Monday, October 22, 2012

Ear Mites

Ear mite

General Information

Ear mites which are microscopic organisms that look kind of like clear ticks when viewed under a microscope. Ear mites commonly cause problems in young, outdoor/stray animals and are not as commonly seen in mostly indoor pets. There is, unfortunately, a tendency for people to see a pet's inflamed ear with discharge and assume it is an ear mite infection. This leads to weeks of inappropriate treatment with over-the-counter remedies while the infection gets worse. It is important to distinguish an ear infected with yeast or bacteria (the more common cause) from one infected with mites.

The mite lives on the surface of the ear canal skin, although it sometimes migrates out onto the face and head of its host. Eggs are laid and after 4 days of incubation they hatch. Then the larvae take approximately three weeks to mature into adult mites. The adult mite can live for two months. They feed off the ear wax and skin oils found in the ear canals. Ear mites readily transmit from host to host by physical contact.

Clinical Signs

Typical appearance of ear cerumen in a cat with ear mites. Ear mite infections often produce a characteristically dry black ear discharge, said to resemble coffee grounds. Because of the classical appearance of this discharge, infection is often diagnosed based on this discharge alone, although without visual confirmation of the mite under the microscope, it is possible to be led astray. The discharge is composed of ear wax, blood, inflammatory biochemicals, and the ear mites themselves. The dog or cat may have red swollen ears and frequently scratch or shake their head. Secondary complications include yeast or bacterial ear infection and an aural hematoma.

Diagnosis

If you have good vision ear mites can just barely been seen with the naked eye as a small white speck in the ear wax, but most often the diagnosis has to be made by taking a sample of ear wax and looking at it under the microscope.

Treatment

  • The old topical remedies requiring several weeks of ear cleaning and treatment have largely been replaced by far simpler products. These older treatments, that are still available over the counter, contain insecticides that did not kill off the mite eggs so a minimum of three weeks of treatment was required to break the life cycle. Because mites are so easily transmitted by physical contact, often all household pets will require treatment.
  • Prescription topical ear medication called Tresaderm® contains an antibiotic for any secondary bacterial infections, a cortisone derivative for the inflammation, and thiabendazole to kill yeasts and mites. This is an excellent ear product that is able to kill the developing mite eggs as well as treat secondary infections. Treatment with Tresaderm® typically lasts 10-14 days.
  • Today we have the ability to treat uncomplicated ear mite infections with a single dose of medication. There are currently two current products available that are applied directly into a cat's ear canal. Acarexx®, a topical version of ivermectin (the active ingredient in Heartgard®) and Milbemite®, a topical version of milbemycin oxime (active ingredient in Interceptor®). These products are only approved for use in cats in the USA and are only available only through veterinarians. A prescription is required so any website that says otherwise should not be trusted.
  • There are also products available on the market to prevent ear mite infections. These are most beneficial for use on cats that commonly go outdoors and may interact with other outdoor animals. Revolution®, which uses selamectin as an active ingredient, and Advantage Multi®, which uses moxidectin as an active ingredient, are monthly topical medications commonly used for flea control, heartworm prevention as well intestinal parasite prevention. protection.

Sunday, September 30, 2012

Feline rhinosinusitis

General Information

Feline bacterial rhinosinusitis is an upper respiratory tract infection of cats that often follows a herpesvirus or calicivirus infection (viral rhinosinusitis). Infection from these viruses as a kitten can cause permanent damage to the nasal mucosa and turbinates, which could predispose the cat to chronic bacterial rhinosinusitis throughout it's life. These viruses are also difficult for the body to clear completely and though they may go dormant for a time, the cat can become ill from them again, especially in times of stress. Damage of the mucosa and turbinates makes effective antibiotic treatment difficult and relapse is common. Surgical intervention may be necessary for cure to be achieved.

  Clinical Signs

Sneezing, ocular discharge, and yellow-green mucopurulent or bloody nasal discharge, and ocular discharge in one or both eyes are the common clinical signs. Corneal ulcers are common with several of the viral infections as well. Untreated a corneal ulcer can cause permanant vision impairment. Many cats are usually active, have a normal appetite, and are otherwise normal. Treatment becomes necessary if the illness is affecting behavior and appetite.

Diagnosis Often the diagnosis is made based on a physical exam and history. Sometimes a culture and sensitivity can be run to determine the specific bacteria causing the infection. In chronic cases a feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) test should be performed to rule out immunosuppression as an underlying cause. Radiographs may be helpful in identifying other potential causes such as a mass or polyps.

