A 7-week old female gray squirrel weighing 144 grams was admitted to my care. She was emaciated, dehydrated, and her fur was practically standing on end.

Following normal admittance procedures, the squirrel was treated for fleas, lice and ticks and quarantined for 48 hours. By the end of three days she had been fully rehydrated, was taking full strength formula, and much improved. It was time to consider introducing her to another gray squirrel of comparable age.  I would get them acquainted on neutral ground then move them together to the bigger cage.

Tomorrow I was going to combine the squirrels in the new pen. They got along fine, played well together outside of their cages; the new female was gaining weight and eating well. When I was putting the questionable squirrel back in her cage (after playtime) for the evening, I noticed a nodule on the underside of the base of her tail. The growth was perfectly symmetrical, 1/2 inch in diameter, and did not appear to be attached to the bone. After my initial examination it appeared I was looking at a fatty tumor, it could also be the start of Squirrel Fibroma. Until a confirmed diagnoses could be made it would be treated as contagious.

By the afternoon, of Saturday the 18th, I knew that I was looking at a case of Fibroma (commonly called squirrel pox), more nodules had appeared on her stomach, hip, and the side of her mouth. The squirrel had been isolated the night before and now extra sanitary precautions were put in place. After learning that the vector for squirrel pox is most likely biting insects, all of the squirrels in my care were again treated for fleas and lice with Ovitrol Plus (Vet-Kem), and all bedding was washed and disinfected in bleach. Feeding utensils for the symptomatic squirrel were kept separate and she was always fed last. My clothes were changed before any other squirrel was handled. A visit to the veterinarian was scheduled for Monday the 20th.

I put a call out to fellow rehabbers over the Internet for information about Squirrel Fibroma. One friend sent pictures and another sent a paper written by Dr. Erica A. Miller of Willowbrook Wildlife Haven. I needed to do some studying on this disease and have information readily available for the vet. Excerpts from Dr. Miller's paper follow this report for your information.

After careful study of the report several things became apparent.

1. That the antibiotics were used to prevent secondary infections.
2. It was not known with certainty if the vitamin A used to build the immune system helped or if the virus was self limiting in squirrels that produced enough antibodies to fight off the virus.
3. Only 50% survived to be released.

The squirrel in question was the most compromised of the squirrels I had gotten in, so building up her immune system was of vital importance. I needed to get started on something immediately! After a long conversation with Jennifer Simmons of Gore, Virginia, we decided on using Echinacea to help build the immune system, and possibly help her fight off the virus.

There has been some studies indicating that Echinacea does help the immune system in humans.  I bought 400mg capsules of powdered Echinacea, and with Jennifer's help, figured the dosage. The squirrel, now known as Miss Pox, weighed 228 grams. I drew up 20 ml of distilled water, pulled open one Echinacea capsule and emptied the powder into the water. Her dose was .2 ml bid. The squirrels that had been exposed but were not exhibiting symptoms were given .2 ml SID. All squirrels would be given Echinacea for 5 days. No new nodules appeared after the 25th of April and at this time none were effecting her ability to eat or seemed to cause any discomfort.

I bathed the fibromas (typically these are raised, flattened nodules on the skin) 2 times a day in a weak Betadine solution, and applied a light topical coating of Aloe 2000 (Med-Care of Cleveland Ohio). The goal was to keep the nodules clean and in the best possible condition, hopefully preventing ulceration and infection. This was done after her first feeding in the morning and the last thing in the evening.

My veterinarian, Dr. Louis Bremer, was not a bit surprised to have me show up not only with a squirrel in tow, but also a pile of papers and pictures. He is new to the wonderful world of squirrels and appreciates the information that I bring to him. One thing that we completely agree on is the importance of keeping the stress level of a wild animal at a minimum, and not medicating indiscriminately.

