Inflammatory Bowel Disease In Your Ferret – IBD
Ron Hines DVM PhD
All animals have their special health issues. In ferrets, problems within their digestive system often challenge ferrets in their midlife years. The next most common health issues are adrenal gland problems, which you can read about here. Many veterinarians believe that both problems are in part due to the way we care for domestic ferrets – particularly in the United States. We tend to feed them diets that have too much carbohydrate content, we neuter ferrets at too early an age and many ferrets lack sufficient daily exercise and cage space leading to obesity. It is also not that uncommon for older ferrets to suffer from both diseases simultaneously.
Inflammatory Bowel disease in your pet is also called Irritable Bowel Syndrome. Others call it chronic colitis, lymphoplasmacytic gastroenteritis, ferret wasting disease, proliferative colitis, or proliferative bowel disease. When the ferret’s intestinal lining and/or stomach remain irritated over extended periods, immune system cells are found in abundance in those areas (lymphocytes and/or eosinophils). It is unclear if those cells are responsible for the inflammation or arrive to combat it.
Two types of IBD exist depending on which of these two immune system cells predominate: lymphoplasmacytic gastroenteritis and eosinophilic gastroenteritis. Both have a tendency to eventually become cancerous. So, IBD in ferrets might be an underlying cause of adult-onset digestive tract lymphoma, another health issue common in older ferrets.
Many cases that veterinarians once thought were due to Epizootic Catarrhal Enteritis (ECE), Helicobacter infections or Aleutian Disease of Mink are now believed to be ferret IBD.
Although veterinarians can never be sure of the cause(s) of IBD in your ferret, all cases involve some degree of chronic inflammation of its digestive tract. Any portion of the tract – from the esophagus to the colon – can be inflamed more than others. Depending on the digestive tract portion most involved and its severity, stool consistency and color changes, and diarrhea and vomiting are the most common signs. This inflammation often decreases the ferret’s desire to eat. So weight loss is a very common sign. Intestinal inflammation also lowers your ferret’s ability to absorb critical nutrients, so lack-luster hair coats, decreased energy (lethargy) and increased shedding are common. When severe, blood and mucus may also be seen in your ferret’s stools. That blood loss through intestinal ulcerations can eventually lead to anemia.
Your ferret’s liver and gall bladder are also intimate participants in digestion. So liver-associated problems (hepatitis) sometimes occur as well. Lack of liver enzymes and faster transit time through the intestinal tract often lead to poorly digested (“poppy seed”, “grainy” “jelly-like”, “mucousy” greenish) appearing stools. Stools tend to be bulkier and passed more frequently. That can lead to anal irritation.
In most ferrets IBD disease progresses quite slowly. Early signs are easily missed. Stool changes occur gradually – over months or years. These pets loose weigh and condition so gradually that many ferret owners think their pet is just getting old.
Less frequently, the problem appears suddenly, with loose or bloody (tarry) stools, tender tummies, depressed mood, nausea, fever/subnormal temperature and a disinterest in food. When these various symptoms occur suddenly (acutely) IBD can be confused with coronavirus infection of ferrets or intestinal obstruction due to swallowing objects they shouldn’t.
You or your veterinarian might even palpate lumps in the pet’s abdomen when IBD is present. Those are intestinal (mesenteric) lymph nodes that surround the intestines. They have become enlarged in response to the chronic intestinal inflammation.
The speed at which IBD changes occur and their severity varies greatly between ferrets. Many never develop the more severe symptoms. Some just remain underweight, picky eaters. In some, the symptoms come and go. I mentioned earlier that the lymph nodes surrounding the ferret’s intestines often respond to the chronic irritation occurring in the lining of the pet’s digestive tract by producing more lymphocytes. Many veterinarians believe that that can eventually lead to lymphoma, a type of cancer.
Veterinarians suspect that there are a number of issues that can result in IBD in ferrets. The symptoms of IBD, blood analysis, physical exam and even the pathologist’s biopsy reports just confirm that digestive tract inflammation is present – not the reason for that inflammation. Not much money is spent on ferret health research. So, most of what veterinarians suspect is driving the inflammation in your ferret is taken from what they know occurs in other animals and people with similar chronic intestinal problems.
In the future, some theories will probably be proven to be true in ferrets, but others will most likely be found not be valid at all. When your veterinarian is unsure as to what the underlying IBD cause in your ferret might be, it can be scientifically called idiopathic(=cause unknown) IBD.