Treatment

  1. Treatment is supportive and a complete cure is unlikely.
  2. Intermittent therapy may be required throughout your cat's life. It is important to give your cat all medications for the full time prescribed even if your cat seems to be feeling better. Stopping treatment early makes a relapse that is resistant to treatment much more likely.
  3. Humidity is helpful. Use a vaporizer or bring your cat into a steamy bathroom as often as possible.
  4. Clean your cat's nose with warm water at least twice a day to prevent it from becoming plugged with dried nasal secretions. You can also use a saline nasal spray to help moisten your cat's nasal passages. You can find these in the children's section of any pharmacy.
  5. Squinting, excessive ocular discharge, conjunctival swelling should be seen by a vet immediately so treatment can be started and permanant damage prevented.
  6. Be aware that anything that stresses your cat out could lead to a relapse. Boarding, being grommed, a trip to the vet, company visiting, fireworks, a new cat in the neighborhood that your cat sees through the window, etc. are all potential causes of stress.

Prognosis

Prognosis is excellent in the short term. Most infections, except for in the very young and very old, are self limiting and don't even require medication. Long term prognosis is guarded and many cat's will have clinical signs periodically throughout their lives.

Tuesday, September 25, 2012

Canine Cushing's Disease

 General Information

Hyperadrenalism is a slowly progressing disease and the early signs are often not noticed. These include increased appetite, increased drinking and urination, reduced activity and enlargement of the abdomen. As the disease progresses, these signs intensify, and the pet may become fat, pant heavily, and lose hair evenly over each side of the body. In some cases, hair loss may be the only apparent change. These clinical signs are the same as the side effects seen in dogs on steroids such as prednisone of dexamethasone.

Cushing’s Disease is a disorder of the adrenal glands in which excessive adrenal hormones are produced, mainly cortisol. The cause of hyperadrenocorticism (HAC) may be abnormal pituitary gland function (a glan in the brain), a tumor of the adrenal gland, “cortisone” (steroid) therapy, or other unexplained over-activity of the adrenal gland. Pituitary dependant HAC accounts for about 80% of all cases.


Extensive laboratory tests (both blood and urine) and radiographs or ultrasound may be needed to diagnose the condition, find its cause and plan treatment. Unfortunately the tests available today often come back as inconclusive making diagnosis very difficult. Several different tests or repeats of test may be necessary to come to an accurate diagnosis. Treatment of pituitary dependant HAC is more aimed at controlling clinical signs and making your pet more comfortable than actual treatment of the tumor. Adrenal gland tumors can sometimes be cured with surgery (some are to invasive to attempt to remove), but will also respond to medical management. Since treatment is aimed at controlling clinical signs and not at curing the problem, the disease will progress, but your pet will be much more comfortable than without treatment.


Induction of Treatment for Cushing’s Disease with mitotane.


Control, rather than cure, is the aim of treatment in most cases of HAC. Treatment with Mitotane must be carefully monitored, since the drug used in therapy may cause underproduction of adrenal hormones and a shock-like state known as an Addisonian crisis.

Treatment is inducted with a drug called Mitotane (Lysodren) You will be giving the medication twice a day for 7 to 10 days. Then an ACTH Stimulation test is run to determine the response to treatment. The kidneys and electrolytes may be checked at this time also. Dogs with adrenal HAC may not respond as well to medical treatment alone as dogs with pitutitary dependant HAC.

If your dog develops any of the following signs contact your veterinarian immediately:
  • Drinking less than 2oz/kg of water a day- in dogs that were drinking excessive amounts (>3oz/kg/day) before treatment
  • Vomiting or diarrhea
  • Taking 15-30 minutes longer to eat than before start of mitotane therapy
  • Listlessness, depression or weakness
  • Skin condition worsens
If adequate control is not reached after the first ACTH Stimulation test then therapy will continue until a satisfactory ACTH Stimulation test is obtained. The test is run about every 7-10 days

The most-common side-effects of mitotane include lethargy, stomach upset, loss of appetite, vomiting and diarrhea. Although less common, hypoadrenalcorticism and an addisonian crisis also are potential side-effects. In rare instances, dogs may experience central nervous system (CNS) signs, ataxia, weakness and seizures.

Maintenance Therapy for Cushing’s Disease with mitotane.


  1. Once adequate control is reached then your dog will need Mitotane twice a day once a week.
  2. An ACTH Stimulation test will be run in 1 to 3 months after start of maintenance therapy and then every 3 to 6 months after that. It is common for clinical signs to recur during maintenance therapy due to the dose becoming inadequate. If you notice signs returning see your veterinarian so the dose can be adjusted accordingly.

Treatment with Trilostane (Vetoryl).


Trilostane (brand name Vetoryl) was approved for treatment of Cushing's disease in dogs in 2008. It works by blocking the excessive production of cortisol from the adrenal gland.

Treatment is started at a dose calculated based on your pet's weight. You will need to have your pet examined and have bloodwork performed in 2, 4 and 12 weeks to assess effectiveness of treatment and to adjust medication dosing. Then if your dog is stable he/she will need to be seen every 3 months unless something changes. Immediate signs that the treatment is effective include increased activity level, decreased appetite (no longer ravenous), decrease in thirst/drinking, and decreased urination.

