Cancers in rodents

[Diggie's Friend]

Incidents of cancers have been found to commonly occur in rats.

To a lesser degree they have been found to occur in tree squirrels cared for in captivity, this mostly associated with obesity, but also with infections.

This procedure to remove a large cancerous growth from the intestines of a rat, and resection the bowel, was successfully accomplished.

Rather amazing to see this done on such a small animal, yet with todays technology it is now possible. Warning this file contains photos of graphic content!

[cava]

I noticed they were very specific about the amount of Isoflurane v O2 used for induction and maintenance during diagnostics. This info would be valuable for anyone working with a vet who is doing this for the first time with a rodent.

Thanks for sharing!

[Diggie's Friend]

Well spotted Cava!

I have another file on anesthesia I will post under that title.

[Diggie's Friend]

Liver cancers: causes and carcinogenisis

https://focusontoxpath.com/lectures/Models-of-Liver-Carcinogenesis.pdf

[Diggie's Friend]

Liver cancer in notably has the highest incidence in rats and mice of all other organs of the body.

In prairie dogs, a virus has been found to promote liver cancer.

https://journals.sagepub.com/doi/full/10.1354/vp.41-4-353

[Diggie's Friend]

In Germany Liver disease is treated with sources that have one particular compound in common, quercitin.

As noted in a research paper on this issue, Both Milk Thistle seed extract and Pycnogenol contain this same compound, that was originally ignored, for reason of the health promoting properties in the polyphenols that these sources both contain. The other source noted to contain this compound common to these sources is onions; yet onions contain amines that cause anemia in rodents, so that one isn't a whole food that should be included in the diet of rats or tree squirrels.

https://www.researchgate.net/publication/221795706_Hepatoprotective_Effects_of_Pycnogenol_i n_a_Rat_Model_of_Non-alcoholic_Steatohepatitis

[Diggie's Friend]

'Long term' regular consumption of Soy stresses the pancreas which can lead to the development of pancreatic cancer.


https://www.thehealthyhomeeconomist.com/not-just-bad-for-hormones-how-soy-harms-digestion-and-stresses-the-pancreas/

[Diggie's Friend]

Article on the effect of CBD on cancer cells


In 2011, researchers from the Beth Israel Deaconess Medical Center in Boston, MA, examined the effects of CBD on breast cancer cells.

The study was conducted in vitro, meaning either in a test tube or sample dish, rather than on an actual living organism. Nonetheless, the results were impressive:
The researchers found that CBD helped induced the programmed death of the cancer cells while causing minimal damage to healthy cells.

How exactly CBD does this, however, wasn’t clear. We know that CBD interacts with the body’s Endocannabinoid System, but the researchers noted that the effects they observed happened independently of any cannabinoid receptor activity.

They did notice, however, that CBD somehow helped organize autophagy (the destruction of damaged tissue) and apoptosis (programmed cell death).

Seeing that cancer is characterized by the unnatural growth and death of cells, the fact that CBD might help regulate cell growth and death is big news.

In 2011, the journal of Breast Cancer Research and Treatment published another similar study on CBD and its effects on breast cancer cells. This study, however, was done in vivo on mice.

The researchers noted that CBD helped to slow the proliferation of the breast cancer cells.
Furthermore, they also found that CBD helped reduce the metastasis of the tumor cells.

The authors of the study noted that this is clear evidence of CBD’s anti-tumor effects and suggested it is a promising compound that should be the study of further clinical trials.
They also noted that CBD helped reduce the expression of ID-1, a gene that plays a vital role in the development of aggressive breast cancer.

Other studies have also shown similar results on other cancers.
In 2003, for example, researchers found cannabinoid receptors CB1 and CB2 present in both healthy and cancerous skin cells in mice.

https://www.healthline.com/health/cancer/cbd-for-cancer#side-effects

[Diggie's Friend]

This veterinary journal (not a research animal study) is the record of the occurance of a specific form of Lymphoma in an elderly pet Eastern Gray Squirrel. Since most with squirrels in non legal States may not take a pet squirrel to their vet, this journal is of special importance as it provides information on the occurance of a specific form of lymphoma in a tree squirrel.

After the removal of the lesion, that the squirrel didn't have a reoccurance within the time recorded, is notable.

https://www.jstor.org/stable/20460390
In rats lymphomas are mostly fatal.
Other forms of lymphoma occur in rodents, both in rats and tree squirrels; in rats all forms are commonly fatal. In this tree squirrel after the surgical removal of the lesion it apparently didn't return. This isn't to sa that it couldn't, for as the journal specifically notes it was expected to return.

This is just one form. for photos (Fig. 1) see Ratguide.com for this form of lymphoma. It doesn't start out looking crusty, but ends up this way when the lesion breaks open. Other forms of lymphoma in rodents manifest in lumps just under the skin. In most all cases lymphoma is a disease common to rodents of advanced age.

https://ratguide.com/health/neoplasia/lymphomas.php

What is noted in research is advanced age in which the immune system lowers. Exposure to bacteria, viruses, herbicides and pesticides are amongst the other promoters of this disease in aged rodents.

