PetMeds^® Blog

While many feline guardians are familiar with the viruses Feline Leukemia Virus (known as FeLV) and Feline Immune Deficiency Virus (known as FIV or Feline AIDS), a very elusive, yet fairly common virus known as Feline Infectious Peritonitis (FIP) can also dramatically affect the health of infected cats leading to serious illness and often death.

Unlike the more common FeLV and FIV infections where testing is fairly straightforward, with FIP there still remains a lack of definitive diagnostic tests in detecting this infection, despite years of research. While many cats with what is called the “wet form,” will often present abdominal fluid/distention or chest fluid and difficulty breathing which has a characteristic straw-colored appearance and can be tested for by most laboratories for virulent FIP virus to confirm the diagnosis.  However, with the other common form known as the “dry form” of FIP, diagnosis is much more difficult.

Symptoms of the dry form of FIP are very general and nonspecific and can include just about any chronic sign of illness, especially general symptoms of weight loss, fever and inappetence. The fever is not typically responsive to antibiotics, given the viral cause. If the digestive tract is affected, thickened bowel loops as well as periodic or chronic vomiting or diarrhea can occur, as well as localized symptoms of the nervous system and eyes. FIP is a type of virus known as a corona virus in cats, of which there are many types, most of them often not causing any illness or disease.

Despite decades of research, the blood testing for antibodies to the corona virus FIP is not specific for the dangerous variant of this corona virus, and many tests can show up as false positives or negatives. The only way of definitively diagnosing this disease (when no fluid is present in the chest or abdomen) is for a biopsy to be completed of the affected tissues. There is also recent thinking that the many types of corona viruses that cats may carry may change or mutate into the more virulent disease causing FIP to form when under certain conditions of emotional or physical stress. It is believed to also form following simple surgical procedures like spaying or neutering, and in situations of crowding, giving shots or vaccinations and poor nutrition. The disease is highest in pure breed cats, although any breed can be affected.

The active disease seems to be most common in cats under one year of age, although there is also a spike in incidence in older cats, whose immune systems are more delicate.  Many cats can be hidden carriers of all sorts of corona viruses, including the FIP strain. However, there is no way of predicting which cats will become clinically affected in the future.  Treatments to date have yielded very poor results. Vaccination developed back in the 1990s has not performed well in the field in my opinion, and there is some evidence that vaccinating cats may in fact predispose them to worse symptoms of disease, if they should later contract the actual FIP corona virus.

Feline Infectious Peritonitis (FIP) is one virus that needs to always be on our differential list of causes of chronic disease symptoms mentioned above. However, there remains much research to be done by the veterinary profession, both in terms of accurately diagnosing this viral disease, as well as in treating it; which to date has been very unrewarding.

Inflammatory bowel disease is one of the most common causes of chronic diarrhea, vomiting, weight loss, and appetite changes in adult and senior pets. And while many pets can experience occasional digestive upset, it is the chronic digestive issues that are so important to diagnose correctly so that appropriate and early treatment is achieved.   As general practitioners we are often able to resolve greater than 80 percent of acute digestive tract problems with symptomatic and/or dietary therapy without a lot of diagnostic testing.

However, when these issues become chronic, a definitive diagnosis is critical to a successful treatment outcome. In such cases full medical workups including physical exams, CBC/chemistry blood work, urine analyses, x-rays and often abdominal ultrasounds are required.  Depending upon the results of these initial base line tests, further testing is done such as thyroid or adrenal gland testing, 6-8 week strict dietary trials in case food allergies are involved and even an endoscopic exam with stomach or intestinal biopsies, as done in people. Biopsies become especially important to distinguish inflammatory bowel disease from cancer of the digestive tract such as lymphoma, if the initial workups and/or dietary trials fail to resolve the symptoms.

I’ve seen too often many chronically ill pets treated symptomatically with Prednisone for stomach or bowel disorders, often initially helping the situation tremendously, only to have the conditions later relapse with much more intense symptoms. Often these pets have had cancerous lymphoma from the outset, and animal guardians should at least be given the option of a definitive diagnosis and treatment early on with their chronically ill pet. This is even more critically important for pets with digestive symptoms, as those pets with gastrointestinal lymphoma (which can mimic symptoms of inflammatory bowel disease) that are first treated with Prednisone only are much more difficult to treat with effective chemotherapy protocols if diagnosis is delayed at a later date.