Possible side effects include poor/reduced appetite, vomiting, lethargy/dullness, diarrhea, and weakness. Occasionally, more serious reactions, including severe depression, hemorrhagic diarrhea, collapse, hypoadrenocortical crisis or adrenal necrosis/rupture may occur, and may result in death.


Treatment with Anipryl (selegiline HCl).


There is an alternative to Mitotane called Selegiline HCl (Anipryl). The benefits of this treatment are no worry of an Addisonian crisis as it does not destroy part of the adrenal gland. The drawbacks are it is expensive, especially for larger dogs, and has a variable success rate. Treatment with Anipryl consists of a pill once a day for life and includes regular monitoring of the disease through bloodwork.

Prognosis and disease progression.


The average life expectancy for dogs with adrenal dependant HAC is 36 months. The average life expectancy for dogs with pituitary dependant HAC is approximately 30 months with younger dogs living longer (i.e. 4 years or more).

Many dogs ultimately die or are euthanized due to complications related to Cushing’s disease such as pituitary macrotumor syndrome, systemic hypertension, pulmonary thromboembolism, diabetes mellitus, infection, etc.
  • Pituitary macrotumor syndrome is a result of the tumor on the pituitary gland expanding into other parts of the brain. The dog will begin showing neurologic signs such as aimless wandering, pacing, circling, and behavior alterations. These signs usually develop 6 months or more after diagnosis.
  • Pulmonary thromboembolism is most commonly seen shortly after treatment. The presenting sign is sudden respiratory distress or difficulty breathing. Once this occurs the prognosis for recovery is grave. It usually requires 7 to 10 days on oxygen therapy if the animal survives.
  • Development of diabetes mellitus is also another potential problem with Cushing’s disease. The high levels of steroids in the blood stream can cause insulin resistance. The signs of diabetes are very similar to the signs of Cushing’s disease so it is important to notify your doctor if you notice them returning. Many dogs can have their diabetes controlled for a time with regular insulin therapy.
  • Infections are common in animals with Cushing’s disease due to the overproduction of steroids. Steroids suppress the immune system and therefore prevent the animal from fighting off infection. One of the goals of treatment is to lower the animal’s blood levels of steroids to prevent this from happening. Urinary tract infections and skin infections are most commonly seen. The more severe and life threatening ones include sepsis and pyelonephritis (kidney infection).

Friday, September 7, 2012

Feline Vaccines

Why do we vaccinate?

According to the AAHA(1) Position Statement on Vaccine Issues(2):"The vaccination needs of dogs and cats should be assessed at least yearly and, if appropriate, vaccination schedules should be modified on the basis of changes in the patient's age, health status, home and travel environment, and lifestyle. Vaccinations should be considered just one component of an individualized, comprehensive preventive health-care plan based on the age, breed, health status, environment (potential exposure to harmful agents), lifestyle (contact with other animals), and travel habits of the dog or cat. We at HPVS believe whole-heartedly in this. Over-vaccination may be just as dangerous as not vaccinating, so getting the right balance is important.

Rabies

Rabies is a preventable viral disease of mammals most often transmitted through the bite of a rabid animal. The rabies virus infects the central nervous system and once clinical signs appear is almost always fatal. All known mammals are possible carriers of rabies, however small mammals such as mice and squirrels are rarely ever found to carry the disease. In Florida Raccoons are the most common carrier of rabies with foxes and bats coming in second. Cats are the most common domestic animal to test positive for rabies (62.2% of domestic cases in 2010)(3).

Because of the link between vaccines and feline fibrosarcomas (cancer), guidelines for cats are a little different than for dogs. The AAFP (American Association of Feline Practitioners) Vaccine Advisory Panel(2) "suggests that veterinarians use less inflammatory products whenever possible." In the case of the rabies virus vaccine the least inflammatory is a non-adjuvanted Canarypox virus-vectored recombinant (rRabies) made by Merial. The Purevax Rabies is currently only labeled as a one year vaccine, though we are hoping they will have the research in the near future to get a three year label.

As an aside AAHA Guidelines for dogs, cats, and ferrets recommend that "a single dose of a "3-yr" rabies vaccine be administered within 1 yr after administration of the initial dose, regardless of the animal's age at the time the initial dose was administered. Subsequently, revaccination with a "3-yr rabies" vaccine should be administered every 3 yr thereafter."

FL Statute 828.30(1)"All dogs, cats, and ferrets 4 months of age or older must be vaccinated by a licensed veterinarian against rabies with a vaccine that is licensed by the United States Department of Agriculture for use in those species. The owner of every dog, cat, and ferret shall have the animal revaccinated 12 months after the initial vaccination. Thereafter, the interval between vaccinations shall conform to the vaccine manufacturer's directions. The cost of vaccination must be borne by the animal's owner. Evidence of circulating rabies virus neutralizing antibodies shall not be used as a substitute for current vaccination in managing rabies exposure or determining the need for booster vaccinations."

