There are many different cancers which can occur in dogs, including some which are rare in other animals. Just like in humans, a cancer can be growing for some time before symptoms show and even when they do, they can mimic other conditions which are found more commonly and so time can be wasted on the wrong medical regime. A careful owner will weigh up all of the signs they see and take the dog to the vet if the animal is clearly unwell. It will help diagnosis if the owner has a good working knowledge of the dog’s usual behaviour, to explain to the vet.
Lumps and Bumps
Not all cancers are felt as a lump, of course, osteosarcoma in its early stages, leukaemia, brain tumours being just some, but it is important to remember that not every bump is a malignancy. But it is equally important not to shy away from the facts and to get to know your animal so that any unusual swelling or bump is dealt with appropriately. If a lump is felt on a dog, or if the dog’s behaviour, rubbing on the ground, for example, biting or scratching draws attention to it, it is important to get treatment urgently. It may be an abscess or a bite, which can be just as serious as cancer, in that it is acute and may have consequences in hours rather than weeks or months. If the lump turns out to be malignant, early surgical intervention if often all that is required.
Another reason for really knowing your dog is so you can recognise behaviours likely to indicate serious illness quickly. Often the first sign of a brain tumour, whether benign or malignant, is an unusual pattern of walking, head shaking or mood swings. A brain tumour does not have to be malignant to be life threatening – the build up of pressure in the skull can have its own consequences, even though the tumour itself is non-invasive and will not cause secondaries elsewhere. In some slowly growing brain tumours the first signs that one is present is that the dog will have fits. As these can be very slight and would appear in a human as ‘petit mal’, a fit in which no falling or tremor is exhibited, they can be very hard to spot, especially if your dog is the kind who likes to sleep a lot and so is often drowsy and a bit lethargic. Snappy moods are something else altogether and should be dealt with immediately – this is not just for the good of the dog, but for general health and safety, especially if the dog is likely to be coming into contact with children.
Loss of Appetite
Loss of appetite in cases of cancer can occur because the dog is feeling generally very unwell and simply doesn’t fancy food, or it may be because it has an obstruction due to a bowel malignancy. Bowel cancer occurs in people more than seventeen times as frequently as it does in dogs and if dogs were fed a totally natural diet this could perhaps be explained that way. However, many dogs are fed a highly processed diet, so there is as yet no explanation for the difference. More likely is that the dog is just feeling ill and the lack of appetite is just a general marker for ill health. It is important not to let this state of affairs go on too long, even with no other symptoms, as it takes a healthy dog to beat any disease process and in the case of some cancers the treatment is quite aggressive so it will need to be in good condition other than its underlying condition.
Blood in Urine
Blood anywhere it shouldn’t be is always a marker for disease, but blood in the urine is a very scary thing to notice in your pet, although almost always it simply means that the dog has a urinary tract infection. If this does not respond to antibiotics, a biopsy is often undertaken and then bladder cancer is often found to be the cause. Treatment with surgical intervention is tricky and it is usually found that the cancer has metastasised by diagnosis, so the usual route is chemotherapy or radiotherapy, which can give reasonable survival rates if used aggressively.
Cancer can be a silent killer and amongst the most insidious onsets is that of haemangiosarcoma, a cancer of the lining of the blood vessels. As the cells affected are epithelial cells this cancer is very similar in aggression to many skin cancers and this cancer is essentially untreatable. It occurs mostly in dogs over middle age for their breed and for unknown reasons tends to be more commonly found in Golden Retrievers and Alsatians. It is basically a painless cancer with no real symptoms until it has metastasised extensively and fewer than 50% of dogs who develop this disease live longer than six months. Many dogs which suffer from it are never even diagnosed, as internal bleeding of catastrophic onset is usually both the first symptom and the cause of death.
General Signs to Watch for
As with any disease process, cancer can strike at anytime and anywhere. Apart from some cancers which have a proven environmental link, it is not possible to prevent the onset of a malignancy although keeping the dog in general good health and in a stress free, happy environment will go a long way to ensuring that it avoids many of the more serious diseases to which it could otherwise fall prey. Careful monitoring of the animal is crucial and setting aside time in every day for some quiet time with your pet could be as beneficial to you as to the animal, as experiments have shown that stroking a dog can bring down the blood pressure in the human half of the partnership, as well as making for one happy dog!