I mean that two ways.

1) Do you know what a bully stick actually is?

2) Do you know what’s in it?

A recent study headed up by Dr. Lisa Freeman, published in this month’s Canadian Veterinary Journal (Freeman et al., CVJ 2013;54:50-54), looked into this by asking people what they thought bully sticks were made of, and testing the treats for calorie count and bacterial contamination.

The answer to question 1 is: bully sticks are raw, dried bull penis (which explains the need for a cuter name).

  • Only 44% of people surveyed knew that.

Also, bull penis is considered a by-product, yet 71% of people that fed bully sticks to their dogs said they avoid by-products in food.

  • This just shows a lack of understanding about what by-products are and their nutritional value. Many people classified things that are prohibited from by-products as being by-products, such as hooves, horns, road kill and euthanized pets. By-products aren’t always bad and can, in fact, have good nutritional value. Also, they can be environmentally friendly and ethical since they are often made from nutritionally valuable parts of the animal that might otherwise be thrown out, thereby providing food for pets without taking anything out of the human food supply chain.

"What’s in it?" was approached from 2 standpoints:

Firstly, caloric content was assessed.

  • Treats often get ignored when thinking about a pet’s caloric intake, but calorie-dense treats can certainly contribute to obesity. Fifty percent of people surveyed underestimated the calorie counts of bully sticks. The average caloric density was 3 calories/gram, and given the variation in size of bully sticks, total calorie counts for a single stick ranged from 45-133 calories (9-22 calories/inch). So, yes, size matters.

Secondly (my bit part in this study), we looked at contamination by a select group of bacteria.

  • Salmonella wasn’t found, which was encouraging since high Salmonella contamination rates have previously been found in some treats (mainly pig ears), and contact with pet treats has been implicated in some outbreaks of salmonellosis in people. We found Clostridium difficile in 1 treat (4% overall). That doesn’t worry me too much since it’s increasingly clear that we encounter this bacterium regularly. With common sense and handwashing, it’s probably of little risk, but in some people (e.g. elderly, people on antibiotics, people with compromised immune systems) it might be more of a concern. We also found methicillin-resistant Staphylococcus aureus (MRSA) in one sample. This was a "livestock-associated" MRSA strain that can cause infections in people, but the risk is unclear. Theoretically, it’s a potential source of exposure. If someone got MRSA on their hands from the treat then touched their nose (where MRSA likes to live) or a skin lesion (where it can cause an infection), then it could potentially cause a problem. Overall, the risk is probably quite low, but it’s another reason to wash your hands after handling treats.

None of this means dog owners need to avoid bully sticks. It does mean that you should pay attention to what you feed your pet, think about treats when considering your pet’s caloric intake (especially if your dog is overweight), keep treats away from high risk people (e.g. don’t use a bully stick as a teething toy) and wash your hands after handling dog treats (of any kind).

Photo: A variety of bully sticks (also known as pizzle treats) often fed to dogs as chew treats (photo credit: Gergely Vaas 2006 (click for source))

Zoo Atlanta has closed its parakeet exhibit after one of the birds died of Chlamydophila psittaci infection. The concern is that this bacterium can cause infection in people (sometimes called parrot fever). Infection of humans is uncommon and usually just causes flu-like disease, but it can be very serious, especially if not diagnosed properly in a timely manner.

The zoo is going to test the flock and decontaminate the facility. The question is, "what will happen if other birds are positive?" Actually, the question probably should be "what will happen when other birds are identified as being positive?"

Chlamydophila psittaci gets the "psittaci" component of its name because it is commonly found in psittacine birds (e.g. parrots, parakeets and other related birds). The dead bird got the bacterium from somewhere, and living communally with other psittacines means that the odds are very good that multiple birds are now carrying it, since birds can carry this bacterium without any signs of disease. Varying carriage rates in psittacines have been reported in different studies, but in some groups (e.g. breeding colonies) rates can be very high.

Concern about the aviary is reasonable, since this bacterium can be spread through the air, mainly through inhalation of contaminated material that’s been aerosolized (e.g. dried feces that end up in dust in the air). If there’s no direct contact with birds, through, the risk to the public is probably very low. Some management practices can be used to reduce the risk of aerosolization of the bacterium and reduce the risk of exposure of the public. These could include using cage litter that isn’t dusty, regular and thorough cleaning of the area and cleaning in a manner that reduces the risk of aerosolizing the bacterium (e.g. wetting things down before cleaning, not using a vacuum unless it has a HEPA filter).

So, what about testing? One of my standard lines is "never do a diagnostic test without a plan to use the results." Hopefully, the zoo has thought about what they’ll do with positive results, since it’s likely they’ll have many.

