Are Animals Stuck In Time?

Dog owners, who have noticed that their four-legged friend seem equally delighted to see them after five minutes away as five hours, may wonder if animals can tell when time passes. Newly published research from The University of Western Ontario may bring us closer to answering that very question.

The results of the research, entitled "Episodic-Like Memory in Rats: Is it Based on When or How Long Ago," appear in the current issue of the journal Science.

William Roberts and his colleagues in Western's Psychology Department found that rats are able to keep track of how much time has passed since they discovered a piece of cheese, be it a little or a lot, but they don't actually form memories of when the discovery occurred. That is, the rats can't place the memories in time.

The research team, led by Roberts, designed an experiment in which rats visited the 'arms' of a maze at different times of day. Some arms contained moderately desirable food pellets, and one arm contained a highly desirable piece of cheese. Rats were later returned to the maze with the cheese removed on certain trials and with the cheese replaced with a pellet on others.

All told, three groups of rats were tested in the research using three varying cues: when, how long ago or when plus how long ago.

Only the cue of how long ago food was encountered was used successfully by the rats.

These results, the researchers say, suggest that episodic-like memory in rats is qualitatively different from human episodic memory, which involves retention of the point in past time when an event occurred.

"The rats remember whether they did something, such as hoarded food a few hours or five days ago," explained Roberts. "The more time that has passed, the weaker the memory may be. Rats may learn to follow different courses of action using weak and strong memory traces as cues, thus responding differently depending on how long ago an event occurred. However, they do not remember that the event occurred at a specific point in past time."

Previous studies have suggested that rats and scrub jays (a relative of the crow and the blue jay) appear to remember storing or discovering various foods, but it hasn't been clear whether the animals were remembering exactly when these events happened or how much time had elapsed.

"This research," said Roberts, "supports the theory I introduced that animals are stuck in time, with no sense of time extending into the past or future."

Source: William Roberts
The University of Western Ontario

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Paralysis Outbreak In Meat Workers Handling Pigs' Brains

The US Centers for Disease Control and Prevention issued an update last week to its investigation of an outbreak of a paralysing condition that is affecting certain meat processing plant workers who use compressed air to remove the brains from the heads of pig carcases.

The illness is called Progressive Inflammatory Neuropathy (PIN) and its symptoms range from acute paralysis to gradual increase of weakness on both sides of the body, which in some cases happens over 8 days and in others over 213 days. The symptoms vary in severity from slight weakness and numbness to paralysis that affects mobility, mostly in the lower extremities.

The current thinking, which is yet to be proved, is that the meat workers are being exposed to splatter and aerosol droplets of pig brain tissue created by the compressed air blast, which liquefies the tissue before expelling it from the pig skull. Once inhaled, small particles of pig brain tissue are then is attacked by the worker's immune system which uses antibodies that also attack the body's own almost identical human nerve tissue.

Following the PIN outbreak in a Minnesota meat processing plant, the CDC launched a nationwide survey of large slaughterhouses and found two more meat plants that had used the compressed air system recently. One of the plants was also reporting cases of a neurologic illness among its meat processing workers.

The outbreak came to the attention of the Minnesota Department of Health (MDH) in October last year, when it started getting reports of an unexplained neurologic illness among meat processing workers in a swine slaughterhouse in Southeast Minnesota, and which the CDC calls "plant A".

The MDH conducted a full and detailed investigation of the plant, which employs some 1,200 workers and processes 18,000 pigs a day. They interviewed workers and looked at health records, and found a total of 12 employees who have either been confirmed as having PIN (8 so far), probably have it (2), or possibly have it (2).

The 12 workers, six of whom are female, started having symptoms between November 2006 and November 2007 and reported being healthy beforehand. They ranged in age from 21 to 51 years.

According to the MDH, 11 of the 12 workers affected showed evidence of axonal or demyelinating peripheral neuropathy (damage to nerve fibres and surrounding protective tissue). Spinal fluid taken from 7 of the workers showed they had high protein levels with little or no rise in pleocytosis or white blood cell count. A raised white blood cell count is usually evidence of inflammation.

