Brown Recluse Spiders More Abundant, Threat to People & Pets


The brown recluse is not a dude you want to meet in a dark alley. Due to the rainy late Spring and early Summer, and for reasons perhaps only they know, it seems there are lots and lots of them this year. Or that the reclusive spider has taken to a more outgoing personality.

Generally, bites only occur when the secretive spider feeds trapped; they are not aggressive to people or dogs – though their bite is toxic. Brown recluse spiders, also known as the “fiddle-back,” or “violin” spider on account of the violin-shaped pattern on its back, is a member of the genus Loxosceles reclusa. While that violin-shape on their back doesn’t always exist, it’s one way to identify the 8 to 15 mm. spider with longish 2 to 3 cm legs.

They’re most active at nice – though not truly nocturnal….that is when most bites to pets or people occur. And it’s almost always an accidental meeting, like a person or a dog rolling over onto a spider.

The bite from a recluse can be classified by its necrotizing nature. Reaction typically occurs at the site of the bite, with an ulcerated necrotic wound that results in the death of the surrounding soft tissue. The wound is slow to heal, leaving an open wound that is at risk of further infection. Serious complications occur when the ulcer progresses to gangrene, or when the venom enters the blood stream and is carried to the internal organs. Destruction of red cells, renal failure, coagulation disruption, and death are all possible known complications of a recluse bite. These complications are rare in people or pets but have been known to occur.

Symptoms as a result of brown recluse bites in dogs:

-There may be no symptoms

-Local pain and stinging (may last 6–8 hours), followed by itching and soreness

-Less common – anemia with bloody urine in the first 24 hours

-Other possible systemic manifestations within the first 2–3 days after the bite – fever, chills, rash, weakness, rapid growth of white blood cells, nausea, joint pain.

For dogs who are extremely ill, in which case, intravenous therapy provided in a hospital setting will be necessary, and perhaps a blood transfusion. If the venom is mild, cold compresses are sometimes adequate for reducing inflammation and reducing pain. If there has been a lot of cell destruction at the wound site, your doctor will need to surgically remove some of the dead tissue. If the venom was very potent, with a lot of cellular and tissue damage, your dog may need skin grafting after the lesion reaches full maturity.

In some cases, the necrotizing spreads, causing tissue death to the degree that the entire limb will need to be removed. The faster this is diagnosed, the better chance you will have of preventing complications.

Many dogs, maybe most, though have few obvious symptoms – and owners are unaware under all that dog hair that there was even a bite in the first place.