Another interesting article forwarded by Mr Nigel Tonkin BCSA Secretary

Hamilton & District BS is a Canadian ClubI am trusting the info that you are receiving is of value Cheers

Nigel Tonkin (Acting BCSA Secretary)

Take an in-depth look at both benign and malign avian tumors, their

treatment and prognosis.

By Rebecca Sweat

Pet birds can and do develop abnormal lumps and bumps, both on their

skin and inside their body. Of course, these bumps may or may not be

tumors. Some lumps are abscesses, which are areas of tissue that have

become swollen and inflamed by bacterial infections. Other masses are

actually large deposits of fat that are beneath the skin, similar to a

"spare tire" in people. If the bird is a female, an abdominal bulge

may in fact be an egg. Swellings can also be due to an organ, such as

the kidney or liver, enlarging from disease.

 

Many times though, a lump is actually a cyst. A cyst is a tissue sac

that is filled with fluid or other loose material. Feather cysts, for

instance, are filled with keratin. "Cysts are not cancerous and do not

grow or spread like tumors do, although they might get bigger because

they have fluid inside," noted David Phalen, DVM, an avian researcher

and associate professor at Texas A & M University. Cysts are generally

not serious, he added.

 

In contrast, a tumor (or "neoplasm" as it's known by medical

professionals) is a solid mass of tissue and, depending on the type of

tumor, it may grow very quickly and spread. A tumor can occur anywhere

on the body, and may protrude from the skin, under the skin, or grow

inside the body. Tumors are usually much more urgent matters than the

other kinds of lumps and bumps just mentioned.

 

Benign Vs. Malignant

 

Tumors come in two main types: the benign (non-cancerous) ones and the

malignant (cancerous) kinds. Either type of tumor can be

life-threatening to pet birds, but benign growths are generally

considered to be less serious than malignant tumors.

 

"Benign tumors tend to stay within one location in the body and do not

spread to other areas. They may still grow, but they proliferate very

slowly," explained Richard Nye, DVM, a veterinarian in Illinois. He

said benign tumors can normally be removed without too much trouble,

and in most cases, do not come back.

 

Malignant tumors, on the other hand, can invade and damage nearby

tissues and organs. This is done through the process of metastasis,

wherein cancer cells break away from a malignant tumor and travel

through the bloodstream or the lymphatic system to form new, secondary

tumors in other parts of the body. "Even if a malignant tumor is

removed, its cells may have gone to other tissues in the body,

resulting in the development of additional tumors," Nye said.

Malignant tumors also tend to grow faster than benign tumors, he added.

 

But while benign tumors do not metastasize, they are still not

something to just ignore, Nye stressed. "If a benign tumor's not

getting any bigger and it's in a spot where it's not causing any

problems, it may not need to be removed, but you still need to watch

it" he said. "If the tumor suddenly starts growing, that would warrant

a trip to the veterinary clinic to have the mass taken off."

 

Your veterinarian may also want to remove a benign tumor even if it

isn't growing if it is in a spot that's bothering your bird in some way.

 

Internal benign tumors can also put pressure on the bird's organs,

which can be painful or uncomfortable. "A tumor takes up space, and

wherever it is in the body, if it continues to grow, it's going to

displace or change what's going on with the surrounding organs,"

Phalen said. A benign kidney tumor, for example, can put pressure on

the sciatic nerves to the leg and make it painful for the bird to use

that foot.

 

How Tumors Form

 

Tumors are caused by errors or mutations in the DNA of cells. These

abnormal cells do not divide and replicate themselves to a certain

point and then stop, like they should. For instance, a normal skin

cell will divide and multiply just enough to make a new layer of skin

and then quit. The abnormal cell, however, will keep dividing and

forming more cells without order or control. These cells just keep

multiplying, with no end in sight.

 

These out-of-control cells can be a tough enemy to stop. For one

thing, "the outside of these cells appears as `self,' so the body's

immune system does not try to destroy them or stop them,"

Johnson-Delaney said. Furthermore, tumor cells are not controlled by

the endocrine and neurological controls that the body's cells are

normally under. "Normally a cell is programmed to die after a certain

period of time," Johnson-Delaney explained. "A cancer cell, however,

doesn't have death programmed into it properly, so it doesn't die when

it's supposed to. Instead it continues to multiply and pass on its

errors to succeeding cells."

 

Most medical researchers believe that factors such as environmental

toxins, carcinogens in the diet, nutritional deficiencies, inbreeding,

and old age can all contribute to errors in cell replication and

weaken the body's immune system. "It's your immune system's job to

clean up aberrant cells," Johnson-Delaney said. "Anything that

compromises your immune system is going to increase the odds that some

of these aberrant cells are going to slip through the cracks."

 

Common Tumors In Birds

 

There are literally hundreds of types of cancers that can affect pet

birds, everything from ovarian cancer and brain tumors, to leukemia,

lymphoma and melanoma. Older birds and excessively bred birds are most

likely to get cancer, however neoplasms can develop in any avian species.

