Disease #1
Most abscesses are caused by a bacterial overload. Normally, bacteria in few numbers do not cause any problem in the body and are removed by the white cells in the blood or in the liver. Abscesses can occur anywhere in the body; although many are caused by puncture wounds on the skin. Most puncture wounds occur during cat and or dog fights, getting caught on a fence or trap and many other ways. Common bacteria that cause abscesses are Staphylococcus sp, Streptococcus sp and Pseudomonas sp.
When bacteria overload the immune system in huge numbers, in any cavity, an abscess is the result. Bacteria reproduce rapidly and an abscess can form in a very short period of time. I have treated abscesses literally from the tip of the nose to the tip of the tail. Bacteria also produce toxins that can lead to sepsis; which is the presence of bacteria and associated toxins in the blood. Pus is eventually produced and the abscess comes to a head. It can open on its own, which is good, or remain closed and continue to grow. If that is the case, surrounding tissues may become damaged and infected. If left untreated, abscesses can become life threatening.
Abscesses are not only seen on the skin but can also form in the liver, lungs, kidneys and other organs. Depending upon the organ affected, clinical signs may vary. In general cases, most dogs and cats usually start out with a low grade fever. Fever is a good thing in low doses, as it stimulates the immune system. At high levels, such as 105 degrees and higher, it causes lethargy, lack of appetite and often dehydration. A swollen limb or ear that just happened may very well be an abscess. The abscess may have opened and a foul smelling green substance is oozing out of a hole. Abscesses are extremely painful and an animal may yelp out in pain after getting up to walk or picked up by its owner. Cats are very difficult creatures when it comes to abscesses. As a general rule, they hide when they are sick and when they come out they look healthy but are extremely ill by the time they are presented to a medical facility.
Lab Work is necessary to diagnose any abscess. Most dogs and cats should have a CBC (Cell Blood Count) and Serum Chemistries run to look at the red and white cell counts plus organ function. If a deep abscess is suspected, x-rays or other imaging may be performed. A small sample of the draining wound may be sent to the lab for a bacterial culture. If a deep abscess in a particular organ is suspected sensitive imaging may be performed as well as a biopsy.
All doctors need a minimal database to diagnose a medical condition. In the case of an abscess; a good history and physical exam plus lab work are needed to diagnose an abscess effectively. Sometimes, the diagnosis is not so obvious so doctors do their best to cover all the bases.
Antibiotics are always used to treat an abscess. One or multiple antibiotics may be used. Clavamox® and Baytril® are popular combinations because they work! Antibiotics may be changed after the culture results are received. There may be bacteria present that are resistant to antibiotics currently being used or bacteria present that are not susceptible to the antibiotics being used. Supportive care such as appetite stimulants, pain control and fluid needs are often provided. The owner must keep the abscessed area clean and this is done with hydrogen peroxide infused into the wound and around it. Warm compresses may also help, if the dog or cat allows it. In severe cases of abscessation resulting in sepsis, more aggressive measures are needed such as intravenous antibiotics, intravenous fluids and hospitalization.
The prognosis for most abscesses is very good, as long as medical care is sought promptly. If an animal is allowed to become septic the prognosis is guarded until the medical condition improves with prescribed medications and hospital care. Sepsis leads to decreased blood pressure, renal failure and clotting issues of the blood known as DIC (Disseminated Intravascular Coagulopathy).
The most common Adenoviruses in pets are the Adenovirus-1 and the Adenovirus-2. The latter causes respiratory disease in dogs. The former is the causative agent of Infectious Canine Hepatitis.
Adenovirus-1 has a predilection, once in the body, to replicate and cause disease in the lungs, liver and spleen. Its pathological effects can also result in blood clotting issues.
Infectious Canine Hepatitis is most commonly seen in young dogs; since their immune system is so immature. It is not commonly seen, since most dogs in the U.S. are vaccinated against it by use of the attenuated adenovirus-2. Many animals show no signs but can shed the virus from anywhere from 6 months to a year in their urine. Dogs are infected by the ingestion of contaminated urine and feces. Animals usually present with a low grade to mid grade fever. They often are anorexic and display petequial hemorrhages on their bodies due to deficiencies in the clotting mechanisms.
A CBC and Chemistry Profiles should be performed. A low white cell count, clotting difficulties and a high fever are often diagnostic hallmarks of the disease. Absence of vaccination status may also point the diagnosis in the direction of ICH.
A tentative diagnosis of ICH is usually made by the presence of a relatively high fever and blood clotting disorders seen over the body. The absence of vaccination against ICH and clinical signs seen in young animals may point the diagnosis in the right direction.
ICH is caused by a virus hence no antibiotic is going to kill it. Treatment is via supportive care only; which includes antibiotics to prevent secondary bacterial infections as well as blood transfusions if the patient is anemic or has clotting issues. Animals that are very ill are hospitalized with intravenous fluids and other supportive care.