Testing is a somewhat controversial area. It’s been recommended that birds in areas where they will be exposed to a lot of people be tested. That could apply here, depending on how the birds are managed. One issue with testing is it’s far from 100% accurate, so it’s only one part of the control program and testing limitations need to be understood. Testing makes the most sense in a population of birds that is closed, meaning there are no new birds coming in. That way, a couple of rounds of negative tests can give you pretty good assurance that the group is negative. Positive birds can be quarantined and treated to try to eliminate the bacterium. If most of the group is positive, it makes it pretty difficult to eliminate. A single round of testing or testing and then bringing in new birds doesn’t help too much.

Overall, the risk is greatest for zoo personnel who work with the birds and their environment. Good infection control protocols should already have been in place to reduce the risk of disease transmission, but presumably those are being revisited. It’s often a controversial subject since use of barriers such as eye protection and an N95 mask are often recommended when cleaning cages, but this is rarely done and there’s (reasonable) reluctance to do so because of the rarity of disease, the commonness of the procedures and the fact that people have been doing this for years without these extra precautions. It’s a tough area to address and it requires careful consideration of the costs and benefits. Other important points for psittacosis control include avoiding bringing in new birds, avoiding mixing of different groups of birds, checking new birds for signs consistent with C. psittaci infection before bringing them to the facility, quarantining new arrivals and educating people who work with the birds.

One key factor, regardless of what’s done, is that people who work with psittacines need to know that they are at increased risk of psittacosis. Their physicians also need to know that they work with psittacines (and that psittacosis is a potential concern). In this situation, people who have worked with the affected bird (and any other bird that might be a carrier) should know to see a doctor if they develop respiratory or flu-like illness.

Plague cases tend to get a lot of press. The fact that this disease killed a large percentage of the human population in a few different pandemics (albeit centuries ago for the most part) probably plays a role in that. Despite the impression by some that it’s just a historical disease, plague is alive and well in certain parts of the world, including parts of the US, and infects a few thousand people every year.

Plague is caused by the bacterium Yersinia pestis, which lives in various wild rodents and is circulated by fleas. Transmission to people historically has been via fleas that jump from rats to people. However, plague isn’t just a rat-human disease, as it can infect other animal species. Among domestic animals, cats seem to be most commonly infected, probably because of exposure while hunting.

The problem with plague and pets has been shown once again a case of plague in an Oregon man who likely picked up the infection from his cat. (Oregon is outside of the main range of plague in the US, where the disease is most common in the southwest). The man was bitten by the cat while retrieving a dried, decayed mouse carcass from its mouth. He developed septicemic plague (infection of the bloodstream), and then pneumonic plague (infection of the lungs), which is the worst case scenario. At last report, he was in critical condition and the prognosis for survival is probably guarded.

There’s no mention of the cat’s health. Most cases of cat-human plague occur in people taking care of sick cats (especially veterinarians). If a person is infected by a cat bite, I would expect the cat to have been sick with plague, although transmission has been reported from apparently healthy cats. Some other possible routes may need to be considered. If the cat in this case was exposed to plague, then plague’s obviously in wildlife in the area, so you have to consider that the infected man might have been bitten by an infected flea (that came directly from an infected wild animal or that the cat tracked in) or from direct contact with wildlife, especially if his house had a rodent infestation.

Regardless, it’s important for people in plague-endemic (and neighbouring) areas to be aware of plague and take measures to reduce the risk of exposure for themselves and their pets, such as:

  • Avoid contact with wild rodents (and wildlife in general, since larger wildlife species can also be infected).
  • Keep cats inside.
  • Don’t let pets with outdoor access roam unobserved, where they might be more likely to encounter wildlife.
  • Have a flea control program for pets.
  • Address any animal/household flea infestations promptly and aggressively.
  • Make sure sick pets get prompt and appropriate medical attention, since diagnosing plague in a pet may be a critical factor in prompt treatment of people infected by the pet. Plague is an example of a disease for which diagnosing infection in the pet might save the owner’s life.

People that work with animals are at increased risk for certain infectious diseases. That’s pretty clear. Pet shop employees fit into this group as well, and they may be at particular risk for specific diseases because of their close contact with young animals, birds, rodents and reptiles. A suspected case of psittacosis in a Toronto pet shop worker is an example of this.

A bird in the pet store where this person worked supposedly died of avian chlamydiosis in mid-March (although the initial test results have been called into question). Avian chlamydiosis is caused by the bacterium Chlamydophila psittaci. This organism is relatively common in psttacine birds (parrot family), especially in breeding colonies, but can also be found in other types of birds. It can cause serious disease in birds, but it is also commonly carried by healthy birds. People can become infected from breathing in the bacterium, often from aersolized dust containing dried bird droppings. The disease in people is called psittacosis. The pet store worker developed signs that could be consistent with psittacosis: cough, lethargy and difficulty breathing.  However, these signs are still fairly non-specific and could also be caused by numerous other respiratory pathogens.  Test results are still pending.