However, five patients showed evidence of inflammation when examined by spinal MRI (magnetic resonance imaging), four of them in peripheral nerves or roots and one in the anteorior spinal cord.


All 12 affected workers said they either worked at or had contact with the area of the plant where pig heads were processed (called the "head table"). The head table was in an area of the plant known as the "warm room".

The MDH conducted a case-controlled study that included 10 of the 12 workers (the 8 confirmed and the 2 probable cases of PIN), and two control groups: a random selection of 48 healthy workers from the warm room, and all 65 healthy workers from the head table. After examining throat swabs and blood samples from the consenting participants, the MDH to date has not found any infectious agent that could explain the PIN symptoms.

Futher results from the case-control study showed that 7 of the 10 workers with PIN (70 per cent of the case patients) were seven times more likely to have worked at the head table than the controls from the warm room (25 per cent, or 12 of 48). Case patients were also more likely to have handled brains and muscle from pigs' heads than members of either control group.

Travel outside the US or inside the US, exposure to chemicals, including fertilizers and insecticides, or having had vaccinations, were also not found to be causes of the PIN illness.

The health authorities then investigated the processing methods and safety equipment in the warm room and the head table in particular, and concluded, for now, that the compressed air method used to liquefy and remove the brain tissue from the pigs' heads could be causing the PIN through creating aerosol droplets of brain tissue that is then inhaled by the workers.

The plant operator has suspended use of the compressed air equipment voluntarily and stepped up use of personal protective equipment (PPE), including face shields and long sleeves for the head table workers and any other workers who want to use additional PPE, said the CDC report.

Following the Minnesota plant A outbreak report, the CDC surveyed all 25 federally inspected swine slaughterhouses in the US with more than 500 employees. They found three plants, including Minnesota plant A, using the compressed air method to remove pigs' brains. The other two are in Nebraska and Indiana. Of those, only the Indiana plant has reported cases of suspected PIN, which are currently being further assessed. In the meantime, all three plants have stopped using the compressed air method to remove brain tissue, said the CDC.

The CDC said that:

"Whether compressed-air devices are being used for pig-brain extraction in other slaughterhouses or processing facilities, in the United States or internationally, is unknown."

"Clinicians should provide CDC with information regarding swine slaughterhouse workers who might have illnesses similar to PIN, including patients with peripheral neuropathy, myelopathy, or features of both."

If doctors se any patients who work in slaughterhouses with these symptoms, they should report them to their state health department and also let the CDC know on 770-488-7100.

A puzzling feature of this outbreak was raised by the plant owner at one of the affected plants, who started as a floor walker in 1970. He told the Washington Post that they had been "harvesting pig brains since 1998, using the same method and the same 70-pound pressure air hose." So why did the outbreak not take place ten years ago, when they started using the method? The plant owner said that was the "million-dollar question".

"Investigation of Progressive Inflammatory Neuropathy Among Swine Slaughterhouse Workers --- Minnesota, 2007---2008:."

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Treating Dog And Cat Bites To The Hand: Gnawing At Solutions To This Prevalent Problem

An estimated two million Americans are bitten by a domestic animal each year and 50 percent of Americans will be bitten in their lifetimes, posing a potential major public health issue. According to a study published in The Journal of Hand Surgery, dog and cat bites to the hand can result in serious injury, sometimes requiring hospital admission and surgery. Many of these injuries, however, can be lessened or prevented through early treatment and more careful animal handling.

The old adage, "Don't bite the hand that feeds you," apparently does not apply to man's four-legged friends: In more than 80 percent of domestic bite incidents, the victim knows the animal. Of the nearly 4.7 million dog bites that occur each year -- accounting for approximately 80 percent to 90 percent of domestic animal bites -- about 2 percent of these bites require hospitalization, constituting 1 percent of all U.S. emergency room visits.

The study, which was an extensive review of 111 cases of dog or cat bites to the hand, wrist or forearm, found that injuries ranged from relatively minor wounds to major injuries that included open fractures and persistent deep infections. Approximately two-thirds of patients in the study group required hospital admission at least for intravenous antibiotics, and approximately one-third of animal bite victims in the study required at least one surgical procedure. More than 10 percent of patients required long-term intravenous antibiotics and/or multiple surgeries, incurring medical expenses in excess of $77,000.