Many cases of chronic intestinal inflammation in pets and humans are caused by errors in immune system function – mistakes in what that system determines to be a threat to the body. That could be specific ingredients in the diet (“food allergies”) or other environmental factors yet to be identified. It could be genetic defects in the immune system due to inbreeding. It could be exposure to a virus, bacteria or parasite that permanently alter immune system function or induces autoimmunity. (read here)
We know that a particular bacteria, Helicobacter mustelae, can be isolated from many ferrets that have inflammatory gastrointestinal problems. (read here) However, that bacteria is also present in ferrets that appear perfectly healthy. Very few, if any, suppliers of pet ferrets can keep their colonies free of this organism. At one time veterinarians believed that this bacteria might be the primary cause of ferret IBD. But now it appears that some other stress must be present to weaken the ferret before Helicobacter can result in gastrointestinal problems. When it does, the type of pathology seen is an invasion of the stomach lining with lymphocytes and plasma cells, two defensive cells of the body. The idea that Helicobacter is important in this condition is reinforced by the fact that many ferrets get relief when they are given antibiotics. However, the fact that the symptoms of IBD have natural peaks and valleys makes it hard to be sure if the pet actually improved because of the antibiotic that were given. Besides, antibiotics are most often given to ferrets in combination with dietary changes and immunosuppressive medications like prednisone that are known to decrease inflammatory symptoms.
Another organism, Lawsonia intracellularis, was isolated in the mid-1980s from weanling ferrets with intestinal inflammation – and once from a mature pet ferret in 1989. Whether this organism is important in the common clinical problems veterinarians see in pet ferrets is unknown.
A variety of other opportunistic environmental bacteria can take advantage of an inflamed intestine (dysbiosis). This overgrowth of these undesirable bacteria can add to an already existing IBD problem. In that situation antibiotics to suppress the growth of these unwanted organisms or dietary probiotics might lead to a decrease in IBD symptoms.
Coronavirus have been associated with intestinal inflammation in ferrets. (read here) The disease is called Epizootic Catarrhal Enteritis. When this virus is associated with intestinal disease, it is usually in very young ferrets. We do not know if a prior coronavirus infection plays any part in the chronic intestinal problems so common in mature ferrets, but such things have been known to happen subsequent to viral infections or when viral infections are persistent such as the cat coronavirus. (read here & here) Rotavirus have also been implicated in a similar disease in young ferret kits.
Veterinarians know that chronic diarrheas occur in dogs and cats due to allergies and intolerances to food ingredients. What most ferret owners feed their pets is not a very good approximation of what ferrets would eat in the wild. Some cases of IBD in ferrets improve when the meat protein content of the pet’s diet is increased or the meat source is changed and when the carbohydrate/starch content is reduced. It is certainly worth a try.
Stress alone is capable of causing diarrhea in ferrets. I find ferrets less expressive than dogs, cats and people in showing overt signs when they are under stress. In that sense, they are more like wild animals – concealing stress and illness in an attempt not to get eaten. Stress has a direct influence on the intestinal motility of all animals. Just ask your vet’s techs how much time they spend moping the waiting room. Things like excessive room temperature, overcrowding, noise, fear and over-exertion all have the potential to cause diarrhea in ferrets. If these stresses occur chronically the problems will be chronic as well. Remember that any combination of the above stressors can exist together and that a venting outlet, once established, can be hard to cure.
There is a report from McGill University that a lack of sufficient vitamin A in ferret diets causes diarrhea, cataracts and behavioral changes in ferrets. You can read that article here. The best natural sources of vitamin A are egg yolks and liver. Too much vitamin A in capsule or injectable form can be toxic.
The diagnosis of a probable case of IBD is usually not difficult when you describe typical signs to your veterinarian.
It is considerably harder when the signs are subtle. Blood analysis in those cases can be normal, but in some instances serum lipase and ALT levels are abnormally high. It is also common for the ferret’s blood globulin level to also be elevated. In the United States, those tests are best performed at an experienced central veterinary diagnostic laboratory such as Idexx or Antech Diagnostics rather than “in house”. However, elevation of any of these test results also occur in a number of non-IBD related ferret health issues. Their greatest value, when any of these tests are elevated, is in judging the effectiveness of treatment in bringing them down to normal levels.
When the diagnosis is still in question, or when your veterinarian desires to know if the chronic intestinal inflammation associated with IBD has progressed to intestinal lymphoma cancer, the only reliable method of diagnosis is obtaining small snippets of tissue from the pet’s intestine and surrounding tissues (biopsies). Because of their small size, it is difficult to obtain these samples using a non-surgical endoscope. Most veterinarians prefer obtaining these samples surgically (through laparotomy). Confirmation that IBD exists does not increase your veterinarian’s treatment options.
X-rays of your ferret’s abdomen might show enlarged intestinal lymph nodes suggestive of IBD – but they are not diagnostic.
If your pet is young and your veterinarian suspects that coronavirus might be involved, your vet might collaborate with the Michigan State University ferret interest group.
However, in the vast majority of cases, the diagnosis of IBD is made because the ferret gets better when known IBD treatments work.
