Monday, May 18, 2015

Feline Immunodeficiency Virus (FIV): Frequently Asked Questions

Blanco, a 15 year old FIV-positive cat

Is this the same virus that causes AIDS in people?

No. The Feline Immunodeficiency Virus (FIV) is also sometimes called the Feline AIDS Virus.  It is likened to the Human Immunodeficiency Virus (HIV) that affects people because of the similarities in the two diseases which result.  Fortunately, most viruses are species specific.  This is the case with HIV and FIV.  The Human Immunodeficiency Virus only affects humans, and the Feline Immunodeficiency Virus only affects cats.

FIV is a type of retrovirus called a "lentivirus" (slow virus) that attacks many of the cells of the
immune system, leaving the cat at risk for diseases that a healthy immune system can usually fight. Once infected, the virus takes up residence in a cat's lymph nodes and infects T-lymphocytes. Sometimes, the lymph nodes can become enlarged tempporarily as the virus spreads to other lymph nodes.

How do cats get FIV?

FIV is transmitted primarily by biting that usually accompanies cat fights.  Other interactions of cats,
such as sharing common food and water bowls or grooming each other, have not been shown to be significant in transmission. FIV affects up to 3% of the healthy cat population in any given area, and is much higher in populations of high-risk or ill cats. In some cases, isolated stray or feral colonies my have up to 100% of the population infected but apparently healthy. Male cats, especially intact males, are at highest risk for disease as they are more likely to fight and spread the virus.

How is it diagnosed?

Evidence of exposure to FIV can be detected by a simple blood test.  A positive test means the cat has been exposed to the virus and will likely be infected for the remainder of its life.  A negative may mean that the cat has not been exposed; however, false negatives occur in two situations:

1.         From the time of initial virus inoculation into the cat, it may take up to two years for the test to turn positive.  Therefore, for up to two years, the test may be negative even though the virus is present in the cat.

2.         When some cats become terminally ill with FIV, the test may again turn negative.  This occurs because antibodies (immune proteins) produced against the virus become attached and bound to the large amount of virus present.  Since the test detects antibodies which are free in circulation, the test may be falsely negative.   This is not the normal occurrence, but it does happen to some cats.

What does a positive test result mean in a kitten?

The vast majority of kittens under 4 months of age who test positive have not been exposed to the virus.  Instead, the test is detecting the immunity (antibodies) that were passed from the mother to the kitten.  These antibodies may persist until the kitten is about 6 months old.  Therefore, the kitten should be retested at about 6 months of age.  If it remains positive, the possibility of true infection is much greater.  If the kitten tests negative, there is nothing to worry about.

How can a kitten become infected?

If a kitten is bitten by an FIV infected cat, it can develop a true infection.  However, the test will usually not turn positive for many months.  If a mother cat is infected with the FIV at the time she is pregnant or nursing, she can pass large quantities of the virus to her kittens.  This means of transmission may result in a positive test result in just a few weeks. 

What type of disease does the FIV cause?

An FIV infected cat will generally go through a prolonged period of normal life with normal risk for health issues (viral dormancy) before it becomes ill.  This incubation period may last 6-8 years or more.  Thus, we generally do not diagnosis an FIV sick cat at an early age.

When illness occurs, we usually see a variety of severe chronic illnesses. This is because the cat's immune system becomes weakened and can no longer fight off the normal bacteria, viruses, fungi and protozoa that a healthy immune system would easily eliminate from the body. The most common illness is a severe infection affecting the gums.  Abscesses from fight wounds that should heal within a week or two may remain active for several months.  Respiratory infections may linger for weeks.  The cat may lose weight and go through periods of not eating well; the hair coat may become unkempt.  The cat may have episodes of treatment-resistant diarrhea.  Ultimately, widespread organ failure occurs, and the cat dies.

What are the signs of an active FIV infection?

  • Poor coat
  • Persistent fever
  • Poor appetite
  • Poor oral health - gingivitis, stomatitis, dental abscesses
  • Chronic, persistent or recurrent infections of the skin, respiratory system or bladder
  • Weight loss
  • Cancer and blood diseases
  • Reproductive failure
  • Seizures, behavior changes, neurological disorders

Is there a treatment for it?

There is no treatment that will rid the cat of FIV.  Sometimes, the disease state can be treated and the cat experiences a period of recovery and relatively good health.  However, the virus will still be in the cat and may become active at a later date.  Therefore, the long term prognosis is not good.

