Miscellaneous Diseases

Diseases Of Interest

It's only natural for people who handle the carcasses or parts of wild animals like taxidermists do, to wonder if they are at risk of contracting any of the diseases that wild creatures carry. I would also imagine that while going about the task of recreating the beauty the live animal once carried some taxidermists may wonder about the future of the species they have studied and are now trying to render as life-like as possible. I'm hoping that as you read this, you are nodding your head in agreement and will find the following discussion of some common wildlife diseases and the role of taxidermists in safeguarding wildlife health of interest.

RABIES
     Certainly rabies is at the top of this list. Rabies is caused by a virus that dies when it dries, is exposed to UV light (including sunlight), or disinfectants like a solution of regular household bleach, each measure of bleach diluted with 9 measures of water. However, if live virus is present in any tissue when it is frozen it will still be viable when thawed.
     Nearly all rabies infections are caused by a bite. There are other but much less common ways it can infect new hosts, but bite transmission is part of the way the virus has evolved to sustain itself in nature. These other ways that may be of interest to taxidermists include splashing infected saliva, or in some rare cases other bodily fluids, onto the membranes around the eye or in the oral cavity. Power tools being used to open the skull can aerosolize virus that is in the brain. If saliva is present on the hair coat it can infect after entry via breaks in the skin.
     Usually, an animal is bitten and saliva-containing virus is deposited near a peripheral nerve. The virus usually does not reproduce in muscle or on these small nerves; silver-haired bat strain is a notable exception. Instead it migrates up to the brain where it reproduces in great numbers. The time it takes for this journey from bite site to brain can vary from weeks to months. Recently a dog infected in the Phillipines immigrated to the US with its family and two years later became clinically rabid and bit a family child. This is why it is virtually never too late to get the post-exposure treatment if you discover that you have been exposed. Once it reproduces in the brain it migrates to the salivary glands and is available for transmission via a bite. It also travels on to other nerves and this is the way that corneal transplant patients have contracted rabies. This takes from a few to about ten days, and coincides with the development of clinical signs of rabies. When people ask about these clinical signs we have to say they vary quite a lot but to remember that it is usually an abnormal behavior that signals a suspect. Any abnormal behavior should make us question if there has been an opportunity for exposure. Here's a tip: if an animal other than a skunk has the smell of skunk, it should be handled with great caution as it is statistically more likely to have died of or with rabies. Likewise for the presence of quills in the nose or paws.
     Even though humans are susceptible to any strain of rabies virus, all but three of the cases of human rabies since records began are attributed to the bat strain. In part this is because they are small, nocturnal and their bites are nearly painless. Children sleeping deeply are particularly at risk. Any bat found in a dwelling should be tested. Here's something else for you to think about. The bobcat that attacked the cyclist in south central Pennsylvania was infected with the big brown bat strain of rabies. The coyote from the southeast and the fisher from the southwest had the raccoon strain. So you can see that prevention in the form of awareness and religious use of personal protective equipment to include disposable gloves and safety glasses can be key to your safety from this nearly always fatal disease.

MANGE
     Mange is a term that describes two diseases. The one, which is also called "red mange", is caused by a mite called Demodex. This is not communicable to other animals so we won't discuss it here. Its only concern to a taxidermist is the need to cover up those small often curcular patches of hair loss on the face or paws that are caused by the Demodex mite.
     A mite called Sarcoptes causes the other mange. As with Demodex, there is a mite in this genus that is specific to the species in which it causes disease. Bears are unique in that they are affected by two, the other is called Ursacoptes. Even though the mite is largely species specific, it can, unlike Demodex, cause a milder version of the disease on other species like Taxidermist humanii. People who get mites from affected dogs, or even recently dead infected animals can develop small red, intensely itchy swellings, often around the waist or on the hands and arms. Though it may not be a pleasant wait, if the person has a robust and capable immune system it will kill those mites within 7-10 days. However, if the person is one of the 10% of humans who are especially susceptible, or is taking immunosuppressive drugs, or have an immunosuppressive disease a persistent infection with non-human scabies can occur. Since the mites have to walk across some physical bridge to the new host and they can apparently hide out off of the host for a period of time, though how they do this is not well understood.
     The disease itself varies, depending on the vigor of the host's immune system. Usually what we see is some degree of hair loss but there can be other noticeable signs as well. Underlying it all is the host's immune response to the presence of the mite. The cells it mobilizes to get rid of the mite have substances in them that cause itching. Once the skin is broken down by the action of rubbing, itching, and chewing, bacteria and yeasts that are already on the skin gain a foothold and we can see any combination of sores, crusts, thickened and discolored skin, and smell a musty odor. It seems logical to me that severly affected animals would be unlikely to turn up in a taxidermist's shop, but less affected ones or those with new unapparent infections just might.