 

The most common external tumor is in pet birds is squamous cell

carcinoma (malignant skin cancer). This form of cancer typically

occurs on the skin of the head, on and around the beak, on the eyelids

and around the uropygial (preen) gland. It is most often seen in

parakeets, lovebirds and cockatiels, although any species can be

affected. Certain factors that make the skin less healthy, such as

"vitamin-A deficiency and repeated skin injuries, may make birds more

susceptible to this type of cancer," speculated Larry Nemetz, DVM, an

exotics-only veterinarian in Santa Ana, California. Birds that are

skin mutilators may be especially prone to this disease. "When a bird

chews up its skin and mutilates an area over and over again, the cells

can start losing their way and become cancerous," he said.

 

Tumors of the fibrous, connective tissue — Fibromas or "fibroid

tumors," which are benign, and fibrosarcoma, which are malignant --

are commonly seen in pet birds. "These are fairly easy tumors to spot

and may simply show up as an unusual bump on the skin, or there may be

a couple feathers sticking up in a strange way on the bird's body,"

Nye said. Fibroids and fibrosarcomas most often appear on the wings,

legs, junction of the beak and face, neck and sternum. The birds most

often involved are budgerigars, parakeets, cockatoos and macaws.

 

Probably the most common internal tumor in pet birds is an

intra-abdominal mass, which is a tumor of either the reproductive

organs (ovaries or testicles) or kidneys. These could be either

malignant or benign. Abdominal masses are most often seen in budgies

that are between 5 and 8 years of age, according to Burge. More often

than not, these types of tumors are not detected until the bird is

emaciated and acting very sick. This, Burge said, "can be due to the

pressure the tumor puts on the digestive tract, making it difficult

for food to pass through, or droppings may accumulate around the vent

causing blockage." Some of these birds may be presented with labored

breathing as the main symptom due to the large tumor causing collapse

of the air sacs. Lameness may also be a presenting sign when the tumor

puts pressure on the nerve supply to one leg.

 

Many birds also develop cancer of the lymphatic system. In a healthy

animal, the lymphoid system is an important part of the body's immune

system defense against infectious agents such as viruses and bacteria.

Lymphoid tissue normally is found in many parts of the body including

lymph nodes, liver, spleen, gastrointestinal tract and skin. If

malignant cells invade these tissues, the disease is known as

lymphosarcoma. If the cells are benign, the disease is called lymphoma.

 

Lipomas are benign tumors that are composed of mature fat cells. "Most

of them are found just under the skin, rarely infiltrating into

muscles or organs," Burge noted. "They are very commonly found on the

upper chest and over the abdomen, although they may be found in other

locations on the bird's body." Lipomas don't usually cause birds a lot

of problems unless they get so big that they interfere with leg

movement. If they are becoming a problem, many times putting the bird

on a low-fat diet will be enough to shrink down the fatty tumor, or

even get rid of it all together. In extreme cases, lipomas can also be

surgically removed. These tumors generally occur in overweight birds

and are most commonly seen in budgerigars; and Gallah, rose-breasted

and sulphur-crested cockatoos.

 

Unlike the other tumors on this list, papillomas are not caused by

out-of-control cells but by a virus called Psittacid herpesvirus.

Papillomas appear as wart-like lesions of the oral cavity of the mouth

and of the vent. "The lesions are benign, and can sometimes come and

go without treatment," Phalen noted. "Other times they just keep

getting worse and worse, and [can] be very irritating to the bird and

start bleeding." In that situation, the papillomas would need to be

surgically removed. South American species (especially Amazons and

macaws) are seen with papillomas more often than other species.

 

Detecting Tumors

 

Like with cancer in people, the sooner you notice an abnormal mass in

your bird, the greater the success rate in treatment and the better

the prognosis. Many times, though, tumors are not discovered until

they are quite large. Or, sometimes pet owners will find a lump but

choose to just wait and see if it will go away by itself, according to

Burge. Then by the time they do take their bird to the veterinary

clinic, the tumor has reached an enormous size and may have

metastasized. "It is much safer and less expensive to remove a tumor

or cyst when it is small," Burge said, "rather than waiting until it

is the size of the bird's head!"

 

Regularly look your birds over and check them for unusual lumps and

bumps. External tumors are usually fairly easy to detect. You may see

a mass on the bird's skin or be able to feel an unusual bulge

underneath the feathers. Or you may notice an irregular displacement

of the feathers and that may clue you in. It's a good idea to have a

regular time set aside every couple weeks to give your bird a quick

examination.

 

If in doubt, consult with your avian veterinarian. The veterinarian

may determine that the mass is suspicious and needs to be biopsied,

where a tiny portion of it is taken and sent to a pathologist for

examination. "The doctor cannot tell you what type of tumor it is

without having a pathologist examine it since many different benign

and malignant tumors may look the same," Burge said.

