Welcome to Just Answer! I would like to help you and your Teacup Chihuahua, but need a bit more information, please.
When did this all start?
When did he last eat?
Could he have gotten into something he should not have (people food, garbage, etc)?
When did you last give Karo syrup?
I am very concerned that your dog may be suffering from HYPOGLYCEMIA (low blood sugar). I would like you to go right now and treat him for this by giving him a teaspoon of honey, karo syrup, corn syrup or maple syrup. See if he will lick it off your finger, or rub it on his gums.
Go do this now, and then let me know how he is after 1- 2 minutes!
There are a number of things that could be going on with your little dog. From what you are describing, I am VERY concerned that without prompt veterinary care he might die. For a dog this size to not eat anything for 4 or more days, he is certainly going to have seizures due to low blood sugar. This means that there is no food for his brain. His blood sugar is likely dangerously low, and I fear he might not survive the night without care.
As I said, there are a lot of different possibilities for what may be going on with your dog. The ones that I would be considering if he came to see me are:
1. One of the things that I think of first in a young dog is that he may have a Gastrointestinal Foreign Body. Dogs eat the strangest things - plastic bags, children's toys, bones, bits of towel, socks, rocks and other things. Often, these foreign bodies pass through the intestinal tract, but sometimes they do not. They may get caught in the stomach or the small intestines.
The symptoms of a GI foreign body are generally vomiting, loss of appetite, depression and dehydration. If your dog consumed an object that is caught in the small intestines, it might explain the symptoms that you are seeing. This would be particulary true if the object were something like a ball that could bob over pylorus (outflow from the stomach) and then move away again. Thus, water could pass through but not food.
In the case of an obstruction, surgery is often needed to remove the foreign object. I will include further information about GI foreign bodies:
If I examined your small dog and was concerned about a foreign body, I would probably recommend x-rays to see if a foreign object were visible. A plastic bag would not show up on x-rays. It does, however, show up very well if the dog is given some barium (a type of milkshake like drink) by mouth. Then a determination can be made about how best to get this out of the dog, or whether it might move through on its own.
2. It is possible your little dog simply has gastroenteritis from eating something he shouldn't have. Table scraps or twigs and leaves could be the culprit! Gastroenteritis is an inflammation of the stomach and intestines and can be caused by a large number of things, including sudden dietary changes.
3. Another possibility is Parasites. Here is a link to information about whipworms which are notoriously hard to identify by fecal analysis, and are not killed with pyrantel pamoate (standard puppy dewormer):
4. A bacterial infection: Dogs can be affected by overgrowths of bacteria in the intestines. In an adult dog these might not be more than a nuisance, but in a pup they can be serious. The 3 most common are Campylobacter, Salmonella and E.Coli. Here is a link with more information:
5. Parvo virus. Parvo is a highly contagious virus that causes vomiting and diarrhea, often with blood. It causes severe dehydration, and untreated often results in death. Usually, it would take a couple of days of untreated vomiting and diarrhea before the dog died.
Puppies are routinely vaccinated for Parvo virus as part of their regular vaccines. These are usually given at 8, 12 and 16 weeks. Once fully vaccinated, there is a virtually zero chance of a dog getting Parvo virus. Some breeds are more susceptible to Parvo - this means that they get sicker and take longer to recover than other breeds. The susceptible breeds are Rottweillers, Dobermans and Labrador Retrievers.
Here are links to more information:
The botXXXXX XXXXXne is that there are a number of possibilities for what may be going on. Your vet would need to do a physical exam and possibly some diagnostic tests to figure out what the underlying problem is. I would start with a fecal sample, blood test and abdominal x-rays. It sounds like it is time to find out what is going on!
I realize that there may be financial limitations on your ability to seek veterinary care. I will give you some links to financial aid in order to help you.
I'd start with the local animal shelters to see if they know of any low cost or subsidized vet care in your area. Nationally here are some groups that might help you afford the vet bills: American Animal Hospital Association http://www.aahahelpingpets.org/ " Through the AAHA Helping Pets Fund, veterinary care is possible for sick or injured pets even if they have been abandoned or if their owner is experiencing financial hardship." Angels 4 Animals http://www.angels4animals.org/ "Our services range from financial aid to complete treatment to those pets and pet owners in need." Care Credit http://www.carecredit.com/ A credit card company for health care, including veterinary care. "With a comprehensive range of plan options, for treatment or procedure fees from $1 to over $25,000, we offer a plan and a low monthly payment to fit comfortably into almost every budget." God's Creatures Ministry http://www.all-creatures.org/gcm/help-cf.html "This fund helps pay for veterinarian bills for those who need help." Help-A-Pet http://www.help-a-pet.org/home.html "Our efforts focus on serving the elderly, the disabled, and the working poor." IMOM http://www.imom.org/ "We are dedicated to insure that no companion animal has to be euthanized simply because their caretaker is financially challenged." The Pet Fund http://thepetfund.com/ "The Pet Fund is a registered 501(c)3 nonprofit association that provides financial assistance to owners of domestic animals who need urgent veterinary care." United Animal Nations http://www.uan.org/lifeline/index.html "The m ission of LifeLine is to help homeless or recently rescued animals suffering from life-threatening conditions that require specific and immediate emergency veterinary care. We strive to serve Good Samaritans and rescue groups who take in sick or injured animals. In certain cases, LifeLine can also assist senior citizens and low-income families pay for immediate emergency veterinary care."
They also keep a list of local and national help resources here http://www.uan.org/index.cfm?navid=163
I wish there were a quick and easy home remedy that I could give you for your little Teacup Chihuahua, but there just isn't. He really needs to see a vet! This is urgent!!
If this has been helpful, please accept my answer and leave feedback. I will still be here to provide more information if you need it!
Best wishes and good luck to you and your pet! Fiona