FVRCP

FVR=Feline Viral Rhinotracheitis is caused by feline herpesvirus-1. It is a highly contagious upper respiratory disease of cats that can lead to pneumonia and ulcers in the eyes. Young kittens and older or sick cats are much more susceptible and have a higher mortality rate. Cats that are infected with the herpes virus are considered lifetime carriers and may show clinical signs of the disease during times of stress. Some cats that have severe infections may have permanant damage to their eyes or respiratory tract.

Unfortunately the way the disease enters and acts on the body makes the current vaccines available unable to prevent infection and shedding of virus, but they do greatly reduce local disease and protect vaccinated cats against serious systemic disease(4).

C=Calicivirus is also a highly contagious respiratory disease in cats. There are numerous strains of this virus and they cause anything from mild sneezing to severe pneumonia and rapid death in young kittens and old cats. Common signs of this virus are very similar to the herpes virus but can also include severe conjunctivitis (pink eye). Permanant damage and reoccuring clinical signs are also a possibility. Vaccination also does not prevent infection or shedding of this disease, but significantly reduces or eliminates clinical signs associated with it.

P=Parvovirus (also known as Panleukopenia, Feline Distemper, and Feline infectious enteritis) is a highly contagious disease in cats that results in severe suppression of all types of white blood cells (panleukopenia) GI signs such as vomiting and diarrhea, high fever, and sudden death. Mortality rate may reach up to 90% in kittens under 6 months of age and may be as high as 50% in unprotected adult cats. It is shed mainly in the feces of infected cats, but the virus can remain in the environment for months to years. The vaccine is highly effective in producing complete immunity to this disease.

AAFP Guidelines recommend "Vaccines should be administered at intervals of 3 to 4 weeks until kittens are 16 weeks old starting at 8 to 9 weeks of age. The minimum vaccination interval during the primary series is 2 weeks, and the maximum recommended interval is 4 weeks. Kittens presented for booster vaccination 6 weeks or longer following administration of the previous dose of vaccine should receive at least 2 doses of vaccine, 3 to 4 weeks apart." Adult cats with unknown vaccine history should recieve two doses 2-4 weeks apart. The vaccine should be boostered in one year and then every three years thereafter.

FeLV (Feline Leukemia Virus)

FeLV is a retrovirus that is a widespread disease in cats. It is present in about 5% of all cats in the USA(5) making it one of the most common life-threatening disease in cats. The virus is spread through contact with infected saliva, blood, or from mother to kitten. Many cats will develop immunity to it, but in the ones that do not, the virus spread to the bone marrow causing immunosuppression and can lead to leukemia or lymphoma. Some cats can be carriers and show a negative test, but are spreading the virus through their body fluids and may become clinically ill from the diseaes in time of stress. Average lifespan of a FeLV positive cat is less than three years. They often die from other diseases due to the immunosuppression caused by the virus.

AAFP guidelines recommend that all kittens should be vaccinated for FeLV even when the cat is intended to be a totally indoor cat. The highest susceptibility to infection occurs in cats under one year of age(6). All cats that have direct contact with cats of known positive or uncertain status, such as outdoor cats should also be vaccinated. Adult cats that are confined to a screen porch do not need vaccination.

As an aside all new cats should be tested for FeLV before being introduced into a new household and then retested based on their age in 3 to 6 months. Any sick cat that has even had a chance of exposure to the virus should be tested again as well. The virus is very fragile outside the cat's body and almost all common household cleaners will kill the virus.

FIV (Feline Immunodeficiency Virus)

FIV is a lentivirus that is most commonly seen in adult male cats that spend time outdoors. The virus is mainly spread through bite wounds from an infected cat. Cats may remain clinically unaffected for months to years, but the FIV is slowly causing degredation of the immune systom and eventually leads to immunosuppression and higher rate of infections and cancers. Infected cats can cohabitate with FIV negative cats as long as they are minimally aggressive since general contact, including sharing a food bowl and mutual grooming is not enough to transmit the disease.

The FIV vaccine is not considered a core vaccine by the AAFP. Consider FIV Vaccination in cats living with FIV-positive cats, particularly if there is fighting and in cats that go outside and fight or are attacked. Cats vaccinated with the current FIV vaccine will test positive for FIV antibodies. A visible (collar) and permanent (microchip) identification is strongly recommended for cats vaccinated against FIV since a positive test in an animal shelter may result in rapid euthanasia.