What should I do with a cat that is FIV positive but is not ill?

If you have a cat that tests FIV positive but is not ill, it is not necessary to euthanize it immediately.  As long as it does not fight with your other cats or those of your neighbors, transmission is not likely to occur.  However, if it is prone to fight or if another cat often instigates fights with it, transmission is likely.  In fairness to your neighbors, it is generally recommended to prevent an FIV positive cat from roaming the neighborhood. Owners of infected cats must be responsible so that the likelihood of transmission to someone else's cat is minimized. Additionally, living an indoor life will reduce the positive cat's exposure to communicable diseases, parasites and other infectious agents that are common in the outdoor environment.

Wellness visits should be scheduled every 6 months, and you should keep a close eye on your FIV positive cat's weight, since weight loss is often the first sign that a cat is feeling ill.

FIV is not a contraindication for spay and neuter surgeries. 

Cats that are FIV positive should not eat a raw diet or unpasteurized dairy.  Food borne illnesses or parasites that a healthy cat is likely able to fight off are a higher risk for immunosuppressed cats.

There is a growing body of research into anti-viral therapies, but so far, no therapy stands out as a conclusive benefit to the health and longevity of FIV positive cats.

If an FIV positive cat has spent a period of time in your house, you will want to use normal cleaning and disinfecting methods to sanitize the area where the cat lived. FIV does not last long outside the body of a cat, however any secondary infections - bacterial, viral, fungal or protozoal, may linger on food dishes, bedding, litter pans and toys. A dilute bleach solution should be sufficient to clean these items.

For a little more information about one of our patient who is currently a 15 year old FIV survivor, you can read about Blanco on our blog!

Is there a vaccine for FIV?

Unfortunately, there is not a recommended vaccine available for FIV. Vaccination with the currently available FIV vaccine will cause your cat to test positive on an FIV test.

When should FIV testing be performed?

As a general rule, it takes 8-12 weeks for antibodies to appear after infection, so a post-exposure test should be performed a minimum of 60 days after a known exposure, such as a bite wound from an unknown animal. The antibody test is the standard initial screening test, and can be performed in the veterinary office within a few minutes. However, if the test is positive, it is generally recommended to confirm the test using an alternate method. In the past, the Western Blot test has always been the gold standard of confirmation testing, however, PCR tests are extremely sensitive (possibly too sensitive at this time?) and are showing promise as a superior testing method. 
  • Sick cats
  • Untested cats, or cats with an uncertain history of testing
  • Newly adopted cats
  • After a possible exposure (escaping out of the house with or without an obvious bite wound, living in a house with cats with unknown FIV status or uncertain testing history)
  • After definite exposure (spending time in the vicinity of a positive cat with or without a bite wound) 
Additional Resources:

Oral Health-Retrovirus Connection

Monday, May 11, 2015

Bite Wounds

Please note: Some images of wounds will be presented in this article

We see a significant number of bite wounds, here at Exclusively Cats. Sometimes, the wounds are on indoor/outdoor cats, other times, we find them on stray or feral cats that are brought in for limping. Occasionally, we are called on to treat bite wounds in indoor-only cats - usually after a fight between housemates that got a little out of hand.

Bite wounds often harbor multiple kinds of bacteria
Sometimes, we see the bite wound when it is fresh, and we can prescribe medications and treatments to decrease pain and inflammation, as well as prevent infection. Other times, we see bite wounds after they have become abscesses. An abscess is a pocket of infection that can develop after a wound. This occurs because the canine teeth create small punctures in the skin that do not bleed much. The sharp, conical tooth acts like a needle, injecting bacteria deep into the skin or muscle. Since the wound does not bleed much, the bacteria remain at the bottom of the wound, and when the injury scabs over, a warm, moist area is left behind, which is a great environment for bacterial growth. As the bacteria grow, white blood cells flock to the area to fight the infection. Eventually, there is too much "stuff" (bacteria, diseased tissue, white blood cells and other inflammatory cells) to fit in the puncture wound and the abscess starts to swell. It may be warm to the touch. As it swells, eventually damaged tissue will fail and the abscess will open to the outside and begin to drain. If antibiotics are not started, the wound will scab over again and the process will start anew. 

A bite wound or abscess can happen anywhere on the body, but common locations are on the legs and feet, especially the hind legs, as many cats will get bitten while running away. Other common places to find these wounds are the head and neck, ears, and tail.