The most common causes of premature disease and sometimes death in cats are cancer and kidney failure. With regard to kidney disease, our discreet felines often exhibit only very subtle if any signs of early kidney problems, making early diagnosis sometimes difficult. While kidney disease can occur in a cat at any age, it’s most common in middle age and older cats. Causes of acute kidney failure most commonly include acute infections, toxic exposure and certain drugs such as the use of nonsteroidal anti-inflammatory drugs such as aspirin, Tylenol (which can kill a cat), and even on occasion prescription Metacam.

These cats typically present acutely ill with recent history of drug exposure.  The more common diagnosis of chronic kidney disease certainly presents a more difficult diagnostic challenge. While infections, reactions to drugs, chemicals and/or vaccinations can be involved, in the vast majority of cases, conventional veterinarians rarely find out the cause of chronic kidney failure, often leaving us with palliative management at attempting to preserve kidney function and slow down kidney decline. However, once elevations in blood creatinine and BUN (blood urea nitrogen) occur in cats with chronic renal failure, greater than 80% of kidney function has been irreversibly destroyed when the disease is often first detected, which makes long term management much more difficult.

The diagnosis of chronic kidney failure in cats is based on a combination of blood work, urine analysis, and potentially urine culture and ultrasound done at the veterinary office.  Once diagnosed, attempts are made to slow down kidney decline and metabolic complications. Secondary urinary infections are treated with antibiotics.  High blood pressure is treated with drugs like Amlodipine. Low protein and low phosphorus diets are fed to ease workload on the kidneys, preferably homemade, but there are commercially available diets as well. Some veterinarians will prescribe appetite stimulants and anti-nausea drugs such as Cyproheptadine, Pepcid AC, Metoclopromide, and Mirtazapine. Because elevations of blood phosphorus occur, many veterinarians will prescribe phosphate binders to be given at meal times such as Epakitin. There has been some excellent clinical responses of cats with kidney disease to the probiotic Azodyl, as well which seems to draw the toxins of kidney failure right out of the blood into the digestive tract.

Many cats with chronic kidney disease benefit from animal guardians administering subcutaneous fluids under the skin at home several times weekly, which can be easily taught to guardians by veterinarians or veterinary technicians. Rarely some animal guardians will see if their pet is a candidate for kidney transplants. Limitations here include limited facilities across the country that provide this service, VERY high cost, as well as risk of donor kidney organ rejection in the sick patient. Holistic veterinarians will often prescribe nutritional supplements, herbs and/or homeopathic remedies in helping the feline cope with this very difficult disease.  The best thing guardians can do is be aware of the early signs of kidney disease in cats. These include:

• Increased thirst/urination

• Subtle weight loss

• Nausea, vomiting

• Drooling from oral ulcers

• Losses of appetite

With routine annual to semiannual exams, blood work/urine analyses and blood pressure measurements, kidney disease in cats can be detected early. And with early detection the disease can often be better managed for an improved and enhanced quality of life for your cat.

One of the most common questions asked by animal guardians whenever their pet has a skin problem is whether or not their pet could have mange.  The term mange applies to a mite overgrowth on a pet’s skin.  In canine medicine, the most common cause of mange is overgrowth of the demodex mite. Although low numbers of demodex mites are present on normal dog or cat skin, these mites will sometimes overgrow producing variable presentations of localized or generalized hair loss, crusting, and sometimes secondary skin infection.

By far the most common presentation of demodectic mange is in young pets under the age of one year, where a genetic immune deficiency is thought to be the underlying cause. Most common areas affected include the face, head, and forepaws often with focal area of hair loss, however, any area of the animal can be affected. Diagnosis is quite simple and based on skin scrapes done at a veterinary office, which are looked at under the microscope to identify the mites. This is NOT something that animal guardians can diagnose at home. In fact, in most pets over the age of one, skin allergies are the most common cause of hair loss, skin crusting, etc.

In many pets a localized form of demodectic mange often resolves on its own within weeks to a few months. But in other younger pets a more generalized form can develop affecting multiple areas on the pet’s body.  Once a pet is sexually mature, demodectic mange is much less common until we hit middle age to older animals. During this phase other immune suppressive diseases or cancers, and even certain drug therapies like overuse of Prednisone, can on occasion cause overgrowth of demodex mange mites. It is important for animal guardians to know that this most common cause of mange is NOT contagious to other animals or people in the home.