Possible Side Effects of Vaccines

Side effects most commonly observed include: reduced or loss of appetite (lasting for one or two feedings), pain at the injection site (possibly mild limping), lethargy (lack of activity), reluctance to walk and/or run, and mild fever. Treatment is usually not indicated and it is essential to NEVER give cats aspirin, tylenol, Advil, Alieve or other anti-inflammatories that you would take for a fever. Even a single dose of these medications could prove fatal to your cat. Hives, swelling of the face, vomiting, and diarrhea are signs of a slightly more severe reaction that usually requires treatment with an antihistamine +/- a steroid for a few days. An anaphylactic reaction is a medical emergency. Signs include sudden collapse, difficulty breathing, paleness of gums, sever swelling around head and neck. If you see any of these signs contact your vet immediately. There are a few very rare conditions associated with vaccinations that can occur a few weeks after administration. In using the non-adjuvanted, recombinate virus vaccines versus the whole killed virus vaccines we are significantly reducing the risk of a vaccine associated reaction. Not all vaccines are created equal.

Cats also have a unique complication of vaccine induced tumors called fibrosarcomas. The chance of a vaccine induced tumor is higher with the killed whole virus rabies and FeLV vaccines. It occurs at a rate of about 1 tumor per 10,000 vaccine doses given. While this risk is small it doesn't help if your cat is the one to get the tumor. The AAFP recommends cats be vaccinated low on their extremities (over the knee and near the elbow) so if a tumor appears the limb can be amputated to cure the cancer. While this sounds like a drastic and horrible approach, a cat developing a fibrosarcoma between his shoulder blades has no chance of being cured.

References

  1. AAHA Position Statement on Vaccine Issues
  2. The 2006 American Association of Feline Practitioners Feline Vaccine Advisory Panel Report
  3. "Rabies surveillance in the United States during 2010" Jesse D. Blanton, mph; Dustyn Palmer, ba; Jessie Dyer, msph; Charles E. Rupprecht, vmd, phd
  4. Povey RC, Koones H, Hays MB. Immunogenicity and safety of an inactivated vaccine for the prevention of rhinotracheitis, caliciviral disease, and panleukopenia in cats. J Am Vet Med Assoc 1980;177:347-350.
  5. Levy JK, Scott HM, Lachtara JL, et al. Seroprevalence of feline leukemia virus and feline immunodeficiency virus infection among cats in North America and risk factors for seropositivity. J Am Vet Med Assoc 2006;228:371-376.
  6. Hoover EA, Olsen RG, Hardy WD Jr, et al. Feline leukemia virus infection: age-related variation in response of cats to experimental infection. J Natl Cancer Inst 1976;57:365-369.

Monday, September 3, 2012

Canine Vaccines

Why do we vaccinate?

According to the 2011 AAHA(1) Canine Vaccination Guidelines(2): "Vaccines provide proven life-saving benefits, are associated with minimal risk, and should be part of routine preventative health care. Life stage and lifestyle, risk of exposure, and underlying medical conditions should all be considered when developing a vaccination protocol."
We at HPVS believe that each animal must be evaluated based on his/her health status, life-style, environment, breed, sex, age, etc. to determine which vaccines to administer and how frequently. Over-vaccination may be just as dangerous as not vaccinating so getting the right balance is important.

Rabies

Rabies is a preventable viral disease of mammals most often transmitted through the bite of a rabid animal. The rabies virus infects the central nervous system and once clinical signs appear is almost always fatal. All known mammals are possible carriers of rabies, however small mammals such as mice and squirrels are rarely ever found to carry the disease. In Florida Raccoons are the most common carrier of rabies with foxes and bats coming in second.

AAHA Guidelines recommend that "a single dose of a "3-yr" rabies vaccine be administered within 1 yr after administration of the initial dose, regardless of the animal's age at the time the initial dose was administered. Subsequently, revaccination with a "3-yr rabies" vaccine should be administered every 3 yr thereafter."

FL Statute 828.30(1) "All dogs, cats, and ferrets 4 months of age or older must be vaccinated by a licensed veterinarian against rabies with a vaccine that is licensed by the United States Department of Agriculture for use in those species. The owner of every dog, cat, and ferret shall have the animal revaccinated 12 months after the initial vaccination. Thereafter, the interval between vaccinations shall conform to the vaccine manufacturer's directions. The cost of vaccination must be borne by the animal's owner. Evidence of circulating rabies virus neutralizing antibodies shall not be used as a substitute for current vaccination in managing rabies exposure or determining the need for booster vaccinations."

DHPP (DA2PP)

D=Canine distemper is a highly contagious disease of dogs spread through the air. Clinically, it is characterized by a fever, excessive production of mucous in both the respiratory and GI systems, pneumonia, low white blood cell count, and possibly neurologic complications. Dogs that survive the disease often have lasting effects such as chronic respiratory problems, seizures, altered mentation, etc. This disease is also very preventable with proper vaccination.

H=Canine hepatitis (Canine adenovirus) is also a highly contagious disease. It is spread through urine, feces, or saliva. Fortunately this disease has become rare in areas who's dog population is well vaccinated. Adenovirus attacks the liver, kidneys, spleen, and lungs and can cause clotting problems and lead to death (more common in young dogs).