Since IBD is a catchall diagnosis of uncertain origin, tests do not tell your veterinarian the best way to proceed. Treatment is through trial and error – generally concentrating on test periods on alternative diets aided by medications like prednisone that are known to calm intestinal inflammation. Your vet will probably include other things: perhaps an off-the-shelf probiotic (I prefer those with multiple strains of “good” bacteria such as Marshall’s ProBiotic 11), perhaps antibiotics to lessen intestinal bacterial overgrowth. When diarrhea and/or weight loss is not severe, I prefer trying products one at a time to see which really help.
Diet Changes
Some ferret owners find that hypoallergenic diets designed for cats improve their ferret’s situation. Those can be diets containing novel proteins such as duck, rabbit, venison, etc. in place of beef or chicken. They can also be feline diets that have been processed to only include small meat protein amino acid segments (hydrolyzed). That is thought to make them less allergenic (e.g. Purina HA feline®, Hill’s Z/D feline®, etc.). When you change your ferret’s diet, do so gradually.
Sick ferrets need to be coaxed to eat and drink. Delightful meat smells are the best way I know of to do that. Ferrets do not mobilize their body stores of energy well when fasting, so they must not go with insufficient food for extended periods. Ferrets that vomit or have diarrhea become dehydrated rapidly and exhaust their body stores of fluid and electrolytes as well. So, they need to be provided with electrolytes such as Pedialyte™ when they are still drinking or with subcutaneous fluids when they are not. If your ferret is tuning its nose up at its food or if it is simply losing weight, Gerber’s chicken baby foods often help. However, baby foods are not nutritionally adequate as a sole, long-term, diet for your ferret. I have several webpages devoted to a new appetite stimulation product called Entyce®. If you have experience giving it to ferrets, let me know.
The most common medication given to ferrets to decrease the gastrointestinal tract inflammation associated with IBD is the corticosteroid, prednisone. Citing the many side effects of corticosteroids like prednisone and prednisolone, some veterinarians suggest that ferrets with IBD receive azathioprine (Imuran®), a drug that also suppresses immune system function, as an alternative. However, I question whether the potential side effects of azathioprine are any less severe than those of prednisone. If side effects on either of these medications are unacceptable to you, try the other. If you can avoid either altogether or give them only sporadically, do so.
Because intestinal inflammation decreased the ferret’s ability to absorb crucial nutrients, many veterinarians include a multivitamin supplement (especially one containing cobalamin =Vitamin B-12) in their treatment plans. Some give the initial dose(s) by injection.
Many ferrets have shown marked improvement soon after being placed on oral amoxicillin or metronidazole antibiotics. Because neither of these medications are dangerous when given in the correct dosage, one, both or an alternative antibiotic are included initially in most IBD therapy plans. Even when the underlying IBD problem is not directly caused by bacteria, metronidazole seems able to lessen the diarrhea. Perhaps this is through some unique property of the drug; perhaps it is by removing opportunistic bacteria and other pathogens that are secondary invaders taking advantage of your weakened pet.
Medications that coat, soothe and protect the lining of the stomach and intestine help in all forms of intestinal inflammation. The most common ones used in ferrets are salicylate-free bismuth subsalicylate and sucralfate. Do not give these medications to your ferret without your local veterinarian’s supervision.
Some find medications that decrease stomach acidity also to be helpful. These are called H-2 antagonists (e.g. Tagamet®) and Proton-pump inhibitors (Prilosec®, etc.). Do not give these medications to your ferret without your local veterinarian’s supervision.
Antispasmodics are medications that decrease gastrointestinal tract motility. Relaxing these organs often lessen nausea, vomiting and diarrhea. They also have a number of side effects and, like antacids, should not be given other than on the advice of your personal local veterinarian.
ALT is an enzyme whose blood level tends to increase when a ferret’s liver has been damaged. If your ferret’s blood work shows an increased level of ALT (normal ferrets have an ALT average of 110.0 iu/L [normal range=49.0–242.8 iu/L ]), an ursodeoxycholic acid supplement might be helpful. Simply not eating can raise that enzyme lever in cats as they develop hepatic lipidosis. The same might be true in ferrets, but we are unsure of that. (read here) The supplement is frequently prescribed to women for early onset liver issues (itching, etc.) associated with pregnancy.
Ferrets that are feeling under the weather need special care and pampering. Don’t play or exercise them more than they are cheerfully willing to do. Protect them from your children, other pets and other ferrets. Give them their own special places and see to it that the temperature of their environment is neither too hot nor too cold. Purchase a digital scale and keep a diary of the ferret’s weight. Monitor your pet’s rectal temperature. It should remain between 101.5 and 102.5 F (38.6 – 39.1 C).
With that special care, proper diet and medications, flare-ups can be minimized – but never completely eliminated. Carefully monitor your pet’s food intake and weight regularly and keep its life as stress-free as possible. Do not board them. With time, you will see flare-ups coming and know what will get your pet through them successfully. Ferrets with IBD issues have lived quite a long time. If you have other suggestion you wish to add, please let me know, and I will post them here.
