Alerting pet owners to potentially fatal and
often undiagnosed order. |
Beagle Pain Syndrome by Darlene Verenski Does your Dog Suffer from this Potentially Fatal and often Undiagnosed Disorder? It began on Sunday night when our ten-year- old beagle, Dallas, wouldn’t eat his dinner. By Friday morning he was blind and by that afternoon it appeared to be a life or death situation. Thanks to his general vet he was referred to a veterinary neurologist and diagnosed with a disorder known as “beagle pain syndrome” in time for treatment. What is “Beagle Pain Syndrome”? “Beagle pain syndrome” (BPS), the name used by researchers at the College of Veterinary Medicine, Cornell University, is the most common name for a naturally occurring disorder characterized by recurring episodes of fever and neck pain that persist for at least 3-7 days. Inflammation occurs in the brain and spinal cord as well as inside and around the small to medium sized arteries throughout the body, specifically in the extramural coronary arteries of the heart. The few studies done to date have not discovered a cause. It is speculated that the condition is an immune mediated disorder due to its course of flare- ups (exacerbations) and remissions and also because of its response to corticosteroids (Veterinary Pathology, July, 1995). There is possibly a genetic factor: one study mated two affected beagles and one in seven of their offspring were also affected with onset of symptoms at a young age. What are the Symptoms? Patricia M. Robidoux, breeder of beagles for over thirty years and Webmaster of the Regal Beagle website, relates her experience with her dog Spencer: “We first noticed Spencer was lethargic, shuddering and seemed to be in pain. He walked with a "hunch" in his back and was hesitant about climbing up on the sofa or going up steps.” These symptoms are commonly the first observed in the syndrome. Most frequently observed symptoms in this syndrome include lack of appetite, fever over 101 degrees, discomfort when being lifted, painful opening of the mouth and an unwillingness to move. The characteristic “hunched stance” is a unique feature of Beagle Pain Syndrome. The dog stands with back arched, neck extended and head lowered (Toxicologic Pathology, 1989). The tail is also lowered due to neurological changes that affect the muscles of the hindquarters. Diarrhea is a less common symptom. Poor coat and skin condition have also been reported. Blindness, which affected Dallas, is considered a rare effect. What can be Expected During the Course of the Syndrome? We noticed the first symptom in our beagle, Dallas, on Sunday night when he refused his dinner. This was unusual for him, but we had traveled that weekend and assumed that he was simply tired and out of routine. The next morning, he was very lethargic. His tail, which usually wagged eagerly, was hanging limply. Within twenty-four hours he could no longer manage to climb the six-inch step into the house on his own. Tuesday morning I scheduled an appointment with the vet. By the time we got there he seemed much better; tail wagging, walking normally, acting interested in his surroundings. The vet noticed that his coat was a bit thin and suggested that a thyroid disorder might be the problem. Dallas had blood drawn, and we went home to await results. Dallas was doing so much better that he was able to go for his walk that evening. Wednesday morning was a different story. His posture was hunched and he seemed unable to lift his head or his tail. He walked with a staggering gait and lost his balance with every few steps. He was unable to lift either of his back legs to urinate, and he yelped when we tried to pick him up. He refused all food we offered to him. Studies have shown that BPS has a sudden onset that usually occurs in young beagles; the age of onset was between four and forty months in most studies. Clinical symptoms last approximately three to seven days followed by two to four weeks of remission (no noticeable clinical symptoms). Most laboratory results return to normal during the periods of remission as reported by Terence J. Hayes, V.M.D., Ph.D., (Toxicologic Pathology, 1989, the Society of Toxicolgic Pathologists). There is typically a repeat of this pattern for several cycles followed by a long period of remission. Symptoms in some cases, however, continued unremittingly for one to two months. Ensuing loss of physical condition, especially atrophy of head and neck muscles, and increased head and neck pain can be expected as the syndrome progresses. We adopted Dallas when he was already approximately 5 years old. Since he was nearly 10 years old when we first saw symptoms it is likely that he had the first onset as a puppy and was in a state of remission until this occurrence. What Tests are Used to Diagnose the Syndrome? The diagnosis of B.P.S. is often a process of elimination. When other reasons for the symptoms are eliminated the diagnosis becomes clearer. The first test the vet suggested for Dallas was a blood workup to determine whether or not his thyroid was functioning properly. Hypoactive thyroid can cause lethargy, poor skin condition and deconditioning of coat. When the results of the thyroid test came back negative and Dallas’s muscle pain was increasing, the vet suspected an arthritis like condition called Polymyositis