P- Parainfluenza virus is a common disease of the upper respiratory tract spread through the air. It often causes mild clinical signs and can go undiagnosed. It's major health concern is that it predisposes the airways to other infections such as bronchitis or pneumonia.

P-Parvovirus is a deadly virus that most commonly affects young, unvaccinated puppies. It is spread through the feces and can stay in the environment for 6 months or more. Clinical signs consist of bloody vomit and diarrhea. Death occurs in a large percentage of cases despite hospitalization. The patients that survive usually do so after a 7 to 10 day period of hospitalization with a bill in the thousands of dollars.

Current AAHA guidelines recommend vaccination for these viruses starting at 8 weeks of age. Boosters are are given every 3-4weeks until 14 to 16 weeks of age. Then a booster in one year is given. After that based on numerous studies done over the past 30 years re-vaccination is recommended every 3 to 5 years based on risk assessment.

Leptospirosis

Unlike most things we vaccinate for, which are viruses, leptospirosis is a bacteria. There are actually numerous serovars(distinct variations within a species of bacteria or viruses) of Leptospirosis, but we only vaccinate against two or four. Leptospirosis is a zoonitic disease, meaning people can catch it. Dogs can contract the disease and become carriers and continually shed the bacteria in their urine becoming a risk to people. Dogs contract the disease by coming in contact with urine of an infected animal (raccoons, opossums, etc.) or standing water that has been contaminated with the bacteria. Acute kidney failure occurs in 80-90% of dogs that become clinically ill from lepto and about 20% of these progress into liver failure as well. The dogs that survive tend to have permanent kidney and/or liver damage requiring lifelong treatment.

In the past the vaccines that were available had a high rate of vaccine reactions due to the large size of the lepto bacteria. More modern vaccines are made up of only parts of the bacteria and are no more likely to cause a reaction than any other vaccine. Since there are several types of vaccines available it is important to be aware of which one your pet is getting. Insist on a 4-way lepto vaccine (includes the canicola, icterohaemorrhagiae, grippotyphosa, and pomona serovars).

In young puppies and small breed dogs (slightly increased risk of a vaccine reaction), I recommend that the leptospirosis vaccine be given separately from the DHPP. This decreases the likelihood of a reaction. The lepto vaccine is considered a non-core vaccine by AAHA and should only be given to dogs that are at risk of contracting the disease. It has to be re-administered every 6 to 12 months due to the short lived immunity created against bacteria.

Bordetella

Bordetella bronchiseptica is often incorrectly considered the only cause of kennel cough. It is a bacteria that can cause tracheobronchitis (inflammation of the trachea) leading to a loud "goose-honk" like cough that can last for weeks. Canine distemper and parainfluenza are also two possible causes for "kennel cough" that we vaccinate for, but there are many, many more possible causes. Kennel cough is often an annoying, but self limiting disease unless it becomes complicated with secondary viral or bacterial infections and progresses into pneumonia. This most often occurs in very young puppies or old/sick dogs.

Bordetella is considered a non-core vaccine and should only be given to dogs that will be in contact with other dogs. This includes dogs that are boarded, go to doggy-daycare, play at a dog park, go to a groomers, dog shows, etc. This vaccine also needs to be boostered every 6-12 months for at risk dogs.

Canine Influenza

Canine influenza is caused by a non-human influenza virus (H3N8) that mutated from an equine virus. It was first seen in 2005 in greyhounds. Because it is a new disease almost all dogs that come in contact with the virus will display some clinical signs from a mild cold to pneumonia. The mortality rate is very low and most dogs recover with no issue. At this time the CDC sees no risk to the human population from this influenza virus.

AAHA recommends vaccinating only dogs that are considered at high risk since the vaccine does not actually prevent the disease. The vaccine is meant to decrease the severity of clinical signs.

Lyme Disease

Lyme disease is a zoonotic disease caused by the bacteria Borrelia burgdorferi(boar-ELL-ee-uh burg-dorf-ERR-eye). It is transmitted by the blacklegged tick (or deer tick, Ixodes scapularis) in the northeastern and central United States, and the western blacklegged tick (Ixodes pacificus) on the west coast. The incident of Lyme disease is very rare in Florida. Dogs that live full time in Florida do not need to be vaccinated for Lyme disease unless they are commonly in heavily wooded areas known to contain the deer tick. Dogs that travel to the new England states should consider being vaccinated.

Coronavirus

Canine coronavirus is a much debated virus in veterinary medicine. It tends to cause very mild gastrointestinal signs such as vomiting and/or diarrhea when any clinical signs are seen at all. The disease was thought to only be a problem when it occurred in conjunction with canine parvovirus. Coronavirus tends to be a rapidly mutating virus which means new strains are occurring all the time. In the few fatal cases where coronavirus is the only pathogen isolated the puppies are all under 10 weeks of age, most are under 8 weeks of age.

