Category Archives: Uncategorized

Raccoon roundworms – the hidden horror

By Anthony Olszewski

“It’s often an autopsy diagnosis; it’s horrible.” (Around 73:00)
Dr. Daniel Griffin, MD and a co-host of the Podcast, “This Week in Parasitism” at

Raccoon at outdoor cat food dish in Jersey City
What’s for breakfast!
A local volunteer caring for outdoor cats found this new face at the feeding station one morning.

Baylisascaris procyonis is a roundworm (similar to those commonly found in dogs and cats) carried by many raccoons. In the small intestine of the raccoon, this roundworm may be little more than a nuisance. The eggs are spread by raccoon dung.

Baylisascaris also infests a wide range of birds and mammals – including people. When Baylisascaris finds itself in animals other than raccoons, it bores through the intestinal tract, attacking the liver, lungs, eyes and brain.

Raccoon roundworms can be a death sentence for pigeons, doves, parrots, chickens and other birds.

Raccoon roundworm larva in a cross section of a human brain.

Raccoon roundworm larva in a cross section of human brain tissue.

In humans, detection is often difficult and too often too late. Debilitating illness, blindness, permanent afflictions and death can result. And the cases of disease discovered by doctors quite likely are far from the total number of infections. People are big so a small number of roundworms tunneling through tissue may only cause non-specific symptoms. (The eye is an exception. If only one of the parasites gets there, serious damage results.) This is far from good news. Even if the parasite fails to send a victim to an emergency room or a morgue, there’s no such thing as an acceptable number of worms eating away at the brain or other organs.

The raccoon long was an icon of the deep forest and only was expected to be found there. Indeed, the coonskin cap is associated with Davy Crockett and other frontiersman. When raccoons just inhabited rural areas, city dwellers had no reason to worry about Baylisascaris. This now is the strange new One World that has such diseases in it. Like viruses of the African rain forest that have made their way to New York, parasites of the back woods now can be found here. Raccoons — and their roundworms — reside in Manhattan, the other Boroughs and throughout the Metropolitan area.

A specific risk to public health is the increasingly common – and publicly promoted – caring for outdoor cats, if not responsibly done. Large quantities of food placed out at night or before dawn will surely attract raccoons. Regularly eating somewhere, raccoons will be regularly relieving themselves nearby and so posing a danger to people. As raccoons are secretive and only active after dark, most people will never see them. Once the animal excrement becomes part of the soil, that hides the roundworm eggs. People – especially children – then can be easily infected.

Community cats eating in street

The managing of colonies of outdoor cats is important, but must be properly implemented.

The answer is not the elimination of cats or the persecution of raccoons, but common sense. Feed community cats after sunrise and well before sunset. Only put out as much as the felines will consume, not leaving any extra for “guests.” Raccoons are native animals and so they are our neighbors. These furry fellows with the bandit mask have every right to live their lives in peace.

Anthony Olszewski is the founder of Metro Cat Rescue.

# # #

Baylisascaris Larva Migrans
USGS Circular 1412
By: Kevin R. Kazacos

Baylisascaris procyonis-the raccoon roundworm
Professor Emeritus of Veterinary Parasitology at the Purdue University College of Veterinary Medicine, Kevin Kazacos, DVM, PhD talks on Outbreak News Today about this little known, but very dangerous parasite.

Parasitic Diseases, 6th Edition – Free Download

Myxomatosis in Australian Wild Rabbits — Evolutionary Changes in an Infectious Disease by Frank Fenner

Myxomatosis in Australian Wild Rabbits — Evolutionary Changes in an Infectious Disease
Frank Fenner
Department of Microbiology, John Curtin School of Medical Research, Australian National University, Canberra, Australia

The Harvey Lectures
Delivered under the auspices of The Harvey Society of New York
1957 – 1958

Access the paper as a PDF.


A pioneer on the Web in 1996, the Web Site continues to provide unique information on a range of companion animals, especially focusing on birds and fish.

PETCRAFT was founded by Anthony Olszewski. Mr. Olszewski has published many articles on cage birds in avicultural journals in the United States, Great Britain and other countries. He authored a chapter on avian genetics for a veterinary text book and worked as an editor at a magazine produced by TFH, the world’s largest publisher of pet books. Anthony Olszewski also has written for major tropical fish journals about Lake Malawi African Cichlids and Discus. He managed a retail pet shop and ran a wholesale bird seed business.

Anthony Olszewski offers consulting services for the maintenance, breeding, and research of cage birds (particularly budgerigars, canaries, and zebra finches) to manufacturers, educational institutions and government.

PETCRAFT is very interested in contacting manufacturers of pet products seeking representation in the United States, particularly the New York City metro area. We are also eager to hear from breeders of american parakeets, canaries, cockatiels, finches and lovebirds. Please email


The very attractive Pied budgerigar has long been a favorite with pet owners and show breeders alike. Pied parakeets have irregular patches of yellow, for Green birds, or white, for Blue birds. No two birds are marked exactly alike. The distinct splashes of bright color give us feathered kaleidoscopes.
Pieds are most often seen in three different varieties: the Australian Pied, the Danish Pied, and the Continental Clearflight.