in which the muscles become painfully inflamed. A blood test was done to measure serum muscle enzyme concentrations. The enzyme concentrations were found to be normal. Dallas was kept overnight at the vet clinic and scheduled to see the neurologist the next morning. He was kept on I.V. fluids to avoid dehydration and given a mild painkiller. When we picked him up the next morning to take him to the neurologist we were told that things had become worse over night. Dallas was now blind. Dr. Mimi Noonan, D.V.M., specializing in neurology, examined Dallas and although she suspected “beagle pain syndrome” his blindness was of concern to her. She believed that glaucoma might have been the cause. She called a veterinary ophthalmologist and Dallas was sent over for an emergency evaluation. The ophthalmologist determined that the blindness was due to pressure on the back of the eye from swelling in the brain. Dallas was whisked back to the neurologist. Since Dallas had such a great amount of brain swelling by the time he returned to the neurologist, a spinal tap would have been more dangerous than helpful in her opinion. In order to take the swelling down fast and give him the best chance of survival he was treated with I.V. Manitol and Dexamethasone. In most studies of beagle pain syndrome blood tests were done first. Results consistently showed elevated white blood cell counts that increased with progression of the syndrome. Hemoglobin and hematocrit were usually slightly decreased. Serum total protein was normal, however most dogs showed an imbalance between albumin levels (decreased) alpha 2 globulins (increased). During active episodes of the syndrome most dogs show a nonregenerative anemia. Blood was also tested for infectious organisms and none were found. Urinalysis is commonly done to test for aerobic and anaerobic bacteria, mycoplasma and fungi. In studies performed by J.C. Scott- Moncrieff et al urinalysis in all dogs was normal (Jour. Amer. Vet. Med. Assoc., Nov. 15, 1992). The next test usually performed is a spinal tap to determine if there is a bacterial or viral cause for the brain and spinal cord swelling. In beagle pain syndrome, these tests are negative. This test was not done with Dallas due to the severity of his case and the necessity to begin treatment as quickly as possible (after treatment to decrease the brain swelling any spinal fluid tests would be invalid). Following a negative cerebrospinal fluid analysis some dogs were tested for Systemic Lupus Erythematosus, which has symptoms similar to the debilitating symptoms of BPS. A negative SLE test makes beagle pain syndrome the most likely diagnosis. How is Beagle Pain Syndrome Treated? Antibiotics were used unsuccessfully in several studies of beagle pain syndrome, even in animals that showed signs of bacteria in feces or urine (no bacteria were found in cerebrospinal fluid). Dogs treated with Prednisone, a corticosteroid, (1.1mg/kg of body weight, by mouth every 12 hours) showed dramatic improvement within the first 12 hours of treatment. All clinical signs and laboratory abnormalities disappeared. Dogs maintained on a low-dose, alternate-day administration of prednisone (.25 to .50mg/kg every other day) for several months remained free of clinical signs. Symptoms returned within two weeks of stopping the corticosteroid treatments (Jour. Amer. Vet. Med. Assoc., Nov. 15, 1992). It was shown in some studies that the corticosteroids treatments could be gradually reduced over a one to two month period and then eliminated without the return of symptoms. It is important to monitor the dog for symptoms in the future and restart corticosteroid treatment if symptoms return. Side effects of steroid treatments include increased appetite and increased thirst. “Because of the high dosages of steroids, Spencer drinks water by the bucketful and wants to eat everything in sight. The medication also tends to make him quite sluggish, so he lies around a lot. Basically he acts like a 10-year-old dog except when food and water are involved,” explains Patricia Robidoux. Dallas was treated initially with I.V. Manitol and Dexamethasone to quickly bring down his brain inflammation. Within the first 24 hours he dramatically improved, although he remained blind and was still weak. He began eating normally and his tail was once again wagging. He even barked when he heard us come into the clinic to take him home. After the initial I.V. treatment he was put on a course of Dexamethasone pills, .50 mg every eight hours, to keep the inflammation from returning. Every two weeks we reduced his dose by one pill per day. Finally, almost 4 months later we eliminated the Dexamethasone. Dallas has remained symptom free for the past five months, and although he is now farsighted, his vision is fairly normal. Spencer is also doing well. “You would never know that Spencer had ever been so ill,” writes Robidoux, “He's a very active little dog who loves to play! Although he still shows symptoms of necrotizing vasculitis* every few months, we treat him with Prednisone the second we notice a problem.” *Necrotizing Vasculitis is one of the many other names for B.P.S. Addendum: Our beagle, Dallas passed away on March 25, 2010 at the age of 18. He had a long and fairly healthy life after overcoming this syndrome. He will be greatly missed. |