The prognosis depends upon the severity of the disease and age of the animal presented. Dogs presented with higher body temperatures often have a more severe form of the disease therefore the prognosis is much more guarded compared to a mildly infected dog. Vaccination of all dogs for ICH would prevent a lot of suffering. This vaccination is included in the "annual boosters" that veterinarians administer.
The cause of Addison's disease is unknown although there may be an immune-mediated side of it. The disease is also known as hypoadrenalcorticism. This means a deficiency in hormone production in the adrenal glands.
Adrenal glands (in the cortex) produce several important hormones known as mineralocorticoids and glucocorticoids. The most important mineralocorticoid is aldosterone which is responsible for sodium regulation. Cortisol is the most important glucocorticoid found in the body responsible for many physiological effects. A deficiency in one or the other or both lead to the clinical signs seen in the dog. This is rarely seen in cats.
Clinical signs of Addison's disease can be insidious and difficult to diagnose. This disease is seen most commonly in young to middle aged dogs. Making it difficult, is that only vomiting, diarrhea, weight loss and anorexia may be seen before the animal goes into shock. Aldosterone not only regulates sodium levels but also potassium levels. A deficiency leads to elevated serum potassium levels which leads to a slowdown in the heart rate and eventual shock and renal failure. Some dogs may also show similar signs due to additional depletion of cortisol.
The most commonly used diagnostic test is the ACTH Stimulation Test. 0 hour samples and 2 hour blood samples show extremely low levels of cortisol.
Diagnosis is made by the history, physical exam and diagnostic responses to the ACTH Stimulation Test.
The majority of dogs only lack aldosterone. An acute case of Addison's disease is a medical emergency and requires hospitalization with intravenous fluids and glucocorticoids that will repair the hypotension and sodium levels. Fluids will also lower the excess potassium levels but sodium bicarbonate may also be used for such purpose. After all animals are stable, homonal replacement therapy is in order. The most commonly used drug is Percorten®, which is administered every 26-28 days. Dogs that are deficient in glucocorticoids are given varying doses of prednisone or prednisolone.
The prognosis for Addison's disease is very good. Dogs live normal lives while on hormonal replacement therapy. The crucial role of the owner is to obtain monthly hormonal replacement therapy plus regular visits to the hospital for electrolyte levels; mainly sodium and potassium.
The causes of allergies are too numerous to be mentioned but an allergy be it acute, chronic, food related, contact or inhalant is a response to the presence of a foreign protein named an allergen. The most common types of allergies are: parasitic (fleas and ticks), food (different types of meat or grains), horticultural (tree and grass pollen), insect bites (spiders and ants) plus to vaccines and their components. Each individual is different and any protein can cause an allergic reaction in any animal!
Allergies can effect any part of the body. Once a foreign allergen invades the body via inhalation, direct contact, or ingesting food, the allergen sets up a reaction. This reaction involves special cells in the blood known as macrophages (and others) that release histamine. This leads to the root of all allergic reactions. These reactions can be acute (anaphylactic shock) or delayed and can be manifested in a myriad of different ways such as asthma (breathing difficulties), itching of the skin (flea and food allergies), ear infections and many more.
The most common clinical sign of allergies is scratching and digging at the skin. The skin is the largest organ in the dog and cats body and itch (also known as pruritus) can lead to interrupted sleep patterns, hairloss, inflamed skin plus bacterial skin infections once the skin surface is broken. Ears also are "skin" and many pets suffer from ear infections. Other allergies such as reactions to vaccines and insect bites can cause an acute swelling of the eyes, lips and limbs (if bitten by a wasp such as a yellow jacket). These require immediate medical attention. These are the most common signs. Finding the cause is the difficult part.
If an animal is suspected of having a form of allergy it makes sense to do a CBC and Chemistry profile to make sure the dog or cat is healthy and to check the level of eosinophils; one of the 5 types of white cells. Eosinophils are almost always elevated in allergies. In an attempt to figure out exactly what is causing the allergy, an allergy blood panel is done. To do this right, all dogs have to be off of all forms of corticosteroids for at least 2 months! One of the best testing programs is offered by Heska. Once the cause is found, immunotherapy (a vaccine) can be started.
Diagnosis is made by the physical exam, the time of year plus the breed of dog. Breeds such as Pit Bulls, Retrievers, West Highland Terriers, Shar-Pei's, English Bulldogs and others are predisposed to allergies via a genetic path. In many parts of the country it is cold in fall in winter. Most plant allergens and insects are dormant. Noticing an itchy dog in the winter is either dry skin, food allergy or the Cheyletiella mite in puppies. In South Florida, where I live, it never gets cold so insect and tree allergens are a constant year round problem. Surgical skin biopsies, using a biopsy punch, may be taken to rule out other non allergy causes of skin irritation.