The other type of mange seen in dogs is known as scabies mange. Scabies is usually acquired externally from either other dogs or rolling in dirt or grass, and causes INTENSE itching in most pets.  The areas most commonly affected are the thinly haired areas on the pet such as the ear flaps, elbows, ankle areas of hind legs and the abdomen. Not only is hair loss present, but varying degrees of sores, crusting and secondary infections often accompany these very itchy dogs afflicted with scabies mites. While skin scraping at the veterinarian’s office is again the common way of diagnosing this condition, 75% of the time skin scrapes can be negative because of the low number of mites on the pet’s skin.  In those cases veterinarians and veterinary dermatologists will often treat these itchy dogs if they suspect scabies mites (based on the clinical presentation), as these mites can potentially be passed to people and other dogs in the home.

Some veterinary dermatologists will suggest treating the home with products that kill fleas, as there is some suspicion that scabies mites may be able to live in the environment for a short period of time. I should say that both demodectic mange and scabies mange are a less common skin problem in cats. Treatment for demodectic mange may involve shampooing with a benzoal peroxide shampoo such as Oxydex Shampoo followed by Mitaban Dip every 1-2 weeks until the lesions resolve and skin scrapes are negative, or other products such as Ivomec in certain breeds, which is often given daily to severely affected pets. It can take sometimes several months for complete resolution to occur.

If scabies mites are suspected or confirmed by skin scrape, these can also be treated with Ivermectin once a week for one month, or using a prescription product like Revolution applied once every 2 weeks for 3 or 4 treatments. No matter which approach or medication is used, pets afflicted with either type of mange need to be under the care and supervision of a veterinarian, not only in which drugs are most appropriate, but also for follow-up skin scrapes to insure that the mange is completely resolved.

The most common hormonal disorder seen in cats today is an overactive thyroid gland known as hyperthyroidism. While it was only recently characterized and identified as an illness in cats in 1979 at the Animal Medical Center in New York City, the incidence of this disorder has expanded tremendously over the past three decades. While it is most commonly a disease of cats over the age of ten, we are now identifying this disorder in younger and younger cats due to more accurate testing, including measurement of both a T4 and Free T4 thyroid levels.

The most common cause of this hormonal imbalance is due to a benign but functional tumor of the thyroid glands that leads to an overproduction of thyroid hormone. The debate in the veterinary community rests on what causes this benign tumor to develop.  The largest consensus rests on environmental factors, including potentially contaminant metals in certain screw top canned cat foods, to environmental toxins in carpets, as well as over vaccination where immunity to most viruses lasts for years to life of the pet.

As with most chronic disorders in our pets, it is believed to be an autoimmune reaction, where the immune system reacts against its own tissues leading to the development of this functioning tumor of the thyroid glands. Symptoms of this disease include increased thirst/urination and appetite, however, with concomitant weight loss at the same time. Also, greasy or matted coats including excessive shedding can develop as well.  Behavioral changes include easy overheating and panting, restlessness, vocalization, aggression and even changes in litter box habits resulting in feline house soiling.

If left undiagnosed, high blood pressure, subsequent kidney and heart damage, and secondary disease of the heart muscle called cardiomyopathy can develop as well.   Treatment options include the prescription drugs Tapazole or generic Methimazole. 15 to 20% of cats may develop side effects on these drugs including lethargy, loss of appetite and vomiting. A lesser percentage can develop problems of the bone marrow, liver failure and even less common intense itching of the head and face.  In roughly 20% of cats treated with Methimazole, elevation of kidney enzymes and possibly future renal failure can be seen. That’s why it’s so important for cats treated with medications for this condition to be adequately monitored through periodic exams, blood testing and blood pressure measurements. And while surgical removal of the thyroid glands used to be a popular treatment option, it has for the most part fallen out of vogue because of the close proximity of the parathyroid glands, as well as the surgical risk in many older cats.

The preferred method of treatment by many feline experts includes the injection of a single bolus of radioactive iodine, which selectively destroys only the functioning tumor of the thyroid glands. Most cats tolerate this treatment quite well, with the only down sides in my opinion, being the initial expense of $1200 to $1500 dollars for the workup before the treatment, as well as the cat being isolated for at least a few days away from the guardian during the treatment period, in order to avoid radioactive exposure of the human guardian family. As with all other hormonal diseases, I always recommend good vitamin supplementation,  including Soft Vitachews for Cats, Vetri-DMG, fatty acids such as Be Well Cat or Nordic Naturals Pet Cod Liver Oil, as well as liver support such as Denamarin, or the lesser expensive Denosyl or Marin for Cats, in order to protect the liver against the toxic effects of long term drug therapies.