However the study also found that many of those cases would have been far less severe if the patient had sought treatment earlier. The average time from injury to evaluation by an orthopaedic hand surgeon was nearly eight days.

"If you have an animal bite to your hand, even from a pet you know, you should seek treatment immediately," stressed lead author of the study, Leon S. Benson, MD, orthopaedic surgeon at the Illinois Bone and Joint Institute in Glenview, Ill., and Fellow of the American Academy of Orthopaedic Surgeons. "Most people don't -- they think it's not that serious or worry there will be consequences for the pet -- so they wait to see a physician and then the injury is more difficult to treat."

Dr. Benson noted that a bite might just need antibiotics on the day it happened, but once an infection has had a few days to set in, the bite could end up requiring far more extensive and costly treatment. Many of the injuries seen in the study could have been prevented if the patient had known to exercise more caution with the animal.

"Most of the animals biting people are not strays or dangerous pets," Dr. Benson said. "They're biting because they're in a position where an animal would naturally bite: They're hurt or frightened, or they're fighting with another animal and the victim tried to separate them."

Because the study's patient population was selected from a small geographic area over a relatively short collection period, the results also suggest that domestic animal bite injuries may represent a major public health issue.

"Early treatment is going to make or break an injury," Dr. Benson emphasized. "If you get bitten, go to the emergency room right away so the bite can be assessed and treated early."

No external funding was provided for Dr. Benson's study. An orthopaedic surgeon is a physician with extensive training in the diagnosis and nonsurgical as well as surgical treatment of the musculoskeletal system including bones, joints, ligaments, tendons, and nerves.

With more than 29,000 members, the American Academy of Orthopaedic Surgeons (http://www.aaos.org ) or (http://www.orthoinfo.org ) is the premier not-for-profit organization that provides education programs for orthopaedic surgeons and allied health professionals, champions the interests of patients and advances the highest quality musculoskeletal health. Orthopaedic surgeons and the Academy are the authoritative sources of information for patients and the general public on musculoskeletal conditions, treatments and related issues. An advocate for improved patient care, the Academy is participating in the Bone and Joint Decade ( http://www.usbjd.org ) -- the global initiative in the years 2002-2011 -- to raise awareness of musculoskeletal health, stimulate research and improve people's quality of life.

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Dog Allergies

For a person with dog allergies, life in a dog-loving country isn't easy. Nearly 40% of U.S. households have a dog. Dog dander gets everywhere, including places where dogs have never set a paw. According to the National Institutes of Health, detectable levels of pet dander are in every home in the U.S.
So how can you get through life with an allergy to man's best friend? Here's a rundown of the causes and treatments of dog allergies, along with tips on reducing your exposure.

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Symptoms of Dog Allergies

The symptoms of dog allergies are usually like those of any other nasal allergy. They include:

• coughing and wheezing
• red, itchy eyes
• runny, itchy, stuffy nose
• sneezing

Some people with dog allergies also have skin reactions. For instance, their skin might break out where a dog licks them. Others with more severe allergies might develop hives on their face or chest. People with asthma as well as pet allergies can have especially serious symptoms.

Causes of Dog Allergies

You may have heard that some dog breeds trigger allergy symptoms while others don't, or that short-haired dogs are safe while long-haired dogs prone to shedding are not. But on the whole, experts say that isn't the case. In fact, one dog and another of the same breed can give off very different levels of allergen.
It's not the dog's hair or fur that's the real problem. Instead, people are usually allergic to the dander -- flakes of dead skin -- as well as the saliva and urine. So no matter how long or short the hair, any dog can potentially cause an allergic reaction.
You might wonder why dog dander has such an effect on you. People with allergies have oversensitive immune systems. Their bodies overreact to harmless substances -- like dog dander -- and attack it as they would bacteria or viruses. The sneezing and watery eyes are just the side effects of your body's attempt to destroy or flush out the allergen.

