the diet. The role of insulin is much like that of a gatekeeper: it stands at the surface of body cells and opens the door, allowing glucose to leave the blood stream and pass inside the cells. Glucose is a vital substance that provides much of the energy needed for life, and it must work inside the cells. Without an adequate amount of insulin, glucose is unable to get into the cells and it accumulates in the blood, leading to high blood sugar or hyperglycaemia. When insulin is deficient, the cells become starved for a source of energy. In response to this, the body starts to breakdown stores of fat and protein to use as alternative energy sources. This leads to a series of metabolic changes that result in the signs of diabetes mellitus developing.

How common is Diabetes Mellitus?

Diabetes mellitus is a relatively common disorder and is diagnosed in approximately 1 in every 400 to 500 dogs and cats.

Is my pet at risk of developing Diabetes Mellitus?

It is known that certain breeds of dogs have a higher risk of developing diabetes mellitus than others. These include the Poodle, Dachshund, Miniature Schnauzer, Beagle, King Charles Cavalier Spaniel, Scottish Terrier, Miniature Pinscher and Cairn Terrier. Diabetes mellitus in the Keeshond is an inherited condition ie. is passed from one generation to the next. No apparent breed predilections have been noted in cats. Female dogs are diagnosed with diabetes mellitus twice as much as male dogs. Male cats (particularly desexed) are more likely to develop the disorder than female cats. The average age of dogs that develop diabetes mellitus is 8 years. It is rare for dogs under 6 months of age to become diabetic. 75% of cats that are diagnosed with diabetes mellitus are 8 to 13 years of age. Overweight dogs and cats have a higher risk of suffering from diabetes mellitus.

What causes Diabetes Mellitus?

The exact cause of diabetes mellitus may not be determined in every case and there are still causes of diabetes mellitus that are unknown. Some of the causes are thought to be:

1. Genetic susceptibility
2. Infectious diseases
3. Immune-mediated disease
4. Pancreatitis
5. Predisposing diseases
6. Drugs
7. Obesity
8. Cancer of the pancreas

1. Increased drinking (polydipsia)
2. Increased urination (polyuria)
3. Increased appetite (polyphagia)
4. Weight loss

1. Anorexia
2. Lethargy and depression
3. Vomiting and/or diarrhoea
4. Muscle wastage along the back in cats
5. Oily coat with dandruff in cats
6. Sudden onset of cataracts
7. Blindness secondary to degeneration of the retina in the eye
8. Coma and death
9. Unusual hind limb gait
   1. is seen only in cats
   2. affected cats walk with their hocks (or ankles) touching the ground

Anorexia, lethargy, depression, vomiting, diarrhea and coma are all indications of a life-threatening form of diabetes mellitus called ketoacidosis. Ketoacidosis occurs in those diabetic animals that are not treated soon enough or correctly. It represents a very serious disruption to the animal's metabolism and will most likely result in the animal's death if left untreated.

Why does my diabetic pet drink and urinate so much?

Blood is made up of two components. These are:                                                                                         

• Cellular component o       
  • contains such cells as red blood cells and white blood cells                                                                                          
• Fluid component o       
  •  is called plasma o       
  • contains a large amount of dissolved chemicals and nutrients

The kidneys act as one of the blood's filter systems. Blood passes through the kidneys and is separated into its cellular and fluid components. Waste materials and toxins are removed from the blood by the kidneys and excreted from the body in the urine. Along with these wastes and toxins, nutrients such as glucose also pass into the urine. In a normal animal, the kidney reabsorbs all of these useful nutrients so they can be utilised by the body. In diabetic animals excessive amounts of glucose pass into the urine. This excessive amount overwhelms the kidneys' ability to reabsorb the glucose. The glucose in the urine attracts more water from the fluid component of the blood into the urine via a process called osmosis. As a result an increased amount of urine is produced. To avoid dehydration from the excessive urine production the animal must drink increasing amounts of water.

Why is my diabetic pet always hungry but has lost weight?

The liver, fat tissue and muscle of the body rely on insulin to allow glucose to pass from the blood stream into the cells so the glucose can be used for energy. Without the glucose the cells essentially "starve". This results in weight loss. As a response to this, the part of the brain known as the "feeding centre" is stimulated to increase the amount of food consumed. In addition to this, the part of the brain called the "satiety centre" is switched off. The "satiety centre" is responsible for creating the sensation of having eaten enough after a meal. This sensation is caused by an increase in the blood sugar after a meal resulting in more glucose passing into the "satiety centre" and switching it on. The passage of the glucose is controlled by insulin. Because diabetic animals have no insulin the glucose is unable to pass into the "satiety centre" and thus it is not switched on and the animal will continue to eat.

How is Diabetes Mellitus diagnosed?

Diabetes mellitus is diagnosed on the basis of:

1. The animal's symptoms
2. An abnormally high blood glucose measurement

Diabetes mellitus is not the only cause of an elevated blood glucose measurement. Stress, particularly in cats, is a common cause of an increased blood glucose level. This increase does not persist but in certain cases it may be difficult to distinguish if the high blood glucose level is due to diabetes mellitus or to stress. An analysis of the animal's urine may be performed. Diabetic animals will consistently have large amounts of glucose in their urine. Alternatively, a blood test to determine the level of a protein called fructosamine can give an indication of the animal's blood glucose level for the previous 3 weeks. Diabetic animals have an increased fructosamine level while those animals with an elevated blood glucose level due to stress have a normal fructosamine level.Because diabetes mellitus is such a complex disease there are often other metabolic abnormalities or diseases occurring in conjunction with an elevated blood glucose level. These include various degrees of liver dysfunction, dehydration, inflammation, electrolyte abnormalities and urinary tract infections. As a consequence of this, it is often necessary to perform more extensive blood tests to assess the animal's overall health before the correct treatment can be given.  