AAHA guidelines do not recommend administration of the coronavirus vaccine because "neither the MLV (modified live virus) vaccine nor the killed vaccines have been shown to significantly reduce disease." Also because fatality seems to only be a concern in puppies under eight weeks of age, by the time they are old enough to be effectively vaccinated they are old enough to survive the disease.

Possible Side Effects of Vaccines

Vaccine reactions occur at a rate of about 13 reactions for every 10,000 doses of vaccine given(3). Side effects commonly observed include: reduced or loss of appetite (lasting for one or two feedings), pain at the injection site, lethargy (lack of activity), reluctance to walk and/or run, and mild fever. Treatment is usually not indicated. Hives, swelling of the face, vomiting, and diarrhea are signs of a slightly more severe reaction that usually requires treatment with an antihistamine +/- a steroid for a few days. An anaphylactic reaction is a medical emergency. Signs include sudden collapse, difficulty breathing, paleness of gums, sever swelling around head and neck. If you see any of these signs contact your vet immediately. There are a few very rare conditions associated with vaccinations that can occur a few weeks after administration.

Young (1 to 3 years old) neutered males under 10 pounds body weight have the highest rates of vaccine reactions.(3) As body size increases the rate of adverse reactions decreases. An increased chance of reaction also occurs with administering multiple vaccines at once. If you have a small breed dog talk to your vet about potentially pre-treating your dog with medication or splitting up the vaccines. They have to be given at least two weeks apart so they don't interfere with each other.
 
  1.  AAHA= American Animal Hospital Association
  2. Members of the American Animal Hospital Association (AAHA) Canine Vaccination Task Force: Link V. Welborn, DVM, DABVP (Chairperson), John G. DeVries, DVM, DABVP, Richard Ford, DVM, MS, DACVIM, (Hon)ACVPM, Robert T. Franklin, DVM, DACVIM, Kate F. Hurley, DVM, MPVM, Kent D. McClure, DVM, JD, Michael A. Paul, DVM, Ronald D. Schultz, PhD, DACVM
  3. Moore et al, "Adverse events diagnosed within three days of vaccine administration in dogs." JAVMA 227:1102–110 October 1, 2005, Vol. 227, No. 7, Pages 1102-1108

Thursday, August 23, 2012

Testicular Cancer- warning graphic photos.


I had a fun (for me) surgery today involving a ten year old, mixed breed dog named Prince. His owner noticed that his testicles had grown suddenly. It turns out that only his right testicle had grown and it was about 10x the size of the left one.  He had also developed gynecomastia, or enlarged mammary tissue.  This makes the mass most likely to be a seminoma or a sertoli cell tumor.  Testicular cancer is very common in intact male dogs.  One study showed 27% of intact male dogs will develop testicular cancer.  Dogs that are cryptorchid (have a testicle that did not descend from the abdomen into the
There are 3 common types of testicular cancer in dogs.  Seminomas, sertoli cell tumors, and Interstitial (Leydig) cell tumors.
  • Seminomas arise from the cells in the testicle that produce sperm.  They can cause feminization (such as gynecomastia) from the production of estrogens.  They are very slow to metastasize.
  • Interstitial cell tumors arise from the cells in the testicle responsible for the production of testosterone.  They are often small and an incidental finding.  They rarely spread or cause a problem.
  • Sertoli cell tumors are the more aggressive tumor and are more likely to metastasize, but even then only about 15-20% do.  They can produce large amounts of estrogen that can cause severe bone marrow suppression leading to anemia (low red blood cells).  The estrogen can also cause the feminization in the male dog.
We removed Prince's mass today and are hoping that it had not spread to other parts of his body.  We could have taken radiographs and done an ultrasound to look for metastasis, but his owners were more interested in keeping him comfortable and getting rid of the mass that was bothering him.  If the mass is malignant then at least he will feel good for a while.
The surgery was performed a little differently than a regular neuter.  In a regular neuter we don't like to go through the scrotum because they tend to be very vascular and can bleed a lot.  In this case we had no choice but to go through the scrotum.  I also removed the scrotum to prevent possible post-op complications.
 The first image is of the normal left testicle (bottom) next to the testicular mass (top).  The testicles are both still within the testiculat tunic.  The second image is of the actual mass once it has been removed from the tunic.  The large white area is the actual testis.  The slightly darker pink area on top is the epididymis.  The large red cord on the right is pampiniform plexus which is a bunch of blood vessels that supply the testicle with blood. 
Prince is recovering well and is hopefully now cured!
 
