The Dog Cancer Survival Guide (43 page)

I use this approach with Palladia, often combined with oral cyclophosphamide to treat dogs. I am seeing early, promising results with osteosarcoma, anal sac carcinoma and thyroid carcinoma. The effectiveness of this approach needs to be monitored in further studies.

This new approach is less expensive (because you’re using less drug), easier to administer and, certainly, less toxic. However, oncologists are still learning which drugs work best with this method. There is a lot to learn about dosing, schedules and types of tumors, which respond best to metronomic chemotherapy. It’s certainly worth checking with your vet about the possibilities for your own dog’s case.

Here’s something that surprised – flabbergasted – me, when I first discovered it: certain drugs are more effective and have lower toxicity at certain specific times of day.

I spoke to the American expert on chronotherapy, Dr. William Hrushesky, about the efficacy and safety of chemotherapy drugs in relation to when they are given. According to him, cisplatin, an extremely potent and sometimes extremely toxic drug, is most effective and least toxic between 4 and 6pm.

Doxorubicin (Adriamycin) – another potent drug – is best in the early morning, right after waking. It’s more potent then, with fewer side effects, than if given at any other time of day.

Timing drug administration to the time of day – chronotherapy – is just about unheard of in the United States (although it’s not in Europe, where it has been the subject of some intense study in French human cancer trials).

All life forms (dogs, people, worms, plants, algae) share a similar “biological clock,” or circadian cycle. As the sun rises in the morning and sets in the evening, certain enzymes turn on and off at appointed times, hormones surge in and out, and organ systems accelerate or slow down.

These processes can all influence the way the body handles drugs. Perhaps, an enzyme that is very active at 10am is helpful in activating a chemotherapy drug – and helpful in suppressing nausea at the same time. Perhaps, a cocktail of hormones is released at that time, which facilitates the drug’s absorption into the cancer cells (the mechanisms are not all understood or mapped out yet).

Giving a drug at a time when it is most effective and least toxic can really help us to boost a treatment’s safety and efficacy. On the other hand, giving it when it is most toxic and least effective can have a serious impact on your dog’s health.

If the drug is more effective and less toxic, a bigger dose can be delivered – which means a bigger impact on the cancer, longer life expectancies and maybe, even a cure.

I asked Dr. Hrushesky if I could use his findings about chemotherapy drugs to help dogs in my practice, and he graciously agreed to share them with me. I am going to share them with you, too, and I want to be very clear that these results are his findings, based on studies in rats and humans (not dogs). Although these times may not yet be published in peer-reviewed journals, they represent the best, most up-to-date findings from a researcher who spends his life examining the use of circadian rhythms in administering medications.

Here are his findings:

*based on human and rodent studies

No matter which conventional treatment you use – surgery, radiation, or chemotherapy – managing side effects will be your first priority. Symptoms like nausea, vomiting, diarrhea, decrease in appetite, weight loss, anemia and immune suppression can cause a downturn in your dog’s quality of life – whether they are caused by the cancer or by the treatments. Managing these side effects can help to keep your dog’s spirits high, which is one of the most loving (and therapeutic) things you can do for your dog. We’ll talk about both conventional and alternative treatments in this section.

If your dog refuses food completely (anorexia), drools or approaches food, but doesn’t eat it, he may be nauseous. If you’ve ever been nauseous (and who hasn’t?), you know just how uncomfortable it can be. Most vets will give you some instructions on how to manage nausea at home; here are some tips:

• Withhold food completely when you first notice the symptoms of nausea.
  
• Most vets or oncologists will prescribe “just in case” medication to take home after surgery, chemotherapy or radiation. Start the anti-nausea medication as prescribed. Common prescriptions include Cerenia (maropitant, a once-per-day pill that Dr. Ettinger feels is very effective, both at home and as a preventative during treatments, if necessary) and metoclopramide (brand name Reglan).
  
• Every few hours, offer ice cubes to keep him hydrated, and see if he’s interested in putting anything in his mouth.
  
• After twelve hours, feed a series of very small meals (instead of one large one), and use the bland diet recommended for vomiting, below.
  

In addition to these measures, you can also use ginger and cimetidine, an “old-fashioned” conventional nausea medication, which has evidence for helping to slow cancer spread. These are discussed below.

