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Mia – Mystery Bite, Amazing Recovery


Mia enjoying the weather

This is the story of Mia, a four year old spayed female siamese mix, who had an amazing recovery from a condition that is 98% fatal in cats.

Mia came to Best Friends Animal Hospital last weekend on emergency after her owners noticed her limping on her left front leg. She was diagnosed with a bite wound, her leg was clipped and cleaned, and she was treated with antibiotics. We see cat bite wounds quite frequently and they typically respond well to this treatment regimen. Later in the day, her owners brought her back in because she had become very weak and could barely stand up. On examination, she was laying in lateral recumbency and could not rise. Bloodwork was unremarkable and we began symptomatic therapy with fluids, steroids, and antihistamines – in case this was an allergic reaction. The following morning Mia looked increasingly worse. She could barely lift her head, she was VERY uncomfortable and would growl any time she was touched. The wound on her leg had extensive bruising. She had not improved at all since starting the symptomatic therapy the evening before.


Because of the extent of the persistent neurologic signs and the bite wound, the Doctors feared Mia had been bitten by a black widow spider. Unfortunately black widow spider bites are 98% fatal in cats. After a bite, the average survival time is 115 hours and the victims develop progressive neurologic signs due to the neurotoxin in the black widow’s venom. We made a difficult call to Mia’s owners and relayed our thoughts and her poor chances of survival.

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Here is a picture Dr. Gocke took of the black widow spider found in her garage, one year after moving in to a new house. Black widow spiders are common in Billings, MT.






Fortunately, one of Mia’s owners works at a nearby human hospital and, as luck would have it, they had one vial of black widow anti-venom which had expired only a few days previously. Black widow anti-venom, although not very expensive, is extremely hard to get. In fact, right now hospitals can only order this anti-venom in the case of a confirmed black widow bite to a human. Administering the anti-venom can be risky because of the risk of anaphylactic reaction, however with cats it is really the only good chance of survival. We discussed trying this anti-venom on Mia and all agreed because of the horrible prognosis and her steadily worsening clinical signs, that it was worth a try. This is a picture of Mia visiting with her family before the anti-venom injection:

Mia before anti-venomC


A short time later, Mia was receiving intravenous black widow anti-venom and, with her family, we monitored her for any signs of anaphylactic reaction. She handled the injection rather well and supportive care with intravenous fluids, antihistamines, steroids, and pain medication was continued. Shortly after the injection, she became more alert and started moving her head. Although we thought this could be due to the stimulation of seeing her family and moving her around, we were cautiously hopeful. By that evening, she continued to be alert and held her head up several times and would flick her tail. There were even occasions when she would sit sternally. Her pain level seemed to decrease and she seemed more comfortable. This is an image of Mia 6 hours after receiving the anti-venom.


The following morning Mia looked even better. She would sit sternally quite frequently and was very alert. She could even sit up completely for short periods of time. When we would stand her up, her legs were still weak and she would knuckle over on her front feet. Her left leg (with the bite wound) was still very bruised and she had a fair amount of swelling, or edema, in her left armpit area. We were thrilled at her improvement but now a little worried about the fate of her left front leg. Supportive care continued throughout the day. Towards the end of the day, she could stand on all four feet and even started using the litterbox.

The next morning, Mia was sitting up in her cage and walking around as we did her morning assessment. The swelling in her left front leg had greatly receded and the bruising was fading. Although still not 100% normal, she looked like a different cat than the one who presented barely able to move, 2.5 days before. We monitored her through the day and she went home later in the afternoon.

Our entire staff was thrilled to see Mia’s progress over the course of her ordeal. We have never seen a cat survive a black widow bite, but we have never treated one with anti-venom either. In this case, she survived due to two key factors:

1. Prompt veterinary care including the diagnosis of the bite,

2. Administration of anti-venom as soon as possible.

Even with the appropriate diagnosis, Mia likely would have succumbed to this condition without treatment with anti-venom. Because of her proactive owner, she received the anti-venom and is alive today. There is not much data about black widow bites in cats and their chance of survival after anti-venom – probably because the anti-venom is not readily available and bites are not easy to diagnose. Mia’s family had an exterminator come to their house and although he did not find any black widow spiders, he did find a black widow web with an egg sac. Their house was treated inside and out for black widow spiders.

We are happy to share this very interesting case and are thrilled Mia had a favorable outcome. It is our hope that more of these bites are diagnosed and treated appropriately with anti-venom!

Update 7-14-10 Mia’s owners report that she is 100% normal now 🙂 Here are pictures of Mia enjoying the outdoors and one of her fierce “black widow hunting” face.

Mia hunting black widows