After reading the papers I gave him, Dr. Bremer performed some skin scrapings that proved negative for mange mites, so he altered the treatment. He said that because the skin scrapings were negative, he felt it was best not to use Ivermectin because it can cause an unpleasant reaction in some animals. Miss Pox was a lanky and rather nervous squirrel and Dr. Bremer said he felt the IM injections could cause undue stress. There is also the possibility of nerve damage or infection at the injection site. He prescribed Amoxicillin at 10mg/lb SID for 7 days as an aid in supportive care and to guard against secondary infections.

Miss Pox was not eating well, so Nutrical (approximately 1/8 tsp.) was added to her formula. She was also given Bene-Bac two hours before her dose of Amoxicillin. Because of her mandatory isolation from other squirrels and knowing that they develop and thrive when with conspecifics extra care was taken to keep her mentally challenged and happy.

Taking the holistic approach meant bringing in many extras from the outside, a 9-foot tree complete with leaves was added for climbing and her environment was changed on almost a daily basis. Along with her formula she was also being provided rodent chow, monkey biscuits and natural forage. Her appetite did improved after the Amoxicillin was discontinued; however we never had a problem with loose stools.

On this Sunday I did as I always do and checked the bump on Miss Pox's tail (by far the worst of the nodules) first and found that it had receded dramatically overnight.  She was winning this battle. Over the next weeks, Miss Pox became healthy and the other squirrels in my care never contracted the Fibroma. She had won.

Miss Pox shot out of the hatch of the release pen and raced up a tree. Here was one tough squirrel that sure deserved her freedom in the trees, and now she had the chance. As she climbed that first tree, I gave her a silent round of applause.

Because only one squirrel had contracted Squirrel Fibroma, I was not able to set up any sort of control group nor vary treatments with different groups. I am, therefore, unable to state with certainty which step (if any) in the treatment used on Miss Pox helped, and which (if any) did not. However, I do feel comfortable enough with the steps I followed that if another case comes through my door I would do the same thing.

A special thanks to Sue Bernard of Paradise, California, Pat Isaacs of Fort Mill, South Carolina (who had me loaded up with information minutes after I asked for it) and Jennifer Simmons who added her thoughts, insight and moral support.

The virus is present in the blood the host animal and is spread by blood exchange between individuals. Mosquitoes have transmitted the disease under laboratory conditions (5). Mosquitoes, other insects, and arthropods are believed to transmit the disease in the wild (1).

The pathogenesis occurs as with other pox viruses: after invading the skin, multiplication begins in the regional lymph nodes within 24 hours, and the virus enters the blood stream (primary viremia) by the second day. The virus then multiplies in the spleen and liver and re-enters the blood stream (secondary viremia) at about day 5 to 6 post- exposure. Focal lesions first appear as fibromas in the skin, the target organ, after only 7 to 13 days (5). Antibody formation begins at about this time, but metastasis to multiple skin nodules occurs over the next 14 to 33 days. The severity (in terms of number and size of lesions) is probably inversely proportional to the antibody formation. The virus may be shed from the ulcerated skin papules to the environment as early as 10 to 12 days following the initial infection (2).

Lesions are cutaneous nodules primarily present on the limbs, tail, head, and abdomen. The nodules are usually thick, elevated, flattened on top, and firm. These fibromas may ulcerate, become encrusted with cellular debris (4), and become infected with secondary bacterial orfungal agents (9). The skin around the face and genitals maybe thick and reddened, with or without demonstrating discrete nodules (4). The virus may present as a generalized disease in which anorexia, lethargy, and respiratory dyspnea accompany the skin lesions (6,10).

The diagnosis is often based on clinical signs and can be confirmed by histopathological examination of the skin lesions.

The paper also states that squirrels were checked for skin mange mites, and subsequently treated with Ivermectin. Other supportive therapy included a form of injectable Vitamin A to help build the immune system and Dual-Pen for secondary infections given IM every other day. The outcome was that 50% of the squirrels survived to be released.

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