If an abscess or bite wound is not obvious due to moist hairs around the wound, or hair loss, you may notice a strong, unpleasant odor - this foul odor is characteristic of  infection. A cat that does not have other obvious signs of a wound may seem painful to the touch, may lick at an area excessively, or may run a fever. Feverish cats often do not have an appetite, so weight loss or disinterest in food can also be signs of a bite wound or abscess. Depending on the location of the wound, you may also note limping, squinting, ear-flicking or the holding of an ear at a strange angle, a reluctance to lie on one side or the other, restlessness, or discomfort when sitting.

Usually, when we are examining a bite wound, we will find a set of 4 wounds (from all four canines), but not all four wounds will be the same severity - some teeth will puncture further than others. Sometimes only one of the four wounds becomes infected. Most of the time, a wound can be flushed and cleaned while the cat is under anesthesia, and then sutured as needed if the wound is large. Warm compresses twice daily will allow the wound to remain open to drain, which will help the wound heal more quickly and prevent the wound from scabbing over and beginning the process all over again. In some cases, the wound is in a location where it can't drain well, and a drain tube will have to be placed. In other cases, the wound has started to heal, but some of the tissue around the wound is too badly infected to recover. In these
This wound required a 12 day stay in the hospital for intensive wound care
cases, the diseased tissue will need to be surgically removed to allow healthy tissue to replace it. This is called "debriding". In extreme cases, there may be enough badly diseased tissue that needs to be removed that the wound cannot be sutured closed and we must use special bandaging techniques to encourage the wound to heal.

An important thing to remember when dealing with bite wounds is that, aside from bacterial infections, other complications can arise from this situation. A cat that has been bitten by another cat will be at high risk for feline-specific viral diseases that can be transmitted through saliva, such as Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) (although FeLV is more likely to be transmitted by long term contact between two individual cats than a single bite wound, the fact that a cat has obvious contact with other cats outdoors suggests that a bitten cat should be tested for FeLV out of due diligence).  Additionally, a cat that has been bitten by any other mammal - cat, dog, raccoon, fox, bat, etc. runs the risk of rabies exposure. If the animal that bit your cat is known - for example a neighbor's cat or dog, it is a good idea to ask what that pet's vaccination status is. If the animal that bit your cat is unknown, it is recommended to have your cat re-tested for FeLV and FIV about 2 months after the bite wound occurred. In Michigan, if your cat's rabies vaccine is up to date, the bitten cat should be re-vaccinated and observed carefully for 45 days for any signs of illness. If the bitten cat has not been vaccinated for rabies, or the vaccine has lapsed, the situation becomes more complicated, as the choices outlined by the Michigan Department of Community Health are either immediate euthanasia or strict quarantine for 6 months. This is one of the reasons that we emphasize keeping your cat's rabies vaccine current.

Michigan Department of Community Health Rabies Protocol
For more about bite wounds:
Frequently Asked Questions About Bite Wounds
Abscesses From Bite Wounds
Bite Wound Abscesses in Cats

Friday, May 1, 2015

Meet Mr. May: Sarge


 Age: 12 years
Weight: 11.05 pounds - good body condition
Demeanor at the vet: Nice cat!

On 3/25/05 we got a call from Oakland County Animal Control. They thought they had a cat with Cerebellar Hypoplasia, and adult, possibly 1-2 years old.   I went to see him.  What a sweetheart.  Though he walked strangely (walked on the hocks of his rear feet, and crossed his front legs when he sat upright), I didn't think he had CH, but certainly, the rescue would take him in.   We named him Sarge because he walked flatfooted and sat at attention. 

Sarge sits at attention
He was a part of Elizabeth Lake Animal Rescue for the next year and a half, joining my father and I up at his cabin for company.   October of 2006, he officially became a Stephenson.
His condition worsened very slowly, to now where he won't walk unless it is carpeted or a rug put down. So he spends his day watching the world go by, and napping, on the couch. He comes down by use of a small carpeted staircase, to his cage with his litter pan and waterproof mattress covers.  Occasionally he is joined by one of his furry siblings for a nap.   He talks to us all the time and comes to lean against you if you sit on "his" couch.  He will chat with you for 15 or 20 minutes, responding to each statement or question you make to him.  He doesn't have a normal cat life, but he is very content in the life he has.  We enjoy his company and his furry grandmother makes it a point of visiting with him when she comes over.