Treatment goals are based on: avoiding the allergen causing the problem, controlling the inflammation and itch associated with the allergy plus a long term plan to manage allergy manifestations. Avoiding the allergen is difficult. I often commented to my clients in Ohio (which has a high pollen count on average) that to avoid atopic dermatitis they would need to move to Phoenix! Very difficult. The only thing that provides immediate relief to allergy suffering is corticosteroids. These go by the name of prednisone (oral) or DepoMedrol® (injectable). These drugs should be used sparingly as long term use can lead to Cushing's Syndrome and, being an immunosuppressant, more prone to picking up other infections such as cystitis. Over the counter antihistamines such as Benedryl® do nothing other than make the dog sleepy. Avoid antihistamines in cats. Hyroxyzine is the only antihistamine that works to control itching in cats. It is by prescription only. Atopica® (manufactured by Novartis Animal Health) is also another effective way to control itchy, red skin caused by atopic dermatitis. Antibiotics may be needed to control secondary infections known as pyodermas. Medicated shampoos are great and relieve some itching and lift off scale and other debris so that the skin can "breathe". Always bathe animals in cool water. It also numbs the skin making the animal feel better. Never use hot water. Regardless if fleas or other parasites are seen, flea control should always be started. Fleas can make a dog or cat suffering from grass allergies worse since the immune system is already primed and anything can set it off. Many allergies are seasonal and I have treated many dogs for the same thing within a day or so the following year. Long term management entails using special prescription hypoallergenic diets such as manufactured by Hill's® Canine, Hills® Feline or Royal Canin® Canine and Royal Canin® Feline. Environmental control is crucial. This means control of fleas and other parasites by using professional sprays and foggers plus changing the home air handler filter more often. Washing and or changing animal bedding also helps rid the "allergy hot spot" where an animal hangs out or sleeps. Tired of it all? Try investing in immunotherapy offered by your veterinarian via Heska.
With modern high tech veterinary medicine, the prognosis for the management of allergies has never been better! Research is continually being done to make pet lives more full-filling through the advances in veterinary science. Most dog and cat allergies can be controlled via numerous means and the overall prognosis is good. In my 30 plus year career, I have only had to euthanize only a few animals suffering from chronic, debilitating atopic dermatitis.
Alopecia is a condition causing abnormal hair loss on an animal's body. The causes are numerous. Some are congenital in that they are born without hair follicles. Examples of this are the hairless patterns seen on the Chinese Crested Dog and the recessive gene seen in the Sphinx Cat. The majority of alopecias are acquired meaning the animal is not born with the condition. Any condition that destroys or damages the hair follicle can cause problems. Examples are allergies caused by fleas and other parasites plus bacterial and fungal diseases. Some alopecias are caused by a hormonal imbalance such as canine hypothyroidism and canine hyperadrenocorticism (Cushing's Disease). Atopic Dermatitis in the dog and cat is perhaps one of the most common causes of alopecia. In the cat, psychogenic alopecia is common and it is usually symmetrical. This is caused by hypergrooming and usually you will see a one inch zone of alopecia on each side of the cat.
Regardless of the cause, all alopecias have the same thing in common. They all destroy or alter the local anatomy and physiology of the hair follicle. Atopic dermatitis causes the dog to itch and damage the hair follicle. Fungal diseases such as Microsporum canis (ringworm) reside and multiply in hair follicles causing damage to them.
Clinical signs associated with alopecia depend upon the cause. Allergic conditions cause intense itch, inflammation and pain while endocrine disease such as Cushing's cause little inflammation and there are no brittle hairs around the alopecia zones compared to atopic dermatitis. Fungal diseases will have a white circular appearance and most are not pruritic. Parasitic infections such as Demodex canis and Sarcoptes scabeii produce zones of alopecia which are pruritic; especially so with Sarcoptic Mange.
Common lab work used to diagnose alopecia depend upon the suspected cause of the condition. Skin scraping, fluorescent lights, biopsies, endocrine tests and cultures are used commonly.
Diagnosis of alopecia is made by obtaining a solid medical history and physical exam plus understanding the breed differences that predispose a certain breed of dog or cat to a certain cause of alopecia. Understanding the basics and interpretation of appropriate lab work usually points the veterinarian in the right direction.
The treatment plan used is based upon the cause of alopecia. For atopic dermatitis and staph pyodermas, corticosteroids and antiobiotics may be used. For hormonal disorders in both species, hormonal replacement therapy is in order. Some cats with psychogenic alopecia may receive corticosteroids or even Prozac® (fluoxetine).
The prognosis for most causes of alopecia are good, especially so when a definitive cause can be found. Some conditions may become chronic but early diagnosis and treatment facilitate a good prognosis. Read more about feline alopecia.