Cancer is defined as abnormal uncontrollable cell growth that spreads to other body parts. It is also technically called neoplasm. Neoplastic cells are described with three P’s: Persistent Purposeless Proliferation.  

Canine cancer refers to the development of cancerous cells in dogs. Like humans, dogs can also suffer from various types of cancer, and it is one of the leading causes of death in older dogs. Cancer occurs when normal cells in the body undergo genetic mutations that cause them to divide and grow uncontrollably. These abnormal cells can then form masses or tumors, invade nearby tissues, and spread to other parts of the body. 

There are 65 million dogs in the United States as per Animal Cancer Foundation. Roughly six (6) million new cancer diagnoses in dogs are made each year. However, it is important to note that this increase in incidence could be due to increased awareness and the number of pet parents seeking veterinary care for canine cancer. 

• Lymphoma - cancer develops from lymphocytes, a cell of the immune system that circulates through the blood. It causes enlargement of multiple lymph nodes and systemic disease. 
  
  
• Hemangiosarcoma - cancer that develops from the blood vessels and tumors found in different parts of the body but mostly in the spleen, liver, skin or heart. Internal bleeding is a common episode causing pale gums, weakness, decreased appetite, lethargy, and a painful abdomen.
  
  
• Osteosarcoma - common in large breeds and usually starts in one of the limbs leading to lameness.
  
  
• Mast Cell Tumor - most common skin cancer in dogs arising under the skin and occasionally in chest or abdominal cavities. Interior tumors may be hard to recognize but exterior ones may be visible non painful masses.
  
  
• Soft Tissue Sarcoma - slow growing masses that occur anywhere in the body. It originates from the connective tissues of the body forming groups of tumors and histologically graded I to III according to how rapidly the tumor is dividing. It includes many different types of sarcoma. 
  
  
• Tumors of the Oral Cavity - most common ones are  squamous cell carcinoma and fibrosarcoma, melanoma.

• Nasal Tumors - tumors found in the nasal cavity and sinuses. Signs could range from epistaxis (nose bleeding), sneezing, facial disfigurement or protrusion of an eyeball. Because these are also signs of other diseases, CT scan is usually recommended to confirm if it is a case of cancer. 
  
  
• Anal Sac Cancer - tumors affecting the scent glands located in the anus of dogs with high possibility of becoming malignant (apocrine gland adenocarcinoma). It affects both sexes aging around 10 years of age. This is a serious condition requiring immediate medical intervention. It can infect one or both sacs, but usually a unilateral case. 
  
  
• Liver Cancer - a localized tumor called a “silent killer in dogs” due to the absence of apparent clinical signs. Hepatocellular carcinoma is the most common type which is a single large tumor within the liver.
  
  
• Bladder Cancer - there are different types of bladder cancer but the most common is the Transitional Cell Carcinoma (TCC). This is usually seen in older small-breed dogs with genetic predisposition in Scottish terriers.
  
  
• Stomach Cancer - one of the most devastating cancers in dogs though not common. It usually does not show any signs until it reaches its advanced stage. A benign case could be mast cell tumor whereas malignant cases could be gastric adenocarcinomas, leiomyosarcomas, and alimentary or gastrointestinal lymphomas.
  
  
• Mammary/Breast Cancer - mammary tumors in dogs can occur in any of their 10 mammary glands but mostly found in the two sets close to the hindlimbs of intact female dogs (botch) over seven years of age.
  
  
• Testicular Cancer - these are tumors found in the testicles of male dogs of any age. Although they commonly occur in dogs 10 years or older or those which have undescended testicles (cryptorchid). The most common types are Sertoli cell tumors, interstitial (Leydig) cell tumors and seminomas. 
  
  
• Skin Cancer - each layer of the skin can develop certain types of tumor. Some of the most common skin cancers in dogs are Malignant melanoma, Mast cell tumors, Squamous cell carcinoma, Histiocytic cell tumors, and Fibrosarcoma. Mast cell tumor is the most common skin cancer in dogs arising under the skin. Aside from skin, melanoma can also develop in lips, eye, toenail bed, intestine and other unusual places.
  
  
• Thyroid Cancer -  tumors that affect the thyroid gland which is responsible for releasing important hormones regulating metabolism and help control major functions of the body.

Diagnosing cancer in dogs involves a combination of clinical examination, diagnostic imaging, laboratory tests, and sometimes, biopsy or other specialized procedures. Here are some common steps and methods involved in the cancer diagnosis process for dogs:

• Physical Examination - Upon presentation, veterinarians begin with a thorough physical examination of the dog. They look for any lumps, bumps, or abnormalities, check for changes in weight, and assess the overall condition of the animal.
  
  
• Blood Tests - Blood work can provide information about the overall health of the dog and may indicate the presence of certain types of cancer. Aside from Complete Blood Test (CBC) and Blood chemistry, specific blood tests, such as those measuring tumor markers, may be recommended in some cases.
  
  
• Diagnostic Imaging
  • X-rays (Radiography) - X-rays can help identify abnormalities in the internal organs and bones.
  • Ultrasound - Ultrasound imaging is useful for examining soft tissues and organs, such as the liver, spleen, and lymph nodes. Changes in echogenicity show abnormalities of contents. Growths can also be measured. 
  • CT Scan or MRI - These imaging techniques provide more detailed cross-sectional images of the body and are particularly helpful in identifying the extent of the disease. Blockages in the blood vessels can also be observed.
    
    
• Fine Needle Aspiration Cytology (FNAC) - involves examining cells obtained from a mass or tumor. The sample is taken with a needle, placed in a clean glass slide, fixed and added with stain. It helps determine if a mass is cancerous and, if so, what type of cancer it is.
  
