**Core Concept**
Toxoplasmosis is a parasitic infection caused by the protozoan Toxoplasma gondii, primarily transmitted to humans through the feces of infected cats (Felidae), not dogs. Dogs can be intermediate hosts but are not the definitive hosts responsible for the transmission of this parasite.

**Why the Correct Answer is Right**
Toxoplasmosis is a zoonotic disease, meaning it can be transmitted from animals to humans. The primary mode of transmission is through the feces of infected cats, which contain oocysts that can be ingested by humans. Dogs, while they can be infected with Toxoplasma gondii, do not play a significant role in the transmission of this parasite to humans. In fact, dogs can become infected through contact with contaminated cat feces or through the consumption of infected meat.

**Why Each Wrong Option is Incorrect**

**Option A:** Hydatid disease, caused by the Echinococcus parasite, is indeed transmitted through the feces of infected dogs. Dogs serve as the definitive hosts for this parasite, and their feces contain eggs that can be ingested by humans, leading to infection.

**Option C:** Kala-azar, also known as visceral leishmaniasis, is transmitted through the bite of an infected sandfly (Phlebotomus spp.). Dogs are the primary reservoir for this disease, and they can transmit it to humans through the bite of an infected sandfly.

**Option D:** Toxocara canis is a parasitic roundworm that infects dogs and can be transmitted to humans through contact with contaminated feces or contaminated soil. Dogs are the definitive hosts for this parasite, and their feces contain eggs that can be ingested by humans, leading to infection.

**Clinical Pearl / High-Yield Fact**
It's essential to note that dogs can be intermediate hosts for various parasites, including Toxoplasma gondii, but they are not responsible for the transmission of these parasites to humans. Instead, they can become infected through contact with contaminated feces or meat, making them a potential source of infection for other animals and humans.

**✓ Correct Answer: B. Toxoplasmosis**