People that have close contact with pet birds, especially psittacines, need to know that they may be at increased risk of psittacosis. They also need to ensure that their physicians know about their increased risk. This is important because early signs of psittacosis are very vague, such as fever and cough. Psittacosis would presumably not be high on the doctor’s list of possible diagnoses for the average person coming in with fever and a cough. If the doctor knows a person has contact with birds, hopefully psittacosis would be considered earlier so prompt diagnosis and appropriate treatment can be given. This disease is readily treatable if diagnosed early, so awareness of the possibility on the part of the patient and physician are important.

This report also demonstrates why determining a final diagnosis for sick or dead pets is critical. While the diagnosis may not help the animal (especially if it’s already dead), it may play an important role in protecting the health of people or other animals. If the bird in this case was not tested, it’s hard to say how long it would have taken for psittacoiss to be considered in the case of the pet store worker.

More information about psittacosis can be found in a document from the National Association of State Public Health Veterinarians. More information about good management practices to reduce the risk of disease transmission from birds can be found in the information sheets on pet birds on the Worms & Germs Resources page.

Image from: http://www.cbc.ca/health/story/2009/04/01/parrot-fever.html

Pig EarPet treats derived from raw animal products such as rawhides and pig ears (yes, pig ear treats are actually dried, raw pig ears) are widely available and commonly fed to pets, particularly dogs. Being a raw product, there is an inherent risk of contamination with potentially harmful bacteria such as Salmonella. In 1999, an outbreak of salmonellosis linked to contact with raw pet treats was identified in people in western Canada. A subsequent investigation found Salmonella in over 50% of pig ear treats and 38% of other animal-derived treats. Similar results were reported by a later study in the US, and other outbreaks of disease have been reported. In Canada, the pet treat industry and government groups met and made various recommendations to reduce the risk of contamination.

To evaluate the effect of these changes, a Canadian follow-up study was performed. Only 4% of treats were contaminated with Salmonella, which was a marked contrast to the earlier study. Even so, the fact that Salmonella was present in a detectable percentage of treats means that certain precautions are warranted.

  • Always wash your hands thoroughly after handling pet treats such as rawhides and pig ears
  • Avoid buying treats from ‘bulk bins’, as there may be an increased risk of cross-contamination between treats in the bin
  • Buy packaged treats so that you don’t have to touch them directly when buying them or bringing them home
  • Never store treats in areas where other food is kept or prepared
  • Ask whether the treats you are buying have been produced under the Guidelines for the Manufacturing of Natural Pet Treats for Pets.  There guidelines were developed by the American Pet Products Manufacturers Association with input from the Food and Drug Administration (FDA)
  • Avoid buying raw treats if you have young children or anyone with a weakened immune system living in the household, as these treats may pose a small but unnecessary risk of exposure to Salmonella
  • Contaminated treats seem to be a bigger problem for people than pets, however Salmonella can also cause disease in pets. If your pet develops diarrhea after eating an animal-product treat, be sure you tell your veterinarian

Image: Pig ear dog treat from www.foodpoisonblog.com

Once again, a pet store is being sued following a death related to a pet sold at the store. Earlier, we reported a pet store being sued by a woman whose husband died of lymphocytic choriomeningitis virus. Now, a pet store is being sued after a man died of psittacosis. This disease is caused by Chlamydophila psittaci, a bacterium that is most commonly found in psittacine birds (parrot family). It can cause disease in birds but can also be carried by healthy birds. The family had purchased a cockatiel prior to the man’s illness, although details about the timing of disease, the bird’s health and whether the bird was identified as carrying Chlamydophila psittaci aren’t clear.

Typically, psittacosis causes flu-like disease and is easily treated, if diagnosed properly, however more severe disease can develop. Infected birds can shed the bacterium through feces and nasal secretions. People usually become infected by inhaling aerosolized bacteria from dried feces or nasal secretion.

Psittacosis is an uncommon disease. Only 125 human cases were reported to the CDC in the US between 2000 and 2006, however many more cases probably occurred. The risk of acquiring psittacosis from a pet bird is very low.

  • Bird owners should make sure that their physician is aware that they have contact with birds. Psittacosis should be considered in people with flu-like disease that have bird contact.
  • Do not buy birds that look unhealthy (lethargy, nasal or eye discharge, ruffled feathers…).
  • If you have other birds, isolate new birds for 30 days before allowing them to have contact with existing birds.
  • Reduce aerosolization of materials when cleaning cages. Lightly wetting cage paper will reduce the risk of aerosolization.
  • Wash your hands after handling birds or cleaning their cage.

More information on psittacosis is available in the National Association of State Public Health Veterinarians’ Psittacosis Compendium.