Your dog most likely has peri-anal tumors. These are masses that form on the perinium, which is the area between the anus and the vaginal opening in a female, and the area between the anus and the testes or the base of the penis in a male. These growths can be either benign or malignant. They have nothing to do with the anal glands, but if they get large, they can block the rectum and interfere with the dog's ability to pass feces. They also can spread to other organs and tissues, particularly vital organs like the liver and spleen. If your vet won't at least test your dog without charging you a fortune, you need to find a different VET. It wouldn't hurt to get a second opinion anyway, because this might just give you some peace of mind.
Needle biopsy of something like this should NOT cost $700. That's insane. The blood work for my dog, when she developed a couple of these tumors last spring only cost me about $225, and that was to check for evidence of high calcium levels. High Ca levels indicate impaired kidney function, and they can indicate cancer. My dog was given a clean bill of health, fortunately. And she hasn't had any issues with them since the spring.
So what I would do is start looking around for a different vet, and take your dog to see that vet. Don't offer any information about what your current vet has said- let the consulting vet examine your dog and develop his/her own opinion of what is going on and what should be done. Then you can decide what the best course of action is, once you have all the facts.
My dog has this type of peri-anal tumor. In her case, they turned out to be benign and not dangerous. She just turned 12.
· 2 months ago