LYME DISEASE
     This is a bad disease to get, but pretty easy to prevent if you put your mind to it. Rather than go into the details of the life cycles I'll stick to the points you need for prevention. It is a bacterial disease and is transmitted by a tick called Ixodes of which there is one on the east coast. (I. scapularis) and one on the west coast (I. pacificus). If you avoid the tick you avoid the disease. If you find that a tick is attached you still have about 24 hours from the attachment before the bacteria migrates from the gut of the tick into you as it feeds. Removal of tick is straightforward. Forget the matches, Vaseline, and magic incantations. Just get an instrument like tweezers or hemostats, grab the tick firmly without crushing, as close to the skin as you can get, and pull straight back perpendicular to the skin. Then wash your hands and the instrument thoroughly with soap and water. Remember that this advice applies to the Brown dog tick, the Lone Star tick and the American dog tick too. Ticks of all stripes can make you sick with diseases like Rocky Mountain spotted fever, Ehrlichiosis, and tularemia, to name a few. If the tick has engorged with your blood, you should save it and seek medical attention from a doctor that knows something about tick borne diseases.
     The keys to prevention are practices like taping trouser legs, wearing pyrethrum impregnated clothing, and frequent tick checks. It's your health!

WHAT ABOUT THE FUTURE?
     Chronic Wasting Disease (CWD) is unique among diseases and I am extremely pleased to have a chance to offer some important food for thought to a group of professionals that play a role in its prevention. As you all probably know, it is a disease of the deer family to include elk and is caused by a disease agent that is neither a virus, a bacteria, or a parasite. The agent is called a prion and it is very dangerous. Part of what is dangerous is that it can be present in the animal before it becomes ill. In addition, once it does become ill, it can look like numerous more common diseases. To make matters worse, we know that once the prion is in the environment, as with butcher waste, it will last there for at least five years. The prion of the disease called Scrapie in sheep will last up to 18 years in the environment in Iceland, and maybe the CWD prion will too. If we've learned one thing from the states that do have CWD, it is that once you have it you must live with it. New York is the unique exception to that rule. Did you know that CWD came to New York in a head that was left with a taxidermist for mounting? This person was also a rehabilitator and a deer farmer. He is reported to have spread salt used to cure the animal's hide along his fence for weed control, and the rest is history.
     The Game Commission wants to keep CWD out of the Commonwealth. So does the Agriculture Department because of all of the propagators in the state. But we can't do it alone. We are testing any animal that comes to us that has or has died because of clinical signs consistent with CWD. We are doing our best to educate hunters who pursue elk, deer or moose in states that have CWD about our ban on bringing back high-risk parts like nervous tissue. We are also testing many elk and deer that are harvested in Pennsylvania. As you probably know, we require all elk harvested in the state to be checked. If the animal is not going to be mounted we take the CWD tissues right then and there. If it is, either for a head mount or a European mount, we provide a paid mailer with ice packs and instructions for mailing it back to the lab. We ask the hunter to get the elk to their taxidermist as soon as possible, and emphasize to the taxidermist that we need those tissues and ask them to skin and mail the head as soon as possible because the tissues will rot and lose their value. With all that is at stake I, and maybe you, would think that a taxidermist would assign some sort of urgency to this important task, but at least last year many didn't. I had to call and beg some to get the head in and when they arrived many had been either frozen (which we hope to avoid because freezing detracts from the ability to see the prion) or had rotted too much to be of use. In one case, the minimal paperwork was handled so sloppily that it wasn't clear which head was which. If one of these animals is positive we have to be able to go back to where it was shot to begin the search for other infected animals. I'm hoping that this year when the November elk season rolls around we will have better compliance. I know that's a very busy time for all of you but THIS COULD NOT BE MORE IMPORTANT, and we need your help.
     I'd like to close by encouraging all Pennsylvania taxidermists to go to our web site and view the CWD brochure and Part Ban. If you don't use a computer or would like some copies to have in your shop you may contact me and I would be happy to see that some are sent to you.

* * Walt is available to give talks to interested groups on
wildlife disease issues — give him a call. * *