How is Diabetes Mellitus treated?

Before deciding to treat their diabetic pet an owner MUST consider two important factors:

1. Personal commitment

• diabetes mellitus CANNOT be cured and as such the animal will require DAILY medication for the REMAINDER OF ITS LIFE
• the aim of treatment is to manage the diabetes mellitus so that the animal is as close to normal as possible

1. Financial commitment

• the cost of treating a diabetic dog or cat can vary depending on how sick the animal is when it is diagnosed with diabetes mellitus
• once the animal is stabilized the costs are relatively constant
• the initial treatment costs and the cost of ongoing treatment will be explained to you to allow you to make a decision on whether you want to treat your diabetic pet or not

• Intensive Care Treatment

• Diet

1. These diets reduce the risk of the animal becoming obese

• overweight diabetic animals are more difficult to stabilize and control their diabetes as they require more insulin and they can develop resistance to the insulin’s effects

1. These diets take a longer time to be digested

• this means that the glucose in the food is more slowly absorbed from the intestine into the blood stream
• the result of this is that there is not a sudden surge in the blood glucose level after eating and thus the animal does not have to process a large amount of glucose at one time
• this makes controlling diabetes mellitus easier

Soft, moist foods (ie. canned foods) tend to be low in fiber, high in fat and contain low amounts of complex carbohydrates and for these reasons should be avoidedThe problem with diets that are high in fiber, low in fat and high in complex carbohydrates is that they are often not very palatable and animals will not eat them! The aim is to feed them a consistent diet that they will reliably eat. Obese animals should be fed a diet that will result in gradual weight loss over 2-3 months. All diabetic animals should be regularly weighed.Diabetic animals should be fed the same amount of food each day. It is best to weigh out or measure the food each day rather than guessing the amount. This ensures the animal eats the same amount of glucose each day allowing for more accurate control of the diabetes.The timing of feeding is also very important. It is best to feed animals with diabetes mellitus twice daily. The animal should be fed 1/2 its daily food intake in the morning (preferably at the about the same time each day) and the other 1/2 some 8-10 hours later. Treats and scavenging of food should be avoided.

Activity

Diabetic animals should receive a similar amount of exercise each day. Variations in the amount of exercise will alter the animal's energy requirement. This in turn will vary the glucose requirement and affect the control of the diabetes.

Insulin

The administration of insulin is the most important aspect of controlling diabetes mellitus. A diabetic animal will require insulin injections every day for the rest of its life - this means you will have to give them! Most animals require only one injection of insulin per day though occasionally two may be needed. Your Veterinarian will determine this.Once your pet has been diagnosed with diabetes mellitus, the attending veterinarian will inject your pet with a certain amount of insulin and then take several blood glucose measurements during the day. These measurements give the veterinarian an indication of what effect the dose of insulin has had and whether the dose needs to be increased or decreased. Once the dose has been determined then you will be shown how to administer the insulin and your pet will be sent home. In the initial stages of treatment you will need to bring your pet into the hospital fairly regularly to have the blood glucose measurements taken. The veterinarian will determine the frequency of these visits. As the diabetes becomes stabilized, these visits will become less frequent and ultimately may only have to be performed every 4-6 months.

How are diabetic animals monitored?

It is important to closely monitor diabetic animals to ensure their diabetes is under control. There are several ways this is achieved.

1. Home Monitoring

• owners of diabetic animals should be constantly aware of their pet's appetite, weight, water consumption and urine output. Changes in water consumption are a good indicator that re-testing is needed
• diabetic animals should be weighed at least each month and it is best to use the same scales each time
• normal animals and stabilised diabetics should drink between 50 to 100mls of water per kilogram of body weight per 24 hours (eg. a 20 kg dog should normally drink 1 to 2 litres of water per day)

1. Blood Glucose Measurements

• the most accurate way of determining if the diabetes is under control is to measure the animal's blood glucose level throughout the day
• as already mentioned, once the diabetes is controlled this should only need to be performed every 4-6 months

What does blood glucose monitoring involve?

The aims of the blood glucose measurements are:

1. To determine the highest blood glucose level

• this is usually in the morning just before the insulin injection is given

1. To determine the lowest blood glucose level

• this is usually 6-8 hours after the insulin injection is given
• the aim is to have the blood glucose level drop to between 5 and 10 mmol/L

1. To determine the duration of action of the insulin ie. how long does the insulin work for?

How long will my pet live with Diabetes Mellitus?

With proper treatment and commitment most diabetic animals can lead a normal life and live to their normal life expectancy. Once stabilization has begun you should see a reduction in your pet's water intake and urine production within a few days. After a few weeks your pet's appetite should return to normal and their weight should begin to normalize.

Does hypoglycemia occur in cats and dogs?

Hypoglycemia is the correct name for low blood sugar. Hypoglycemia occurs in diabetic animals for 2 reasons:

1. The insulin dose is too high

• although most animals require the same dose of insulin for long periods of time, it is possible for their insulin requirements to change
• the most common cause for this change is a reduction in food intake and an increase in exercise or activity

2. Too much insulin is given

• this occurs if the amount drawn out was incorrect or two family members give the animal the insulin without realising that the other person already has