 

Internal tumors are much harder to detect. You may just notice that

your bird won't stand on one of its feet, or maybe it is eating less,

sleeping more or has lost some weight. Of course these symptoms are

the same as would be present with many infectious diseases. The only

way to know for sure what it wrong with your bird is to take it into

the veterinary clinic for an examination. Your veterinarian will

probably do a number of diagnostic tests, including blood tests,

radiographs (X-rays) or even exploratory surgery in order to determine

what's going on with your bird.

 

Tumor Treatment & Prognosis

 

In most cases, surgical removal of the tumor is recommended. The only

exceptions would be if it is a benign tumor that is not growing or

changing, and if it is in a location on the body where it is not

interfering with the bird's normal behavior and activities. However,

if the benign tumor is getting larger or is just in a spot on the

bird's body where it is making the bird feel uncomfortable, that tumor

should be taken off.

 

In general, benign growths have a better prognosis than malignant

tumors. It may just be a matter of removing the tumor or the tissue

where the growth is located and then, for all practical purposes, the

bird is cured.

 

Malignant tumors are much more difficult to deal with because of their

propensity for metastasizing (spreading to other areas of the body).

The sooner these kinds of tumors are removed, the less likely they

will have metastasized.

 

If it's an external malignant tumor, the tumor, as well as the tissue

surrounding the growth, is usually removed. Johnson-Delaney has had

cases where she's had to amputate a bird's wing or leg because the

tumor cells were deep in the muscle or bone. "It may sound like a

radical procedure," she said, "but sometimes this is what it takes to

save a bird's life."

 

Kidney, reproductive and other internal tumors are the most difficult

to surgically remove, because the tumor will usually have a large

blood supply, and it often adheres to other organs. Trying to remove

the tumor would cause the bird to bleed to death.

 

"It's a lot easier doing this kind of surgery on dogs and cats,

because they're much bigger animals," Phalen said. "The challenge with

birds is if they have cancer in their kidney, usually we can't get to

it surgically because the breastbone and other organs are in the way.

Plus, it's doubtful that the bird is even going to survive the

surgical procedure."

The budgerigar — one of the birds most prone to developing kidney and

reproductive tumors — only weighs around 35 grams on average. "With a

small bird, there's not a lot of room for blood loss," Phalen said.

 

The sad truth for bird owners is there's not always a lot can be done

for a bird with a cancer, other than supportive care (IV fluids,

etc.). Sometimes veterinarians will try to "debulk" the tumor

(removing as much of it as possible) to reduce the tumor's mass. "This

is obviously not a cure," Johnson-Delaney said. "It just buys the

animal some time and takes away some of the pain it is probably

experiencing."

 

Chemotheraphy & Radiation Treatment For Birds

 

In some cases, chemotherapy and radiation are utilized to treat

malignant tumors, especially if it's suspected that they have spread.

Usually these treatments are used in conjunction with surgery, and

only in situations where the bird is in such bad shape that it has

"nothing to lose" by undergoing them.

 

Chemotherapy and radiation have not been used in pet birds very long,

so most veterinary practitioners have not had experience with them.

They are still considered to be radical or experimental treatments. If

you did opt for either of these procedures for your bird, you would

probably have to go to a specialty veterinary clinic or a veterinary

teaching hospital at a university to have it done.

 

"Chemotherapy uses harsh, dangerous, very toxic drugs," Nemetz said.

"What you're basically trying to do is poison the cancer but not

poison the animal. There's no guarantee it's going to work, and

there's no guarantee your bird is going to survive the treatments."

 

The two chemotherapy drugs used, Cisplatin and Carboplatin, definitely

kill cancer cells, but they can damage the cells in the bone marrow

that are producing the white blood cells and the red blood cells. Any

bird that is on this kind of treatment will be closely monitored to

make sure the white blood cell count doesn't go down too low.

 

Radiation treatments can also have a lot of negative side effects.

With birds in particular, Nye cautioned, "it's especially challenging

to try to confine the radiation to the small area that needs it, so

you end up radiating the entire animal. You kill the cancer cells, but

you also blow the bone marrow out and every other rapidly growing cell

in the body of the bird."

 

What's The Prognosis

 

If you find a lump on your bird, what are the chances of a good

prognosis? "It depends on what kind of tumor it is, where the tumor is

located, and how soon you catch it," Phalen replied. If it's a benign

external tumor that only recently appeared, chances are your bird will

be fine. But if the tumor is malignant and it's located somewhere

inside your bird's body where surgeons are not going to be able to get

at it, the prognosis, unfortunately, is probably not going to be very

good.

 

Cancer is a tough enemy to confront, and that holds true whether

you're talking about birds, people, dogs, cats or any animal. Still,

the treatment options are more plenteous for people, dogs and cats

than they are for pet birds.

 

"We're still very much in our infancy in our understanding of how to

best treat the different kinds of cancers that we see in pet birds,"

Phalen said. If a person, for instance, develops liver cancer, there

are definite treatment protocols that have been established. We don't

have that yet for pet birds, in big part due to the fact that there

are 300-plus psittacine species that each needs its own treatment

protocols.

Excellent topic..........many thanks