Introduction
Cancer is one of the most common and serious diseases affecting companion animals such as dogs and cats. Advances in veterinary medicine have significantly improved the ability to detect, diagnose, and treat various types of cancer early, improving survival rates and quality of life.
One of the most valuable diagnostic tools available today is computed tomography (CT) scanning. CT scans provide detailed, cross-sectional images of internal body structures, allowing veterinarians to accurately locate tumours, assess their size and spread, and plan appropriate treatment strategies.
At Malahide Veterinary Clinic, we have direct access to CT through our sister practice, meaning no referral is required in many cases. If you’d like to learn more about what we offer, you can also explore our full range of veterinary services.
Understanding CT Scanning
Computed tomography (CT) is an imaging technique that uses X-rays and computer processing to create detailed, three-dimensional images of tissues and organs inside the body. Unlike traditional X-rays, which produce flat, two-dimensional images, CT scans take multiple images (called “slices”) from different angles around the body.
A computer then reconstructs these slices into detailed cross-sectional images that can be viewed individually or combined into a 3D representation.
In veterinary practice, CT scanners are similar to those used in human medicine. Your pet is usually placed on a motorised table that moves through a circular scanner. Because the animal must remain perfectly still, sedation or general anaesthesia is often required. The entire process typically takes between 10 and 30 minutes, depending on the region being scanned and the level of detail required.
If you’d like to browse more CT-related educational posts, you can view our CT Scans articles.
How CT Scanning Detects Cancer
Cancer can develop in almost any organ or tissue, including the bones, lungs, liver, lymph nodes, and brain. One of the key challenges in diagnosing cancer is identifying tumour location, size, and the extent of spread (metastasis).
CT scanning is particularly useful because of its high spatial resolution and ability to distinguish between different types of tissue based on density.
When an animal undergoes a CT scan, X-ray beams pass through the body and are absorbed in varying amounts by different tissues. The computer measures these differences and constructs a detailed map of internal structures. Tumours often appear as abnormal masses or regions that differ in density from surrounding healthy tissue.
In many cases, veterinarians also use contrast agents — special dyes injected into the bloodstream — to highlight specific organs or blood vessels. Contrast-enhanced CT scans can help differentiate tumours from normal tissues and reveal blood flow patterns that can be important in cancer diagnosis.
Advantages of CT Scanning in Veterinary Oncology
CT scanning offers several advantages over other diagnostic imaging techniques such as radiography (X-rays) and ultrasound:
1) High Detail and Accuracy
CT provides highly detailed images, allowing veterinarians to detect even small or subtle abnormalities that might be missed on standard X-rays. This is especially important in detecting early-stage cancers or small metastases.
2) Three-Dimensional Visualisation
Unlike flat radiographs, CT scans can be reconstructed into three-dimensional models. This helps veterinarians visualise the exact location and extent of tumours relative to surrounding tissues, blood vessels, and organs.
3) Assessment of Bone and Soft Tissue
CT is particularly effective for imaging both soft tissues and bone structures. This makes it ideal for detecting cancers of the nasal cavity, skull, lungs, abdomen, and bones, where overlapping structures can make standard X-rays difficult to interpret.
4) Pre-Surgical Planning
Accurate localisation of tumours through CT scans allows surgeons to plan procedures more effectively, minimising damage to healthy tissue and improving the chances of complete tumour removal.
Common Applications in Dogs and Cats
CT scanning has a wide range of applications in veterinary oncology. Some of the most common uses include:
1) Nasal and Sinus Tumours
Dogs, in particular, are prone to nasal tumours that can cause chronic sneezing or nasal discharge. CT scans can show the extent of the tumour, invasion into surrounding bone or sinuses, and whether it has spread to nearby structures.
2) Lung and Chest Tumours
CT is considered the gold standard for detecting lung metastases in both dogs and cats. It can reveal small nodules that are not visible on standard radiographs, helping determine whether cancer has spread beyond its original site.
3) Brain and Spinal Tumours
While MRI is often preferred for detailed brain imaging, CT remains a valuable tool for detecting tumours in the skull or spine, especially when MRI is not available.
4) Abdominal and Liver Masses
CT can identify tumours in the liver, spleen, kidneys, and other abdominal organs. It helps distinguish between benign and malignant masses and assess whether the cancer has spread to other organs.
5) Bone and Joint Tumours
CT is particularly useful for diagnosing osteosarcoma, a common and aggressive bone cancer in dogs. The scan can reveal how far the tumour has invaded surrounding bone and soft tissue, guiding treatment decisions such as limb amputation or radiation therapy.
Conclusion
CT scanning has revolutionised the way veterinarians diagnose and manage cancer in dogs and cats. Many Malahide pets have benefited from our direct access to CT scanning. By providing highly detailed, three-dimensional images of internal structures, CT allows for accurate detection and localisation of tumours, evaluation of metastases, and precise treatment planning.
Although CT requires specialised equipment, trained staff, and sedation/anaesthesia, the diagnostic benefits often outweigh the limitations in most cases. As technology continues to advance, CT imaging will play an increasingly central role in improving cancer care for companion animals — helping pets live longer, more comfortable lives.