  
• Biopsy - A biopsy involves taking a small sample of tissue from the suspicious area for examination under a microscope. This is often the most definitive way to diagnose cancer and determine its type.

• Histopathology - After a biopsy, the collected tissue is sent to a board certified pathologist for histopathological examination. This detailed analysis helps confirm the type and grade of cancer.
  
  
• Specialized Tests - Depending on the suspected type of cancer, additional tests may be conducted, such as immunohistochemistry or molecular diagnostics.
  
  
• Staging - If cancer is confirmed, staging helps determine the extent of the disease and whether it has spread to other parts of the body. Staging is crucial for planning an appropriate treatment strategy.

Treatment options for canine cancer may include chemotherapy, radiation therapy, and, in some cases, surgery. The specific treatment plan depends on the type and stage of cancer, as well as the overall health and status of the dog. Chemotherapy is commonly used and can be effective in inducing remission. These drugs could be Vincristine, Lomustine, Cyclophosphamide, Chlorambucil, Prednisone, or L-Asparaginase.

Alongside medical treatments, supportive care is important. This may include managing symptoms, providing a balanced and nutritious diet, and addressing any side effects of treatment.

• Gastrointestinal Upset (Nausea and vomiting)
• Decreased Appetite
• Lethargy and Fatigue
• Bone Marrow Suppression
• Hair Loss (Alopecia):
• Mucositis
• Allergic Reactions
• Changes in Blood Chemistry
• Infection Risk

Cannabidiol (CBD) is a naturally occurring compound in the cannabis plant without psychoactive properties. The oil is extracted from the CBD plant through carbon dioxide extraction, ethanol extraction, isopropyl extraction, lipid infusion or steam distillation. 

Full spectrum CBD oil also contains other cannabinoids and other plant substances because they are the least processed extract type. Paw Origins CBD Full-Spectrum (1,000MG) Happy-Furever™ Oil takes advantage of the benefits of the “entourage effect”. 

Broad-spectrum CBD oil has undergone further process to remove the THC content but the other cannabinoids are still retained. This process removes the beneficial effects of THC observed in full-spectrum CBD products due to the “entourage effect”.

Gallily, Yekhtin, and HanušCBD Oil isolate is a pure isolated form of CBD product. It underwent further processes to remove all the other cannabinoids. By removing all the other components, the benefits of “entourage effect” is also displaced.This refined CBD product has no discernible odor or taste, however, beneficial effects may be less notable as well. As noted in the study of Gallily, Yekhtin, and Hanuš (2015), CBD isolate has more clinical limitations in pain and inflammation as compared to full-spectrum CBD product.

Entourage effect is the concept that substances that are taken together would give better results than when taken individually due to their synergistic interaction. In the context of CBD, this is the teamwork of the 80+ cannabinoids, 100+ terpenes, and flavonoids found in the hemp plant working together to produce the desired “healing effect”.

The endocannabinoid system (ECS) is an ubiquitous major lipid system in the dog’s body consisting of endogenous ligands (endocannabinoids), their receptors and enzymes, providing homeostatic balance of the different organ systems, particularly the nervous and immune system. 

Platto, et al (2022)CBD Oil could alleviate canine cancer due to its healing properties such as:

• Anti-Tumor Medication - CBD inhibits tumor cell viability, invasion, metastasis, angiogenesis, and the stem-like potential of cancer cells (McAllister, Soroceanu & Desprez, 2015). Another study showed that CBD was able to produce a significant antitumor activity both in vitro and in vivo, suggesting a possible application of CBD as an antineoplastic agent.
  
  
• Reduce Inflammation and Pain - Gamble, et al (2018) reported that 2 mg/kg twice daily of CBD oil significantly decreases pain and increases activity in dogs. 
  
  
• Enhance Sleep - CBD blocks anxiety-induced REM (Rapid Eye Movement) sleep alteration via its anxiolytic effect (Hsiao, et al, 2011). According to Platto, et al (2022) anxiety-related behaviors in dogs before and during the Covid-19 lockdown in China were associated with changes in their sleeping habits, which might suggest a deterioration of their welfare.
  
  
• Help with Nausea - CBD has both anti-nausea/anti-emetic effects (Parker, Rock, and Limebeer, 2011)
  
  
• Boost Immune System - CBD has anti-inflammatory and immuno-modulating properties in dogs' immune cells by reduction in IL-6 and TNF-α production (Gugliandolo, et al,  2021).
  
  
• Improve Appetite - there is still no concrete conclusion yet as to how CBD increases appetite in dogs. However, some human scientific studies show that CBD increased appetite as a side effect  to epileptic patients given with CBD (Corroon and Phillips, 2018; Iffland and Grotenhermen, 2018; Hussain et al, 2015)

CBD comes in different forms with different benefits.

CBD oil tinctures are CBD oil mixed with carrier oil and added with flavors to make it tastier and easier to take. The container often comes with a dropper to administer the CBD oil directly in the dog’s mouth or to add to dog food.

CBD capsules are CBD oil placed in a capsule to mask the oil taste, so it may be easier to get your dog to take these.

CBD treats come in both crunchy and chewy forms with CBD oil, to suit your dog's taste buds. These are consumed as they do their other treats.

CBD topical products are also available for dogs for skin-related symptoms or localized symptoms under the skin. These are applied like any other lotion or other topical product.

The supportive potential of CBD Oil in dogs' cancer care is promising. Some of the preliminary studies on the role of CBD in cancer have been presented in this article. We can say that CBD alleviates the symptoms of CBD and side-effects of chemotherapy. However, it is important to note that cancers can’t be totally cured with a high incidence of recurrence. In some severe cases, euthanasia had been an option. Nonetheless, managing cancer should focus on the dog’s quality of life.