 
 

Saturday, August 18, 2012

Internet Rumors: Fact or fiction

Just the other day as Cheryl and I were driving to an appointment we some how got onto the topic of bon bons.  You know the old saying "Sitting on the couch eating bon bons."  Almost at the exact same time we asked each other so what exactly is a bon bon.  Since I was driving Cheryl got out her iPhone and looked up what a bon bon is (its basically the French word for candy for those that want to know).  I remember the days when I had to go look through my dad's Encyclopedia Britannica or go to the library to find an answer.  Now you can find it in a matter of seconds on your tiny little phone.  The downside to this is the information you look up may or may not be truth.
When looking up information about your pet I recommend going to reputable sites such as universities, government, or well know organizations.  It is so easy to make something sound true and be completely wrong.  Here are some common things circulating on the Internet recently.

  1. The cardboard tube in toilet paper rolls contains toxic levels of zinc.  False! Not sure who came up with this one, but it has absolutely no basis or foundation.


  2. Febreeze is toxic to pets. False!  When Febreeze was first marketed in the United States for a very short period of time (less than 6 months) it contained zinc chloride as a stabilizer.  Zinc chloride is a known lung irritant. The chemical was in such small concentrations in the Febreeze that even before they removed the zinc chloride from the formula it was safe to use.  The only potential issue with Febreeze is if it is scented and you have pets with allergies.  Any scented product could make allergies worse (for people too!)


  3. Swiffer Wet Jet cleaning solution contains a chemical that is one molecule away from antifreeze and causes liver failure. False and False! First of all let me point out that Anti-freeze, a known common toxin, causes kidney failure in mammals and not liver failure.  Second of all the definition of a molecule is "a group of like or different atoms held together by chemical forces."  This means the statement, while making it sound plausible actually makes it nonsense. 


  4. Sugar free chewing gum can kill your dogTrue! Sugar free gums and candies that contain the ingredient xylitol can cause dogs to become severely hypoglycemic leading to seizures.  It can also cause liver damage in some cases.  Dogs so far appear to be the only species that is sensitive to the xylitol.  The amount present in most products is unknown because they are not required to disclose that information so assume any human product with xylitol in it is to be avoided. (As an aside AquaDent, a drinking water additive for dental care, does contain xylitol but in very low concentrations and is safe to use).

  5. Tennis Balls are bad for dogs and can cause cancer. False, but a little true.  There are rumors going about that the tennis balls contain toxic gases or have lead in them and will therefore give dogs cancer.  This is not true.  What is true about tennis balls not being so great for dogs is they are a potential foreign body to a dog that chews one up and swallows a piece.  They are also very abrasive to the dogs teeth if they are prone to chewing the ball.  Just play fetch with the tennis balls and don't let your dog chew on them much and all is good!


  6.  Ornamental sago palms are very toxic. TRUE!  Sago palm plants are a very common plant in Florida landscaping.  I myself have one in the front of my yard and it is a pretty plant, but deadly.  I have lost a patient that ate the sago palm nuts despite all of our efforts to treat him.  If you have one of these plants in your yard please make sure your pet (or child) can not chew on any part of it.


  7. Heartworm prevention is a poison and it is better to just treat if your dog gets heartworms. False! This rumor assumes that the medication we give as a heartworm preventative and the medication we use to treat heartworms are the same thing.  This is not true.  The common heartworm preventatives we have today are ivermectin or milbemycin and their derivatives.  They are given in very low doses to kill of a certain stage of the heartworm life cycle.  They are almost completely out of the body within 24 hours so there is no lingering effect.  The medication we use to treat heartworms is another matter.  It is much safer than what we had in the past, but is still a harsh and potent drug.  It also is only given once heartworms have been diagnosed, which means the worms have already taken root in the heart and have been causing damage since the last negative heartworm test.  This damage is irreversible.  Giving the preventative is much, much safer than the alternative. 


  8. Collies and their cousin breeds should not get heartgard (or several other drugs). False.  The collie breeds can have a gene mutation called the MDR1 gene.  Dogs with this gene are very sensitive to certain medications including ivermectin (the active ingredient in Heartgard), loperamide (Immodium), certain chemotherapy drugs to name a few.  This means that these dogs must be given a much lower dose than a normal dog of their size.  The amount of ivermectin in Heartgard is well below the toxic level even to dogs with this gene so it is safe to give.


  9. Pregnant women or immunocompromised individuals should not own a cat. False.  Part of this myth came about because of the fact that cats are known to sometimes carry the organism Toxoplasma gondii which can cause fetal deformities or death.  It is estimated that 22% of people in the United states over the age of 12 years are carriers.  Most people get it by eating raw or undercooked meats or playing in the sand or soil (sandbox, playground, gardening).  Cats do play a significant role in the transmission of the disease, but the toxo oocysts shed in the cat's feces don't become infectious for 1-5 days.  Scoop the litter box on a daily basis and you have no worries.

If you have any "facts" you want clarified or validated let me know.  I'm all for well educated pet owners.  It makes my job keeping the pets healtier easier!

**Thank you to Sharon Gwaltney-Brant, DVM, PhD, DABVT, DABT for her rounds presentation on VIN that gave me the idea and some of the tumors for this blog.