In the Australian Pied the light patches occur most often about the lower half of the parakeet. Also, all Australian Pieds have a light patch at the nape of the neck. A sub variety of this color mutation is the Banded Pied. Through selective breeding, parakeet fanciers have developed birds that show the mottling in the form of a light ring or `belt’ about the middle. These particularly attractive Banded Pieds are alway in great demand.

Exhibition enthusiasts have crossed the Australian Pieds with the more common colors of the English show budgerigar. These pioneering fanciers have produced big Australian Pieds with broad heads that win prizes at the shows. A particular plus for this variety is that all of the colors are as bright as those of the more regularly marked parakeets.

With the Danish Pied the splashing is concentrated about the head, shoulders, and chest. Though also very attractive, the Danish Pied is not often raised as a show bird. Breeders have not been very succesful in producing competition quality Danish Pieds. These birds tend to be small, on the style of the pet parakeets. This does not stop Danish Pieds from being very good pets.

The Danish Pied mutation has some secondary effects apart from the mottled patches. The depth and brightness of all the colors is somewhat subdued and reduced. To compensate for this breeders often raise the Danish Pieds in the Violet (purple), Cobalt (dark blue), and Olive (very dark green) color varieties. Since Violets, Cobalts, and Olives possess a deeper color to start with, the slight fading effect of the Danish Pied mutation is offset.

There are two other unusual facts about the Danish Pieds. When young, all parakeets have dark eyes. After the bird matures, much of the color in the eye is lost. As an adult, only the pupil will be dark, the iris ring white. This does not happen in the Danish Pieds. Here the eye remains dark through out the life of the bird.

Also, the gender of the Danish Pieds can not be distinguished by the color of the cere. The cere is the fleshy part of the bird around the nostrils, above the beak. With most colors of parakeets, the cere of the male is bright blue, the hen’s may be any other color. For the Danish Pieds, both male and female have pink or tan ceres. An educated guess can be made. In adult parakeets, the cere of the male is smooth while the hen’s tends to become rough.

The Continental Clearflights are not as dramatically marked as the other pied mutations. Here, ideally, the flight feathers and the tail feathers should be clear. Very often some of these feathers will be normally colored. Continental Clearflights also have a patch of light feathers at the nape of the neck. Sometimes a Continental Clearflight will have all of the flight and tail feathers regularly marked. In this case they can only be told from the normal birds by means of the light patch by the base of the skull.

The Continental Clearflight also is not often seen at the shows.

A curious phenomenon occurs when the Continental Clearflight mutation is combined with the Danish Pied. This blend gives rise to Black Eyed Clears. Black Eyed Clears are, as the name suggests, pure white or yellow parakeets with black eyes. Like all Danish Pieds, the entire eye remains black. This dark eye prevents any confusion with Albinos or Lutinos. Albinos are pure white birds with red eyes. Lutinos are pure yellow keets with red eyes. Black eyed clears are in great demand as pets.


The Australian Pied is a dominant mutation. This means simply that a bird must show it; they can’t be `carrying’ this mutation. Australian Pieds, like all dominant mutations, come in two forms:single factor and double factor. If you mate a single factor Australian Pied with any other parakeet, half of the nest will be Australian Pieds. When using a double factor Australian Pied, all the young will be Australian Pieds. Whether an Australian Pieds is a double or single factor can sometimes be determined by visual inspection. The double factor birds are often very light in color. Only by actually breeding the bird in question, is a true identification possible. The Continental Clearflights are also a dominant mutation. The inheritance of this mutation is of the same pattern as the Australian Pied.

Danish Pieds are a recessive mutation. With recessive genes, only the double factors will show the mutation. Birds with one factor are called `carriers’ or `splits.’ Carriers (splits) don’t look like recessive pieds, but when mated together will produce Danish Pieds.

Since the Black Eyed Clear is an blend of a dominant mutation, the Continental Clearflight, and a recessive, the Danish Pied, it takes two generations to produce. Mate, a Continental Clearflight with a Danish Pieds. Half of the babies will be Continetal Clearflights and half will appear like reguar birds. None will be Danish Pieds, unless, the Continental Clearflight parent was split for Danish Pied. In any event, pair up the babies that are Continental Clearflights. On the average, three young out of every sixteen produced from these pairings will be Black Eyed Clears.

All of the Pieds are most impressive when brightly colored. When combined with the more delicately colored keet colors, the Pastels and Greywings, for instance, much of the appeal is lost.


Please post all bird questions and news at the PETCRAFT Aviculture bird breeding Facebook Group. You also can participate in the discussions there.

Everybody is welcome to comment on each post here at PETCRAFT.

Unfortunately, due to time constraints, it’s just not possible for us to email personal replies to pet care questions. If you have any reason to believe that an animal in your care is sick, the only advice that PETCRAFT can offer is to consult a veterinarian immediately.

For all other questions about the PETCRAFT Web Site, please e-mail

The mailing / delivery address is:
297 Griffith St.
Jersey City, NJ 07307

We are very interested in hearing from manufacturers of pet products seeking representation in the United States, particularly the New York City metro area.

Thank you for your interest in PETCRAFT!