What To Do If a Spider Bites Your Dog

In the most important of ways, your dog is your best buddy. But just as probably is the case with your human best friend, your pup probably gets into scrapes once in a while. Being bitten by a spider is a case in point. Whether the incident stems from your pooch sticking his nose where it didn’t belong or sleeping in a dark, enclosed space that an arachnid calls home, the end result is a situation that may require medical attention from your vet.

The thing about dogs is that they are generally quite stoic. Because your pup isn’t likely to bring the bite to your attention, it’s your job as his human companion to be able to recognize the signs of a spider bite and to determine whether it is serious and requires further investigation.

Did you know that there are over 3500 species of spiders in the United States? You would virtually need to have a PhD in these insects in order to recognize each of their specific bites. The good news is that only a small number of these many types can actually cause harm to your dog. The first thing you can do is to research which venomous spiders live in your area so that you can learn to identify the symptoms of their particular bite.

Venomous Spiders That Can Be Dangerous to Your Dog

If the area where you live or visit contains any of these insects and you believe your dog has been bitten, you need to seek veterinary attention right away:

Black widow

Don’t delay in calling the vet if your dog is bitten by a black widow spider. The female of this species is the most recognizable venomous spider. She has a shiny, round black body with a red or orange hourglass on the underside. Immature black widows have red or orange stripes and a brownish body and can also produce toxic venom. The only U.S. state where this species is not found is Alaska, although they are most prevalent in the south and the southwest. They prefer to live in isolated, dark spaces and generally spin their webs in secluded corners near the ground. As it happens, this is where dogs enjoy exploring, making them susceptible to the bite of the disturbed spider. Although the jaws of the male spider are too small to go through your dog’s skin, the female’s jaws are larger and can actually cause a dangerous bite. The bite appears as two puncture marks and is very painful. Pain originates at the bite site and spreads throughout the dog’s body over the next eight hours or so. The venom affects the nervous system and causes symptoms that include pain (leading to whining and crying), tremors, muscle spasms, breathing difficulties, vomiting or diarrhea, balance issues, stomach cramps, elevated heart rate and blood pressure, seizures, paralysis and even death. The severity of the bite depends on the size of your dog and of the spider, your dog’s age and health status and the location of the bite. Although there is no test to diagnose a black widow bite, bloodwork may show elevation of an enzyme called creatine kinase, which indicates muscle damage caused by the bite. Treatment is designed to mitigate the symptoms and generally involves pain medications, IV fluids, muscle relaxers and drugs to relieve nausea and minimize seizures. Hospitalization can last two to three days, and full recovery may not happen for several months.

Brown recluse

Seek emergency treatment right away if your dog is bitten by a brown recluse spider. This spider is brown and has a darker, violin-shaped area on its back. Because this “violin” darkens as the spider ages, it may not be visible on all brown recluses. Additionally, this spider has six (not eight) eyes and long, tan legs. The brown recluse is found mostly in the midwestern and southern U.S. ranging from Louisiana to northern Illinois and as far east as Tennessee and Georgia. It is also sometimes seen in southern California, southern New Mexico and western Arizona. Brown recluses like to live in dry, sheltered areas such as under piles of rocks, in shoes or closets and even in dogs’ bedding. Because the brown recluse can only bite if something is pressing against it, most bites to dogs occur when the dog lies on top of the spider. The bites generally are sustained to the dog’s legs and may at first appear to be red or itchy. Within two to eight hours of the bite, the toxins in the venom will begin to kill surrounding tissues, resulting in a white and purple bull’s-eye area surrounded by reddened skin. Over time, the area expands, with deadened tissue turning black. The dog becomes sick, with potential organ failure possible if the venom goes into the animal’s bloodstream. Other symptoms of the bite include anemia, fever, red or brown urine, vomiting, lethargy and weakness, bruising and slowed clotting and liver and kidney damage. Blood tests can reveal indicators of the bite, and, if given early enough, there is a drug called Dapsone that can minimize tissue death. Other interventions include antibiotics, wound treatment and pain medications, with surgery and blood transfusions necessary in the most severe cases. Recovery can occur in one to eight weeks.

Chilean recluse

The bite of the Chilean recluse requires immediate veterinary care and is an emergency. This spider is the more dangerous but less common relative of the brown recluse. It has a brown body with a black line that looks like a violin. Not all Chilean recluses have this identifying mark, however. Like its brown cousin, this spider has only six eyes. The Chilean recluse primarily lives in South America but is also found in the Los Angeles area and has been seen in Kansas, Florida and Massachusetts. The signs and symptoms, appearance of the bite and treatment are similar to the brown recluse. However, the venom is more toxic.

Red widow

This relative of the black widow is similarly shaped but has a different coloration, with the upper body being orange-black and the lower abdomen black with bright red markings of various shapes, including hourglass and triangular. The red widow can only be found in the sand dune habitats and palmetto scrublands of central and southern Florida. While the bite of this spider is less toxic than that of its black widow cousin, it can still be dangerous, particularly to a small dog. The symptoms and treatment are similar to those for the black widow.

Brown widow

The bite of the brown widow can be serious and might be an emergency. Smaller than the black widow, the brown widow has long legs and a brown body with red or orange markings. Found in Hawaii, California, Georgia, South Carolina and the gulf states, this spider likes to live in more exposed areas such as mailboxes and beneath railings. Although its venom may be more toxic than that of the black widow, it injects less poison. Most symptoms are limited to the area of the bite, but especially smaller dogs may also experience muscle rigidity, pain and vomiting.

How to Prevent Spider Bites

The most effective way to keep your dog safe from spider bites is to rid your environment of as many spider-friendly places as possible. Clean out crevices and dark corners, remove leaves and debris and get rid of wood piles and mounds of stones. Traps and insecticides may be effective but could also pose dangers to the pets you are trying to protect. To that end, choose products or services that are non-toxic to animals. Discourage Fido from exploring in spider-friendly dark or debris-strewn areas, and keep his bedding clean and away from cracks, crevices, doors or windows.

When it comes to spider bites, be your dog’s best friend. If you suspect that a bite from a dangerous arachnid has occurred, contact your vet right away. Time can be of the essence in promoting minimal pain and a full recovery.