Hello, I am sorry to hear about what Pablo is going through. It is wonderful that he made it through the hospitalization. This is not always the case with cats diagnosed with panleukopenia. It can be a devastating disease.
The hallmark of panleukopenia pathology is crypt epithelial cell necrosis of the small intestines. In English, the first layer of the intestines which include the glands dies from the virus. This sloughing leads to diarrhea which is often bloody. To make matters worse, the name of the disease “panleukopenia” describes what occurs to the blood and immune system. Pan = all, leuko = white blood cell, penia = lack of. The defenses are decimated by reducing the numbers of all types of white blood cells. As a result, the cat is rendered defenseless and is at high risk for secondary infection.
The widespread inflammation and destruction of the intestinal layer is highly painful which, in part, accounts for the vomiting. As the infection resolves, the clinical signs of infection should resolve as well.
With vomiting occurs weeks after the viral infection, there are several different possibilities. There could be residual pathology and inflammation from the virus however we need to rule out other possibilities first. The virus can generate extensive damage which can lead to scarring in some cases. If the scarring is severe enough, it could lead to motility issues which cause vomiting. Depending on the situation, there may be surgical methods to correct this.
Other possibilities include secondary or primary bacterial or parasitic infections. The patient is fairly young for inflammatory bowel disease or lymphoma. However, if a biopsy to evaluate if continued viral effects exists is performed, then it would also rule these out.
My recommendation would be to recheck with your veterinarian and ask her or his opinion on next steps. Has Pablo been also dewormed, had a fecal, and a follow-up blood test? Therapeutic diets can also not only replace water-soluble vitamins, pre-biotics, and provide highly-digestible proteins but are often enriched in glutamine which help increase intestinal healing. Probiotics are also helpful. However, before you make any changes, I would consult your veterinarian and have a recheck examination.
I hope that this helps clarify the background biology of this condition and potential sequelae. Best of luck and please let us know how Pablo is doing.