Vomiting is one of the most distressing symptoms guardians confront. Most of us are familiar with how painful throwing up can be; seeing a sick dog vomit is just plain awful. Most vets will give you detailed instructions on how to handle vomiting, and here are some tips:

• First, withhold all food and water for 12 to 24 hours. Most guardians hate doing this and find it very stressful, but it is important for your dog’s wellbeing.
  
• If the vomiting is mild (a small amount or just one or two episodes), start the anti-vomiting or anti-nausea medication from your vet. The two most common, again, are Cerenia and metoclopramide (brand name Reglan).
  
• If there is no more vomiting for 12 to 24 hours, offer small amounts of water, or ice cubes, to test for nausea.
  
• If she does not vomit, after drinking water or eating ice cubes within the first 24 hours, offer a small amount of a very bland diet. You could offer her protein in the form of boiled chicken, boiled ground beef that has been strained of fat, or cottage cheese, mixed with a little white rice. Another option is a commercial diet such as Eukanuba Low Residue or Hill’s ID.
  Chapter 14
  lists diet recommendations and my strong opinions about not feeding white rice to cancer patients. The exception is in the case of vomiting or diarrhea. If your dog is experiencing these symptoms, she is feeling really badly, and that is our top priority. A little white rice to stop the rollercoaster in her intestines is perfectly fine.
  
• If the first small meal does not trigger vomiting, continue to feed the bland food in small meals every few hours and gradually mix in her regular diet until she is eating her normal food in normal amounts again.
  
• If the vomiting is severe (three or more episodes, large amounts, or blood in the vomit), if it persists for more than 24 hours, or if it is accompanied by a fever of 103° or higher, bring her in for emergency care immediately.
  

Ginger and Cimetidine can also both help with vomiting, as discussed below.

Diarrhea is both messy and irritating – both for you and your dog. If your dog’s feces are runny and smelly, and he can’t seem to control when or where he goes, here are some tips:

• Offer your dog the bland diet described above at his next meal. Also make sure to offer him fresh water in a clean bowl. As his feces return to normal, you can gradually add his normal food to the bland diet, until he’s eating his regular food in regular amounts with no diarrhea.
  
• If you were sent home with an anti-diarrheal medication, start the medication, as prescribed. Common choices include metronidazole (brand name Flagyl), sulfasalazine and tylosin (brand name Tylan).
  
• If that doesn’t work, or if you don’t have a prescription anti-diarrheal, you could use the over-the-counter medication, bismuth subsalicylate (brand name Pepto-Bismol) every six hours. Give 2 to 2.5 ml of the liquid version for every ten pounds of body weight (there are 5 ml in a teaspoon). Some dogs dislike the taste of Pepto-Bismol; refrigeration can help to dull the flavor. Pepto-Bismol turns stools a gray-black or greenish color, which can make it hard to see blood in the stool. A possible cause of vomiting is a bleeding ulcer, which would turn the stool bright red or black and tarry, depending upon where the ulcer is in the digestive tract. To make sure you can evaluate the poop for blood, you may want to use Imodium (see below).
  
• In any case, do not use Pepto-Bismol for longer than five days. Pepto-Bismol rarely causes any other side effect.
  
• An alternative to Pepto-Bismol is another over-the-counter medication, loperamide, brand name Imodium. It uses a different mechanism to relieve diarrhea, and is an opiate, so it has more side effects than Pepto-Bismol. If your dog becomes constipated (strains or cannot eliminate), seems depressed or has slowed heart or breathing rates, contact your vet immediately. Collies and related breeds are particularly sensitive to Imodium. Check with your veterinarian before using Imodium, because certain health conditions can make it harmful, including respiratory diseases, severe kidney disease, hypothyroidism, and Addison’s disease. The dosage for dogs is 0.2 mg/ml per pound by mouth every eight to twelve hours. It comes in either liquid or capsule form; the dosages are the same for each. Stop using Imodium if your dog is still experiencing diarrhea 48 hours after starting the medication.
  
• If diarrhea is severe, bloody, or black, or if it persists for more than 48 hours, or if it your dog has a fever of 103° or higher, bring your pet in for emergency care, immediately. See how to take your dog’s temperature on
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