Testing for Dog Allergies

Your doctor can do either a skin test or a blood test called a RAST (radioallergosorbent test) to find out if you have dog allergies. Even if you're pretty certain that you're allergic, testing is always a good idea. Some people who assume that they have dog allergies turn out not to have them. Instead, they're allergic to the pollen or mold that the dog is carrying in on its coat from outside.
While allergy tests are helpful, they're not always conclusive. So if you own a dog, your doctor might want you to try living without it for a while to see how you do. To get a good sense of your symptoms, it might take some extended time apart. It often takes months before the level of dander in the house drops down to a level resembling that of a house without a dog.

Treating Dog Allergies

Dog allergies can be treated with standard allergy drugs. Your doctor might recommend:

• Antihistamines , which block the effects of a chemical that triggers dog allergy symptoms. They're sold over the counter -- like Allegra, Claritin, Benadryl, or Zyrtec -- or some by prescription. Some antihistamines are available as nasal sprays -- for instance, Astelin.
• Decongestants , which reduce swelling in the nose and relieve congestion. Examples are over-the-counter Sudafed and Allegra-D.
• Other medicines, which affect allergy or asthma symptoms in different ways. Prescription steroids -- such as Flonase or Nasonex sprays -- are a common treatment for allergies.

Allergy shots are another option for people with dog allergies. They don't work for everyone, and a full course of treatment can take years. But they can really help some people with pet allergies. Talk about the pros and cons with your doctor.

Your Environment and Dog Allergies

Most allergists agree that although medicine may help, the best way to control dog allergies is to avoid contact with dogs. Here are some tips:

• Keep your distance. Don't touch, pet, or kiss a dog. As best you can, avoid going to homes with dogs. If you have to stay in a house with a dog, ask if it can be kept out of the room in which you'll sleep for a few weeks beforehand.
• Use your medicine. If you know that you'll be coming into contact with a dog soon, prepare by starting up your medicine a few weeks ahead of time. By taking medicine preventatively, you can stop an allergic reaction before it starts.
• Be wary of visitors who own dogs. Dog dander can cling to clothing and luggage. So even if your house guests leave their dogs at home, they can bring the dander with them -- and that can cause you a lot of trouble.

Of course, some of the above advice won't help that much if you already have a dog in your home. Even then, there are still things you can do:

• Clean fanatically. Dog dander can get everywhere. So you need to sweep and mop the floors, vacuum rugs and clean furniture regularly. If possible, get a vacuum with a HEPA filter. Regular vacuum filters can't catch the allergens and just send them back into the air.
• Make your home easier to clean. Pull up the carpet. Get rid of the rugs and drapes. Ditch the dusty, overstuffed furniture. Reducing the number of items that can catch dust and dander can help with your dog allergy symptoms.
• Filter the air. Central heat and air conditioning can push dog dander into every room in your house -- even those that the dog isn't allowed in. A central air cleaner -- as well as filters on the vents themselves -- can help.
• Keep the dog out of your bedroom. Since you spend a third of every day in the bedroom, it's key to keep it as free of dog dander as possible. A closed door won't completely seal out the allergens, but it will help.
• Don't give the dog free rein. Protect yourself by making other areas of the house dog-free too. Depending on your climate and surroundings, you can also consider keeping the dog outside as much as possible.

Your Environment and Dog Allergies continued...

Will bathing your dog have any effect on your allergy symptoms? Experts aren't sure; some studies have shown that baths reduce the amount of airborne dander, while others haven't found a difference. You can certainly try out weekly baths and see what happens. Just make sure that someone without dog allergies is doing the actual bathing.
You may find that these techniques help your dog allergies. But if they don't, you have to consider more drastic measures -- like giving the dog up. It's hard to do, but you have to think realistically. It's unfair to people with dog allergies if they can't be in their own homes without enduring a runny nose and relentless sneezing fits. Uncontrolled allergies can also contribute to asthma, which is a serious disease.
So if you or a family member has dog allergies, talk to a doctor. Getting control of your symptoms will not only make you feel better, but it will help protect you from becoming sicker.

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