Spider Bites in Dogs

We usually talk about bee or wasp stings in dogs, but the truth is they can also be bitten by other insects or arachnids, such as spiders.

Although these are wounds that usually aren't serious at all, in some cases a reaction can occur at the bite site, or significant harm can result depending on which spider is behind the bite, as we'll explain in this article.

What Are Spider Bites Like?

Often, we won't even realize our dog has been bitten by a spider. Just like in our own case, the result of its bite is usually a small lesion that heals within a few days with hardly any discomfort and without us having to do anything at all. At most, cold can be applied after thoroughly washing the area.

In some cases, a reddish mark can be seen, like a dot, but generally there's no need to take any action or see the vet. The exception is dogs in whom the bite causes itching and the resulting scratching, or becomes infected. In that case, we'll notice warmth around the bite, redness, pain, and even pus discharge.

It's a good idea to see the vet. Of course, we should also visit the clinic if the dog has an allergic reaction to the bite. But sometimes the picture becomes much more complicated. This is what happens if the bite was from a spider belonging to a species dangerous to dogs.

Spider Bites Poisonous to Dogs

In this section, we'll highlight the famous black widow (Latrodectus spp.) and the brown recluse (Loxosceles reclusa). These are species able to inject venom when they bite, hence the negative consequences for the dog.

How severe these are will depend on the amount injected, the dog's characteristics, the bite location and number, or how long it takes to get veterinary care. It's a good idea to find out about the spiders living in your area, or in the places you travel to with your dog.

Symptoms of Spider Bites in Dogs

A red mark or slight swelling in one spot are usually the only signs that, if we notice them, could make us think of a spider or insect bite. But if the spider that bit our dog is toxic to it, we'll notice symptoms such as the following:

• Very intense pain around the bite and in the joints and muscles. If it's a brown recluse bite, necrosis occurs at the bite site.
• Restlessness — the dog will seem very nervous.
• Fever. General weakness and stiffness.
• Trouble coordinating movement, in some cases leading to paralysis.
• Seizures. Excess salivation. Vomiting and diarrhea.
• Shock and death. This unfortunate outcome is associated with black widow spider bites.
• Remember that bites inside the mouth or nose can swell to the point of causing suffocation.

Locations of Spider Bites

Just like with people, dogs can be bitten anywhere on their body. That said, there are more sensitive areas than others, such as any part lacking fur.

Dogs at Risk From Spider Bites

Any dog, regardless of age, sex, or size, is susceptible to spider bites. The likelihood will be higher or lower depending on where we live and the living conditions of the dog in question.

For example, those living or spending a good part of the day outdoors, or that walk through areas with sheds or ruins where spiders can settle, will have a higher risk of being bitten.

What to Do If My Dog Is Bitten by a Spider?

In principle, faced with a bite with no other symptoms, there's no need to do anything. But if the affected area looks bad or is infected, we do need to see the vet. Of course, we'll go immediately if we notice any of the symptoms mentioned, especially if we live in an area with spiders toxic to dogs.

The clinical picture they trigger is consistent with other conditions, which is why it's important to see the clinic as soon as possible, since treatment and prognosis will depend on reaching a good diagnosis.

That's why, to make and speed up the task, if possible it's a good idea to bring a photo, or even the arachnid responsible for the bite. This way it can be identified more quickly. That said, don't try catching spiders if you don't have the means or aren't sure they're not dangerous to you.

Antidotes for Spider Bites

There are antidotes to counteract the venom injected by toxic species, and the vet will be responsible for administering them intravenously or intramuscularly. Treatment will be completed with the appropriate drugs based on the symptoms the dog shows. Even so, the prognosis is guarded.

How to Act Around Spiders

Unless there are potentially dangerous spiders where you live, there's no need to take any special measures. If at any point you spot these arachnids on your dog, it will be enough to shake them off — don't crush them against its body, as a precaution. Either way, find out about the species present in your area to avoid the dangerous ones.

Bibliography Carlson and Giffin. 2002. Manual práctico de veterinaria canina. Madrid. Editorial el Drac.