Should you have had a squirrel in the past or present that developed one of these three forms of lymphoma;I I would welcome you to post your experience on this thread, along with any photos of your or another's squirrel while it was alive. Pleases also include a warning to other members that viewing the photos may be upsetting.

Thank you, DF

[Diggie's Friend]

In cancers common to rodents, viruses, toxins, and aging are the most common factors.


"Secondary testicular tumors can develop when metastasis has occurred from another area of the body.
Metastatic conditions that can be responsible for secondary tumor development in the testicles are lymphoma and leukemia."



"Even though it is rare in rats for testicular tumors to metastasize to other areas of the body;
the recommended treatment for these tumors is orchiectomy (neutering or removal of the testicles).
This is because the inevitable growth of these tumors can cause ureteral and bowel obstruction."

To read more on various forms of testicular cancers in rodents, see Ratguide.com .

[island rehabber]

DF, does your research mention anything about dietary causes of tumors in rats?

The nature center where I work adopted three young rattie brothers, all albino, to keep them from being sold as boa or python food. Somewhere in the course of learning about them, I read that citrus fruits should never be given to male rats as they cause cancerous tumors. We do feed tangerines and oranges to other animals at the center, so i wanted to be sure we should keep avoiding these. (The bro's smell the citrus fruits and really want them!)

[Diggie's Friend]

See my PM :grin2

[Diggie's Friend]

Along with advanced age, viruses are also noted to promote cancers.


Abstract
Cutaneous epitheliotropic T-cell lymphoma with liver metastasis was diagnosed in a 10-year-old eastern chipmunk (Tamias striatus). Physical findings included intracutaneous swellings, ulcerated plaques and nodules, hypotrichosis and erythema of the skin. Fine needle aspiration from the skin lesions showed a population of large lymphocytes and lymphoblasts, and was helpful in establishing the diagnosis antemortem. The post-mortem examination revealed epitheliotropic lymphoma with liver metastasis. [B] Immunohistochemistry proved the T-cell origin both in the liver and skin tumours. Electron microscopy did not reveal any viral particles within the tumour. To the authors' knowledge, this is the first case of lymphoma described in this species .

[Diggie's Friend]

https://www.jstor.org/stable/20460390

A 12 year old gray squirrel which was found to have developed Epitheliotropic Lymphoma.


There was no local recurrence, new lesions, or evidence of metastasis 10 mo after surgical excision.

I repost this file to emphasize the importance of seeking veterinary support for both diagnosis and potential treatment as soon as any growth or lesion is discovered on the outside of the body, or lump that can be felt under the skin, is found. This for reason of the potentiality that it might turn out to be a form of cancer, or benign tumor which some forms are also known to spread also resulting in damage to internal organs and structures.


Journal Information
The Journal of Zoo and Wildlife Medicine publishes original research findings, clinical observations, and case reports in the field of veterinary medicine dealing with captive and free-ranging wild animals. It also publishes editorials, review articles, and special reports relevant in this field.

[Diggie's Friend]

Liver cancer found to occur in Woodchucks from WHV Hepatitis-B Virus


Woodchuck hepatitis virus (WHV) infects naturally the Eastern woodchuck (Marmota monax) that habitats large areas within North America, including most eastern and midwestern states in the United States, southeastern Alaska, and southern Canada[22]. WHV was initially discovered in 1977 at the Philadelphia Zoo in a colony of woodchucks where several animals died due to chronic hepatitis B and HCC


Woodchuck hepatitis virus in natural woodchuck populations
G V Tyler, J W Summers, R L Synder
PMID: 7241716 DOI: 10.7589/0090-3558-17.2.297

Abstract

Woodchuck hepatitis virus (WHV) was discovered in serum samples from captive woodchucks (Marmota monax) at the Penrose Research Laboratory in December, 1977. WHV belongs to the same class of viruses as hepatitis B virus (HBV), the cause of serum hepatitis in man. Both appear to be associated with chronic hepatitis and hepatocellular carcinoma in their respective hosts. Woodchucks were trapped and blood samples collected to determine the prevalence of WHV in natural woodchuck populations. Sera from 217 woodchucks trapped from southeastern Pennsylvania, central New Jersey, and north central Maryland during the spring and summer of 1978 and 1979 were tested for evidence of WHV infection. In 1978, 7 of 51 (13.7%) woodchucks were positive for WHV antigens and in 1979, 28 of 166 (16.9%) tested positive. In addition, 49 of 166 (29.5%) woodchucks trapped in 1979 had antibodies to WHV antigens. The data indicate a high prevalence of WHV in woodchucks from the areas surveyed.

[Diggie's Friend]

Forms of lymphoma in rats: https://ratguide.com/health/neoplasia/lymphomas.php